Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - 4 hours 15 min ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 AM CDT Mon Jun 26 2017 Valid 271200Z - 281200Z ...CRITICAL FIRE WEATHER AREA FOR GUSTY WINDS AND LOW RH ACROSS PORTIONS OF CENTRAL/NORTH-CENTRAL AZ... ...Synopsis... Shortwave trough over the northern Rockies at the beginning of the period -- 12Z Tuesday -- will progress eastward through the northern Plains, reaching the upper MS Valley early Wednesday morning. Farther east, a pair of phased shortwave troughs will move through the upper trough initially over the eastern CONUS. Progression of these shortwave troughs will act to deamplify the parent upper trough. As a result, a largely zonal pattern is anticipated across the CONUS by 12Z Wednesday. At the surface, high pressure will shift eastward into OH and TN valleys while a low moves eastward across the Dakotas. Cold front attendant to this low will move across the northern and central High Plains. ...Southwest...Great Basin...Central Rockies... Another day of above-average temperatures and afternoon RH values in the single digits is anticipated across much of the western CONUS, including portions of the Southwest, Great Basin, and central Rockies. Some breezy winds are also anticipated, primarily a result of the enhanced mid-level flow coupled with deep boundary-layer mixing. Best combination of windy and dry conditions with dry fuels is expected across portions of the central/north-central AZ. Critical fire weather conditions are expected here with elevated to locally critical conditions anticipated across the remainder of the region. ...Southwest WY... Thunderstorms are expected across much of the northern Rockies during the afternoon. However, high storm coverage, modest storm motions, and high PWs suggest mainly wetting rains with much of this activity. The only exception appears to be across southwest WY where a deep mixed boundary layer will support high cloud bases and ample sub-cloud precipitation evaporation. Mean storm motion is this area is also expected to be around 35-40 kt. These meteorological conditions support increased fire danger due to isolated dry thunderstorms. ..Mosier.. 06/26/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - 4 hours 27 min ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0245 AM CDT Mon Jun 26 2017 Valid 261200Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR SCATTERED DRY THUNDERSTORMS ACROSS EAST-CENTRAL WA AND SOUTHWEST ID... ...CRITICAL FIRE WEATHER AREA FOR STRONG WINDS AND LOW RH ACROSS NORTHEAST NV... ...CRITICAL FIRE WEATHER AREA FOR STRONG WINDS AND LOW RH ACROSS SOUTHERN/EASTERN NV...SOUTHWEST UT...AND NORTHEAST AZ... ...Synopsis... Shortwave trough currently off the northern CA coast will continue progressing east-northeastward, reaching central OR by the early afternoon and southern ID by the evening. Continued eastward progress of this shortwave trough will take it through much of the northern Rockies by 12Z Tuesday. Overall progression of this system will result in the breakdown of the upper ridge which has remained in place across much of the Intermountain West for the past week. Additionally, the passage of the this shortwave trough will result in both wind-driven and lightning-caused fire weather threats today from the Pacific Northwest south into AZ today. Farther east, upper troughing covering much of the central/eastern CONUS at the beginning of the period will shift eastward as several shortwave troughs track quickly through its base. ...Great Basin...AZ... Strengthening mid-level flow coupled with deep boundary-layer mixing and a tightening surface pressure gradient will support gusty winds from southern OR across much of the Great Basin and into central AZ. The strongest winds (i.e. sustained 20-25 mph) are anticipated across northeast NV, where the mid-level flow is the strongest, and across southern/eastern NV and adjacent southwest UT and northwest AZ where the surface pressure gradient is the tightest. Above-average temperatures are anticipated areawide with minimum RH values ranging from the mid-teen to upper single-digits. As a result, critical fire weather conditions are expected in those areas where the winds are strongest. ...Pacific Northwest...Northern Rockies... Mid-level moisture associated with the approaching shortwave trough will advect into the Pacific Northwest/northern Rockies atop a very dry antecedent airmass. Forecast soundings across much of the region reveal deeply mixed inverted-v profiles by the early afternoon. During the afternoon, PW values will likely range from around 1" across central OR to closer to 0.60" across south-central ID. This gradient in moisture combined with a deeply mixed boundary layer and at least moderately fast storm motions (around 30 kt) will result in an environment supportive of dry thunderstorm. The highest coverage of dry storms is expected across east-central OR and southwest ID. A more hybrid storm mode is anticipated across the remainder of Oregon and into WA. Less storm coverage is anticipated across the remainder of ID, with most of this storms expected to be on the drier side. ...Mountains and Western/desert Foothills of Southern CA... Strong onshore flow is expected across much of the interior portions of southern CA today. Best overlap of the windy and dry conditions with receptive fuels will be across the higher elevations and western/desert foothills during the afternoon and evening. Elevated to locally critical fire weather conditions are anticipated across these areas. ..Central/Eastern MT... A strong surface pressure gradient will exist over the region between the lower pressures to west (associated with the aforementioned shortwave trough) and remnant high pressure across the northern Plains/upper MS valley. This gradient will support breezy southeast surface winds (i.e. 15-20 mph) from the early afternoon through the evening. Above-average temperatures (i.e. highs in the 90s) amidst a dry airmass will support afternoon RH values from 15 to 20 percent. Guidance still suggests some dissociation between the strongest winds (over north-central MT) and the lowest RH (over southeast MT). Resulting conditions support an elevated fire weather threat but the dissociation between the strongest winds and lowest RH values currently precludes a critical delineation. ..Mosier.. 06/26/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - 6 hours 14 min ago

000
AXNT20 KNHC 260603
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
202 AM EDT Mon Jun 26 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 10N26W
to 02N27W, moving W at 10-15 kt within the last 24 hours. The
wave is in a region of favorable wind shear, is in a moderate
moist environment with some patches of dry air according to CIRA
LPW and is under an area of diffluent flow aloft, which is
supporting scattered showers from 02N-10N E of 32W.

A tropical wave is in the central Atlc with axis extending from
14N40W to 01N45W, moving W at 5-10 kt within the last 24 hours.
The wave is in a region of favorable to neutral wind shear.
However, the CIRA LPW imagery show some dry air in the wave
environment, which coincide with Meteosat enhanced imagery of
Saharan dry air and dust. This is supporting lack of deep
convection at the moment.

A tropical wave is in the E Caribbean with axis extending from
18N65W to inland Venezuela near 08N66W, moving W at 20 kt within
the last 24 hours. The wave is in a region of unfavorable wind
shear N of 15N and is in a moderate moist environment with some
patches of dry air according to CIRA LPW. Upper level divergence
support in the SE basin support scattered showers S of 15N between
the Windward Islands and 68W. Isolated showers are elsewhere in
the NE Caribbean.

