Aggregator

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

875
ABPZ20 KNHC 210521
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sat Sep 20 2025

For the eastern and central North Pacific east of 180 longitude:

Off the Coast of Southern Mexico (EP97):
A broad area of low pressure located a couple of hundred miles south
of the southern coast of Mexico continues to show signs of
organization. Environmental conditions are favorable for additional
development, and a tropical depression or tropical storm is expected
to form within the next day or so, while the system moves
west-northwestward at 5 to 10 mph, roughly parallel to the coast of
southern and southwestern Mexico. Locally heavy rainfall is
possible along portions of the coast of southern and southwestern
Mexico through Monday. For additional information, including gale
warnings, please see the High Seas Forecasts issued by the National
Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Jelsema

MD 2107 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF NORTHEASTERN OKLAHOMA AND ADJACENT PORTIONS OF THE GREAT PLAINS
Mesoscale Discussion 2107 NWS Storm Prediction Center Norman OK 0902 PM CDT Sat Sep 20 2025 Areas affected...parts of northeastern Oklahoma and adjacent portions of the Great Plains Concerning...Severe potential...Watch unlikely Valid 210202Z - 210400Z Probability of Watch Issuance...5 percent SUMMARY...Lingering strong thunderstorm activity may pose a continuing risk for a localized downburst or two through 10-11 PM CDT. DISCUSSION...Vigorous convective development persists in an evolving, but still not particularly organized, cluster near and northwest through north of Tulsa. Much of the stronger convection is being forced above the eastward propagating portion of an expanding cold pool at the surface, near a stalled, remnant surface frontal zone, along which low-level moisture is maximized and may be contributing to CAPE in excess of 2000 J/kg. This convection will probably gradually consolidate with a smaller immediate downstream cluster supported by lift associated with warm advection along the boundary. This is occurring in the presence of westerly deep-layer ambient mean flow on the order of 10-15 kt, with negligible deep-layer shear. However, lower/mid-tropospheric thermodynamic profiles may be unsaturated enough to contribute to a continuing risk for another strong downburst or two through late evening. ..Kerr/Bunting.. 09/21/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TSA... LAT...LON 36909590 36689502 36209455 35939481 35829521 35889565 36019602 36499658 36909590 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sat Sep 20 2025 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms remain possible across parts of the south-central Plains this evening. ...South-central Plains... A few strong to locally severe storms are ongoing this evening from the TX Panhandle into western/northern OK. Moderate buoyancy remains in place across areas that have not been convectively overturned, while deep-layer shear is marginally sufficient for briefly organized storms capable of isolated severe gusts and hail. Enhanced SRH is still in place near a remnant outflow across northeast OK (as noted on the KINX VWP), and there still a window of opportunity for a supercell or two within this regime, which could pose a threat of a brief tornado and large hail. Some clustering is possible later this evening across the eastern TX Panhandle into western OK, and also across parts of the Ozarks, associated with separate branches of a modest nocturnal low-level jet. Some severe threat could persist into late evening, before convection becomes increasingly elevated overnight. ...Mid MS Valley into lower MI... A storm cluster across western lower MI has recently produced strong gusts, with other isolated strong storms noted from western IN into IL. Isolated strong storms may persist into late evening across this region within a modestly unstable environment, though a gradual weakening trend is expected with time. ...Parts of KS overnight... Guidance generally suggests that convection will increase overnight and spread eastward from northwest into central KS. MUCAPE near/above 1000 J/kg could support a few strong storms, but generally weak effective shear and modest midlevel lapse rates are expected to limit the organized severe threat. ..Dean.. 09/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sat Sep 20 2025 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms remain possible across parts of the south-central Plains this evening. ...South-central Plains... A few strong to locally severe storms are ongoing this evening from the TX Panhandle into western/northern OK. Moderate buoyancy remains in place across areas that have not been convectively overturned, while deep-layer shear is marginally sufficient for briefly organized storms capable of isolated severe gusts and hail. Enhanced SRH is still in place near a remnant outflow across northeast OK (as noted on the KINX VWP), and there still a window of opportunity for a supercell or two within this regime, which could pose a threat of a brief tornado and large hail. Some clustering is possible later this evening across the eastern TX Panhandle into western OK, and also across parts of the Ozarks, associated with separate branches of a modest nocturnal low-level jet. Some severe threat could persist into late evening, before convection becomes increasingly elevated overnight. ...Mid MS Valley into lower MI... A storm cluster across western lower MI has recently produced strong gusts, with other isolated strong storms noted from western IN into IL. Isolated strong storms may persist into late evening across this region within a modestly unstable