Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Thu Nov 09 2023 Valid 091200Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR THE LAS ANGELES AND VENTURA COUNTY MOUNTAINS... ...Synopsis... Within the last 6 hours, Critical fire weather conditions have been observed at 6 observation sites across southern California. The LAX/TPH gradient is currently -9.3 at 06Z , down from a peak of -10.5 at 03Z. Expect this gradient to maintain into the morning hours before starting to relax by late morning. Expect Elevated fire weather concerns to wane by this evening as the gradient continues to weaken. Some dry and breezy conditions are expected across the northern Plains/Upper Midwest this afternoon, but fuels remain moist in this region and therefore, no fire weather highlights are necessary. ..Bentley.. 11/09/2023 ...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 0200 AM CST Thu Nov 09 2023 Valid 091200Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR THE LAS ANGELES AND VENTURA COUNTY MOUNTAINS... ...Synopsis... Within the last 6 hours, Critical fire weather conditions have been observed at 6 observation sites across southern California. The LAX/TPH gradient is currently -9.3 at 06Z , down from a peak of -10.5 at 03Z. Expect this gradient to maintain into the morning hours before starting to relax by late morning. Expect Elevated fire weather concerns to wane by this evening as the gradient continues to weaken. Some dry and breezy conditions are expected across the northern Plains/Upper Midwest this afternoon, but fuels remain moist in this region and therefore, no fire weather highlights are necessary. ..Bentley.. 11/09/2023 ...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 0200 AM CST Thu Nov 09 2023 Valid 091200Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR THE LAS ANGELES AND VENTURA COUNTY MOUNTAINS... ...Synopsis... Within the last 6 hours, Critical fire weather conditions have been observed at 6 observation sites across southern California. The LAX/TPH gradient is currently -9.3 at 06Z , down from a peak of -10.5 at 03Z. Expect this gradient to maintain into the morning hours before starting to relax by late morning. Expect Elevated fire weather concerns to wane by this evening as the gradient continues to weaken. Some dry and breezy conditions are expected across the northern Plains/Upper Midwest this afternoon, but fuels remain moist in this region and therefore, no fire weather highlights are necessary. ..Bentley.. 11/09/2023 ...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 0200 AM CST Thu Nov 09 2023 Valid 091200Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR THE LAS ANGELES AND VENTURA COUNTY MOUNTAINS... ...Synopsis... Within the last 6 hours, Critical fire weather conditions have been observed at 6 observation sites across southern California. The LAX/TPH gradient is currently -9.3 at 06Z , down from a peak of -10.5 at 03Z. Expect this gradient to maintain into the morning hours before starting to relax by late morning. Expect Elevated fire weather concerns to wane by this evening as the gradient continues to weaken. Some dry and breezy conditions are expected across the northern Plains/Upper Midwest this afternoon, but fuels remain moist in this region and therefore, no fire weather highlights are necessary. ..Bentley.. 11/09/2023 ...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 0200 AM CST Thu Nov 09 2023 Valid 091200Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR THE LAS ANGELES AND VENTURA COUNTY MOUNTAINS... ...Synopsis... Within the last 6 hours, Critical fire weather conditions have been observed at 6 observation sites across southern California. The LAX/TPH gradient is currently -9.3 at 06Z , down from a peak of -10.5 at 03Z. Expect this gradient to maintain into the morning hours before starting to relax by late morning. Expect Elevated fire weather concerns to wane by this evening as the gradient continues to weaken. Some dry and breezy conditions are expected across the northern Plains/Upper Midwest this afternoon, but fuels remain moist in this region and therefore, no fire weather highlights are necessary. ..Bentley.. 11/09/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2268 CONCERNING FREEZING RAIN FOR NORTHERN NY...VT...WESTERN NH
Mesoscale Discussion 2268 NWS Storm Prediction Center Norman OK 0136 AM CST Thu Nov 09 2023 Areas affected...northern NY...VT...western NH Concerning...Freezing rain Valid 090736Z - 091200Z SUMMARY...Freezing rain rates 0.05 to 0.15 inches per 3 hours are forecast through 12 UTC. Mixed precipitation type in the form of snow/sleet/freezing rain will also occur before a gradual warming of the profile favors sleet/freezing rain. DISCUSSION...Radar mosaic the past few hours has shown a moderate to heavy precipitation shield over the Lake Ontario vicinity. This precipitation is mainly in response to zone of strong low-level warm-air advection/isentropic lift spreading northeast from the Lower Great Lakes into New England tonight. Surface temperatures are at or below freezing across the Adirondacks into VT where initial precipitation has been in form of snow/sleet/freezing rain across northern NY. As additional warming in the 850-700 mb layer occurs tonight (especially with south extent), precipitation will likely transition from snow to sleet to sleet/freezing rain during the 09-12 UTC period. Model QPF and current radar trends indicate appreciable freezing rain rates (0.05 to 0.15 inches per 3 hours) may occur in areas where cold air in the low levels is slow to modify and where longer duration of freezing rain occurs. ..Smith.. 