A tropical wave is in the W Caribbean with axis extending from
19N80W to the coast of Panama near 10N80W, moving west at 20
knots within the last 24 hours. The wave is in a region of
neutral to unfavorable wind shear and is in a moderate moist
environment with patches of dry air mainly N of 14N. Scattered
heavy showers and isolated tstms are in the SW Caribbean, but
mainly associated with the EPAC monsoon trough.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the Africa coast near 19N16W to
08N22W. The Intertropical Convergence Zone axis begins near
07N31W and continues to 08N42W...it then resumes W of a tropical
wave near 07N44W to 03N51W. For convection information see the
tropical waves section. Otherwise, scattered heavy showers are
from 04N to 03S between 35W and 40W and within 120 nm N of the
ITCZ W of 45W.

...DISCUSSION...

GULF OF MEXICO...

A broad middle to upper level trough over the eastern USA extends
S to a base over the northern Gulf of Mexico, thus supporting a
cold front extending across the SE CONUS to the Florida Panhandle
near 29N85W to 29N87W where it transitions to a stationary that
continues westward towards the coast of Texas near 29N94W. This
frontal boundary is supporting isolated showers and tstms along
the northern coastal waters of the Gulf. A middle level low over
the SW Gulf reflects as a surface trough along 26N92W to 18N93W,
which along with upper level diffluence continue to support heavy
showers and tstms over the W Gulf S of 27N, including the Bay of
Campeche where convection is stronger and with possible gusty
winds. Light and variable winds prevail elsewhere.

CARIBBEAN SEA...

The main features in the basin are two tropical waves already
discussed in the waves section above. Aside from the convective
activity associated with them, latest scatterometer data continue
to show fresh to strong winds in the vicinity of the waves S of
17N, increasing to near gale winds S of 14N. Otherwise, scattered
heavy showers and tstms are in the lee of Cuba between 78W and
83W. Isolated showers are elsewhere between the Windward Passage
and the Leeward Islands. The westernmost wave will move over EPAC
waters within 24 hours while the easternmost wave races towards
the central basin. A new tropical wave will enter the SE Caribbean
waters Monday night.

...HISPANIOLA...

Upper level southerly winds continue to advect moisture to
Hispaniola, thus supporting cloudiness with possible isolated
showers. Showers and tstms are expected to develop across the
Island Monday as a tropical wave moves to central Caribbean
waters.

ATLANTIC OCEAN...

Two tropical waves are crossing the tropical Atlantic waters.
Please refer to the tropical waves section for more details.
Otherwise, the remainder of the Atlc is under the influence of a
surface ridge anchored by a 1023 mb high centered S of the Azores
near 34N29W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Ramos
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sun, 06/25/2017 - 18:56

000
AXNT20 KNHC 252356
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
756 PM EDT Sun Jun 25 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...TROPICAL WAVES...

A tropical wave is in the far eastern Atlantic with the axis
extending along 25W south of 12N and is moving W at 15 to 20 kt.
Scattered moderate isolated strong convection was noted from
04N to 09N between 27W and 30W. Scattered moderate was noted
elsewhere within 240 nm W of the axis.

A large amplitude tropical wave is in the central Atlantic with
the axis extending from 15N38W to 03N44W and is moving W at 15-20
kt. The wave is easily identifiable on the latest visible
satellite imagery. Scattered moderate convection was noted from
10N to 12N between 38W and 40W, and from 08N to 10N between 44w
and 46W.

Another fairly large amplitude tropical wave is located over the
Lesser Antilles with the axis extending along 62W/63W S of 19N
and is moving W at 15 kt. The wave is in a region of favorable to
neutral wind shear. Scattered moderate isolated strong convection
was noted from 12N to 16N within 240 nm W of the wave axis.

A tropical wave is located in the central Caribbean with the
axis extending along 76W/77W south of 20N to Colombia and is
moving west at 15 kt. Water vapor imagery indicates that the wave
is in a region of unfavorable wind shear and convection is
minimal.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the Africa coast near 12N15W to
07N23W. The Intertropical Convergence Zone axis begins near
07N27W and continues to 07N40W to 04N51W. For convection
information see the tropical waves section.

...DISCUSSION...

GULF OF MEXICO...

A sharp middle/upper level trough over the NW gulf extends from
the coast of Louisiana southward through 26N91W 22N94W. The trough
is moving eastward at 15 kt across the northern half of the gulf.
Moderate SW winds aloft are located on the east side of the
trough. Diffluent flow aloft SE of the trough was maintaining
scattered moderate to strong convection within 120-180 nm E of a
surface trough over the Bay of Campeche from 25N93W to 18N95W.
Additional scattered to numerous strong convection was emerging
off the coast of Yucatan into the Bay of Campeche. At the surface
a weak cold front extended from near Apalachicola, Florida to
28N91W to near Corpus Christi, Texas. The portion of the front W
of 90W was in the process of dissipating. Light and variable
winds prevailed over the Gulf south of the cold front with light
to locally moderate NE winds north of the front.

CARIBBEAN SEA...

A fairly large upper level cyclone covered the Caribbean W of
76W with moderate subsidence within 240 nm of the core of the
upper low. Further east, broad anticyclonic flow prevailed over
the remainder of the Caribbean in the vicinity of the tropical
wave along 62W/63W with some of the subsidence in the area
becoming entrained into the convection associated with the
tropical wave allowing the convection to weaken. At the surface,
an ASCAT scatterometer pass from 1450 UTC showed moderate to
strong trades of 20-25 kt from 11N to 16N between 69W and 75W and
also over the Windward islands. Light winds prevailed over the NW
Caribbean.

...HISPANIOLA...

Moderate upper level southwesterly winds amidst some subsidence
aloft was noted over Hispaniola. A cluster of strong
thunderstorms was in progress over Haiti and in interior portions
of the Dominican Republic. The 12Z rawinsonde from Santo Domingo
showed low to mid level moisture to about 550 mb with precipitable
water values approaching 2.00 inches.

ATLANTIC OCEAN...

An expansive mid-to upper level cyclonic circulation is located
over the west central Atlantic near 27N54W drifting to the WSW.
Further east,a fairly sharp middle/upper level trough has its
axis along 29W/30W north of 26N and is digging to the southeast.
A large anticyclone dominated the flow over the tropical Atlantic
between 30W and 60W with strong deep layered subsidence noted
from 10N to 20N between 40W and 52W. The strongest subsidence
coincided with an area of extensive Saharan dust as noted in the
Seviri dust imagery. At the surface a trough extended from 31N52W
to 25N54W. A 1026 mb high is centered near 32N47W. This high
dominated the surface flow over a majority of the subtropical
Atlantic.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Cobb
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sun, 06/25/2017 - 12:44

000
AXNT20 KNHC 251743
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
200 PM EDT Sun Jun 25 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...TROPICAL WAVES...

