Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1025 AM CST Wed Dec 20 2023 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. Severe weather is not expected. ...Discussion... Low-amplitude ridging aloft will prevail across much of the country today, as eastern U.S. troughing continues to slowly depart the Northeast. The main feature of interest with respect to convective potential remains an upper low off the coast of California, which will continue moving slowly southward. Within the warm conveyor region of this system, and just ahead of a weak surface front moving onshore, a disorganized band of convection is indicated -- the strongest portion of which will gradually move onshore over San Luis Obispo and Santa Barbara Counties over the next few hours. Ahead of this band, onshore instability remains very weak and low-topped -- as evidenced by the overall lack of lightning. This, combined with weak low-level shear precludes any appreciable risk for severe weather, though gusty winds may accompany any stronger convective elements. Elsewhere, sporadic lightning will continue across portions of the Southwest, in conjunction with a weaker mid-level disturbance moving slowly eastward across the Four Corners states. Thunderstorms are not expected across the remainder of the U.S., where surface high pressure and accompanying cool/stable conditions prevail. ..Goss/Thornton.. 12/20/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1025 AM CST Wed Dec 20 2023 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. Severe weather is not expected. ...Discussion... Low-amplitude ridging aloft will prevail across much of the country today, as eastern U.S. troughing continues to slowly depart the Northeast. The main feature of interest with respect to convective potential remains an upper low off the coast of California, which will continue moving slowly southward. Within the warm conveyor region of this system, and just ahead of a weak surface front moving onshore, a disorganized band of convection is indicated -- the strongest portion of which will gradually move onshore over San Luis Obispo and Santa Barbara Counties over the next few hours. Ahead of this band, onshore instability remains very weak and low-topped -- as evidenced by the overall lack of lightning. This, combined with weak low-level shear precludes any appreciable risk for severe weather, though gusty winds may accompany any stronger convective elements. Elsewhere, sporadic lightning will continue across portions of the Southwest, in conjunction with a weaker mid-level disturbance moving slowly eastward across the Four Corners states. Thunderstorms are not expected across the remainder of the U.S., where surface high pressure and accompanying cool/stable conditions prevail. ..Goss/Thornton.. 12/20/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Wed Dec 20 2023 Valid 201700Z - 211200Z ...NO CRITICAL AREAS... No changes, the potential for critical fire-weather conditions is low. ..Lyons.. 12/20/2023 .PREV DISCUSSION... /ISSUED 1249 AM CST Wed Dec 20 2023/ ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ...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 1026 AM CST Wed Dec 20 2023 Valid 201700Z - 211200Z ...NO CRITICAL AREAS... No changes, the potential for critical fire-weather conditions is low. ..Lyons.. 12/20/2023 .PREV DISCUSSION... /ISSUED 1249 AM CST Wed Dec 20 2023/ ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ...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 1026 AM CST Wed Dec 20 2023 Valid 201700Z - 211200Z ...NO CRITICAL AREAS... No changes, the potential for critical fire-weather conditions is low. ..Lyons.. 12/20/2023 .PREV DISCUSSION... /ISSUED 1249 AM CST Wed Dec 20 2023/ ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ...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 1026 AM CST Wed Dec 20 2023 Valid 201700Z - 211200Z ...NO CRITICAL AREAS... No changes, the potential for critical fire-weather conditions is low. ..Lyons.. 12/20/2023 .PREV DISCUSSION... /ISSUED 1249 AM CST Wed Dec 20 2023/ ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ...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 1026 AM CST Wed Dec 20 2023 Valid 201700Z - 211200Z ...NO CRITICAL AREAS... No changes, the potential for critical fire-weather conditions is low. ..Lyons.. 