environment, though a gradual weakening trend is expected with time. ...Parts of KS overnight... Guidance generally suggests that convection will increase overnight and spread eastward from northwest into central KS. MUCAPE near/above 1000 J/kg could support a few strong storms, but generally weak effective shear and modest midlevel lapse rates are expected to limit the organized severe threat. ..Dean.. 09/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sat Sep 20 2025 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms remain possible across parts of the south-central Plains this evening. ...South-central Plains... A few strong to locally severe storms are ongoing this evening from the TX Panhandle into western/northern OK. Moderate buoyancy remains in place across areas that have not been convectively overturned, while deep-layer shear is marginally sufficient for briefly organized storms capable of isolated severe gusts and hail. Enhanced SRH is still in place near a remnant outflow across northeast OK (as noted on the KINX VWP), and there still a window of opportunity for a supercell or two within this regime, which could pose a threat of a brief tornado and large hail. Some clustering is possible later this evening across the eastern TX Panhandle into western OK, and also across parts of the Ozarks, associated with separate branches of a modest nocturnal low-level jet. Some severe threat could persist into late evening, before convection becomes increasingly elevated overnight. ...Mid MS Valley into lower MI... A storm cluster across western lower MI has recently produced strong gusts, with other isolated strong storms noted from western IN into IL. Isolated strong storms may persist into late evening across this region within a modestly unstable environment, though a gradual weakening trend is expected with time. ...Parts of KS overnight... Guidance generally suggests that convection will increase overnight and spread eastward from northwest into central KS. MUCAPE near/above 1000 J/kg could support a few strong storms, but generally weak effective shear and modest midlevel lapse rates are expected to limit the organized severe threat. ..Dean.. 09/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sat Sep 20 2025 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms remain possible across parts of the south-central Plains this evening. ...South-central Plains... A few strong to locally severe storms are ongoing this evening from the TX Panhandle into western/northern OK. Moderate buoyancy remains in place across areas that have not been convectively overturned, while deep-layer shear is marginally sufficient for briefly organized storms capable of isolated severe gusts and hail. Enhanced SRH is still in place near a remnant outflow across northeast OK (as noted on the KINX VWP), and there still a window of opportunity for a supercell or two within this regime, which could pose a threat of a brief tornado and large hail. Some clustering is possible later this evening across the eastern TX Panhandle into western OK, and also across parts of the Ozarks, associated with separate branches of a modest nocturnal low-level jet. Some severe threat could persist into late evening, before convection becomes increasingly elevated overnight. ...Mid MS Valley into lower MI... A storm cluster across western lower MI has recently produced strong gusts, with other isolated strong storms noted from western IN into IL. Isolated strong storms may persist into late evening across this region within a modestly unstable environment, though a gradual weakening trend is expected with time. ...Parts of KS overnight... Guidance generally suggests that convection will increase overnight and spread eastward from northwest into central KS. MUCAPE near/above 1000 J/kg could support a few strong storms, but generally weak effective shear and modest midlevel lapse rates are expected to limit the organized severe threat. ..Dean.. 09/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sat Sep 20 2025 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms remain possible across parts of the south-central Plains this evening. ...South-central Plains... A few strong to locally severe storms are ongoing this evening from the TX Panhandle into western/northern OK. Moderate buoyancy remains in place across areas that have not been convectively overturned, while deep-layer shear is marginally sufficient for briefly organized storms capable of isolated severe gusts and hail. Enhanced SRH is still in place near a remnant outflow across northeast OK (as noted on the KINX VWP), and there still a window of opportunity for a supercell or two within this regime, which could pose a threat of a brief tornado and large hail. Some clustering is possible later this evening across the eastern TX Panhandle into western OK, and also across parts of the Ozarks, associated with separate branches of a modest nocturnal low-level jet. Some severe threat could persist into late evening, before convection becomes increasingly elevated overnight. ...Mid MS Valley into lower MI... A storm cluster across western lower MI has recently produced strong gusts, with other isolated strong storms noted from western IN into IL. Isolated strong storms may persist into late evening across this region within a modestly unstable environment, though a gradual weakening trend is expected with time. ...Parts of KS overnight... Guidance generally suggests that convection will increase overnight and spread eastward from northwest into central KS. MUCAPE near/above 1000 J/kg could support a few strong storms, but generally weak effective shear and modest midlevel lapse rates are expected to limit the organized severe threat. ..Dean.. 09/21/2025 Read more

