Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1111 AM CST Thu Feb 01 2024 Valid 021200Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF SOUTH-CENTRAL TEXAS AND THE EDWARDS PLATEAU... ...SUMMARY... Isolated to scattered severe thunderstorms will be possible beginning late afternoon Friday across parts of the southern Great Plains. ...Synopsis... A blocking pattern over central North America will be undercut by a powerful eastward-moving upper jet streak located over northern Mexico and the southwest U.S. border states. Strong difluence and implied ascent will overspread the southern Great Plains during the day-2 period as 60+ meter per 12 hour height falls and associated cooling mid-level temperatures move east into TX/OK. In the low levels, a lee trough over the south-central High Plains will evolve into a surface low centered over southeast CO by early Saturday morning. ...Southern Great Plains... Southerly low-level flow will aid in modest low-level moistening east of a dryline over the southern High Plains. In agreement with previous forecast thinking, it seems marginal buoyancy will develop during the afternoon within a meridional deep-layer wind profile. An arc of isolated thunderstorms is expected from the TX Big Country north along the OK/TX Panhandle border during the mid-late afternoon. A couple of transient supercells capable of an isolated threat for large hail may accompany the stronger activity. Farther south in west TX, high-based convective development should initially form west of the dryline during the late afternoon, with more prominent development likely in the evening as the Pacific cold front pushes east. It is over portions of the Edwards Plateau that there is greater confidence for widely scattered supercell development during the late afternoon/early evening. This activity should spread east across south-central TX through the late evening/overnight. Although low-level moisture (primarily 50s dewpoints) will reside across the area, cooling 500-mb temperatures (-16 to -20 deg C) will yield 1000-2000 J/kg MUCAPE. This magnitude of buoyancy and long hodographs supporting supercells suggest a threat for large hail. The latest convection-allowing model guidance explicitly supports this notion. Storm intensity is forecast to wane during the overnight into the pre-dawn hours. Nonetheless, any robust remaining storms will gradually move into a slightly more moist environment over the coastal plain with perhaps a lower-end threat for an embedded supercell tornado/wind gust. ..Smith.. 02/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Thu Feb 01 2024 Valid 011630Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... A highly amplified large-scale trough will continue eastward from the eastern Pacific Ocean into the western CONUS through the period. This evolution will be aided by the eastward progression of a strong jet streak moving across the Baja Peninsula and northwest Mexico. Cooling midlevel temperatures/steepening lapse rates accompanying the large-scale trough will continue overspreading CA today, supporting sufficient buoyancy for embedded lightning within eastward-spreading bands of convection given strong midlevel height falls/deep-layer ascent. Farther south and east, strong ascent in the left exit region of the upper jet will also support isolated lightning potential across portions of the Four Corners region given weak instability. While sufficient surface-based instability may develop across portions of the southern CA coastline behind the initial round of convection into this afternoon, veering low-level flow and related decreases in deep-layer shear should limit severe thunderstorm potential. ..Weinman/Smith.. 02/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Thu Feb 01 2024 Valid 011630Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... A highly amplified large-scale trough will continue eastward from the eastern Pacific Ocean into the western CONUS through the period. This evolution will be aided by the eastward progression of a strong jet streak moving across the Baja Peninsula and northwest Mexico. Cooling midlevel temperatures/steepening lapse rates accompanying the large-scale trough will continue overspreading CA today, supporting sufficient buoyancy for embedded lightning within eastward-spreading bands of convection given strong midlevel height falls/deep-layer ascent. Farther south and east, strong ascent in the left exit region of the upper jet will also support isolated lightning potential across portions of the Four Corners region given weak instability. While sufficient surface-based instability may develop across portions of the southern CA coastline behind the initial round of convection into this afternoon, veering low-level flow and related decreases in deep-layer shear should limit severe thunderstorm potential. ..Weinman/Smith.. 