11/09/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BTV...ALY...BGM...BUF... LAT...LON 43987576 44617441 44547259 44307200 43917147 43507133 43127160 42947365 43167574 43517599 43987576 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Nov 09 2023 Valid 101200Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across South Texas and the adjacent Texas Coastal Plain on Friday. ...Synopsis and Discussion... Broadly cyclonic flow is forecast to cover the north-central and northeastern CONUS early Friday morning in the wake of a mid-latitude cyclone over eastern Ontario. Enhanced mid-level flow associated with this cyclone will cover much of the eastern CONUS early Friday, but should gradually shift eastward throughout the period as the parent cyclone progresses northeastward. Additionally, the overall upper troughing is expected to deamplify throughout the day as an embedded shortwave trough progresses quickly across the OH Valley and off the Northeast coast. Farther southwest, a southern-stream shortwave trough is expected to gradually move eastward across the southern High Plains during the day, and then more northeastward across OK overnight. This wave is expected to lose amplitude during this time frame as it encounters more confluent flow aloft. To the south and east of this shortwave, a remnant frontal zone will likely stretch southwestward from a weak surface low over southeast TX through deep south TX. This front will make gradual southward progress throughout the day, moving off the TX coast by the early afternoon, if not sooner. Poor lapse rates will limit buoyancy in the vicinity of the front, but persistent and moist southwesterly flow aloft will support very moist profiles (i.e. PWs around 2") and the potential for a few deeper convective cores capable of producing lightning. Across the northwest CONUS, a shortwave trough initially extending from southern British Columbia through eastern WA is expected to continue eastward across the northern Rockies and southern Alberta into southern Saskatchewan and MT. Another shortwave trough will likely move through southern CA by Saturday morning. Moisture will be limited ahead of these waves, precluding thunderstorm development. ..Mosier.. 11/09/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Nov 09 2023 Valid 101200Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across South Texas and the adjacent Texas Coastal Plain on Friday. ...Synopsis and Discussion... Broadly cyclonic flow is forecast to cover the north-central and northeastern CONUS early Friday morning in the wake of a mid-latitude cyclone over eastern Ontario. Enhanced mid-level flow associated with this cyclone will cover much of the eastern CONUS early Friday, but should gradually shift eastward throughout the period as the parent cyclone progresses northeastward. Additionally, the overall upper troughing is expected to deamplify throughout the day as an embedded shortwave trough progresses quickly across the OH Valley and off the Northeast coast. Farther southwest, a southern-stream shortwave trough is expected to gradually move eastward across the southern High Plains during the day, and then more northeastward across OK overnight. This wave is expected to lose amplitude during this time frame as it encounters more confluent flow aloft. To the south and east of this shortwave, a remnant frontal zone will likely stretch southwestward from a weak surface low over southeast TX through deep south TX. This front will make gradual southward progress throughout the day, moving off the TX coast by the early afternoon, if not sooner. Poor lapse rates will limit buoyancy in the vicinity of the front, but persistent and moist southwesterly flow aloft will support very moist profiles (i.e. PWs around 2") and the potential for a few deeper convective cores capable of producing lightning. Across the northwest CONUS, a shortwave trough initially extending from southern British Columbia through eastern WA is expected to continue eastward across the northern Rockies and southern Alberta into southern Saskatchewan and MT. Another shortwave trough will likely move through southern CA by Saturday morning. Moisture will be limited ahead of these waves, precluding thunderstorm development. ..Mosier.. 