000
ABNT20 KNHC 202324
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sat Sep 20 2025

For the North Atlantic...Caribbean Sea and the Gulf of America:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Gabrielle, located over the central subtropical Atlantic.

Eastern and Central Tropical Atlantic:
A tropical wave over the eastern Atlantic is producing disorganized
shower and thunderstorm activity well west-southwest of the Cabo
Verde Islands. Although development is unlikely during the next
couple of days, environmental conditions should gradually become
more favorable for slow development of this disturbance by the
middle to latter part of next week while it moves west-northwestward
to northwestward across the central Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Reinhart

000
ABPZ20 KNHC 202317
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sat Sep 20 2025

For the eastern and central North Pacific east of 180 longitude:

Off the Coast of Southern Mexico (EP97):
A broad area of low pressure located a couple of hundred miles south
of the southern coast of Mexico continues to show signs of
organization. Environmental conditions are favorable for additional
development, and a tropical depression or tropical storm is expected
to form within the next couple of days while the system moves
west-northwestward at 5 to 10 mph, roughly parallel to the coast of
southern and southwestern Mexico. Locally heavy rainfall is
possible along portions of the coast of southern and southwestern
Mexico through Monday. For additional information, including gale
warnings, please see the High Seas Forecasts issued by the National
Weather Service.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 7 days...high...90 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Bucci

No watches are valid as of Sat Sep 20 22:34:01 UTC 2025.

No Mesoscale Discussions are in effect as of Sat Sep 20 22:34:01 UTC 2025.