02/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Thu Feb 01 2024 Valid 011630Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... A highly amplified large-scale trough will continue eastward from the eastern Pacific Ocean into the western CONUS through the period. This evolution will be aided by the eastward progression of a strong jet streak moving across the Baja Peninsula and northwest Mexico. Cooling midlevel temperatures/steepening lapse rates accompanying the large-scale trough will continue overspreading CA today, supporting sufficient buoyancy for embedded lightning within eastward-spreading bands of convection given strong midlevel height falls/deep-layer ascent. Farther south and east, strong ascent in the left exit region of the upper jet will also support isolated lightning potential across portions of the Four Corners region given weak instability. While sufficient surface-based instability may develop across portions of the southern CA coastline behind the initial round of convection into this afternoon, veering low-level flow and related decreases in deep-layer shear should limit severe thunderstorm potential. ..Weinman/Smith.. 02/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Thu Feb 01 2024 Valid 011630Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... A highly amplified large-scale trough will continue eastward from the eastern Pacific Ocean into the western CONUS through the period. This evolution will be aided by the eastward progression of a strong jet streak moving across the Baja Peninsula and northwest Mexico. Cooling midlevel temperatures/steepening lapse rates accompanying the large-scale trough will continue overspreading CA today, supporting sufficient buoyancy for embedded lightning within eastward-spreading bands of convection given strong midlevel height falls/deep-layer ascent. Farther south and east, strong ascent in the left exit region of the upper jet will also support isolated lightning potential across portions of the Four Corners region given weak instability. While sufficient surface-based instability may develop across portions of the southern CA coastline behind the initial round of convection into this afternoon, veering low-level flow and related decreases in deep-layer shear should limit severe thunderstorm potential. ..Weinman/Smith.. 02/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Thu Feb 01 2024 Valid 011630Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... A highly amplified large-scale trough will continue eastward from the eastern Pacific Ocean into the western CONUS through the period. This evolution will be aided by the eastward progression of a strong jet streak moving across the Baja Peninsula and northwest Mexico. Cooling midlevel temperatures/steepening lapse rates accompanying the large-scale trough will continue overspreading CA today, supporting sufficient buoyancy for embedded lightning within eastward-spreading bands of convection given strong midlevel height falls/deep-layer ascent. Farther south and east, strong ascent in the left exit region of the upper jet will also support isolated lightning potential across portions of the Four Corners region given weak instability. While sufficient surface-based instability may develop across portions of the southern CA coastline behind the initial round of convection into this afternoon, veering low-level flow and related decreases in deep-layer shear should limit severe thunderstorm potential. ..Weinman/Smith.. 02/01/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Thu Feb 01 2024 Valid 011630Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... A highly amplified large-scale trough will continue eastward from the eastern Pacific Ocean into the western CONUS through the period. This evolution will be aided by the eastward progression of a strong jet streak moving across the Baja Peninsula and northwest Mexico. Cooling midlevel temperatures/steepening lapse rates accompanying the large-scale trough will continue overspreading CA today, supporting sufficient buoyancy for embedded lightning within eastward-spreading bands of convection given strong midlevel height falls/deep-layer ascent. Farther south and east, strong ascent in the left exit region of the upper jet will also support isolated lightning potential across portions of the Four Corners region given weak instability. While sufficient surface-based instability may develop across portions of the southern CA coastline behind the initial round of convection into this afternoon, veering low-level flow and related decreases in deep-layer shear should limit severe thunderstorm potential. ..Weinman/Smith.. 02/01/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0940 AM CST Thu Feb 01 2024 Valid 011700Z - 021200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no changes needed. Confidence remains reasonably high that the driest conditions across the central High Plains should remain displaced from stronger winds over central OK/KS this afternoon, resulting in limited fire weather concerns. See the previous discussion for additional details. ..Moore.. 