11/09/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Nov 09 2023 Valid 101200Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across South Texas and the adjacent Texas Coastal Plain on Friday. ...Synopsis and Discussion... Broadly cyclonic flow is forecast to cover the north-central and northeastern CONUS early Friday morning in the wake of a mid-latitude cyclone over eastern Ontario. Enhanced mid-level flow associated with this cyclone will cover much of the eastern CONUS early Friday, but should gradually shift eastward throughout the period as the parent cyclone progresses northeastward. Additionally, the overall upper troughing is expected to deamplify throughout the day as an embedded shortwave trough progresses quickly across the OH Valley and off the Northeast coast. Farther southwest, a southern-stream shortwave trough is expected to gradually move eastward across the southern High Plains during the day, and then more northeastward across OK overnight. This wave is expected to lose amplitude during this time frame as it encounters more confluent flow aloft. To the south and east of this shortwave, a remnant frontal zone will likely stretch southwestward from a weak surface low over southeast TX through deep south TX. This front will make gradual southward progress throughout the day, moving off the TX coast by the early afternoon, if not sooner. Poor lapse rates will limit buoyancy in the vicinity of the front, but persistent and moist southwesterly flow aloft will support very moist profiles (i.e. PWs around 2") and the potential for a few deeper convective cores capable of producing lightning. Across the northwest CONUS, a shortwave trough initially extending from southern British Columbia through eastern WA is expected to continue eastward across the northern Rockies and southern Alberta into southern Saskatchewan and MT. Another shortwave trough will likely move through southern CA by Saturday morning. Moisture will be limited ahead of these waves, precluding thunderstorm development. ..Mosier.. 11/09/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Nov 09 2023 Valid 101200Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across South Texas and the adjacent Texas Coastal Plain on Friday. ...Synopsis and Discussion... Broadly cyclonic flow is forecast to cover the north-central and northeastern CONUS early Friday morning in the wake of a mid-latitude cyclone over eastern Ontario. Enhanced mid-level flow associated with this cyclone will cover much of the eastern CONUS early Friday, but should gradually shift eastward throughout the period as the parent cyclone progresses northeastward. Additionally, the overall upper troughing is expected to deamplify throughout the day as an embedded shortwave trough progresses quickly across the OH Valley and off the Northeast coast. Farther southwest, a southern-stream shortwave trough is expected to gradually move eastward across the southern High Plains during the day, and then more northeastward across OK overnight. This wave is expected to lose amplitude during this time frame as it encounters more confluent flow aloft. To the south and east of this shortwave, a remnant frontal zone will likely stretch southwestward from a weak surface low over southeast TX through deep south TX. This front will make gradual southward progress throughout the day, moving off the TX coast by the early afternoon, if not sooner. Poor lapse rates will limit buoyancy in the vicinity of the front, but persistent and moist southwesterly flow aloft will support very moist profiles (i.e. PWs around 2") and the potential for a few deeper convective cores capable of producing lightning. Across the northwest CONUS, a shortwave trough initially extending from southern British Columbia through eastern WA is expected to continue eastward across the northern Rockies and southern Alberta into southern Saskatchewan and MT. Another shortwave trough will likely move through southern CA by Saturday morning. Moisture will be limited ahead of these waves, precluding thunderstorm development. ..Mosier.. 11/09/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Nov 09 2023 Valid 101200Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across South Texas and the adjacent Texas Coastal Plain on Friday. ...Synopsis and Discussion... Broadly cyclonic flow is forecast to cover the north-central and northeastern CONUS early Friday morning in the wake of a mid-latitude cyclone over eastern Ontario. Enhanced mid-level flow associated with this cyclone will cover much of the eastern CONUS early Friday, but should gradually shift eastward throughout the period as the parent cyclone progresses northeastward. Additionally, the overall upper troughing is expected to deamplify throughout the day as an embedded shortwave trough progresses quickly across the OH Valley and off the Northeast coast. Farther southwest, a southern-stream shortwave trough is expected to gradually move eastward across the southern High Plains during the day, and then more northeastward across OK overnight. This wave is expected to lose amplitude during this time frame as it encounters more confluent flow aloft. To the south and east of this shortwave, a remnant frontal zone will likely stretch