MD 2106 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN TEXAS AND OKLAHOMA PANHANDLES INTO WESTERN OKLAHOMA
Mesoscale Discussion 2106 NWS Storm Prediction Center Norman OK 0239 PM CDT Sat Sep 20 2025 Areas affected...Eastern Texas and Oklahoma Panhandles into western Oklahoma Concerning...Severe potential...Watch unlikely Valid 201939Z - 202215Z Probability of Watch Issuance...5 percent SUMMARY...Scattered strong storms capable of marginally severe hail or wind gusts are expected to form by 21-22Z, beginning over the eastern Panhandles, and perhaps developing over southwest Oklahoma as well. DISCUSSION...Surface analysis shows a stationary front over the eastern OK Panhandle and extending eastward just south of the KS border. This boundary arcs southeastward across eastern OK and into central AR as a modifying outflow boundary. Temperatures continue to rise into the upper 80s to lower 90s F over much of central/western OK and northwest TX including the Panhandles, as dewpoints mix into the upper 50s/lower 60s F. Visible satellite imagery shows increasing cumulus fields along the front over the eastern OK Panhandle, and extending southwestward across parts of the central and southern TX Panhandle. Modest MLCAPE values over 1000 J/kg have developed, with forecast soundings depicting midlevel lapse rates on the order of 6.5 C/km. Large-scale forcing is generally weak, and storms will rely on heating/steep low-level lapse rates and surface convergence along the boundaries. Scattered cells are likely to form after 20Z over western areas, moving slowly east/southeast and producing marginal hail and wind gusts. A cool pocket does exist over western OK, and the associated effects of differential heating could yield additional initiation there. ..Jewell/Smith.. 09/20/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...DDC...LUB...AMA... LAT...LON 36329923 36029925 35589904 35239873 35129856 34599838 34389854 34079927 34280051 34570114 34910153 35070170 35560188 35950187 36330172 36800105 37120048 37190000 37019946 36799924 36329923 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0421 PM CDT Sat Sep 20 2025 Valid 221200Z - 281200Z ...Days 3-5/Monday-Wednesday... A mid-level trough and associated cold front across the Northern Rockies on Day 3/Monday will slide southeastward into the Central Plains by Day 5/Wednesday while a ridge builds across the interior West. Surface high pressure across the Northern and Central Rockies along with development of a thermal trough along the West Coast will support an east to northeast flow regime from northern CA to coastal OR and WA on Day 4/Tuesday, possibly into Day 5/Wednesday. The dry post-frontal air mass will support critically low daytime relative humidity, including poor overnight RH recoveries, across the Great Basin and northern CA on Day 4/Tuesday. However, relatively low expected wind speeds and marginal fuel dryness precludes introduction of critical probabilities at this time. Expected wetting rainfall along and west of the Cascade Range Sunday will similarly temporarily subdue fire weather concerns across this area. Southwest flow ahead of a mid-level low west of CA will usher in deeper sub-tropical moisture and rainfall into the southern part of the state Tuesday, reaching into the Sierra Nevada by Day 5/Wednesday bringing the potential for some thunderstorm development but also wetting rains. ...Days 6-8/Thursday-Saturday... The troughing pattern across the eastern U.S. will promote widespread wetting rainfall and more seasonable temperatures across portions of the Midwest, Lower Mississippi Valley and Appalachia through late next week. This should moderate fuel conditions and reduce overall fire weather concerns. The mid-level low and sub-tropical moisture impacting CA midweek is expected to slowly diffuse as it propagates into the Great Basin late next week. This should support a mix of wet and dry thunderstorms across the higher terrain of the Great Basin and Southwest but marginally dry fuels should limit new ignition potential. ..Williams.. 09/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0421 PM CDT Sat Sep 20 2025 Valid 221200Z - 281200Z ...Days 3-5/Monday-Wednesday... A mid-level trough and associated cold front across the Northern Rockies on Day 3/Monday will slide southeastward into the Central Plains by Day 5/Wednesday while a ridge builds across the interior West. Surface high pressure across the Northern and Central Rockies along with development of a thermal trough along the West Coast will support an east to northeast flow regime from northern CA to coastal OR and WA on Day 4/Tuesday, possibly into Day 5/Wednesday. The dry post-frontal air mass will support critically low daytime relative humidity, including poor overnight RH recoveries, across the Great Basin and northern CA on Day 4/Tuesday. However, relatively low expected wind speeds and marginal fuel dryness precludes introduction of critical probabilities at this time. Expected wetting rainfall along and west of the Cascade Range Sunday will similarly