A tropical wave is in the far east Atlc with the axis extending
along 23W/24W south of 14N and is moving W at 10 kt. A 90 nm
wide band of scattered moderate to strong convection is centered
along a line from 08.5N26.5W to 06.5N26W to 06N23.5W.

A tropical wave is in the central Atlc with the axis extending
from 16N35W to 03N42W and is moving W at 15-20 kt. The wave is
easily identifiable on the latest visible satellite imagery.
Scattered heavy showers and tstms are located in the area from
05N to 10N between 34W and 41W.

A well-defined tropical wave is located over the Lesser Antilles
with the axis extending along 61W/62W south of 19N and is moving
W at 15-20 kt. The wave is in a region of favorable to neutral
wind shear. Scattered heavy showers and tstms are located from
11N-17N between 60W-65W.

A tropical wave is located in the central Caribbean with the
axis extending along 75W south of 20N to inland Colombia and is
moving west at 15 knots. Water vapor imagery indicates that the
wave is in a region of unfavorable wind shear and convection is
minimal.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the Africa coast near 12N16W to
09N23W to 08N27W. The Intertropical Convergence Zone axis begins
near 08N27W and continues to 09N40W to 03N45W to 03N52W. For
convection information see the tropical waves section.

...DISCUSSION...

GULF OF MEXICO...

A sharp middle/upper level trough is positioned over the NW gulf
with the axis extending along 93W north of 24N. It is forecast
to move east at 15-20 kt across the northern half of the gulf.
Moderate southerly winds aloft are located on the east side of
the trough. A 1019 mb high is located over the northeast gulf
near 29N84W. A weak frontal boundary over the southern United
States drifted southward into the northern Gulf coast earlier
today with minimal convection either side of the front.

CARIBBEAN SEA...

Broad cyclonic turning aloft covers the Caribbean west of about
76W with broad anticyclonic flow aloft located over the eastern
half of the Caribbean. Dense overcast layered clouds with
numerous heavy showers and scattered tstms are located over
Panama and continue northward to 13N between 75W and 82W in
association with the east Pacific monsoon trough. Refer to the
tropical waves section for details about the tropical wave over
the Lesser Antilles.

...HISPANIOLA...

Isolated showers are over Hispaniola early this afternoon and
are expected to continue through Monday.

ATLANTIC OCEAN...

A well-defined middle/upper level cyclonic circulation is
located over the west central Atlantic at 27N53W and is forecast
to drift northwest over the next 48 hours. Moving downstream a
middle/upper level trough has its axis along 30W north of 26N
and is digging to the southeast. Surface troughs are located
from 30N50W to 27N53W and from 28N60W to 27N64W. A 1026 mb high
is centered near 32N46W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
CAB
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sun, 06/25/2017 - 12:05
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1159 AM CDT Sun Jun 25 2017 Valid 261200Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHWEST NV... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EAST-CENTRAL/SOUTHERN NV...SOUTHWEST UT...NORTHWEST AZ... No changes have been made to the ongoing forecast. ..Cohen.. 06/25/2017 .PREV DISCUSSION... /ISSUED 0239 AM CDT Sun Jun 25 2017/ ...Synopsis... Upper ridge in place from the Southwest into the northern Rockies is expected to breakdown on Monday as a shortwave trough moves from northern CA through the northern Rockies. Farther east, a shortwave trough will move from the northern Plains/upper Midwest southeastward into the upper Great Lakes/OH valley, contributing to an eastward shift of its parent upper trough. At the surface, lower pressures associated with the northern CA shortwave trough will contribute to a tightening of the surface pressure gradient across much of the Intermountain West as well as over the northern Plains. ...Great Basin/AZ... Aforementioned tightening of the surface pressure gradient along with modestly enhanced mid-level flow will contribute to gusty southerly/southwesterly winds in the vicinity of the NV/UT/AZ border intersection. Very warm and dry conditions are also expected in this area with minimum RH values in the single digits. Combination of warm, dry, and windy conditions with dry fuels will support a critical fire weather threat. Critical fire weather conditions are also anticipated across northeast NV where winds around 20 mph are anticipated amidst single-digit RH values and dry fuels. Above-average temperatures and RH values in the single digits are anticipated across much of the remainder of the region but winds are expected to be less than 20 mph, precluding critical fire weather conditions. Shortwave trough resulting in the breakdown of the upper ridge will also support an increase in mid-level moisture across portions of central/eastern OR and western ID. This mid-level moisture will exist atop a warm and dry antecedent airmass, contributing to an environment favorable for dry thunderstorms. Development of these thunderstorms amidst dry fuels will result in increased fire danger. ...Northern Plains... Previously discussed tightening of the surface pressure gradient across the region will result in gusty southeast winds from 20-25 mph from early Monday afternoon through the evening. Above-average temperatures (i.e. in the upper 80s and low 90s) are also expected, supporting afternoon RH values around 15-20 percent. While there will be some dissociation (both spatial and temporally) between the strongest winds and low RH values, enough overlap exists to support an elevated to locally critical fire weather threat. A critical delineation may be needed in subsequent outlooks if guidance suggests stronger winds will persist farther east. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sun, 06/25/2017 - 12:04
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1159 AM CDT Sun Jun 25 2017 Valid 251700Z - 261200Z No changes have been made to the ongoing forecast. ..Cohen.. 06/25/2017 .PREV DISCUSSION... /ISSUED 0230 AM CDT Sun Jun 25 2017/ ...Synopsis... Shortwave trough currently moving through central CA will continue moving north-northeastward into northern CA and southern OR, ahead of a stronger shortwave trough farther off the northern CA coast. Increased mid-level moisture and forcing for ascent will contribute to thunderstorm development across northern CA and central OR (discussed in more detail below). Farther east, upper troughing currently extending from the northern Rockies to the Northeast and covering much of the central and eastern CONUS will persist throughout the day while gradually shifting eastward. ...Northern CA/Central OR... Antecedent dry airmass and deep boundary-layer mixing will contribute to highs in the upper 90s/low 100s and afternoon RH values in the teens. Despite these dry low levels, aforementioned lead shortwave trough is expected to move through the region during the afternoon, helping to moisten the mid levels. Resulting modest instability coupled with forcing for ascent and favorable orographic circulations will result in isolated to widely scattered thunderstorms during the afternoon and evening. Storm motions will not be particularly fast but the warm and dry boundary-layer and high cloud bases will contribute to significant sub-cloud evaporation of any precipitation, resulting in low precipitation totals at the surface. These dry thunderstorms amidst modestly dry fuels will support an increased fire weather threat. ...Northern Plains... Anomalously dry fuels exist across the region due to the below-average rainfall and dry conditions the area has experienced for the past 30 days. Northwesterly winds near 15 mph and minimum RH values around 20-25% will contribute to locally elevated fire weather conditions this afternoon over the region. Below-average temperatures should keep RH values above critical values except on a spotty/localized basis. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sun, 06/25/2017 - 05:42

000
AXNT20 KNHC 251042
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
642 AM EDT Sun Jun 25 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
1030 UTC.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 13N21W
to 03N21W, moving W at 10 kt within the last 12 hours. The wave is
in a region of favorable wind shear, is in a very moist
environment and is under a divergent flow aloft, which is
supporting scattered heavy showers and tstms from 02N-09N E of
30W.