southwestward from a weak surface low over southeast TX through deep south TX. This front will make gradual southward progress throughout the day, moving off the TX coast by the early afternoon, if not sooner. Poor lapse rates will limit buoyancy in the vicinity of the front, but persistent and moist southwesterly flow aloft will support very moist profiles (i.e. PWs around 2") and the potential for a few deeper convective cores capable of producing lightning. Across the northwest CONUS, a shortwave trough initially extending from southern British Columbia through eastern WA is expected to continue eastward across the northern Rockies and southern Alberta into southern Saskatchewan and MT. Another shortwave trough will likely move through southern CA by Saturday morning. Moisture will be limited ahead of these waves, precluding thunderstorm development. ..Mosier.. 11/09/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CST Thu Nov 09 2023 Valid 101200Z - 111200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across South Texas and the adjacent Texas Coastal Plain on Friday. ...Synopsis and Discussion... Broadly cyclonic flow is forecast to cover the north-central and northeastern CONUS early Friday morning in the wake of a mid-latitude cyclone over eastern Ontario. Enhanced mid-level flow associated with this cyclone will cover much of the eastern CONUS early Friday, but should gradually shift eastward throughout the period as the parent cyclone progresses northeastward. Additionally, the overall upper troughing is expected to deamplify throughout the day as an embedded shortwave trough progresses quickly across the OH Valley and off the Northeast coast. Farther southwest, a southern-stream shortwave trough is expected to gradually move eastward across the southern High Plains during the day, and then more northeastward across OK overnight. This wave is expected to lose amplitude during this time frame as it encounters more confluent flow aloft. To the south and east of this shortwave, a remnant frontal zone will likely stretch southwestward from a weak surface low over southeast TX through deep south TX. This front will make gradual southward progress throughout the day, moving off the TX coast by the early afternoon, if not sooner. Poor lapse rates will limit buoyancy in the vicinity of the front, but persistent and moist southwesterly flow aloft will support very moist profiles (i.e. PWs around 2") and the potential for a few deeper convective cores capable of producing lightning. Across the northwest CONUS, a shortwave trough initially extending from southern British Columbia through eastern WA is expected to continue eastward across the northern Rockies and southern Alberta into southern Saskatchewan and MT. Another shortwave trough will likely move through southern CA by Saturday morning. Moisture will be limited ahead of these waves, precluding thunderstorm development. ..Mosier.. 11/09/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 PM CST Wed Nov 08 2023 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the lower Mississippi Valley into south Texas. A few flashes of lightning may also be noted along the Washington Coast. ...Texas/Lower Mississippi Valley... Low-latitude short-wave trough will eject across northern Mexico into west TX Thursday afternoon and then weaken as it approaches the lower MS Valley. This downstream weakening is partly due to high-level confluence that will also encourage surface pressure rises across the southern High Plains. Latest model guidance suggests the associated surface front will advance into northern LA, arcing southwest into deep south TX by early evening. Scattered elevated convection will develop along the cool side of the boundary in response to the short wave, but weak low-level convergence should limit warm-sector coverage/intensity. Seasonally high-PW air mass will extend across south TX into the lower MS Valley. That will ultimately lead to weak buoyancy within a marginal-lapse-rate environment. Forecast soundings across the warm sector exhibit strong bulk shear through 6km, but weak low-level flow/shear. While a few storms may display weak rotation across deep south TX, thermodynamic environment appears too negligible, given the weak low-level convergence, for any meaningful risk of severe. ...Pacific Northwest... Strong short-wave trough will approach the Pacific Northwest Coast by 10/00z. Cooling mid-level temperatures will help steepen lapse rates near/immediately behind the surface front as it moves inland by early evening. A few flashes of lightning appear possible with weak convection associated with this feature. ..Darrow/Bentley.. 