12/20/2023 .PREV DISCUSSION... /ISSUED 1249 AM CST Wed Dec 20 2023/ ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0631 AM CST Wed Dec 20 2023 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...CA to AZ/NM though tonight... A midlevel low is expected to move slowly southward off the central/southern CA coast through early Thursday, while a weak/lead shortwave trough ejects northeastward over AZ/NM. Some midlevel convection occurred overnight across southern AZ in association with the lead wave, where sufficient midlevel lapse rates/moisture contributed to MUCAPE of 100-200 J/kg (rooted near 700 mb). Isolated thunderstorms will be possible through the day from southeast AZ shifting eastward into NM. Otherwise, the primary baroclinic band will overspread the central CA coast today and eventually reach the southern CA coast by tonight. Isolated thunderstorms will be possible near the coast through the period, and across the San Joaquin Valley this afternoon. Forecast wind profiles suggest low potential for embedded organized/weakly rotating storms just offshore, as observed south of San Francisco this morning. However, inland buoyancy should remain too marginal to introduce any damaging wind and/or tornado probabilities. ..Thompson/Broyles.. 12/20/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0631 AM CST Wed Dec 20 2023 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...CA to AZ/NM though tonight... A midlevel low is expected to move slowly southward off the central/southern CA coast through early Thursday, while a weak/lead shortwave trough ejects northeastward over AZ/NM. Some midlevel convection occurred overnight across southern AZ in association with the lead wave, where sufficient midlevel lapse rates/moisture contributed to MUCAPE of 100-200 J/kg (rooted near 700 mb). Isolated thunderstorms will be possible through the day from southeast AZ shifting eastward into NM. Otherwise, the primary baroclinic band will overspread the central CA coast today and eventually reach the southern CA coast by tonight. Isolated thunderstorms will be possible near the coast through the period, and across the San Joaquin Valley this afternoon. Forecast wind profiles suggest low potential for embedded organized/weakly rotating storms just offshore, as observed south of San Francisco this morning. However, inland buoyancy should remain too marginal to introduce any damaging wind and/or tornado probabilities. ..Thompson/Broyles.. 12/20/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0631 AM CST Wed Dec 20 2023 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...CA to AZ/NM though tonight... A midlevel low is expected to move slowly southward off the central/southern CA coast through early Thursday, while a weak/lead shortwave trough ejects northeastward over AZ/NM. Some midlevel convection occurred overnight across southern AZ in association with the lead wave, where sufficient midlevel lapse rates/moisture contributed to MUCAPE of 100-200 J/kg (rooted near 700 mb). Isolated thunderstorms will be possible through the day from southeast AZ shifting eastward into NM. Otherwise, the primary baroclinic band will overspread the central CA coast today and eventually reach the southern CA coast by tonight. Isolated thunderstorms will be possible near the coast through the period, and across the San Joaquin Valley this afternoon. Forecast wind profiles suggest low potential for embedded organized/weakly rotating storms just offshore, as observed south of San Francisco this morning. However, inland buoyancy should remain too marginal to introduce any damaging wind and/or tornado probabilities. ..Thompson/Broyles.. 12/20/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0631 AM CST Wed Dec 20 2023 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...CA to AZ/NM though tonight... A midlevel low is expected to move slowly southward off the central/southern CA coast through early Thursday, while a weak/lead shortwave trough ejects northeastward over AZ/NM. Some midlevel convection occurred overnight across southern AZ in association with the lead wave, where sufficient midlevel lapse rates/moisture contributed to MUCAPE of 100-200 J/kg (rooted near 700 mb). Isolated thunderstorms will be possible through the day from southeast AZ shifting eastward into NM. Otherwise, the primary baroclinic band will overspread the central CA coast today and eventually reach the southern CA coast by tonight. Isolated thunderstorms will be possible near the coast through the period, and across the San Joaquin Valley this afternoon. Forecast wind profiles suggest low potential for embedded organized/weakly rotating storms just offshore, as observed south of San Francisco this morning. However, inland buoyancy should remain too marginal to introduce any damaging wind and/or tornado probabilities. ..Thompson/Broyles.. 