A tropical wave is in the central Atlc with axis extending from
16N33W to 02N39W, moving W at 15-20 kt within the last 24 hours.
The wave is in a region of favorable to neutral wind shear.
However, the CIRA LPW imagery show extensive dry air in the wave
environment, which coincide with Meteosat enhanced imagery of
Saharan dry air and dust. This is supporting lack of convection N
of 8.5N. Scattered heavy showers and isolated tstms associated
with the ITCZ are from 01N-07.5N between 33W and 47W.

A tropical wave is E of the Lesser Antilles with axis extending
from 18N57W to inland Guyana near 06N59W, moving W at 15-20 kt
within the last 24 hours. The wave is in a region of favorable to
neutral wind shear S of 11N and is in a very moist environment
with some patches of dry air according to CIRA LPW. Convection has
increased within the last 6 hours to scattered heavy showers and
isolated tstms from 11N-18N between 56W and 63W.

A tropical wave is in the central Caribbean with axis extending
from 19N73W to inland Colombia near 10N74W, moving west at 15
knots within the last 24 hours. The wave is in a region of
unfavorable wind shear and a deep layer dry environment that
hinder deep convection at the time.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the Africa coast near 11N16W to
09N20W to 08N27W. The Intertropical Convergence Zone axis begins
near 08N27W and continues to 08N36W, then resumes W of a tropical
wave near 03N41W and continues to 03N51W. For convection
information see the tropical waves section.

...DISCUSSION...

GULF OF MEXICO...

High pressure over the western Atlantic has a ridge axis that
extends SW across the north-central and NE Gulf, thus supporting
light to gentle variable winds in that region. An upper level low
that was in the Bay of Campeche Saturday is now over the NW Gulf
waters. Upper level divergence being generated between the low SE
periphery and a broad upper ridge over the EPAC waters just S of
Mexico support numerous heavy showers and tstms S of 23.5N,
including the Bay of Campeche where a surface trough extends from
25N90W to 18N92W. This convective activity is also being
supported by moisture inflow from tropical storm Dora located in
the EPAC waters S-SW of Acapulco Mexico. Heavy showers and tstms
will continue in the SW Gulf and just started in the NW basin
associated with the upper low. This shower activity is forecast
to continue at least through Tuesday. Otherwise, a weak frontal
boundary over the southern United States will drift into the
northern Gulf coast today, increasing chances for showers and
thunderstorms over the northern Gulf coastal waters.

CARIBBEAN SEA...

Scattered to isolated heavy showers and tstms are in the far NW
Caribbean associated with the rainbands of tropical storm Dora
located in the EPAC waters S of Acapulco Mexico. Numerous heavy
showers and tstms are over Caribbean waters between Colombia and
Panama associated with the EPAC monsoon trough, which extends
across Panama and connect with a 1008 mb low over Colombia. A
tropical wave moves across the central basin, thus supporting
fresh to near gale force winds from 11N to 13N between 74W and 76W
and fresh to strong between 68W and 77W. These winds are forecast
to prevail through tonight. Otherwise, a tropical wave E of the
Lesser Antilles has started to generate isolated heavy showers and
tstms across the Windward Islands and SE Caribbean waters. Please
refer to the tropical waves section for more details.

...HISPANIOLA...

Scattered to isolated showers are affecting the Island today due
to a tropical wave moving across Haiti. These showers are forecast
to continue through Monday.

ATLANTIC OCEAN...