11/09/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 PM CST Wed Nov 08 2023 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the lower Mississippi Valley into south Texas. A few flashes of lightning may also be noted along the Washington Coast. ...Texas/Lower Mississippi Valley... Low-latitude short-wave trough will eject across northern Mexico into west TX Thursday afternoon and then weaken as it approaches the lower MS Valley. This downstream weakening is partly due to high-level confluence that will also encourage surface pressure rises across the southern High Plains. Latest model guidance suggests the associated surface front will advance into northern LA, arcing southwest into deep south TX by early evening. Scattered elevated convection will develop along the cool side of the boundary in response to the short wave, but weak low-level convergence should limit warm-sector coverage/intensity. Seasonally high-PW air mass will extend across south TX into the lower MS Valley. That will ultimately lead to weak buoyancy within a marginal-lapse-rate environment. Forecast soundings across the warm sector exhibit strong bulk shear through 6km, but weak low-level flow/shear. While a few storms may display weak rotation across deep south TX, thermodynamic environment appears too negligible, given the weak low-level convergence, for any meaningful risk of severe. ...Pacific Northwest... Strong short-wave trough will approach the Pacific Northwest Coast by 10/00z. Cooling mid-level temperatures will help steepen lapse rates near/immediately behind the surface front as it moves inland by early evening. A few flashes of lightning appear possible with weak convection associated with this feature. ..Darrow/Bentley.. 11/09/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 PM CST Wed Nov 08 2023 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the lower Mississippi Valley into south Texas. A few flashes of lightning may also be noted along the Washington Coast. ...Texas/Lower Mississippi Valley... Low-latitude short-wave trough will eject across northern Mexico into west TX Thursday afternoon and then weaken as it approaches the lower MS Valley. This downstream weakening is partly due to high-level confluence that will also encourage surface pressure rises across the southern High Plains. Latest model guidance suggests the associated surface front will advance into northern LA, arcing southwest into deep south TX by early evening. Scattered elevated convection will develop along the cool side of the boundary in response to the short wave, but weak low-level convergence should limit warm-sector coverage/intensity. Seasonally high-PW air mass will extend across south TX into the lower MS Valley. That will ultimately lead to weak buoyancy within a marginal-lapse-rate environment. Forecast soundings across the warm sector exhibit strong bulk shear through 6km, but weak low-level flow/shear. While a few storms may display weak rotation across deep south TX, thermodynamic environment appears too negligible, given the weak low-level convergence, for any meaningful risk of severe. ...Pacific Northwest... Strong short-wave trough will approach the Pacific Northwest Coast by 10/00z. Cooling mid-level temperatures will help steepen lapse rates near/immediately behind the surface front as it moves inland by early evening. A few flashes of lightning appear possible with weak convection associated with this feature. ..Darrow/Bentley.. 11/09/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 PM CST Wed Nov 08 2023 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the lower Mississippi Valley into south Texas. A few flashes of lightning may also be noted along the Washington Coast. ...Texas/Lower Mississippi Valley... Low-latitude short-wave trough will eject across northern Mexico into west TX Thursday afternoon and then weaken as it approaches the lower MS Valley. This downstream weakening is partly due to high-level confluence that will also encourage surface pressure rises across the southern High Plains. Latest model guidance suggests the associated surface front will advance into northern LA, arcing southwest into deep south TX by early evening. Scattered elevated convection will develop along the cool side of the boundary in response to the short wave, but weak low-level convergence should limit warm-sector coverage/intensity. Seasonally high-PW air mass will extend across south TX into the lower MS Valley. That will ultimately lead to weak buoyancy within a marginal-lapse-rate environment. Forecast soundings across the warm sector exhibit strong bulk shear through 6km, but weak low-level flow/shear. While a few storms may display weak rotation across deep south TX, thermodynamic environment appears too negligible, given the weak low-level convergence, for any meaningful risk of severe. ...Pacific Northwest... Strong short-wave trough will approach the Pacific Northwest Coast by 10/00z. Cooling mid-level temperatures will help steepen lapse rates near/immediately behind the surface front as it moves inland by early evening. A few flashes of lightning appear possible with weak convection associated with this feature. ..Darrow/Bentley.. 