02/01/2024 .PREV DISCUSSION... /ISSUED 1257 AM CST Thu Feb 01 2024/ ...Synopsis... A shortwave trough extending from the broader cyclonic flow off the West Coast will pivot through the Southwest to near the Four Corners by late tonight/early Friday. The flow increase across the southern Rockies will promote a modestly deep lee trough in the central/southern High Plains. While some cloud cover will be possible and limit RH reductions, a few areas could approach 20% by the afternoon. Winds will also be modest at around 15 to perhaps locally 20 mph. Coupled with continued marginally dry fuels, fire weather concerns will be low. ...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 0940 AM CST Thu Feb 01 2024 Valid 011700Z - 021200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no changes needed. Confidence remains reasonably high that the driest conditions across the central High Plains should remain displaced from stronger winds over central OK/KS this afternoon, resulting in limited fire weather concerns. See the previous discussion for additional details. ..Moore.. 02/01/2024 .PREV DISCUSSION... /ISSUED 1257 AM CST Thu Feb 01 2024/ ...Synopsis... A shortwave trough extending from the broader cyclonic flow off the West Coast will pivot through the Southwest to near the Four Corners by late tonight/early Friday. The flow increase across the southern Rockies will promote a modestly deep lee trough in the central/southern High Plains. While some cloud cover will be possible and limit RH reductions, a few areas could approach 20% by the afternoon. Winds will also be modest at around 15 to perhaps locally 20 mph. Coupled with continued marginally dry fuels, fire weather concerns will be low. ...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 0940 AM CST Thu Feb 01 2024 Valid 011700Z - 021200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no changes needed. Confidence remains reasonably high that the driest conditions across the central High Plains should remain displaced from stronger winds over central OK/KS this afternoon, resulting in limited fire weather concerns. See the previous discussion for additional details. ..Moore.. 02/01/2024 .PREV DISCUSSION... /ISSUED 1257 AM CST Thu Feb 01 2024/ ...Synopsis... A shortwave trough extending from the broader cyclonic flow off the West Coast will pivot through the Southwest to near the Four Corners by late tonight/early Friday. The flow increase across the southern Rockies will promote a modestly deep lee trough in the central/southern High Plains. While some cloud cover will be possible and limit RH reductions, a few areas could approach 20% by the afternoon. Winds will also be modest at around 15 to perhaps locally 20 mph. Coupled with continued marginally dry fuels, fire weather concerns will be low. ...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 0940 AM CST Thu Feb 01 2024 Valid 011700Z - 021200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no changes needed. Confidence remains reasonably high that the driest conditions across the central High Plains should remain displaced from stronger winds over central OK/KS this afternoon, resulting in limited fire weather concerns. See the previous discussion for additional details. ..Moore.. 02/01/2024 .PREV DISCUSSION... /ISSUED 1257 AM CST Thu Feb 01 2024/ ...Synopsis... A shortwave trough extending from the broader cyclonic flow off the West Coast will pivot through the Southwest to near the Four Corners by late tonight/early Friday. The flow increase across the southern Rockies will promote a modestly deep lee trough in the central/southern High Plains. While some cloud cover will be possible and limit RH reductions, a few areas could approach 20% by the afternoon. Winds will also be modest at around 15 to perhaps locally 20 mph. Coupled with continued marginally dry fuels, fire weather concerns will be low. ...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 0940 AM CST Thu Feb 01 2024 Valid 011700Z - 021200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no changes needed. Confidence remains reasonably high that the driest conditions across the central High Plains should remain displaced from stronger winds over central OK/KS this afternoon, resulting in limited fire weather concerns. See the previous discussion for additional details. ..Moore.. 02/01/2024 .PREV DISCUSSION... /ISSUED 1257 AM CST Thu Feb 01 2024/ ...Synopsis... A shortwave trough extending from the broader cyclonic flow off the West Coast will pivot through the Southwest to near the Four Corners by late tonight/early Friday. The flow increase across the southern Rockies will promote a modestly deep lee trough in the central/southern High Plains. While some cloud cover will be possible and limit RH reductions, a few areas could approach 20% by the afternoon. Winds will also be modest at around 15 to perhaps locally 20 mph. Coupled with continued marginally dry fuels, fire weather concerns will be low. ...