Three tropical waves are crossing the tropical Atlantic waters.
Please refer to the tropical waves section for more details. Otherwise,
the remainder of the central and eastern Atlc is under the
influence of a surface ridge anchored by a 1025 mb high centered
near the Azores near 37N27W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Ramos
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sun, 06/25/2017 - 02:44
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0239 AM CDT Sun Jun 25 2017 Valid 261200Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHWEST NV... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EAST-CENTRAL/SOUTHERN NV...SOUTHWEST UT...NORTHWEST AZ... ...Synopsis... Upper ridge in place from the Southwest into the northern Rockies is expected to breakdown on Monday as a shortwave trough moves from northern CA through the northern Rockies. Farther east, a shortwave trough will move from the northern Plains/upper Midwest southeastward into the upper Great Lakes/OH valley, contributing to an eastward shift of its parent upper trough. At the surface, lower pressures associated with the northern CA shortwave trough will contribute to a tightening of the surface pressure gradient across much of the Intermountain West as well as over the northern Plains. ...Great Basin/AZ... Aforementioned tightening of the surface pressure gradient along with modestly enhanced mid-level flow will contribute to gusty southerly/southwesterly winds in the vicinity of the NV/UT/AZ border intersection. Very warm and dry conditions are also expected in this area with minimum RH values in the single digits. Combination of warm, dry, and windy conditions with dry fuels will support a critical fire weather threat. Critical fire weather conditions are also anticipated across northeast NV where winds around 20 mph are anticipated amidst single-digit RH values and dry fuels. Above-average temperatures and RH values in the single digits are anticipated across much of the remainder of the region but winds are expected to be less than 20 mph, precluding critical fire weather conditions. Shortwave trough resulting in the breakdown of the upper ridge will also support an increase in mid-level moisture across portions of central/eastern OR and western ID. This mid-level moisture will exist atop a warm and dry antecedent airmass, contributing to an environment favorable for dry thunderstorms. Development of these thunderstorms amidst dry fuels will result in increased fire danger. ...Northern Plains... Previously discussed tightening of the surface pressure gradient across the region will result in gusty southeast winds from 20-25 mph from early Monday afternoon through the evening. Above-average temperatures (i.e. in the upper 80s and low 90s) are also expected, supporting afternoon RH values around 15-20 percent. While there will be some dissociation (both spatial and temporally) between the strongest winds and low RH values, enough overlap exists to support an elevated to locally critical fire weather threat. A critical delineation may be needed in subsequent outlooks if guidance suggests stronger winds will persist farther east. ..Mosier.. 06/25/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sun, 06/25/2017 - 02:44
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0239 AM CDT Sun Jun 25 2017 Valid 261200Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHWEST NV... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EAST-CENTRAL/SOUTHERN NV...SOUTHWEST UT...NORTHWEST AZ... ...Synopsis... Upper ridge in place from the Southwest into the northern Rockies is expected to breakdown on Monday as a shortwave trough moves from northern CA through the northern Rockies. Farther east, a shortwave trough will move from the northern Plains/upper Midwest southeastward into the upper Great Lakes/OH valley, contributing to an eastward shift of its parent upper trough. At the surface, lower pressures associated with the northern CA shortwave trough will contribute to a tightening of the surface pressure gradient across much of the Intermountain West as well as over the northern Plains. ...Great Basin/AZ... Aforementioned tightening of the surface pressure gradient along with modestly enhanced mid-level flow will contribute to gusty southerly/southwesterly winds in the vicinity of the NV/UT/AZ border intersection. Very warm and dry conditions are also expected in this area with minimum RH values in the single digits. Combination of warm, dry, and windy conditions with dry fuels will support a critical fire weather threat. Critical fire weather conditions are also anticipated across northeast NV where winds around 20 mph are anticipated amidst single-digit RH values and dry fuels. Above-average temperatures and RH values in the single digits are anticipated across much of the remainder of the region but winds are expected to be less than 20 mph, precluding critical fire weather conditions. Shortwave trough resulting in the breakdown of the upper ridge will also support an increase in mid-level moisture across portions of central/eastern OR and western ID. This mid-level moisture will exist atop a warm and dry antecedent airmass, contributing to an environment favorable for dry thunderstorms. Development of these thunderstorms amidst dry fuels will result in increased fire danger. ...Northern Plains... Previously discussed tightening of the surface pressure gradient across the region will result in gusty southeast winds from 20-25 mph from early Monday afternoon through the evening. Above-average temperatures (i.e. in the upper 80s and low 90s) are also expected, supporting afternoon RH values around 15-20 percent. While there will be some dissociation (both spatial and temporally) between the strongest winds and low RH values, enough overlap exists to support an elevated to locally critical fire weather threat. A critical delineation may be needed in subsequent outlooks if guidance suggests stronger winds will persist farther east. ..Mosier.. 06/25/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sun, 06/25/2017 - 02:34
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Sun Jun 25 2017 Valid 251200Z - 261200Z ...Synopsis... Shortwave trough currently moving through central CA will continue moving north-northeastward into northern CA and southern OR, ahead of a stronger shortwave trough farther off the northern CA coast. Increased mid-level moisture and forcing for ascent will contribute to thunderstorm development across northern CA and central OR (discussed in more detail below). Farther east, upper troughing currently extending from the northern Rockies to the Northeast and covering much of the central and eastern CONUS will persist throughout the day while gradually shifting eastward. ...Northern CA/Central OR... Antecedent dry airmass and deep boundary-layer mixing will contribute to highs in the upper 90s/low 100s and afternoon RH values in the teens. Despite these dry low levels, aforementioned lead shortwave trough is expected to move through the region during the afternoon, helping to moisten the mid levels. Resulting modest instability coupled with forcing for ascent and favorable orographic circulations will result in isolated to widely scattered thunderstorms during the afternoon and evening. Storm motions will not be particularly fast but the warm and dry boundary-layer and high cloud bases will contribute to significant sub-cloud evaporation of any precipitation, resulting in low precipitation totals at the surface. These dry thunderstorms amidst modestly dry fuels will support an increased fire weather threat. ...Northern Plains... Anomalously dry fuels exist across the region due to the below-average rainfall and dry conditions the area has experienced for the past 30 days. Northwesterly winds near 15 mph and minimum RH values around 20-25% will contribute to locally elevated fire weather conditions this afternoon over the region. Below-average temperatures should keep RH values above critical values except on a spotty/localized basis. ..Mosier.. 06/25/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sun, 06/25/2017 - 01:05

000
AXNT20 KNHC 250605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 AM EDT Sun Jun 25 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...TROPICAL WAVES...

A tropical wave came off the coast of Africa earlier today. There
is a broad area of low pressure associated with the wave, which
axis is near 20W. This wave, not depicted in the 0000 UTC analysis
map, is in a region of favorable wind shear, is in a very moist
environment and is under a divergent flow aloft, which is
supporting heavy showers and tstms from 03N-09N E of 29W.

A tropical wave is in the central Atlc with axis extending from
16N36W to 03N40W, moving W at 20 kt within the last 24 hours. The
wave is in a region of favorable to neutral wind shear. However,
the CIRA LPW imagery show extensive dry air in the wave
environment, which coincide with Meteosat enhanced imagery of
Saharan dry air and dust. This is supporting lack of convection N
of 5N. Numerous heavy showers and isolated tstms associated with
the ITCZ are from 02N-05N between 38W and 47W.

A tropical wave is E of the Lesser Antilles with axis extending
from 17N54W to inland Guyana near 05N57W, moving W at 15-20 kt
within the last 24 hours. The wave is in a region of favorable to
neutral wind shear S of 10N and is in a very moist environment
with some patches of dry air according to CIRA LPW. Scattered to
isolated showers are S of 17N between 52W and 63W.

A tropical wave is in the central Caribbean with axis extending
from 18N71W to inland Venezuela near 08N72W, moving west at 15
knots within the last 24 hours. The wave is in a region of
unfavorable wind shear and a deep layer dry environment that
hinder deep convection at the time.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the Africa coast near 08N13W to
07N21W. The Intertropical Convergence Zone axis begins near
07N21W and continues to 08N30W to 05N38W, then resumes W of a
tropical wave near 03N41W and continues to 04N51W. Aside from the
convection associated with the tropical waves, scattered heavy
showers are from 04N-10N between 32W-36W.

...DISCUSSION...

GULF OF MEXICO...

High pressure over the western Atlantic has a ridge axis that
extends SW across the north-central and NE Gulf where a 1019 mb
high formed near 28N84W supporting light to gentle variable winds.
The upper level low that was in the Bay of Campeche Saturday
morning is now over the NW Gulf waters. Upper level divergence
being generated between its SE periphery and a broad upper ridge
over the EPAC waters just S of Mexico support heavy showers and
tstms S of 25N, including the Bay of Campeche. This convective
activity is also being supported by moisture inflow from tropical
depression four located in the EPAC waters S of Acapulco Mexico.
Heavy showers and tstms will continue in the SW Gulf and will
extend to the NW basin later today. This shower activity is
forecast to continue at least through Tuesday. Otherwise, a weak
frontal boundary over the southern United States will drift into
the northern Gulf coast today, increasing chances for showers and
thunderstorms over the northern Gulf coastal waters.

CARIBBEAN SEA...

