Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - 1 hour 26 min ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0305 AM CDT Thu Aug 17 2017 Valid 181200Z - 191200Z ...Synopsis... A rather strong mid/upper trough is expected to move eastward from British Columbia into the Canadian Prairie provinces on Friday. In conjunction with this trough, a surface low is expected to move across southern AB/SK, with a surface trough extending southward into portions of the northern Rockies/High Plains. Continued warming and drying is expected across most of the interior Northwest into the northern Rockies and High Plains, leading to an elevated fire weather threat where winds are sufficient. ...Montana... Modest westerly flow will result in continued warming/drying across MT on Friday, and critically low RH is possible over much of the state during the afternoon. The primary uncertainty regarding the fire weather forecast is whether wind speeds will be sufficient for at least an elevated threat. While the region will only be glanced by stronger flow associated with the trough to the north, at this time it appears sufficient flow will exist at the top of the boundary layer to support sustained winds of 15-20 mph (with higher gusts) over much of MT. Combined with minimum RH values of 10-20% and receptive fuels, these winds appear sufficient for an elevated fire weather threat. ...Portions of Northern OR...Central/Eastern WA... Warm, dry, and breezy conditions are expected across portions of the Columbia Gorge and in the lee of the Cascades across WA and northern OR. While wind speeds may be somewhat marginal, the potential exists for sustained winds exceeding 15 mph to combine with RH values of 10-20%, resulting in an elevated fire weather threat. ..Dean.. 08/17/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - 1 hour 27 min ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0304 AM CDT Thu Aug 17 2017 Valid 171200Z - 181200Z ...Synopsis... As one mid/upper trough shifts eastward into the northern Plains and another trough approaches the British Columbia coast, a mid/upper ridge is expected to briefly build into portions of the Northwest today. A cold front is expected to move through portions of the northern Rockies and northern High Plains, resulting in some increase in the fire weather threat. ...Montana into the far western Dakotas... A relatively dry and breezy post-frontal regime will result in a threat of elevated fire weather conditions across much of Montana east of the Continental Divide, potentially spreading eastward into the western Dakotas. Sustained winds of 15-20 mph are possible as RH values drop to near or below 20% during the afternoon. While locally critical conditions are possible, especially from central into southeast MT, confidence in sustained winds exceeding 20 mph is too low for an upgrade at this time. ...Washington/Oregon/Idaho... Locally elevated conditions will be possible across portions of central/eastern WA/OR in the lee of the Cascades, and also across portions of the Snake River Valley in Idaho. RH may fall to near critical thresholds across these areas, though wind speeds are expected to remain relatively light outside of localized terrain-favored locations. ..Dean.. 08/17/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - 3 hours 29 min ago

000
AXNT20 KNHC 170605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 AM EDT Thu Aug 17 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.

...SPECIAL FEATURES...

Hurricane Gert is centered near 40.1N 58.4W at 17/0300 UTC or
about 350 nm SE of Halifax Nova Scotia and about 460 nm SSW of
Cape Race Newfoundland moving ENE at 32 kt. Estimated minimum
central pressure is 967 mb. Maximum sustained wind speed is 90 kt
with gusts to 110 kt. Numerous moderate convection and scattered
tstms are from 37N-42N between 54W-59W. Scattered moderate
convection is elsewhere from 36N-46N between 50W-60W. See latest
NHC forecast/ advisory under AWIPS/WMO headers MIATCMAT3/WTNT23
KNHC for more details.

A 1011 mb low is located about 560 nm east of the Lesser
Antilles near 13N50W. Intrusion of Saharan dry air and dust to its
environment is noticed in GOES-16 experimental imagery and CIRA
LPW imagery, however the system looks a little more concentrated.
This being favored in part by low vertical wind shear. Scattered
moderate convection and isolated tstms are within 220 nm W
semicircle from low center. Isolated showers are within 220 nm SE
quadrant of the low. Upper-level winds are forecast to become
more conducive for development during the next day or so while the
low moves westward across the tropical Atlantic Ocean, crossing
into the Caribbean Sea on Friday. Regardless of development,
locally heavy rainfall and gusty winds are expected to spread
across portions of the Lesser Antilles on Thursday night and
Friday. This system has a medium chance of becoming a tropical
cyclone in the next two days.

A tropical wave is in the central Atlc associated with a 1009 mb
low pressure located near 14N38W. The wave axis extends from
21N38W to the low and has been moving W at 15 kt. The wave is in
a region of low to moderate vertical wind shear, however intrusion
of Saharan dry air and dust to the wave environment limit
convection to scattered moderate within 245 nm W semicircle of
low pressure center. Gradual development of this system is
possible during the next few days while it moves WNW, but upper-
level winds are expected to become less conducive for tropical
cyclone formation when the disturbance moves north of the Leeward
Islands this weekend. This system has a medium chance of becoming
a tropical cyclone in the next two days.

...TROPICAL WAVES...

A tropical wave is in the E Atlc associated with a 1013 mb low
near 08N20W. The wave axis extends from 18N18W to the low center.
The CIRA LPW imagery show dry air intrusion to the wave
environment, which has significantly reduced the convection this
wave had when it was coming off the W African coast yesterday.
GOES-16 experimental and Meteosat SAL imagery show Saharan dust
and dry air engulfing this wave. Monsoon moisture and middle to
upper level diffluent flow support scattered moderate convection
and isolated tstms from 06N to 15N E of 25W. Environmental
conditions are forecast to become more conducive for development
over the weekend while the system moves WNW.

A tropical wave is in the E Caribbean with axis extending from
23N61W to 12N66W, moving W at 15-20 kt. There is abundant moisture
associated with this wave that along with upper level divergent
flow support scattered to isolated moderate convection and tstms
from 16N to 24N between 61W and 69W, including Puerto Rico.

A tropical wave is in the W Caribbean with axis extending from
19N85W across Honduras to 10N87W, moving W at 20 kt. The wave is
in a region of low vertical wind shear, however dry air
subsidence continue to limit convection to isolated showers within
90 nm of its axis.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 11N16W to
09N30W. To the west, the monsoon trough and ITCZ is disrupted due
to the tropical lows and tropical waves mentioned above.
Otherwise, scattered moderate convection is from 05N-09N between
25W-45W.

...DISCUSSION...

GULF OF MEXICO...

