Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0638 AM CST Tue Dec 12 2023 Valid 121300Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated non-severe thunderstorms will be possible tonight across west Texas and southeast New Mexico. ...Synopsis... Within a southern stream, a midlevel shortwave trough will move southeastward over NV toward northwest AZ by early Wednesday. Farther east, a modifying air mass will begin to return to south TX and the lower Rio Grande Valley, though moistening farther northwest into west TX/southeast NM will likely occur near and above the 700 mb level. Midlevel lapse rates will be sufficiently steep to allow for the development of weak buoyancy aloft, and warm advection may support a few embedded convective elements capable of producing isolated lightning flashes tonight. Otherwise, gradual low-level moistening will continue across southeast FL in a persistent east-northeasterly flow regime, and across the lower TX coast with onshore flow. Shallow convection/showers are probable in both areas, but the threat for convection deep enough to produce lightning before 12z still appears fairly low. ..Thompson/Gleason.. 12/12/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0638 AM CST Tue Dec 12 2023 Valid 121300Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated non-severe thunderstorms will be possible tonight across west Texas and southeast New Mexico. ...Synopsis... Within a southern stream, a midlevel shortwave trough will move southeastward over NV toward northwest AZ by early Wednesday. Farther east, a modifying air mass will begin to return to south TX and the lower Rio Grande Valley, though moistening farther northwest into west TX/southeast NM will likely occur near and above the 700 mb level. Midlevel lapse rates will be sufficiently steep to allow for the development of weak buoyancy aloft, and warm advection may support a few embedded convective elements capable of producing isolated lightning flashes tonight. Otherwise, gradual low-level moistening will continue across southeast FL in a persistent east-northeasterly flow regime, and across the lower TX coast with onshore flow. Shallow convection/showers are probable in both areas, but the threat for convection deep enough to produce lightning before 12z still appears fairly low. ..Thompson/Gleason.. 12/12/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0638 AM CST Tue Dec 12 2023 Valid 121300Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated non-severe thunderstorms will be possible tonight across west Texas and southeast New Mexico. ...Synopsis... Within a southern stream, a midlevel shortwave trough will move southeastward over NV toward northwest AZ by early Wednesday. Farther east, a modifying air mass will begin to return to south TX and the lower Rio Grande Valley, though moistening farther northwest into west TX/southeast NM will likely occur near and above the 700 mb level. Midlevel lapse rates will be sufficiently steep to allow for the development of weak buoyancy aloft, and warm advection may support a few embedded convective elements capable of producing isolated lightning flashes tonight. Otherwise, gradual low-level moistening will continue across southeast FL in a persistent east-northeasterly flow regime, and across the lower TX coast with onshore flow. Shallow convection/showers are probable in both areas, but the threat for convection deep enough to produce lightning before 12z still appears fairly low. ..Thompson/Gleason.. 12/12/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0638 AM CST Tue Dec 12 2023 Valid 121300Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated non-severe thunderstorms will be possible tonight across west Texas and southeast New Mexico. ...Synopsis... Within a southern stream, a midlevel shortwave trough will move southeastward over NV toward northwest AZ by early Wednesday. Farther east, a modifying air mass will begin to return to south TX and the lower Rio Grande Valley, though moistening farther northwest into west TX/southeast NM will likely occur near and above the 700 mb level. Midlevel lapse rates will be sufficiently steep to allow for the development of weak buoyancy aloft, and warm advection may support a few embedded convective elements capable of producing isolated lightning flashes tonight. Otherwise, gradual low-level moistening will continue across southeast FL in a persistent east-northeasterly flow regime, and across the lower TX coast with onshore flow. Shallow convection/showers are probable in both areas, but the threat for convection deep enough to produce lightning before 12z still appears fairly low. ..Thompson/Gleason.. 12/12/2023 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CST Tue Dec 12 2023 Valid 151200Z - 201200Z ...DISCUSSION... An area-of-interest for increasing severe potential exists during D5-7 over the eastern Gulf to South Atlantic States. Confidence is too low to warrant a 15 percent severe probability highlight for a specific day and area. 00Z deterministic guidance trends have been to indicate phasing of the southern-stream shortwave trough with a northern-stream Alberta Clipper, across the central to eastern states. This evolution may support strong cyclogenesis over the eastern Gulf to on/off the South Atlantic Coast this weekend into Monday. 00Z ECMWF ensemble and GEFS trends have been to increasingly converge towards their parent deterministic runs with effectively unanimous support for cyclogenesis. However, vast spread among guidance exists with the degree of amplification from weak cyclogenesis to bombogenesis, and whether the intensification stays off the South Atlantic Coast or can occur over land. This renders rather low confidence in the timing/location of a potentially favorable warm-sector environment. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CST Tue Dec 12 2023 Valid 151200Z - 201200Z ...DISCUSSION... An area-of-interest for increasing severe potential exists during D5-7 over the eastern Gulf to South Atlantic States. Confidence is too low to warrant a 15 percent severe probability highlight for a specific day and area. 00Z deterministic guidance trends have been to indicate phasing of the southern-stream shortwave trough with a northern-stream Alberta Clipper, across the central to eastern states. This evolution may support strong cyclogenesis over the eastern Gulf to on/off the South Atlantic Coast this weekend into Monday. 