Scattered to isolated heavy showers and tstms are in the far NW
Caribbean associated with the rainbands of tropical depression
four located in the EPAC waters S of Acapulco Mexico. Numerous
heavy showers and tstms are over Caribbean waters between
Colombia and Panama associated with the EPAC monsoon trough, which
extends across Panama and connect with a 1009 mb low over
Colombia. A tropical wave moves across the central basin, thus
supporting fresh to near gale force winds from 11N to 13N between
74W and 76W and fresh to strong between 68W and 77W. These winds
are forecast to prevail through Sunday night. Otherwise, a
tropical wave E of the Lesser Antilles has started to generate
isolated heavy showers and tstms across the Windward Islands and
SE Caribbean waters. Please refer to the tropical waves section
for more details.

...HISPANIOLA...

Widely scattered showers will affect the southern portion of the
island through Sunday as a tropical wave passes to the south.

ATLANTIC OCEAN...

Three tropical waves are crossing the tropical Atlantic waters.
Please refer to the tropical waves section for more details. Otherwise,
the remainder of the central and eastern Atlc is under the
influence of surface ridging anchored by a 1027 mb high centered
N of the Azores near 39N27W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Ramos
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 06/24/2017 - 19:01

000
AXNT20 KNHC 250001
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
710 PM EDT Sat Jun 24 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has an axis that extends from
18N34W to 05N38W, moving westward at 15 to 20 kt. This wave is
embedded in a large 700 mb trough, with Saharan dust across the
wave environment north of 10N. Isolated moderate convection is
within 120 nm of either side of the wave axis south of 10N.

A central Atlantic tropical wave has an axis that extends from
17N54W to 06N57W, moving westward at 15 to 20 kt. This wave
embedded in broad 700mb troughing, with some turning evident in
satellite imagery. Scattered moderate convection is from 09N to
14N between 55W and 59W.

A tropical wave is over the east-central Caribbean with an axis
extending from 18N70W to 08N71W, moving westward at 15 kt. This
wave is indicated by 700 mb troughing in model field data. Dry air
an subsidence over the northern portion of the wave is inhibiting
convection over the Caribbean, with convection mainly confined to
northern Venezuela.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the Africa coast near 07N12W to
07N20W. The Intertropical Convergence Zone axis begins near
07N20W and continues to 08N32W to 05N37W, then resumes W of a
tropical wave near 04N39W and continues to 05N52W. Aside from the
convection associated with the tropical waves, scattered moderate
and isolated strong convection is within 180 nm either side of
the convergence axis.

...DISCUSSION...

GULF OF MEXICO...

High pressure over the western Atlantic has a ridge axis that
extends across the northern Gulf to about 90W along about 28N,
supporting moderate southeast winds across the southern half of
the Gulf. The only exception is light winds in the vicinity of
the ridge axis over the northeastern Gulf. A vigorous upper low
over the SW Gulf and a surface trough along the Yucatan Peninsula
supports scattered thunderstorms mainly south of 24N, between 87W
and 92W. During the next 24 hours a weak frontal boundary over
the southern United States will drift into the northern Gulf
coast, increasing chances for showers and thunderstorms over the
northern Gulf. The upper low will move west toward central Mexico.

CARIBBEAN SEA...

The Caribbean is nearly devoid of deep convection this evening,
as mid to upper level dry air has spread across much of the basin.
Mainly moderate to fresh trades prevail in the Caribbean, except
light winds over the southwest Caribbean south of 11N. A tropical
wave is along 70W. Please refer to the tropical waves section for
more details. By Sunday afternoon, a stronger Atlantic tropical
wave will reach the Lesser Antilles, with increased showers and
thunderstorms.

...HISPANIOLA...

widely scattered showers will affect the southern portion of the
island through Sunday as a tropical wave passes to the south.

ATLANTIC OCEAN...

A pair of tropical waves are crossing the tropical north Atlantic
waters. Please refer to the tropical waves section for more
details. A weak surface trough lacking convection extends from
28N59W to 24N63W. Another weak surface trough, which is the
reflection of an upper low aloft, extends from 30N48W to 26N51W.
This trough also lacks deep convection. High pressure centered
north of the discussion area in the east-central Atlantic has a
ridge axis that extends west-southwestward to northern Florida,
and dominates the remainder of the tropical Atlantic waters.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Mundell
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 06/24/2017 - 12:53

000
AXNT20 KNHC 241752
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
152 PM EDT Sat Jun 24 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1530 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has an axis that extends from
18N31W to 04N34W, moving westward at 15 to 20 kt. This wave is
embedded in a large 700 mb trough, with Saharan dust across the
wave environment north of 10N. Isolated moderate convection is
within 120 nm of either side of the wave axis south of 10N.

A central Atlantic tropical wave has an axis that extends from
17N52W to 04N55W, moving westward at around 20 kt. This wave
embedded in broad 700mb troughing, with notable turning also
evident in satellite imagery. Scattered moderate convection is
from 06N to 12N between 52W and 59W.

A tropical wave is over the eastern Caribbean with an axis
extending from 16N67W to 06N68W, moving westward at 10 to 15 kt.
This wave is indicated by 700 mb troughing in model field data.
Dry air an subsidence over the northern portion of the wave is
inhibiting convection over the Caribbean, with convection confined
to northern Venezuela.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the Africa coast near 08N13W to
07N20W. The Intertropical Convergence Zone axis begins near
07N20W and continues to 08N31W, then resumes W of a tropical wave
near 06N36W and continues to 02N42W to 05N53W. Aside from the
convection associated with the tropical waves, numerous moderate
and isolated strong convection are within 210 nm of either side
of the monsoon trough axis. Scattered moderate convection is from
the equator to 08N between 35W and 48W.

...DISCUSSION...

GULF OF MEXICO...

High pressure over the western Atlantic has a ridge axis that
extends across the northern Gulf to about 90W along about 28N,
supporting moderate southeast winds across the Gulf. The only
exception is light winds in the vicinity of the ridge axis over
the northeastern Gulf. An upper low over the southwestern Gulf
supports scattered thunderstorms mainly south of 24N, west of
89W. Over the next 24 hours a frontal boundary over the southern
United States will drift toward the northern Gulf coast,
increasing chances for showers and thunderstorms over the northern
Gulf. The upper low will move west toward northwestern Mexico.

CARIBBEAN SEA...

The Caribbean is void of deep convection today, as mid to upper
level dry air has spread across much of the basin. Mainly moderate
to fresh trades cover the Caribbean, except light winds over the
southwest Caribbean south of 11N. A tropical wave is crossing the
eastern Caribbean. Please refer to the tropical waves section for
more details. By Sunday afternoon, a strong Atlantic tropical wave
is expected to near the Lesser Antilles with showers and
thunderstorms.

...HISPANIOLA...

Mainly scattered showers will affect the southern portion of the
island through Sunday as a tropical wave passes to the south.

ATLANTIC OCEAN...