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 0940 AM CST Thu Feb 01 2024 Valid 011700Z - 021200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no changes needed. Confidence remains reasonably high that the driest conditions across the central High Plains should remain displaced from stronger winds over central OK/KS this afternoon, resulting in limited fire weather concerns. See the previous discussion for additional details. ..Moore.. 02/01/2024 .PREV DISCUSSION... /ISSUED 1257 AM CST Thu Feb 01 2024/ ...Synopsis... A shortwave trough extending from the broader cyclonic flow off the West Coast will pivot through the Southwest to near the Four Corners by late tonight/early Friday. The flow increase across the southern Rockies will promote a modestly deep lee trough in the central/southern High Plains. While some cloud cover will be possible and limit RH reductions, a few areas could approach 20% by the afternoon. Winds will also be modest at around 15 to perhaps locally 20 mph. Coupled with continued marginally dry fuels, fire weather concerns will be low. ...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 0636 AM CST Thu Feb 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... In mid/upper levels, a progressive and highly amplified pattern is forecast through the remainder of this period and into day-2, as ridging shifts eastward over the northern Plains and Upper Midwest. To its southwest, a large area of cyclonic flow and height falls will continue to build further inland, covering most of the western CONUS by the end of the period. Within that, several embedded shortwaves will contribute to the eastward motion and amplification of mean troughing, including a perturbation evident in moisture-channel imagery over coastal central/northern CA. This feature should dig east-southeastward across the lower Colorado River Valley tonight, reaching central AZ and southern NV by 12Z tomorrow. The strongest, cyclonically curved, 500-250-mb layer jet will remain southwest of the negatively tilted trough, across the Pacific from northern Baja west-northwestward. However: 1. Large-scale ascent associated with the left-exit region will spread across a wide swath of CA, AZ and ultimately NM, as well as strongly difluent mid/upper flow. 2. Midlevel DCVA, and low-level warm advection and frontogenetic forcing, will contribute further to varying scales of lift over parts of the region, while Pacific moisture increases in low/middle levels. These factors should lead to weak but sufficient MUCAPE to support a generally eastward-developing thunder potential with time, across the outlook area. A couple of highly conditional areas for isolated strong storms are apparent, but with potential too low for a severe outlook. Sufficient destabilization may develop to support surface-based, post-frontal convection this afternoon into early evening over the CA Central Valley. However, vertical shear will be weak, keeping activity pulse in nature. Farther south around the L.A. Basin and nearby coastline, enough destabilization for surface-based buoyancy may occur behind the initial frontal band, but also amid veering near-surface flow and weakening shear with time. ..Edwards/Gleason.. 02/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 AM CST Thu Feb 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... In mid/upper levels, a progressive and highly amplified pattern is forecast through the remainder of this period and into day-2, as ridging shifts eastward over the northern Plains and Upper Midwest. To its southwest, a large area of cyclonic flow and height falls will continue to build further inland, covering most of the western CONUS by the end of the period. Within that, several embedded shortwaves will contribute to the eastward motion and amplification of mean troughing, including a perturbation evident in moisture-channel imagery over coastal central/northern CA. This feature should dig east-southeastward across the lower Colorado River Valley tonight, reaching central AZ and southern NV by 12Z tomorrow. The strongest, cyclonically curved, 500-250-mb layer jet will remain southwest of the negatively tilted trough, across the Pacific from northern Baja west-northwestward. However: 1. Large-scale ascent associated with the left-exit region will spread across a wide swath of CA, AZ and ultimately NM, as well as strongly difluent mid/upper flow. 2. Midlevel DCVA, and low-level warm advection and frontogenetic forcing, will contribute further to varying scales of lift over parts of the region, while Pacific moisture increases in low/middle levels. These factors should lead to weak but sufficient MUCAPE to support a generally eastward-developing thunder potential with time, across the outlook area. A couple of highly conditional areas for isolated strong storms are apparent, but with potential too low for a severe outlook. Sufficient destabilization may develop to support surface-based, post-frontal convection this afternoon into early evening over the CA Central Valley. However, vertical shear will be weak, keeping activity pulse in nature. Farther south around the L.A. Basin and nearby coastline, enough destabilization for surface-based buoyancy may occur behind the initial frontal band, but also amid veering near-surface flow and weakening shear with time. ..Edwards/Gleason.. 