00Z ECMWF ensemble and GEFS trends have been to increasingly converge towards their parent deterministic runs with effectively unanimous support for cyclogenesis. However, vast spread among guidance exists with the degree of amplification from weak cyclogenesis to bombogenesis, and whether the intensification stays off the South Atlantic Coast or can occur over land. This renders rather low confidence in the timing/location of a potentially favorable warm-sector environment. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CST Tue Dec 12 2023 Valid 151200Z - 201200Z ...DISCUSSION... An area-of-interest for increasing severe potential exists during D5-7 over the eastern Gulf to South Atlantic States. Confidence is too low to warrant a 15 percent severe probability highlight for a specific day and area. 00Z deterministic guidance trends have been to indicate phasing of the southern-stream shortwave trough with a northern-stream Alberta Clipper, across the central to eastern states. This evolution may support strong cyclogenesis over the eastern Gulf to on/off the South Atlantic Coast this weekend into Monday. 00Z ECMWF ensemble and GEFS trends have been to increasingly converge towards their parent deterministic runs with effectively unanimous support for cyclogenesis. However, vast spread among guidance exists with the degree of amplification from weak cyclogenesis to bombogenesis, and whether the intensification stays off the South Atlantic Coast or can occur over land. This renders rather low confidence in the timing/location of a potentially favorable warm-sector environment. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CST Tue Dec 12 2023 Valid 151200Z - 201200Z ...DISCUSSION... An area-of-interest for increasing severe potential exists during D5-7 over the eastern Gulf to South Atlantic States. Confidence is too low to warrant a 15 percent severe probability highlight for a specific day and area. 00Z deterministic guidance trends have been to indicate phasing of the southern-stream shortwave trough with a northern-stream Alberta Clipper, across the central to eastern states. This evolution may support strong cyclogenesis over the eastern Gulf to on/off the South Atlantic Coast this weekend into Monday. 00Z ECMWF ensemble and GEFS trends have been to increasingly converge towards their parent deterministic runs with effectively unanimous support for cyclogenesis. However, vast spread among guidance exists with the degree of amplification from weak cyclogenesis to bombogenesis, and whether the intensification stays off the South Atlantic Coast or can occur over land. This renders rather low confidence in the timing/location of a potentially favorable warm-sector environment. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CST Tue Dec 12 2023 Valid 151200Z - 201200Z ...DISCUSSION... An area-of-interest for increasing severe potential exists during D5-7 over the eastern Gulf to South Atlantic States. Confidence is too low to warrant a 15 percent severe probability highlight for a specific day and area. 00Z deterministic guidance trends have been to indicate phasing of the southern-stream shortwave trough with a northern-stream Alberta Clipper, across the central to eastern states. This evolution may support strong cyclogenesis over the eastern Gulf to on/off the South Atlantic Coast this weekend into Monday. 00Z ECMWF ensemble and GEFS trends have been to increasingly converge towards their parent deterministic runs with effectively unanimous support for cyclogenesis. However, vast spread among guidance exists with the degree of amplification from weak cyclogenesis to bombogenesis, and whether the intensification stays off the South Atlantic Coast or can occur over land. This renders rather low confidence in the timing/location of a potentially favorable warm-sector environment. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CST Tue Dec 12 2023 Valid 151200Z - 201200Z ...DISCUSSION... An area-of-interest for increasing severe potential exists during D5-7 over the eastern Gulf to South Atlantic States. Confidence is too low to warrant a 15 percent severe probability highlight for a specific day and area. 00Z deterministic guidance trends have been to indicate phasing of the southern-stream shortwave trough with a northern-stream Alberta Clipper, across the central to eastern states. This evolution may support strong cyclogenesis over the eastern Gulf to on/off the South Atlantic Coast this weekend into Monday. 00Z ECMWF ensemble and GEFS trends have been to increasingly converge towards their parent deterministic runs with effectively unanimous support for cyclogenesis. However, vast spread among guidance exists with the degree of amplification from weak cyclogenesis to bombogenesis, and whether the intensification stays off the South Atlantic Coast or can occur over land. This renders rather low confidence in the timing/location of a potentially favorable warm-sector environment. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Tue Dec 12 2023 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...NM and TX... A shortwave trough will continue east across NM into northwest TX by early Friday. A persistent low-level warm theta-e advection regime in conjunction with mid-level DCVA/height falls ahead of the trough will support a nearly continuous swath of elevated convection, shifting east from NM and west TX into central TX by Thursday night. Elevated buoyancy will remain meager, suggesting that thunderstorm coverage will be sporadic. Guidance is consistent that the plume of steep mid-level lapse rates attendant to the trough on D2 will weaken early D3, inferring severe hail potential should be negligible. ...South FL... Rounds of lower-topped convection should continue within a persistent low-level northeasterly flow regime, namely along the southeast coast. Weak mid to upper-level lapse rates, slightly worse compared to D2, suggests instability will be marginal with low-end thunderstorm probabilities. ..Grams.. 