A pair of tropical waves are crossing the tropical north Atlantic
waters. Please refer to the tropical waves section for more
details. A weak surface trough void of convection extends from
27N59W to 24N62W. Another surface trough to the east, which is the
reflection of an upper low aloft, extends from 29N49W to 25N51W.
This trough supports isolated thunderstorms within 120 nm of the
trough axis. High pressure centered north of the area of
discussion over the central and eastern Atlantic has a ridge axis
that extends west- southwest to northern Florida and dominates the
remainder of the Atlantic discussion waters.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Latto
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sat, 06/24/2017 - 12:04
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sat Jun 24 2017 Valid 251200Z - 261200Z No changes have been made to the ongoing forecast. ..Cohen.. 06/24/2017 .PREV DISCUSSION... /ISSUED 0215 AM CDT Sat Jun 24 2017/ ...Synopsis... Upper ridging which has persisted across the western CONUS for the last week is expected to begin breaking down on Sunday as a shortwave trough approaches its northern periphery late Sunday evening/early Monday morning. Increasing mid-level moisture and forcing for ascent will contribute to thunderstorm development across northern CA and central OR. Some of these thunderstorms may be dry (discussed in more detail below). Central/eastern CONUS troughing will remain largely in place throughout the day before becoming a bit more progressive late in the period in response to the aforementioned shortwave trough. At the surface, ridging over the Plains will persist while expanding eastward into the MS valley. A cold front extending from central TX eastward across the Southeast states will become increasingly diffuse. ...Northern CA/Central OR... Model guidance is in good agreement that a shortwave trough will approach the northern CA coast late Sunday night/early Monday morning with a subtle lead disturbance moving through the region Sunday afternoon. Increased mid-level moisture associated with the approaching system will result in modest instability and the potential for isolated thunderstorms, particularly over the higher terrain. Given the deeply mixed boundary layer and precipitable water values around 0.75", most of these storms will produce little to no precipitation at the surface. While fuels are not overly dry, above-average ERCs and below-average 100-hr dead fuel moisture have been observed across the region, suggesting fuels are marginally supportive of fire spread. Resulting combination of isolated dry thunderstorms and modestly receptive fuels will support increased fire danger and an isolated dry thunderstorm area has been delineated to address this threat. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sat, 06/24/2017 - 12:02
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1156 AM CDT Sat Jun 24 2017 Valid 241700Z - 251200Z No changes have been made to the ongoing forecast. ..Cohen.. 06/24/2017 .PREV DISCUSSION... /ISSUED 0211 AM CDT Sat Jun 24 2017/ ...Synopsis... Upper troughing currently in place over much of the central and eastern CONUS is expected to persist throughout the day while gradually shifting eastward. Several shortwave troughs will progress through its base, the strongest of which is now moving into the upper Midwest and is expected to be over the upper Great Lakes by 12Z Sunday. Farther west, upper ridging currently extending from the Southwest northwestward into the northeast Pacific Ocean will gradually shift eastward in response to the eastward shift of the upper trough. At the surface, ridging will build across the Plains while a cold front moves slowly across the southern Plains and Southeast. ...Mountains and Eastern Foothills of Southern CA... Mid-level moisture is expected to move around western periphery of the upper ridge centered near the AZ/NM/Mexico border intersection. This mid-level moisture may support isolated thunderstorm development during the afternoon, especially over the higher terrain. A very warm and deeply mixed boundary layer will support high cloud bases and sub-cloud evaporation of any precipitation that does form, resulting in a threat for dry thunderstorms. Threat for dry thunderstorms coupled with at least modestly dry fuels across the region merits the introduction of an isolated dry thunderstorm threat area with this forecast. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 06/24/2017 - 05:07

000
AXNT20 KNHC 241007
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
607 AM EDT Sat Jun 24 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 17N28W
to 05N29W, moving W at 15-20 kt within the last 24 hours. The
wave is in a region of favorable to neutral wind shear. However,
the CIRA LPW imagery show extensive dry air in the wave
environment, which coincide with Meteosat enhanced imagery of
Saharan dry air and dust. This is supporting lack of convection at
the time.

A tropical wave is in the central Atlc with axis extending from
14N51W to 04N52W, moving W at 15-20 kt within the last 24 hours.
The wave is in a region of favorable to neutral wind shear, is in
a moderate moist environment with some patches of dry air
according to CIRA LPW, and is under a region of upper level
divergence. These factors support scattered showers and isolated
tstms from 05N to 15N between 48W and 58W.

A tropical wave is in the E Caribbean with axis extending from
15N64W to inland Venezuela, moving west at 10-15 knots within the
last 24 hours. The wave is in a region of favorable wind shear.
However, extensive intrusion of Saharan dry air and dust in the
wave environment hinder convection at the time.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from 09N13W to 08N16W. The
Intertropical Convergence Zone axis begins near 08N17W and
continues to 06N27W, then resumes W of a tropical wave near 05N31W
and continues along 03N40W to 05N50W. Aside from the convection
associated with the tropical waves, scattered moderate convection
is from 03S-07N between 33W-48W. Numerous heavy showers and
scattered tstms are off the coast of Africa from 04N-12N E of
17W.

...DISCUSSION...

GULF OF MEXICO...

Stable weather conditions are almost basin-wide being supported
by surface high pressure extending SW from the W Atlc and dry air
subsidence from aloft as indicated by Water Vapor imagery. The
ridge supports moderate to fresh E-SE winds across the basin,
which are forecast to continue through Sunday. A middle to upper
level low centered W of the Yucatan Peninsula is already
supporting scattered heavy showers and tstms over the Bay of
Campeche with possible gusty winds. The low will move W today and
then NW towards Texas adjacent waters generating in its path
heavy showers and tstms over the W Gulf this weekend. Otherwise,
by tonight into Sunday...a weak frontal boundary is expected to
impact the northern waters as it stalls along 30N and dissipates
by Sunday night.

CARIBBEAN SEA...

An upper level low centered over the E Bay of Campeche continue
to support isolated showers over western Honduras and the NW
Caribbean W of 85W. Heavy showers continue across Guatemala and
Belize associated with a broad area of low pressure in the EPAC with
high chances of becoming a tropical cyclone this weekend. A tropical
wave is in the SE Caribbean, however lacking convection due to
abundant Saharan dry air and dust in the region. The northern
portion of this wave is analyzed as a surface trough across the
Leeward Islands where it generates isolated showers. Otherwise,
fresh to strong winds will continue in the south-central basin,
increasing to near gale force on Sunday as the tropical wave moves
into this area. Moderate to fresh trades are elsewhere. Little
change is expected thereafter for the early portion of next week.

...HISPANIOLA...

Mostly clear skies prevail across the island as surface ridging
to the N across the SW North Atlc remains in place providing
mostly fair weather conditions. However, a surface trough moving
along the S-SW periphery of the Atlc surface ridge will bring
moisture across the region, thus supporting showers across the
Island Saturday and Sunday.

ATLANTIC OCEAN...