Except for scattered showers over the E Bay of Campeche associated
with a surface trough along 93W, the remainder basin in under the
influence of a surface ridge anchored by a 1019 mb high near
28N85W. This setup is prividing ESE gentle to moderate flow across
the northern half of the Gulf, except for light to gentle variable
flow in the NE basin around the high center. Otherwise, NE fresh
winds are off the W Yucatan Peninsula coast associated with the
surface trough. The high is expected to persist across the NE
Gulf waters through early Saturday. A surface trough will develop
each evening across the Yucatan peninsula shifting W into the Bay
of Campeche during the overnight hours. Locally higher winds can
be expected in the vicinity of the trough axis.

CARIBBEAN SEA...

A tropical wave is moving across the NW basin and Honduras
supporting isolated showers. A second tropical wave is in the E
Caribbean with axis near 64W, which is supporting scattered to
isolated showers and tstms over the NE basin including Puerto
Rico, the Mona Passage and the Virgin Islands. See tropical waves
section for further details. Genearally, diffluent flow is
obserseved in the SW Caribbean, which is supporting scattered
showers S of 13N W of 70W. Lastly, a diffluent flow pattern
persist between an upper level ridge anchored over S Georgia and a
low centered N of the Windward Passage. This continue to support
scattered to isolated showers across central Cuba. Otherwise, dry
air subsidence and strong vetical wind shear support fair weather
elsewhere W of 70W. Fresh to strong winds in the south-central
waters and in the vicinity of the tropical wave in the eastern
waters are expected through Thursday with moderate to fresh trades
elsewhere.

...HISPANIOLA...

An upper level low is centered N of the Windward Passage ahead
of a tropical wave that is forecast move over the central
Caribbean Thursday. The approaching wave is already supporting
isolated showers over the Dominican Republic, but the activity
will increase during Thursday and into early Friday.

ATLANTIC OCEAN...

The basin N of 23N continue under the influence of the Azores
subtropical high which supports fair weather. For information
about tropical waves, see sections above.

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

$$
Ramos
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Wed, 08/16/2017 - 17:58

000
AXNT20 KNHC 162258
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
658 PM EDT Wed Aug 16 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
2215 UTC.

...SPECIAL FEATURES...
Hurricane Gert is centered near 38.7N 62.4W at 16/2100 UTC or
about 355 nm S of Halifax Nova Scotia and about 630 nm SW of Cape
Race Newfoundland moving NE at 27 kt. Estimated minimum central
pressure is 970 mb. Maximum sustained wind speed is 85 kt with
gusts to 105 kt. Scattered to numerous moderate convection is from
37N-42N between 58W-65W. Widely scattered moderate convection is
elsewhere from 35N-44N between 53W-66W. See latest NHC forecast/
advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more
details.

A tropical wave extends from 14N37W to 24N37W moving W at 10-15
kt. A 1009 mb low is centered at the southern extent of the wave
axis that coincides with maximum low to mid-level 700-800 mb
relative vorticity. Scattered moderate convection is from 14N-16N
between 38W-40W.

A 1009 mb low is centered near 14N49W moving W at 10-15 kt. This
low is also a focus of 850 mb relative vorticity on the southern
periphery of a mid-level ridge anchored over the central Atlc to
the N. Scattered moderate convection is from 12N-16N between
49W-54W.

...TROPICAL WAVES...
A tropical wave extends from 09N18W to 21N14W moving W at 10-15
kt. The wave coincides with broad 700 mb troughing between 13W-27W
that continues to emerge off the coast of West Africa this
evening. A pair of surface lows...one a 1008 mb low centered near
17N18W and the other a 1010 mb low centered at the southern extent
of the wave axis near 09N18W indicates the northern and southern
vortices respectively and the broad nature of spin in the local
environment surrounding the wave. Last evening...very strong and
intense convection was occurring...however this evening only
widely scattered moderate convection is noted from 06N-13N between
12W-22W.

A tropical wave extends from 10N64W to 22N60W moving W at 20-25
kt. The wave coincides with 700 mb troughing between 59W-70W that
continues to provide a favorable environment for scattered
moderate convection from 13N-22N between 58W-68W. This area of
convection also falls within the eastern periphery of an upper
level low noted on water vapor imagery centered near 20N72W.

A tropical wave extends from 10N84W to 21N83W moving W at 15-20
kt. The wave is noted on the southeastern periphery of a 700 mb
ridge anchored over the Gulf of Mexico near 27N87W. Widely
scattered moderate convection is from 09N-17N between 79W-87W.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 11N15W to
08N21W to 11N30W. To the west...the monsoon trough and ITCZ is
disrupted due to the tropical lows and tropical waves mentioned
above. Otherwise...scattered moderate convection is from 06N-10N
between 25W-31W...and from 06N-09N between 35W-50W.

...DISCUSSION...

GULF OF MEXICO...
Upper level divergent flow persists over the lower Mississippi
River valley this evening between a broad upper level low
centered in the western Gulf near 23N93W and an upper level
anticyclone centered near 31N81W. Scattered showers and tstms are
mainly occurring across inland portions of extreme eastern
Texas...Louisiana...and Mississippi...with only a few isolated
showers and tstms noted across the NW Gulf waters N of 26N W of
92W. This activity all lies on the northern side of a surface
ridge extending east to west along 27N/28N and anchored by a 1020
mb high centered near 28N87W. Mostly light to gentle anticyclonic
flow is E of 90W and gentle to moderate S-SE flow is W of 90W.
The high is expected to persist across the NE Gulf waters through
early Saturday. A surface trough will develop each evening across
the Yucatan peninsula shifting W into the Bay of Campeche during
the overnight hours. Locally higher winds can be expected in the
vicinity of the trough axis.

CARIBBEAN SEA...
A tropical wave is analyzed across the western Caribbean this
evening generating scattered showers and tstms across the Gulf of
Honduras region and inland portions of Central America. Overall
middle to upper level divergence is noted to the E of the wave
axis over the SW Caribbean producing widely scattered showers and
isolated tstms S of 13N between 72W-84W. Elsewhere...scattered
showers and tstms have likely peaked in intensity across Cuba and
continue moving offshore into the NW Caribbean waters. With the
loss of daytime heating and instability...this activity will
gradually decrease and then dissipate tonight. Farther east...
another tropical wave is impacting the eastern Caribbean with
scattered showers and tstms remaining E of 70W. Much of this
activity is being enhanced by an upper level low centered N of
Hispaniola near 20N72W. Otherwise...fresh to strong winds in the
south-central waters and in the vicinity of the tropical wave in
the eastern waters are expected through Thursday...with moderate
to fresh trades elsewhere.