02/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 AM CST Thu Feb 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... In mid/upper levels, a progressive and highly amplified pattern is forecast through the remainder of this period and into day-2, as ridging shifts eastward over the northern Plains and Upper Midwest. To its southwest, a large area of cyclonic flow and height falls will continue to build further inland, covering most of the western CONUS by the end of the period. Within that, several embedded shortwaves will contribute to the eastward motion and amplification of mean troughing, including a perturbation evident in moisture-channel imagery over coastal central/northern CA. This feature should dig east-southeastward across the lower Colorado River Valley tonight, reaching central AZ and southern NV by 12Z tomorrow. The strongest, cyclonically curved, 500-250-mb layer jet will remain southwest of the negatively tilted trough, across the Pacific from northern Baja west-northwestward. However: 1. Large-scale ascent associated with the left-exit region will spread across a wide swath of CA, AZ and ultimately NM, as well as strongly difluent mid/upper flow. 2. Midlevel DCVA, and low-level warm advection and frontogenetic forcing, will contribute further to varying scales of lift over parts of the region, while Pacific moisture increases in low/middle levels. These factors should lead to weak but sufficient MUCAPE to support a generally eastward-developing thunder potential with time, across the outlook area. A couple of highly conditional areas for isolated strong storms are apparent, but with potential too low for a severe outlook. Sufficient destabilization may develop to support surface-based, post-frontal convection this afternoon into early evening over the CA Central Valley. However, vertical shear will be weak, keeping activity pulse in nature. Farther south around the L.A. Basin and nearby coastline, enough destabilization for surface-based buoyancy may occur behind the initial frontal band, but also amid veering near-surface flow and weakening shear with time. ..Edwards/Gleason.. 02/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 AM CST Thu Feb 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... In mid/upper levels, a progressive and highly amplified pattern is forecast through the remainder of this period and into day-2, as ridging shifts eastward over the northern Plains and Upper Midwest. To its southwest, a large area of cyclonic flow and height falls will continue to build further inland, covering most of the western CONUS by the end of the period. Within that, several embedded shortwaves will contribute to the eastward motion and amplification of mean troughing, including a perturbation evident in moisture-channel imagery over coastal central/northern CA. This feature should dig east-southeastward across the lower Colorado River Valley tonight, reaching central AZ and southern NV by 12Z tomorrow. The strongest, cyclonically curved, 500-250-mb layer jet will remain southwest of the negatively tilted trough, across the Pacific from northern Baja west-northwestward. However: 1. Large-scale ascent associated with the left-exit region will spread across a wide swath of CA, AZ and ultimately NM, as well as strongly difluent mid/upper flow. 2. Midlevel DCVA, and low-level warm advection and frontogenetic forcing, will contribute further to varying scales of lift over parts of the region, while Pacific moisture increases in low/middle levels. These factors should lead to weak but sufficient MUCAPE to support a generally eastward-developing thunder potential with time, across the outlook area. A couple of highly conditional areas for isolated strong storms are apparent, but with potential too low for a severe outlook. Sufficient destabilization may develop to support surface-based, post-frontal convection this afternoon into early evening over the CA Central Valley. However, vertical shear will be weak, keeping activity pulse in nature. Farther south around the L.A. Basin and nearby coastline, enough destabilization for surface-based buoyancy may occur behind the initial frontal band, but also amid veering near-surface flow and weakening shear with time. ..Edwards/Gleason.. 