An upper level anticyclonic circulation is centered offshore of NE
Florida that continues to support a 1021 mb high centered near
30N65W, which is forecast to dissipate tonight. Otherwise, the
remainder of the central and eastern Atlc is under the influence
of surface ridging anchored by a 1029 mb high centered N of the
Azores near 39N27W. There are two tropical waves in the basin. See
that section above for further details.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Ramos
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sat, 06/24/2017 - 02:20
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0215 AM CDT Sat Jun 24 2017 Valid 251200Z - 261200Z ...Synopsis... Upper ridging which has persisted across the western CONUS for the last week is expected to begin breaking down on Sunday as a shortwave trough approaches its northern periphery late Sunday evening/early Monday morning. Increasing mid-level moisture and forcing for ascent will contribute to thunderstorm development across northern CA and central OR. Some of these thunderstorms may be dry (discussed in more detail below). Central/eastern CONUS troughing will remain largely in place throughout the day before becoming a bit more progressive late in the period in response to the aforementioned shortwave trough. At the surface, ridging over the Plains will persist while expanding eastward into the MS valley. A cold front extending from central TX eastward across the Southeast states will become increasingly diffuse. ...Northern CA/Central OR... Model guidance is in good agreement that a shortwave trough will approach the northern CA coast late Sunday night/early Monday morning with a subtle lead disturbance moving through the region Sunday afternoon. Increased mid-level moisture associated with the approaching system will result in modest instability and the potential for isolated thunderstorms, particularly over the higher terrain. Given the deeply mixed boundary layer and precipitable water values around 0.75", most of these storms will produce little to no precipitation at the surface. While fuels are not overly dry, above-average ERCs and below-average 100-hr dead fuel moisture have been observed across the region, suggesting fuels are marginally supportive of fire spread. Resulting combination of isolated dry thunderstorms and modestly receptive fuels will support increased fire danger and an isolated dry thunderstorm area has been delineated to address this threat. ..Mosier.. 06/24/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sat, 06/24/2017 - 02:19
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0211 AM CDT Sat Jun 24 2017 Valid 241200Z - 251200Z ...Synopsis... Upper troughing currently in place over much of the central and eastern CONUS is expected to persist throughout the day while gradually shifting eastward. Several shortwave troughs will progress through its base, the strongest of which is now moving into the upper Midwest and is expected to be over the upper Great Lakes by 12Z Sunday. Farther west, upper ridging currently extending from the Southwest northwestward into the northeast Pacific Ocean will gradually shift eastward in response to the eastward shift of the upper trough. At the surface, ridging will build across the Plains while a cold front moves slowly across the southern Plains and Southeast. ...Mountains and Eastern Foothills of Southern CA... Mid-level moisture is expected to move around western periphery of the upper ridge centered near the AZ/NM/Mexico border intersection. This mid-level moisture may support isolated thunderstorm development during the afternoon, especially over the higher terrain. A very warm and deeply mixed boundary layer will support high cloud bases and sub-cloud evaporation of any precipitation that does form, resulting in a threat for dry thunderstorms. Threat for dry thunderstorms coupled with at least modestly dry fuels across the region merits the introduction of an isolated dry thunderstorm threat area with this forecast. ..Mosier.. 06/24/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 06/24/2017 - 01:04

000
AXNT20 KNHC 240604
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
204 AM EDT Sat Jun 24 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 18N26W
to 06N28W, moving W at 15-20 kt within the last 24 hours. The
wave is in a region of favorable to neutral wind shear. However,
the CIRA LPW imagery show extensive dry air in the wave
environment, which coincide with Meteosat enhanced imagery
of Saharan dry air and dust. This is supporting lack of convection
at the time.

A tropical wave is in the central Atlc with axis extending from
12N48W to 04N49W, moving W at 15-20 kt within the last 24 hours.
The wave is in a region of favorable to neutral wind shear S of
11N, is in a moderate moist environment with some patches of dry
air according to CIRA LPW, and is under a region of upper level
divergence. These factors support scattered showers and isolated
tstms from 3N to 12N between 46W and 58W.

A tropical wave is in the E Caribbean with axis extending from
14N65W to inland Venezuela, moving west at 10-15 knots within the
last 24 hours. The wave is in a region of favorable wind shear.
However, extensive intrusion of Saharan dry air and dust in the
wave environment hinder convection at the time.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from 08N13W to 08N16W. The
Intertropical Convergence Zone axis begins near 05N30W to 03N40W
to 05N49W. Aside from convection associated with the tropical
waves...scattered moderate convection is from 04S-07N between
33W-46W. Numerous heavy showers and scattered tstms are from
05N-09N E of 14W.

...DISCUSSION...

GULF OF MEXICO...

Stable weather conditions are basin-wide being supported by
surface high pressure extending SW from the W Atlc and dry air
subsidence from aloft as indicated by Water Vapor imagery. The
ridge supports moderate to fresh E-SE winds across the basin,
which are forecast to continue through Sunday. The only exception
is the area from 21N to 23N between 87.5W and 90.5W where NE-E
fresh to strong winds are present, however with seas less than 8
ft. This area of fresh to strong winds is forecast to diminish
within the next 12 hours. An upper level low centered W of the
Yucatan Peninsula will support showers over the Bay of Campeche
and the NW Gulf over the weekend. Otherwise, by Saturday night
into Sunday...a weak frontal boundary is expected to impact the
northern waters as it stalls along 30N and dissipates by Sunday
night.

CARIBBEAN SEA...

An upper level low is centered over the E Bay of Campeche continue
to support scattered to isolated showers over Honduras and the NW
Caribbean W of 80W. The presence of a tropical wave across
southern Mexico is generating heavy showers across Guatemala.
Another tropical wave is in the SE Caribbean, however lacking
convection due to abundant Saharan dry air and dust in the region.
The northern portion of this wave is analyzed as a surface trough
across the Leeward Islands where it generates isolated showers.
Otherwise, fresh to strong winds will continue in the south-
central basin, increasing to near gale force on Sunday as the
tropical wave moves into this area. Moderate to fresh trades are
elsewhere. Little change is expected thereafter for the early
portion of next week.

...HISPANIOLA...

Mostly clear skies prevail across the island as surface ridging
to the N across the SW North Atlc remains in place providing
mostly fair weather conditions. However, a surface trough moving
along the periphery of the Atlc surface ridge will bring moisture
across the region, thus supporting showers Saturday and Sunday.

ATLANTIC OCEAN...

An upper level anticyclonic circulation is centered offshore of NE
Florida that continues to support a 1021 mb high centered near
30N67W. Otherwise, the remainder of the central and eastern Atlc
is under the influence of surface ridging anchored by a 1030 mb
high centered N of the Azores near 39N27W. There are two tropical
waves in the basin. See that section above for further details.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Ramos
Categories: Weather

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