...HISPANIOLA...
An upper level low is centered N of the island near 20N72W and
is providing overall dry conditions this evening...however a
tropical wave extends across the eastern Caribbean Sea and will
move across the island through Friday. Scattered showers and tstms
are expected to spread westward from the Mona Passage region
tonight to the Windward Passage region by Thursday night into
Friday.

ATLANTIC OCEAN...
Widely scattered showers and isolated tstms remain N of 27N
between 65W and 77W associated with frontal troughing extending SW
from Hurricane Gert centered N of the discussion area.
Otherwise...the remainder of the basin generally N of 23N is
under the influence of the Azores subtropical high which supports
fair weather. A 1025 mb high is centered S of the Azores near
35N27W and a 1025 mb high is centered near 32N43W.

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

$$
HUFFMAN

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Wed, 08/16/2017 - 14:58
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Wed Aug 16 2017 Valid 171200Z - 181200Z Only minor changes have been made to the Day 2/Thursday forecast. ...Montana into the far western Dakotas... Breezy post-frontal westerly winds coupled with RH values less than 20% during the afternoon will combine to create elevated fire weather conditions along and east of the higher terrain. Expanded the elevated area slightly eastward to account for the potential of an early frontal passage, as depicted by various model solutions. There is some risk for locally critical conditions, especially from central into eastern/southeastern Montana where best overlap of strong/gusty winds, low relative humidity, and receptive fuels are forecast. However, sustained winds should largely remain at or below 20 mph across most of this area, which should keep the areal extent of critical conditions too limited to justify an upgrade at this time. ..Elliott/Gleason.. 08/16/2017 .PREV DISCUSSION... /ISSUED 0203 AM CDT Wed Aug 16 2017/ ...Synopsis... As one mid/upper trough shifts eastward into the northern Plains and another trough approaches the British Columbia coast, a mid/upper ridge is expected to briefly build into portions of the Northwest on Thursday. In the wake of the leading trough, a cold front is expected to move through portions of the northern Rockies and northern High Plains, resulting in some increase in the fire weather threat. ...Montana into the far western Dakotas... A relatively dry and breezy post-frontal regime will result in a threat of elevated fire weather conditions across much of Montana east of the Continental Divide. Sustained winds of 15-20 mph are possible as RH values drop to near or below 20% during the afternoon. While locally critical conditions are possible, confidence in sustained winds exceeding 20 mph is too low for an upgrade at this time. Elevated conditions may spread into adjacent portions of Wyoming and the western Dakotas, depending on the timing of the frontal passage during the afternoon. ...Washington/Oregon/Idaho... Locally elevated conditions will be possible across portions of central/eastern WA/OR in the lee of the Cascades, and also across portions of the Snake River Valley in Idaho. RH may fall to near critical thresholds across these areas, though wind speeds are expected to remain relatively light outside of localized terrain-favored locations. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Wed, 08/16/2017 - 14:58
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Wed Aug 16 2017 Valid 171200Z - 181200Z Only minor changes have been made to the Day 2/Thursday forecast. ...Montana into the far western Dakotas... Breezy post-frontal westerly winds coupled with RH values less than 20% during the afternoon will combine to create elevated fire weather conditions along and east of the higher terrain. Expanded the elevated area slightly eastward to account for the potential of an early frontal passage, as depicted by various model solutions. There is some risk for locally critical conditions, especially from central into eastern/southeastern Montana where best overlap of strong/gusty winds, low relative humidity, and receptive fuels are forecast. However, sustained winds should largely remain at or below 20 mph across most of this area, which should keep the areal extent of critical conditions too limited to justify an upgrade at this time. ..Elliott/Gleason.. 08/16/2017 .PREV DISCUSSION... /ISSUED 0203 AM CDT Wed Aug 16 2017/ ...Synopsis... As one mid/upper trough shifts eastward into the northern Plains and another trough approaches the British Columbia coast, a mid/upper ridge is expected to briefly build into portions of the Northwest on Thursday. In the wake of the leading trough, a cold front is expected to move through portions of the northern Rockies and northern High Plains, resulting in some increase in the fire weather threat. ...Montana into the far western Dakotas... A relatively dry and breezy post-frontal regime will result in a threat of elevated fire weather conditions across much of Montana east of the Continental Divide. Sustained winds of 15-20 mph are possible as RH values drop to near or below 20% during the afternoon. While locally critical conditions are possible, confidence in sustained winds exceeding 20 mph is too low for an upgrade at this time. Elevated conditions may spread into adjacent portions of Wyoming and the western Dakotas, depending on the timing of the frontal passage during the afternoon. ...Washington/Oregon/Idaho... Locally elevated conditions will be possible across portions of central/eastern WA/OR in the lee of the Cascades, and also across portions of the Snake River Valley in Idaho. RH may fall to near critical thresholds across these areas, though wind speeds are expected to remain relatively light outside of localized terrain-favored locations. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Wed, 08/16/2017 - 14:58
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Wed Aug 16 2017 Valid 171200Z - 181200Z Only minor changes have been made to the Day 2/Thursday forecast. ...Montana into the far western Dakotas... Breezy post-frontal westerly winds coupled with RH values less than 20% during the afternoon will combine to create elevated fire weather conditions along and east of the higher terrain. Expanded the elevated area slightly eastward to account for the potential of an early frontal passage, as depicted by various model solutions. There is some risk for locally critical conditions, especially from central into eastern/southeastern Montana where best overlap of strong/gusty winds, low relative humidity, and receptive fuels are forecast. However, sustained winds should largely remain at or below 20 mph across most of this area, which should keep the areal extent of critical conditions too limited to justify an upgrade at this time. ..Elliott/Gleason.. 08/16/2017 .PREV DISCUSSION... /ISSUED 0203 AM CDT Wed Aug 16 2017/ ...Synopsis... As one mid/upper trough shifts eastward into the northern Plains and another trough approaches the British Columbia coast, a mid/upper ridge is expected to briefly build into portions of the Northwest on Thursday. In the wake of the leading trough, a cold front is expected to move through portions of the northern Rockies and northern High Plains, resulting in some increase in the fire weather threat. ...Montana into the far western Dakotas... A relatively dry and breezy post-frontal regime will result in a threat of elevated fire weather conditions across much of Montana east of the Continental Divide. Sustained winds of 15-20 mph are possible as RH values drop to near or below 20% during the afternoon. While locally critical conditions are possible, confidence in sustained winds exceeding 20 mph is too low for an upgrade at this time. Elevated conditions may spread into adjacent portions of Wyoming and the western Dakotas, depending on the timing of the frontal passage during the afternoon. ...Washington/Oregon/Idaho... Locally elevated conditions will be possible across portions of central/eastern WA/OR in the lee of the Cascades, and also across portions of the Snake River Valley in Idaho. RH may fall to near critical thresholds across these areas, though wind speeds are expected to remain relatively light outside of localized terrain-favored locations. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Wed, 08/16/2017 - 13:07

000
AXNT20 KNHC 161807
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
207 PM EDT Wed Aug 16 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.