12/20/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0631 AM CST Wed Dec 20 2023 Valid 201300Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...CA to AZ/NM though tonight... A midlevel low is expected to move slowly southward off the central/southern CA coast through early Thursday, while a weak/lead shortwave trough ejects northeastward over AZ/NM. Some midlevel convection occurred overnight across southern AZ in association with the lead wave, where sufficient midlevel lapse rates/moisture contributed to MUCAPE of 100-200 J/kg (rooted near 700 mb). Isolated thunderstorms will be possible through the day from southeast AZ shifting eastward into NM. Otherwise, the primary baroclinic band will overspread the central CA coast today and eventually reach the southern CA coast by tonight. Isolated thunderstorms will be possible near the coast through the period, and across the San Joaquin Valley this afternoon. Forecast wind profiles suggest low potential for embedded organized/weakly rotating storms just offshore, as observed south of San Francisco this morning. However, inland buoyancy should remain too marginal to introduce any damaging wind and/or tornado probabilities. ..Thompson/Broyles.. 12/20/2023 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0405 AM CST Wed Dec 20 2023 Valid 231200Z - 281200Z ...DISCUSSION... Medium-range guidance remains consistent in forecasting a southern-stream shortwave trough over AZ D4/Saturday morning. This wave is then expected to continue eastward through the remainder of the Southwest through the day before then progressing more northeastward into the central Plains overnight. A moderately warm and moist air mass will likely be in place over the southern Plains, characterized by upper 50s dewpoints as far west as the TX Big Country and Concho Valley and as far north as central OK. Even with this moisture in place, heating will be limited by abundant clouds and buoyancy will remain modest. Even so, forcing for ascent will be strong and the modest buoyancy will still be more than sufficient for thunderstorm development. Vertical shear will likely be strong enough to support organized convection, but whether the thermodynamic conditions will support deep, sustained updrafts remains in question. As such, severe storms will likely be isolated, with overall coverage too low to introduce any probabilities. In the wake of this lead wave, a series of shortwave troughs are forecast to rotate through the upper troughing expected to be in place over the Plains. Short wavelength between these waves will likely lead to complex evolution, but the general expectation is for upper troughing to persist across the Plains into early next week. An associated surface low is expected to evolve gradually eastward, with an attendant front pushing eastward across the southern/central Plains on D5/Sunday and the Southeast on D6/Monday. Some thunderstorms are possible along this front, although the buoyancy preceding it will likely be limited. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0405 AM CST Wed Dec 20 2023 Valid 231200Z - 281200Z ...DISCUSSION... Medium-range guidance remains consistent in forecasting a southern-stream shortwave trough over AZ D4/Saturday morning. This wave is then expected to continue eastward through the remainder of the Southwest through the day before then progressing more northeastward into the central Plains overnight. A moderately warm and moist air mass will likely be in place over the southern Plains, characterized by upper 50s dewpoints as far west as the TX Big Country and Concho Valley and as far north as central OK. Even with this moisture in place, heating will be limited by abundant clouds and buoyancy will remain modest. Even so, forcing for ascent will be strong and the modest buoyancy will still be more than sufficient for thunderstorm development. Vertical shear will likely be strong enough to support organized convection, but whether the thermodynamic conditions will support deep, sustained updrafts remains in question. As such, severe storms will likely be isolated, with overall coverage too low to introduce any probabilities. In the wake of this lead wave, a series of shortwave troughs are forecast to rotate through the upper troughing expected to be in place over the Plains. Short wavelength between these waves will likely lead to complex evolution, but the general expectation is for upper troughing to persist across the Plains into early next week. An associated surface low is expected to evolve gradually eastward, with an attendant front pushing eastward across the southern/central Plains on D5/Sunday and the Southeast on D6/Monday. Some thunderstorms are possible along this front, although the buoyancy preceding it will likely be limited. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0405 AM CST Wed Dec 20 2023 Valid 231200Z - 281200Z ...DISCUSSION... Medium-range guidance remains consistent in forecasting a southern-stream shortwave trough over AZ D4/Saturday morning. This wave is then expected to continue eastward through the remainder of the Southwest through the day before then progressing more northeastward into the central Plains overnight. A moderately warm and moist air mass will likely be in place over the southern Plains, characterized by upper 50s dewpoints as far west as the TX Big Country and Concho Valley and as far north as central OK. Even with this moisture in place, heating will be limited by abundant clouds and buoyancy will remain modest. Even so, forcing for ascent will be strong and the modest buoyancy will still be more than sufficient for thunderstorm development. Vertical shear will likely be strong enough to support organized convection, but whether the thermodynamic conditions will support deep, sustained updrafts remains in question. As such, severe storms will likely be isolated, with overall coverage too low to introduce any probabilities. In the wake of this lead wave, a series of shortwave troughs are forecast to rotate through the upper troughing expected to be in place over the Plains. Short wavelength between these waves will likely lead to complex evolution, but the general expectation is for upper troughing to persist across the Plains into early next week. An associated surface low is expected to evolve gradually eastward, with an attendant front pushing eastward across the southern/central Plains on D5/Sunday and the Southeast on D6/Monday. Some thunderstorms are possible along this front, although the buoyancy preceding it will likely be limited. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0405 AM CST Wed Dec 20 2023 Valid 231200Z - 281200Z ...DISCUSSION... Medium-range guidance remains consistent in forecasting a southern-stream shortwave trough over AZ D4/Saturday morning. This wave is then expected to continue eastward through the remainder of the Southwest through the day before then progressing more northeastward into the central Plains overnight. A moderately warm and moist air mass will likely be in place over the southern Plains, characterized by upper 50s dewpoints as far west as the TX Big Country and Concho Valley and as far north as central OK. Even with this moisture in place, heating will be limited by abundant clouds and buoyancy will remain modest. Even so, forcing for ascent will be strong and the modest buoyancy will still be more than sufficient for thunderstorm development. Vertical shear will likely be strong enough to support organized convection, but whether the thermodynamic conditions will support deep, sustained updrafts remains in question. As such, severe storms will likely be isolated, with overall coverage too low to introduce any probabilities. In the wake of this lead wave, a series of shortwave troughs are forecast to rotate through the upper troughing expected to be in place over the Plains. Short wavelength between these waves will likely lead to complex evolution, but the general expectation is for upper troughing to persist across the Plains into early next week. An associated surface low is expected to evolve gradually eastward, with an attendant front pushing eastward across the southern/central Plains on D5/Sunday and the Southeast on D6/Monday. Some thunderstorms are possible along this front, although the buoyancy preceding it will likely be limited. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0405 AM CST Wed Dec 20 2023 Valid 231200Z - 281200Z ...DISCUSSION... Medium-range guidance remains consistent in forecasting a southern-stream shortwave trough over AZ D4/Saturday morning. This wave is then expected to continue eastward through the remainder of the Southwest through the day before then progressing more northeastward into the central Plains overnight. A moderately warm and moist air mass will likely be in place over the southern Plains, characterized by upper 50s dewpoints as far west as the TX Big Country and Concho Valley and as far north as central OK. Even with this moisture in place, heating will be limited by abundant clouds and buoyancy will remain modest. Even so, forcing for ascent will be strong and the modest buoyancy will still be more than sufficient for thunderstorm development. Vertical shear will likely be strong enough to support organized convection, but whether the thermodynamic conditions will support deep, sustained updrafts remains in question. As such, severe storms will likely be isolated, with overall coverage too low to introduce any probabilities. In the wake of this lead wave, a series of shortwave troughs are forecast to rotate through the upper troughing expected to be in place over the Plains. Short wavelength between these waves will likely lead to complex evolution, but the general expectation is for upper troughing to persist across the Plains into early next week. An associated surface low is expected to evolve gradually eastward, with an attendant front pushing eastward across the southern/central Plains on D5/Sunday and the Southeast on D6/Monday. Some thunderstorms are possible along this front, although the buoyancy preceding it will likely be limited. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Wed Dec 20 2023 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible on Friday from southern California across much of the Southwest. A few isolated thunderstorms are possible along the Middle Texas Coast Saturday morning as well. ...Synopsis... An upper low is expected to be centered off the southern CA coast early Friday morning before devolving into a more progressive open wave and moving eastward across the Southwest States and northern Mexico. Strong forcing for ascent, cold mid-level temperatures, and increased mid-level moisture will accompany this system, supporting the potential for thunderstorms across much of southern CA and Southwest. Isolated thunderstorms will likely be ongoing over southern CA/AZ early Friday morning, with thunderstorms expected to gradually shift eastward with parent upper system, ending with isolated thunderstorms over southeast NM and far west TX Saturday morning. Given the cold mid-level temperatures and enhanced mid-level flow through the base of this wave, a few instances of small hail are possible. Any hail should be small and sporadic enough to preclude the need for any probabilities. Low-level flow is expected to increase from south TX into the Panhandle ahead of the approaching system Friday night into Saturday morning. Eastern periphery of this increasing flow may interact with enough low-level moisture to support isolated elevated thunderstorm in the vicinity of the Middle TX Coast. ..Mosier.. 12/20/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Wed Dec 20 2023 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible on Friday from southern California across much of the Southwest. A few isolated thunderstorms are possible along the Middle Texas Coast Saturday morning as well. ...Synopsis... An upper low is expected to be centered off the southern CA coast early Friday morning before devolving into a more progressive open wave and moving eastward across the Southwest States and northern Mexico. Strong forcing for ascent, cold mid-level temperatures, and increased mid-level moisture will accompany this system, supporting the potential for thunderstorms across much of southern CA and Southwest. Isolated thunderstorms will likely be ongoing over southern CA/AZ early Friday morning, with thunderstorms expected to gradually shift eastward with parent upper system, ending with isolated thunderstorms over southeast NM and far west TX Saturday morning. Given the cold mid-level temperatures and enhanced mid-level flow through the base of this wave, a few instances of small hail are possible. Any hail should be small and sporadic enough to preclude the need for any probabilities. Low-level flow is expected to increase from south TX into the Panhandle ahead of the approaching system Friday night into Saturday morning. Eastern periphery of this increasing flow may interact with enough low-level moisture to support isolated elevated thunderstorm in the vicinity of the Middle TX Coast. ..Mosier.. 12/20/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Wed Dec 20 2023 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible on Friday from southern California across much of the Southwest. A few isolated thunderstorms are possible along the Middle Texas Coast Saturday morning as well. ...Synopsis... An upper low is expected to be centered off the southern CA coast early Friday morning before devolving into a more progressive open wave and moving eastward across the Southwest States and northern Mexico. Strong forcing for ascent, cold mid-level temperatures, and increased mid-level moisture will accompany this system, supporting the potential for thunderstorms across much of southern CA and Southwest. Isolated thunderstorms will likely be ongoing over southern CA/AZ early Friday morning, with thunderstorms expected to gradually shift eastward with parent upper system, ending with isolated thunderstorms over southeast NM and far west TX Saturday morning. Given the cold mid-level temperatures and enhanced mid-level flow through the base of this wave, a few instances of small hail are possible. Any hail should be small and sporadic enough to preclude the need for any probabilities. Low-level flow is expected to increase from south TX into the Panhandle ahead of the approaching system Friday night into Saturday morning. Eastern periphery of this increasing flow may interact with enough low-level moisture to support isolated elevated thunderstorm in the vicinity of the Middle TX Coast. ..Mosier.. 12/20/2023 Read more