temporarily subdue fire weather concerns across this area. Southwest flow ahead of a mid-level low west of CA will usher in deeper sub-tropical moisture and rainfall into the southern part of the state Tuesday, reaching into the Sierra Nevada by Day 5/Wednesday bringing the potential for some thunderstorm development but also wetting rains. ...Days 6-8/Thursday-Saturday... The troughing pattern across the eastern U.S. will promote widespread wetting rainfall and more seasonable temperatures across portions of the Midwest, Lower Mississippi Valley and Appalachia through late next week. This should moderate fuel conditions and reduce overall fire weather concerns. The mid-level low and sub-tropical moisture impacting CA midweek is expected to slowly diffuse as it propagates into the Great Basin late next week. This should support a mix of wet and dry thunderstorms across the higher terrain of the Great Basin and Southwest but marginally dry fuels should limit new ignition potential. ..Williams.. 09/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0421 PM CDT Sat Sep 20 2025 Valid 221200Z - 281200Z ...Days 3-5/Monday-Wednesday... A mid-level trough and associated cold front across the Northern Rockies on Day 3/Monday will slide southeastward into the Central Plains by Day 5/Wednesday while a ridge builds across the interior West. Surface high pressure across the Northern and Central Rockies along with development of a thermal trough along the West Coast will support an east to northeast flow regime from northern CA to coastal OR and WA on Day 4/Tuesday, possibly into Day 5/Wednesday. The dry post-frontal air mass will support critically low daytime relative humidity, including poor overnight RH recoveries, across the Great Basin and northern CA on Day 4/Tuesday. However, relatively low expected wind speeds and marginal fuel dryness precludes introduction of critical probabilities at this time. Expected wetting rainfall along and west of the Cascade Range Sunday will similarly temporarily subdue fire weather concerns across this area. Southwest flow ahead of a mid-level low west of CA will usher in deeper sub-tropical moisture and rainfall into the southern part of the state Tuesday, reaching into the Sierra Nevada by Day 5/Wednesday bringing the potential for some thunderstorm development but also wetting rains. ...Days 6-8/Thursday-Saturday... The troughing pattern across the eastern U.S. will promote widespread wetting rainfall and more seasonable temperatures across portions of the Midwest, Lower Mississippi Valley and Appalachia through late next week. This should moderate fuel conditions and reduce overall fire weather concerns. The mid-level low and sub-tropical moisture impacting CA midweek is expected to slowly diffuse as it propagates into the Great Basin late next week. This should support a mix of wet and dry thunderstorms across the higher terrain of the Great Basin and Southwest but marginally dry fuels should limit new ignition potential. ..Williams.. 09/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0421 PM CDT Sat Sep 20 2025 Valid 221200Z - 281200Z ...Days 3-5/Monday-Wednesday... A mid-level trough and associated cold front across the Northern Rockies on Day 3/Monday will slide southeastward into the Central Plains by Day 5/Wednesday while a ridge builds across the interior West. Surface high pressure across the Northern and Central Rockies along with development of a thermal trough along the West Coast will support an east to northeast flow regime from northern CA to coastal OR and WA on Day 4/Tuesday, possibly into Day 5/Wednesday. The dry post-frontal air mass will support critically low daytime relative humidity, including poor overnight RH recoveries, across the Great Basin and northern CA on Day 4/Tuesday. However, relatively low expected wind speeds and marginal fuel dryness precludes introduction of critical probabilities at this time. Expected wetting rainfall along and west of the Cascade Range Sunday will similarly temporarily subdue fire weather concerns across this area. Southwest flow ahead of a mid-level low west of CA will usher in deeper sub-tropical moisture and rainfall into the southern part of the state Tuesday, reaching into the Sierra Nevada by Day 5/Wednesday bringing the potential for some thunderstorm development but also wetting rains. ...Days 6-8/Thursday-Saturday... The troughing pattern across the eastern U.S. will promote widespread wetting rainfall and more seasonable temperatures across portions of the Midwest, Lower Mississippi Valley and Appalachia through late next week. This should moderate fuel conditions and reduce overall fire weather concerns. The mid-level low and sub-tropical moisture impacting CA midweek is expected to slowly diffuse as it propagates into the Great Basin late next week. This should support a mix of wet and dry thunderstorms across the higher terrain of the Great Basin and Southwest but marginally dry fuels should limit new ignition potential. ..Williams.. 09/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more