...SPECIAL FEATURES...

Hurricane Gert is centered near 37.4N 65.7W at 16/1500 UTC or
about 308 nm N of Bermuda moving NE at 22 kt. Estimated minimum
central pressure is 975 mb. Maximum sustained wind speed is 80 kt
with gusts to 100 kt. Scattered moderate to strong convection is
from 35N-42N between 60W-67W. See latest NHC forecast/advisory
under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more details.

The 1010 mb low embedded on a tropical wave centered at 14N35W
shows signs of gradual development. There is a medium chance of
tropical cyclone formation within the next 48 hours.

A 1010 mb low is centered over the tropical Atlantic near 14N47W,
moving W at 15-20 kt. This wave in a very moist area based on
SSMI TPW imagery and is also reflected at 700 mb. Scattered
moderate to isolated strong convection is W of the low center from
12N-16N between 49W-53W. The low shows signs of gradual
development. There is a medium chance of tropical cyclone
formation within the next 48 hours.

...TROPICAL WAVES...

A 1010 mb low is off the coast of W Africa near 10N19W embedded in
the monsoon trough. A tropical wave is E of this low, still inland
over W Africa along 15W, moving W at 15-20 kt. This wave in a
very moist area based on SSMI TPW imagery and has a well
pronounced 700 mb trough. Scattered showers are within 120 nm
radius of the low.

A tropical wave is in the tropical Atlantic with an embedded 1010
mb low pressure located near 14N35W. The wave axis extends from
19N34W to the low to 09N35W moving W at 15-20 kt. This wave in a
very moist area based on SSMI TPW imagery and has a well
pronounced 700 mb trough. Scattered moderate to isolated strong
convection is from 13N-16N between 37W-40W.

A tropical wave is over the E Caribbean with axis extending from
22N59W to 16N61W to 09N62W, moving W at 25 kt. The wave has
Saharan dry air and dust N and W of the wave envirnment. Scattered
moderate convection is over the Leeward Islands from 14N-20N
between 57W-63W.

A tropical wave is in the W Caribbean with axis extending from
W Cuba at 22N81W through Panama to the E Pacific at 05N81W,
moving W at 20-25 kt. The wave is in a region of low to moderate
vertical wind shear and dry air subsidence, which is limiting
precipitation to scattered showers within 120 nm of the axis.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 13N17W to
a 1010 mb low near 10N19W to 09N22W to 13N30W. The Intertropical
Convergence Zone axis extends from 11N39W to 13N46W. The ITCZ
resumes W of a low, from 12N50W to 11N55W to 14N60W. Besides the
convection mentioned in the tropical wave section, scattered
moderate convection is along the coast of W Africa from 06N-10N
between 12W-16W. Similar convection is from 07N-11N between 23W-
28W.

...DISCUSSION...

GULF OF MEXICO...

A 1019 mb high is centered over the NE Gulf of Mexico near 28N84W.
5-10 kt anticyclonic winds are noted around the high. 15-20 kt SE
surface winds are over the W Gulf W of 90W. Radar imagery shows
scattered showers over the E Gulf and Straits of Florida, E of
83W. Airmass thunderstorms are now from Louisiana to the Florida
Panhandle. Similar thunderstorms are over the Florida Peninsula.
In the upper levels, an upper level low is centered over the W
Gulf near 23N93W. An upper level high is centered over N Florida
near 30N82W. Expect the surface high to remain quasi-stationary
over the Gulf for the next 24 hours. Expect more airmass
thunderstorms thursday during maximum heating. A surface trough
will develop each evening across the Yucatan peninsula shifting W
into the Bay of Campeche during the overnight hours. Locally
higher winds can be expected in the vicinity of the trough axis.

CARIBBEAN SEA...

Two tropical waves are over the Caribbean. See above. The eastern
extent of the Pacific monsoon trough is producing scattered
moderate to isolated strong convection over Costa Rica and Panama.
Expect the tropical waves to move W with convection over the next
24 hours. Also expect continued convection the SW Caribbean.

...HISPANIOLA...

Presently fair weather is over Hispaniola. Expect convection over
E Hispaniola in 24 hours due to the approach of a tropical wave.

ATLANTIC OCEAN...

Besides the tropical system mentioned above, a 1026 mb high is
centered over the central Atlantic near 33N44W with surface
ridging extending WSW to the N Bahamas. Scattered showers and
isolated thunderstorm are over the N Bahamas.