11/09/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 PM CST Wed Nov 08 2023 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the lower Mississippi Valley into south Texas. A few flashes of lightning may also be noted along the Washington Coast. ...Texas/Lower Mississippi Valley... Low-latitude short-wave trough will eject across northern Mexico into west TX Thursday afternoon and then weaken as it approaches the lower MS Valley. This downstream weakening is partly due to high-level confluence that will also encourage surface pressure rises across the southern High Plains. Latest model guidance suggests the associated surface front will advance into northern LA, arcing southwest into deep south TX by early evening. Scattered elevated convection will develop along the cool side of the boundary in response to the short wave, but weak low-level convergence should limit warm-sector coverage/intensity. Seasonally high-PW air mass will extend across south TX into the lower MS Valley. That will ultimately lead to weak buoyancy within a marginal-lapse-rate environment. Forecast soundings across the warm sector exhibit strong bulk shear through 6km, but weak low-level flow/shear. While a few storms may display weak rotation across deep south TX, thermodynamic environment appears too negligible, given the weak low-level convergence, for any meaningful risk of severe. ...Pacific Northwest... Strong short-wave trough will approach the Pacific Northwest Coast by 10/00z. Cooling mid-level temperatures will help steepen lapse rates near/immediately behind the surface front as it moves inland by early evening. A few flashes of lightning appear possible with weak convection associated with this feature. ..Darrow/Bentley.. 11/09/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1132 PM CST Wed Nov 08 2023 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible across portions of the lower Mississippi Valley into south Texas. A few flashes of lightning may also be noted along the Washington Coast. ...Texas/Lower Mississippi Valley... Low-latitude short-wave trough will eject across northern Mexico into west TX Thursday afternoon and then weaken as it approaches the lower MS Valley. This downstream weakening is partly due to high-level confluence that will also encourage surface pressure rises across the southern High Plains. Latest model guidance suggests the associated surface front will advance into northern LA, arcing southwest into deep south TX by early evening. Scattered elevated convection will develop along the cool side of the boundary in response to the short wave, but weak low-level convergence should limit warm-sector coverage/intensity. Seasonally high-PW air mass will extend across south TX into the lower MS Valley. That will ultimately lead to weak buoyancy within a marginal-lapse-rate environment. Forecast soundings across the warm sector exhibit strong bulk shear through 6km, but weak low-level flow/shear. While a few storms may display weak rotation across deep south TX, thermodynamic environment appears too negligible, given the weak low-level convergence, for any meaningful risk of severe. ...Pacific Northwest... Strong short-wave trough will approach the Pacific Northwest Coast by 10/00z. Cooling mid-level temperatures will help steepen lapse rates near/immediately behind the surface front as it moves inland by early evening. A few flashes of lightning appear possible with weak convection associated with this feature. ..Darrow/Bentley.. 11/09/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0629 PM CST Wed Nov 08 2023 Valid 090100Z - 091200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Strong midlevel height falls are spreading across the Great Lakes ahead of a pronounced short-wave trough approaching the upper MS Valley. In response to this feature, a surface low, currently located over northwest IN, will track into southern ON by 06z before approaching western NY by sunrise. LLJ will also continue to increase ahead of the low, and this, combined with high-level diffluent flow aloft, should maintain a corridor of favorable large-scale forcing for ascent/elevated convection. 00z sounding from DTX exhibited MUCAPE around 400 J/kg if lifting a parcel near 850mb. While lapse rates are seasonally steep across this region, primary risk with this activity should be no more than small hail. ..Darrow.. 11/09/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0629 PM CST Wed Nov 08 2023 Valid 090100Z - 091200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Strong midlevel height falls are spreading across the Great Lakes ahead of a pronounced short-wave trough approaching the upper MS Valley. In response to this feature, a surface low, currently located over northwest IN, will track into southern ON by 06z before approaching western NY by sunrise. LLJ will also continue to increase ahead of the low, and this, combined with high-level diffluent flow aloft, should maintain a corridor of favorable large-scale forcing for ascent/elevated convection. 00z sounding from DTX exhibited MUCAPE around 400 J/kg if lifting a parcel near 850mb. While lapse rates are seasonally steep across this region, primary risk with this activity should be no more than small hail. ..Darrow.. 11/09/2023 Read more