12/12/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Tue Dec 12 2023 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...NM and TX... A shortwave trough will continue east across NM into northwest TX by early Friday. A persistent low-level warm theta-e advection regime in conjunction with mid-level DCVA/height falls ahead of the trough will support a nearly continuous swath of elevated convection, shifting east from NM and west TX into central TX by Thursday night. Elevated buoyancy will remain meager, suggesting that thunderstorm coverage will be sporadic. Guidance is consistent that the plume of steep mid-level lapse rates attendant to the trough on D2 will weaken early D3, inferring severe hail potential should be negligible. ...South FL... Rounds of lower-topped convection should continue within a persistent low-level northeasterly flow regime, namely along the southeast coast. Weak mid to upper-level lapse rates, slightly worse compared to D2, suggests instability will be marginal with low-end thunderstorm probabilities. ..Grams.. 12/12/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Tue Dec 12 2023 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...NM and TX... A shortwave trough will continue east across NM into northwest TX by early Friday. A persistent low-level warm theta-e advection regime in conjunction with mid-level DCVA/height falls ahead of the trough will support a nearly continuous swath of elevated convection, shifting east from NM and west TX into central TX by Thursday night. Elevated buoyancy will remain meager, suggesting that thunderstorm coverage will be sporadic. Guidance is consistent that the plume of steep mid-level lapse rates attendant to the trough on D2 will weaken early D3, inferring severe hail potential should be negligible. ...South FL... Rounds of lower-topped convection should continue within a persistent low-level northeasterly flow regime, namely along the southeast coast. Weak mid to upper-level lapse rates, slightly worse compared to D2, suggests instability will be marginal with low-end thunderstorm probabilities. ..Grams.. 12/12/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Tue Dec 12 2023 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...NM and TX... A shortwave trough will continue east across NM into northwest TX by early Friday. A persistent low-level warm theta-e advection regime in conjunction with mid-level DCVA/height falls ahead of the trough will support a nearly continuous swath of elevated convection, shifting east from NM and west TX into central TX by Thursday night. Elevated buoyancy will remain meager, suggesting that thunderstorm coverage will be sporadic. Guidance is consistent that the plume of steep mid-level lapse rates attendant to the trough on D2 will weaken early D3, inferring severe hail potential should be negligible. ...South FL... Rounds of lower-topped convection should continue within a persistent low-level northeasterly flow regime, namely along the southeast coast. Weak mid to upper-level lapse rates, slightly worse compared to D2, suggests instability will be marginal with low-end thunderstorm probabilities. ..Grams.. 12/12/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Tue Dec 12 2023 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...NM and TX... A shortwave trough will continue east across NM into northwest TX by early Friday. A persistent low-level warm theta-e advection regime in conjunction with mid-level DCVA/height falls ahead of the trough will support a nearly continuous swath of elevated convection, shifting east from NM and west TX into central TX by Thursday night. Elevated buoyancy will remain meager, suggesting that thunderstorm coverage will be sporadic. Guidance is consistent that the plume of steep mid-level lapse rates attendant to the trough on D2 will weaken early D3, inferring severe hail potential should be negligible. ...South FL... Rounds of lower-topped convection should continue within a persistent low-level northeasterly flow regime, namely along the southeast coast. Weak mid to upper-level lapse rates, slightly worse compared to D2, suggests instability will be marginal with low-end thunderstorm probabilities. ..Grams.. 12/12/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Tue Dec 12 2023 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...NM and TX... A shortwave trough will continue east across NM into northwest TX by early Friday. A persistent low-level warm theta-e advection regime in conjunction with mid-level DCVA/height falls ahead of the trough will support a nearly continuous swath of elevated convection, shifting east from NM and west TX into central TX by Thursday night. Elevated buoyancy will remain meager, suggesting that thunderstorm coverage will be sporadic. Guidance is consistent that the plume of steep mid-level lapse rates attendant to the trough on D2 will weaken early D3, inferring severe hail potential should be negligible. ...South FL... Rounds of lower-topped convection should continue within a persistent low-level northeasterly flow regime, namely along the southeast coast. Weak mid to upper-level lapse rates, slightly worse compared to D2, suggests instability will be marginal with low-end thunderstorm probabilities. ..Grams.. 12/12/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ..Wendt.. 12/12/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ..Wendt.. 12/12/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ..Wendt.. 12/12/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Tue Dec 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A cutoff low in the lower Colorado River Valley will shift into the Four Corners and become more of an open wave on Wednesday. With a strong trough exiting the Northeast by the end of the period, surface high pressure will intensify in the East with some maintenance of high pressure within the Great Basin. Cool temperatures and light winds over the driest fuels will again preclude fire weather concerns for most of the CONUS. Offshore flow will continue across southern California, though a slow weakening trend will occur through the period. RH early in the day, when the winds will be strongest, will not likely fall below critical thresholds. A couple hours of elevated fire weather does appear possible by early/mid afternoon. Fuels have dried further at lower elevations. However, the limited spatial extent and short duration of these conditions should keep fire weather concerns localized. ..Wendt.. 12/12/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more