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

$$
Formosa

Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Wed, 08/16/2017 - 11:15
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Wed Aug 16 2017 Valid 161700Z - 171200Z ...NO CRITICAL AREAS... No changes have been made to the ongoing forecast. Latest guidance continues to suggest locally elevated fire weather conditions may occur briefly this afternoon and early evening across parts of eastern WA/OR and north-central MT. However, confidence in a sufficient overlap of sustained winds around 15-20 mph with RH values lowered to near-critical levels remains too low to introduce an elevated area across either the Pacific Northwest or the northern Rockies/High Plains. See the previous discussion below for more information. ..Gleason.. 08/16/2017 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 16 2017/ ...Synopsis... A broad mid/upper-level trough will remain in place over much of the West today, though an upper ridge will start to build back into the Pacific Northwest late in the period. A weak shortwave embedded within the larger-scale trough is forecast to move into portions of BC/AB, potentially leading to a modest increase in wind speeds across portions of the interior Northwest. Elsewhere across most of the West, relatively dry conditions and light winds are expected. ...Interior Northwest into the Northern Rockies... Near-critical RH will be possible across portions of the interior Northwest into the northern Rockies within a weak downslope flow regime. As mentioned above, a modest increase in wind speeds appears possible across terrain-favored portions of central/eastern WA/OR, southern ID, and northern MT as a weak shortwave trough passes to the north. This will lead to the potential for locally elevated fire weather conditions, with the greatest relative risk expected over portions of the Columbia Gorge and in the lee of the Cascades. However, confidence in elevated wind/RH criteria being met on more than a brief and spotty basis remains too low for any delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Wed, 08/16/2017 - 11:15
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1112 AM CDT Wed Aug 16 2017 Valid 161700Z - 171200Z ...NO CRITICAL AREAS... No changes have been made to the ongoing forecast. Latest guidance continues to suggest locally elevated fire weather conditions may occur briefly this afternoon and early evening across parts of eastern WA/OR and north-central MT. However, confidence in a sufficient overlap of sustained winds around 15-20 mph with RH values lowered to near-critical levels remains too low to introduce an elevated area across either the Pacific Northwest or the northern Rockies/High Plains. See the previous discussion below for more information. ..Gleason.. 08/16/2017 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Aug 16 2017/ ...Synopsis... A broad mid/upper-level trough will remain in place over much of the West today, though an upper ridge will start to build back into the Pacific Northwest late in the period. A weak shortwave embedded within the larger-scale trough is forecast to move into portions of BC/AB, potentially leading to a modest increase in wind speeds across portions of the interior Northwest. Elsewhere across most of the West, relatively dry conditions and light winds are expected. ...Interior Northwest into the Northern Rockies... Near-critical RH will be possible across portions of the interior Northwest into the northern Rockies within a weak downslope flow regime. As mentioned above, a modest increase in wind speeds appears possible across terrain-favored portions of central/eastern WA/OR, southern ID, and northern MT as a weak shortwave trough passes to the north. This will lead to the potential for locally elevated fire weather conditions, with the greatest relative risk expected over portions of the Columbia Gorge and in the lee of the Cascades. However, confidence in elevated wind/RH criteria being met on more than a brief and spotty basis remains too low for any delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

No current storm in NHC Atlantic Wallet 4

Weather - Hurricane Matthew - Wed, 08/16/2017 - 07:01
No current storm in NHC AT4 as of Wed, 16 Aug 2017 12:01:38 GMT

NHC Atlantic Tropical Weather Discussion

NWS Weather - Wed, 08/16/2017 - 05:20

000
AXNT20 KNHC 161020
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
618 AM EDT Wed Aug 16 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
1015 UTC.

...SPECIAL FEATURES...

Hurricane Gert is centered near 36.0N 68.4W at 16/0900 UTC or
about 285 nm NW of Bermuda moving NE at 18 kt. Estimated minimum
central pressure is 975 mb. Maximum sustained wind speed is 80 kt
with gusts to 100 kt. Numerous moderate to isolated strong
convection is from 35N-38N between 66W-70W. See latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC
for more details.

...TROPICAL WAVES...

A tropical wave is in the central Atlc associated with a 1011 mb
low pressure located near 13N34W. The wave axis extends from
19N34W to the low to 10N34W and has been moving W at 15-20 kt.
The wave is in a region of low to moderate vertical wind shear,
however intrusion of Saharan dry air and dust to the wave
environment limit convection to scattered moderate within 200 nm
NW quadrant of low pressure center. Showers and thunderstorms
continue to show some signs of organization in association with
the area of low pressure. Gradual development of this system is
possible before upper-level winds become less conducive for
development by the weekend.

A tropical wave is E of the Lesser Antilles with axis extending
from 21N57W to 10N60W, moving W at 25 kt. The wave is in a region
of moderate to strong vertical wind shear and continue to be
affected by Saharan dry air and dust, which is limiting
convection to scattered to isolated showers within 175 nm of its
axis.

A tropical wave is in the W Caribbean with axis extending from
21N79W to 09N80W, moving W at 20-25 kt. The wave is in a region
of low to moderate vertical wind shear and dry air subsidence,
which is limiting convection to isolated showers within 120 nm of
its axis.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 12N16W to
09N22W to 13N30W to 13N40W to 14N45W to 12N48W. The Intertropical
Convergence Zone axis extends from 12N48W to 10N58W. Outside of
convection associated with the tropical waves, scattered heavy
showers and isolated tstms are off the W African coast from 08N
to 16N E of 22W associated with the next tropical wave that will
emerge to E Atlc waters later today. Otherwise, a 1011 mb low
embedded in the monsoon trough near 14N45W support scattered
showers from 12N to 16N between 43W and 51W.

...DISCUSSION...

GULF OF MEXICO...

Upper level divergent flow persists over the northern Gulf coast
between a broad upper level low centered NW of the Yucatan
Peninsula near 22N92W and an upper level anticyclone centered
over Georgia adjacent waters near 31N80W. Scattered showers and
tstms are occurring over Louisiana adjacent waters N of 27N
between 90W- 94W. Isolated showers are over the E Bay of
Campeche associated with a surface trough that extends from
23N87W to 17N94W. Otherwise, the E Gulf is under the influence
of a surface ridge anchored by a 1017 mb high centered near
27N84W. Gentle to moderate SE flow is W of 90W while light to
gentle variable flow is over the eastern half of the basin. The
high is expected to persist across the NE Gulf waters through
Friday. A surface trough will develop each evening across the
Yucatan peninsula shifting W into the Bay of Campeche during the
overnight hours. Locally higher winds can be expected in the
vicinity of the trough axis.

CARIBBEAN SEA...

A tropical wave is in the W Caribbean supporting isolated showers
and tstms. This tropical wave will continue to propagate westward
across the remainder of the basin through tonight. Another
tropical wave is E of the Lesser Antilles where it is supporting
scattered to isolated showers. This second wave will move into E
Caribbean waters later this morning and is forecast to support
showers across Puerto Rico and adjacent waters. The wave will
move to the central basin Thursday supporting showers across
Hispaniola. Diffluent flow between an upper ridge located NE of
Jacksonville, Florida and an upper low centered N of Hispaniola
continue to support isolated showers over the Windward Passage
and E Cuba adjacent waters. Otherwise, fresh to strong winds in
the south-central waters are expected through Thursday with
moderate to fresh trades elsewhere.

...HISPANIOLA...

Showers and tstms are forecast to start overnight due to an
approaching tropical that will be entering the E Caribbean this
morning. The tropical wave will move over the central Caribbean
Thursday supporting showers across the Island.

ATLANTIC OCEAN...

Trailing moisture associated with Hurricane Gert N of the area
continue to support isolated showers in the SW N Atlc between 70W
and 76W. Otherwise, the remainder of the basin generally N of 20N
is under the influence of the Azores subtropical high which
supports fair weather. For information about tropical waves, see
section above.

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

$$
Ramos
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Wed, 08/16/2017 - 02:06
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0203 AM CDT Wed Aug 16 2017 Valid 171200Z - 181200Z ...Synopsis... As one mid/upper trough shifts eastward into the northern Plains and another trough approaches the British Columbia coast, a mid/upper ridge is expected to briefly build into portions of the Northwest on Thursday. In the wake of the leading trough, a cold front is expected to move through portions of the northern Rockies and northern High Plains, resulting in some increase in the fire weather threat. ...Montana into the far western Dakotas... A relatively dry and breezy post-frontal regime will result in a threat of elevated fire weather conditions across much of Montana east of the Continental Divide. Sustained winds of 15-20 mph are possible as RH values drop to near or below 20% during the afternoon. While locally critical conditions are possible, confidence in sustained winds exceeding 20 mph is too low for an upgrade at this time. Elevated conditions may spread into adjacent portions of Wyoming and the western Dakotas, depending on the timing of the frontal passage during the afternoon. ...Washington/Oregon/Idaho... Locally elevated conditions will be possible across portions of central/eastern WA/OR in the lee of the Cascades, and also across portions of the Snake River Valley in Idaho. RH may fall to near critical thresholds across these areas, though wind speeds are expected to remain relatively light outside of localized terrain-favored locations. ..Dean.. 08/16/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Wed, 08/16/2017 - 02:05
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Wed Aug 16 2017 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Synopsis... A broad mid/upper-level trough will remain in place over much of the West today, though an upper ridge will start to build back into the Pacific Northwest late in the period. A weak shortwave embedded within the larger-scale trough is forecast to move into portions of BC/AB, potentially leading to a modest increase in wind speeds across portions of the interior Northwest. Elsewhere across most of the West, relatively dry conditions and light winds are expected. ...Interior Northwest into the Northern Rockies... Near-critical RH will be possible across portions of the interior Northwest into the northern Rockies within a weak downslope flow regime. As mentioned above, a modest increase in wind speeds appears possible across terrain-favored portions of central/eastern WA/OR, southern ID, and northern MT as a weak shortwave trough passes to the north. This will lead to the potential for locally elevated fire weather conditions, with the greatest relative risk expected over portions of the Columbia Gorge and in the lee of the Cascades. However, confidence in elevated wind/RH criteria being met on more than a brief and spotty basis remains too low for any delineation at this time. ..Dean.. 08/16/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Wed, 08/16/2017 - 01:02

000
AXNT20 KNHC 160602
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
202 AM EDT Wed Aug 16 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.

...SPECIAL FEATURES...

Hurricane Gert is centered near 34.8N 70.3W at 16/0300 UTC or
about 310 nm WNW of Bermuda moving NE at 13 kt. Estimated minimum
central pressure is 979 mb. Maximum sustained wind speed is 75 kt
with gusts to 90 kt. Numerous moderate to isolated strong
convection is from 33N-37N between 67W-71W. See latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC
for more details.

...TROPICAL WAVES...

A tropical wave is in the central Atlc associated with a 1011 mb
low pressure located near 14N32W. The wave axis extends from
22N33W to the low and has been moving W at 15-20 kt. The wave is
in a region of low to moderate vertical wind shear, however
intrusion of Saharan dry air and dust to the wave environment
limit convection to scattered moderate within 220 nm NW quadrant
of low pressure center. Slow development of this system is
anticipated during the next day or two, but conditions are
forecast to become more conducive for tropical cyclone formation
by later in the week while the system moves WNW over the tropical
Atlantic.

A tropical wave is E of the Lesser Antilles with axis extending
from 21N55W to 10N59W, moving W at 25 kt. The wave is in a region
of moderate to strong vertical wind shear and continue to be
affected by Saharan dry air and dust, which is limiting convection
to isolated showers within 200 nm of its axis.

A tropical wave is in the central Caribbean with axis extending
from 17N78W to 09N78W, moving W at 20-25 kt. The wave is in a
region of moderate to strong vertical wind shear and dry air
subsidence, which is hindering deep convection at the time.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 08N13W to
14N28W to 14N43W to 10N47W. The Intertropical Convergence Zone
axis extends from 10N48W to 10N57W. Outside of convection
associated with the tropical waves, numerous heavy showers and
isolated tstms are off the W African coast from 08N to 15N E of
21W associated with the next tropical wave that will emerge to E
Atlc waters later today. Otherwise, a 1011 mb low embedded in the
monsoon trough near 14N44W support isolated showers from 11N to
16N between 42W and 48W.

...DISCUSSION...

GULF OF MEXICO...

Upper level divergent flow persists over the northern Gulf coast
and interior portions of the SE CONUS between a broad upper level
low centered NW of the Yucatan Peninsula near 22N91W and an upper
level anticyclone centered near 30N80W. Isolated showers are
occurring over Louisiana adjacent waters N of 26N between 89W-
93W. Similar shower activity is over the E Bay of Campeche
associated with a surface trough that is moving off the W Yucatan
Peninsula. Otherwise, the E Gulf is under the influence of a
surface ridge anchored by a 1018 mb high centered near 26N84W.
Gentle to moderate SE flow is W of 90W while variable light to
gentle flow is over the eastern half of the basin. The high is
expected to persist across the NE Gulf waters through Friday. A
surface trough will develop each evening across the Yucatan
peninsula shifting W into the Bay of Campeche during the overnight
hours. Locally higher winds can be expected in the vicinity of
the trough axis.

CARIBBEAN SEA...

A tropical wave is moving into the W Caribbean, however it lacks
deep convection. This tropical wave will continue to propagate
westward across the remainder of the basin through Wednesday
night. Another tropical wave is E of the Lesser Antilles where it
is supporting isolated showers. This second wave will move into E
Caribbean waters later this morning and is forecast to support
showers across Puerto Rico and adjacent waters. The wave will
move to the central basin Thu supporting showers across
Hispaniola. Diffluent flow between an upper ridge located NE of
Jacksonville, Florida and an upper low centered N of Hispaniola
continue to support isolated showers over Haiti and the Windward
Passage. Similar activity is occurring over E Cuba adjacent
waters. Otherwise, fresh to strong winds in the south-central
waters are expected through Thursday with moderate to fresh trades
elsewhere.

...HISPANIOLA...

Diffluent flow between an upper ridge located NE of
Jacksonville, Florida and an upper low centered N of Hispaniola
continue to support isolated showers over Haiti and the Windward
Passage. This shower activity is forecast to continue today,
increasing overnight due to an approaching tropical wave. The
tropical wave will move over the central Caribbean Thu supporting
showers across the Island.

ATLANTIC OCEAN...

Isolated showers are N of 26N between 68W and 76W associated with
the convective rainbands of Hurricane Gert centered north of the
discussion area. Otherwise...the remainder of the basin generally
N of 20N is under the influence of the Azores subtropical high
which supports fair weather. For information about tropical
waves, see section above.

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

$$
Ramos
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 08/15/2017 - 18:08

000
AXNT20 KNHC 152308
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
708 PM EDT Tue Aug 15 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
2215 UTC.

...SPECIAL FEATURES...
Hurricane Gert is centered near 33.7N 71.2W at 15/2100 UTC or
about 335 nm WNW of Bermuda moving N-NE at 10 kt. Estimated
minimum central pressure is 981 mb. Maximum sustained wind speed
is 70 kt with gusts to 85 kt. Scattered to numerous moderate
convection is from 32N-35N between 69W-73W. Scattered moderate
convection is elsewhere from 28N-33N between 69W-76W. See latest
NHC forecast/advisory under AWIPS/WMO headers MIATCMAT3/WTNT23
KNHC for more details.

...TROPICAL WAVES...
A tropical wave extends from 14N21W to 22N31W moving W at 10-15
kt. A 1012 mb low is centered at the southern extent of the wave
axis and remains embedded within the monsoon trough. Scattered
moderate convection is from 13N-16N between 30W-34W and isolated
moderate convection is elsewhere from 08N-13N between 30W-35W.

A tropical wave extends from 10N59W to 23N53W moving W at 20-25
kt. The wave remains moving beneath dry air aloft associated with
a broad upper level ridge anchored near 20N42W that continues to
hinder any significant deep convection. Isolated to widely
scattered showers are occurring generally from 12N-19N between
52W-61W.

A tropical wave extends from 06N75W to 17N75W moving W at 15-20
kt. The wave is noted on the southwestern periphery of a 700 mb
ridge anchored over the SW North Atlc near 27N64W. Widely
scattered moderate convection is occurring across portions of
northern Colombia.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 13N17W to
15N26W to 13N34W to a 1011 mb low near 14N43W then to 11N48W. The
Intertropical Convergence Zone axis extends from 11N48W to 10N57W.
Outside of convection associated with the tropical waves...
scattered moderate and isolated strong convection is from 08N-12N
between 14W-18W. Widely scattered moderate convection is elsewhere
from 05N-11N between 14W-24W...and from 13N-18N between 43W-48W.

...DISCUSSION...

GULF OF MEXICO...
Upper level divergent flow persists over the northern Gulf coast
and interior portions of the SE CONUS between a broad upper level
low centered near 23N90W and an upper level anticyclone centered
near 30N80W. Scattered showers and tstms are occurring N of 28N
between 86W-94W across the Gulf waters and a large portions of the
SE CONUS from extreme eastern Texas to central Georgia. This
activity all lies on the northern side of a surface ridge
extending east to west along 26N and anchored by a 1018 mb high
centered off the coast of the Florida peninsula near 26N84W.
Mostly light to gentle anticyclonic flow is E of 90W and gentle to
moderate S-SE flow is W of 90W. The high is expected to persist
across the NE Gulf waters through Friday. A surface trough will
develop each evening across the Yucatan peninsula shifting W into
the Bay of Campeche during the overnight hours. Locally higher
winds can be expected in the vicinity of the trough axis.

CARIBBEAN SEA...
A tropical wave is moving into the western Caribbean this
evening. The tropical wave will continue to propagate westward
across the remainder of the basin through late Wednesday. To the
west of the wave...the monsoon trough axis extends along 10N and
is providing focus for scattered showers and tstms remaining
generally S of 11N and continuing to impact Panama and Costa Rica.
Other isolated showers and tstms are occurring across interior
portions of northern Nicaragua and Honduras as divergent middle to
upper level flow persists over Central America. Otherwise...fresh
to strong winds in the south-central waters are expected through
Thursday...with moderate to fresh trades elsewhere.

...HISPANIOLA...
An upper level trough reaching across the region from the central
Atlantic will drift WSW to the north and over the island during
the next couple of days supporting scattered showers and isolated
tstms across the island and adjacent waters through Thursday.

ATLANTIC OCEAN...
Scattered showers and tstms are N of 28N between 70W and 76W
associated with the convective rainbands of Hurricane Gert
centered north of the discussion area. Otherwise...the remainder
of the basin generally N of 20N is under the influence of the
Azores subtropical high which supports fair weather. Farther
east...scattered to numerous moderate and isolated strong
convection is noted across sub-Saharan West Africa from 09N-16N
between 10W-18W. Likely related to the next tropical wave moving
through the region...this convection will move off the coast
during the overnight hours.

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

$$
HUFFMAN

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Tue, 08/15/2017 - 13:51
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0149 PM CDT Tue Aug 15 2017 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Interior Northwest... A tightening surface pressure gradient in the wake of a passing mid-level trough will encourage some breeziness through the Columbia Gorge and in the lee of the Cascades Wednesday. Sustained west/northwesterly winds around 10-20 mph (with higher gusts) will develop during the afternoon and evening. While fuels remain receptive in many spots, RH values should rise fairly quickly as winds increase. Therefore, only locally elevated concerns are anticipated. However, an elevated area could be introduced in later forecast updates if a greater overlap in breezy conditions and low RH is expected. ..Picca.. 08/15/2017 .PREV DISCUSSION... /ISSUED 0255 AM CDT Tue Aug 15 2017/ ...Synopsis... The large-scale trough is expected to persist over much of the West on Wednesday, though an upper ridge may start to build back into the Pacific Northwest during the latter half of the period. A weak shortwave embedded within the larger-scale trough is forecast to move into portions of BC/AB, potentially leading to a modest increase in wind speeds across portions of the interior Northwest. However, the fire weather threat relating to both wind/RH concerns and dry thunderstorms is expected to be relatively low. ...Interior Northwest into the Northern Rockies... Near-critical RH will be possible across portions of the interior Northwest into the northern Rockies within a weak downslope flow regime. As mentioned above, a modest increase in wind speeds appears possible across terrain-favored portions of central/eastern WA/OR, southern ID, and northern MT as a weak shortwave passes to the north. This will lead to the potential for locally elevated fire weather conditions. However, confidence in elevated wind/RH criteria being met on more than a brief and spotty basis is too low for any delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Tue, 08/15/2017 - 13:51
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0149 PM CDT Tue Aug 15 2017 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Interior Northwest... A tightening surface pressure gradient in the wake of a passing mid-level trough will encourage some breeziness through the Columbia Gorge and in the lee of the Cascades Wednesday. Sustained west/northwesterly winds around 10-20 mph (with higher gusts) will develop during the afternoon and evening. While fuels remain receptive in many spots, RH values should rise fairly quickly as winds increase. Therefore, only locally elevated concerns are anticipated. However, an elevated area could be introduced in later forecast updates if a greater overlap in breezy conditions and low RH is expected. ..Picca.. 08/15/2017 .PREV DISCUSSION... /ISSUED 0255 AM CDT Tue Aug 15 2017/ ...Synopsis... The large-scale trough is expected to persist over much of the West on Wednesday, though an upper ridge may start to build back into the Pacific Northwest during the latter half of the period. A weak shortwave embedded within the larger-scale trough is forecast to move into portions of BC/AB, potentially leading to a modest increase in wind speeds across portions of the interior Northwest. However, the fire weather threat relating to both wind/RH concerns and dry thunderstorms is expected to be relatively low. ...Interior Northwest into the Northern Rockies... Near-critical RH will be possible across portions of the interior Northwest into the northern Rockies within a weak downslope flow regime. As mentioned above, a modest increase in wind speeds appears possible across terrain-favored portions of central/eastern WA/OR, southern ID, and northern MT as a weak shortwave passes to the north. This will lead to the potential for locally elevated fire weather conditions. However, confidence in elevated wind/RH criteria being met on more than a brief and spotty basis is too low for any delineation at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 08/15/2017 - 12:14

000
AXNT20 KNHC 151714
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
114 PM EDT Tue Aug 15 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
1645 UTC.

...SPECIAL FEATURES...

Hurricane Gert is centered near 32.8N 72.0W at 15/1500 UTC or
about 365 nm W of Bermuda moving N-NE at 9 kt. Estimated minimum
central pressure is 986 mb. Maximum sustained wind speed is 65 kt
with gusts to 80 kt. Numerous moderate to strong convection is
within 90 nm in the southeast semicircle of the center. Elsewhere, scattered
moderate convection is from 29N to 31N between 70W and 73W. See
latest NHC forecast/advisory under AWIPS/WMO headers
MIATCMAT3/WTNT23 KNHC for more details.

...TROPICAL WAVES...

A tropical wave is W of the Cape Verde islands reaching from
20N29W to 1010 mb low pressure near 13N32W to 10N32W, moving west
at 10 kt. Scattered convection is noted over much of the region
from 11N to 14N between 30W and 33W. The wave is in a region of
low vertical wind shear, however intrusion of Saharan dry air and
dust to the wave environment limit deep convection. Slow
development of this system is anticipated during the next day or
two, but conditions are forecast to become a little more conducive
for tropical cyclone formation by later in the week while the
system moves westward over the tropical Atlantic.

A tropical wave is in the central Atlc with axis extending from
20N52W to 11N54W, moving W at 10 to 15 kt. The wave is entering a
region of moderate to strong vertical wind shear and is being
severely affected by extensive Saharan dry air and dust, which is
hindering convection at the time.

A tropical wave is in the central Caribbean with axis extending
from northeast Colombia to central Hispaniola. The wave is in a
region of strong vertical wind shear and dry air subsidence, which
is hindering deep convection at the time. Divergent flow aloft
between an upper trough over the area and an upper ridge well to
the northwest is support scattered moderate convection from 150 nm
south of the Dominican Republic through the Mona Passage.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the coast of W Africa near 15N17W
to 1010 mb low pressure near 13N32W to a 1009 mb low pressure
area centered near 14N43W, where the intertropical convergence
zone starts and continues to 13N53W then on to near Trinidad.
Scattered moderate to isolated strong convection extends from 06N
to 11N E of 20W. Scattered moderate convection is within 120 nm of
the 1010 mb low pressure near 14N43W.

...DISCUSSION...

GULF OF MEXICO...

A ridge extends from the Straits of Florida to the coast of south
Texas. A broad upper level low is centered just north of the
Yucatan peninsula, which supports isolated showers there and in
the Yucatan Channel. Diffluent flow in the northwest periphery of
the low support similar shower activity off the SE coast of
Louisiana and Mississippi. The gradient between the ridge and
lower pressure over north central Mexico is supporting moderate to
fresh southerly winds across the western Gulf, and light to gentle
breezes elsewhere. A surface trough will develop each evening
across the Yucatan Peninsula shifting W to the Bay of Campeche
during the overnight hours. Locally higher winds can be expected
west of the trough axis.

CARIBBEAN SEA...

A tropical wave is moving through the central Caribbean. Please
see section above. The tropical wave will continue to propagate
westward across the western Caribbean through late Wednesday. A
few showers and thunderstorms are active north of western Panama
off Boca del Toro. Showers are also ongoing over the northwest
Caribbean from near Swan Island to the Bay Islands, in the
divergent flow aloft southeast of the upper low centered north of
the Yucatan peninsula. Otherwise, fresh to strong winds in the
south-central basin will through Thursday.

...HISPANIOLA...

An upper level trough reaching across the area from the central
Atlantic will drift WSW to the north and across the island over
the next couple of days supporting scattered showers over the
island and adjacent waters through Thursday.

ATLANTIC OCEAN...

Scattered showers and tstms are N of 28N between 70W and 74W associated
with the rainbands of Hurricane Gert centered north of the area.
See Special Features section for more information on Gert.
Otherwise, the remainder basin generally N of 20N is under the
influence of the Azores high, which supports fair weather. For
information about tropical waves, see section above. Farther east,
numerous moderate to isolated strong convection is noted across
sub-Saharan West Africa, related tropical wave activity moving
through the region. Some of this convection is observed within 180
nm of the coast from Liberia to Senegal.

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

$$
Christensen
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Tue, 08/15/2017 - 10:41
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1037 AM CDT Tue Aug 15 2017 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast are necessary. See below for more details. ..Picca.. 08/15/2017 .PREV DISCUSSION... /ISSUED 0254 AM CDT Tue Aug 15 2017/ ...Synopsis... A broad upper trough is expected to remain in place across most of the West into the Plains today. Persistent weak downslope flow will result in gradual warming across portions of the interior Northwest and also across portions of western/central MT, with RH falling to near critical levels in some locations. However, wind speeds are generally expected to remain light, limiting the overall fire weather threat. Isolated thunderstorms will be possible across portions of ID/MT, but at this time it appears that any such storms will be limited to areas that are relatively cool and moist, limiting the dry thunderstorm risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
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