02/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 AM CST Thu Feb 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... In mid/upper levels, a progressive and highly amplified pattern is forecast through the remainder of this period and into day-2, as ridging shifts eastward over the northern Plains and Upper Midwest. To its southwest, a large area of cyclonic flow and height falls will continue to build further inland, covering most of the western CONUS by the end of the period. Within that, several embedded shortwaves will contribute to the eastward motion and amplification of mean troughing, including a perturbation evident in moisture-channel imagery over coastal central/northern CA. This feature should dig east-southeastward across the lower Colorado River Valley tonight, reaching central AZ and southern NV by 12Z tomorrow. The strongest, cyclonically curved, 500-250-mb layer jet will remain southwest of the negatively tilted trough, across the Pacific from northern Baja west-northwestward. However: 1. Large-scale ascent associated with the left-exit region will spread across a wide swath of CA, AZ and ultimately NM, as well as strongly difluent mid/upper flow. 2. Midlevel DCVA, and low-level warm advection and frontogenetic forcing, will contribute further to varying scales of lift over parts of the region, while Pacific moisture increases in low/middle levels. These factors should lead to weak but sufficient MUCAPE to support a generally eastward-developing thunder potential with time, across the outlook area. A couple of highly conditional areas for isolated strong storms are apparent, but with potential too low for a severe outlook. Sufficient destabilization may develop to support surface-based, post-frontal convection this afternoon into early evening over the CA Central Valley. However, vertical shear will be weak, keeping activity pulse in nature. Farther south around the L.A. Basin and nearby coastline, enough destabilization for surface-based buoyancy may occur behind the initial frontal band, but also amid veering near-surface flow and weakening shear with time. ..Edwards/Gleason.. 02/01/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 AM CST Thu Feb 01 2024 Valid 011300Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected. ...Synopsis/Discussion... In mid/upper levels, a progressive and highly amplified pattern is forecast through the remainder of this period and into day-2, as ridging shifts eastward over the northern Plains and Upper Midwest. To its southwest, a large area of cyclonic flow and height falls will continue to build further inland, covering most of the western CONUS by the end of the period. Within that, several embedded shortwaves will contribute to the eastward motion and amplification of mean troughing, including a perturbation evident in moisture-channel imagery over coastal central/northern CA. This feature should dig east-southeastward across the lower Colorado River Valley tonight, reaching central AZ and southern NV by 12Z tomorrow. The strongest, cyclonically curved, 500-250-mb layer jet will remain southwest of the negatively tilted trough, across the Pacific from northern Baja west-northwestward. However: 1. Large-scale ascent associated with the left-exit region will spread across a wide swath of CA, AZ and ultimately NM, as well as strongly difluent mid/upper flow. 2. Midlevel DCVA, and low-level warm advection and frontogenetic forcing, will contribute further to varying scales of lift over parts of the region, while Pacific moisture increases in low/middle levels. These factors should lead to weak but sufficient MUCAPE to support a generally eastward-developing thunder potential with time, across the outlook area. A couple of highly conditional areas for isolated strong storms are apparent, but with potential too low for a severe outlook. Sufficient destabilization may develop to support surface-based, post-frontal convection this afternoon into early evening over the CA Central Valley. However, vertical shear will be weak, keeping activity pulse in nature. Farther south around the L.A. Basin and nearby coastline, enough destabilization for surface-based buoyancy may occur behind the initial frontal band, but also amid veering near-surface flow and weakening shear with time. ..Edwards/Gleason.. 02/01/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0351 AM CST Thu Feb 01 2024 Valid 041200Z - 091200Z ...DISCUSSION... Latest guidance continues to converge towards the notion of secondary cyclogenesis in the north-central Gulf vicinity, during the latter half of D3 into D4. This process should occur as the intense mid-level jet, centered on the Rio Grande Valley/south TX into the northwest Gulf at 12Z Sunday, translates eastward across much of the Gulf into the FL Peninsula by early Monday. A potential high-shear/low-CAPE environment remains plausible across roughly the southern third of FL for a 3-6 hour period during Sunday morning to afternoon. A substantial influx of low-level moisture will be necessary after an initially dry air mass lingers over most of the peninsula through D3. Widespread convection is expected to approach the peninsula Sunday morning, within the robust low-level warm conveyor ahead of a sweeping Pacific cold front and diffluent upper flow regime. Instability should be quite limited where low-level shear is large, but this will need careful monitoring over the upcoming days. Severe potential will likely resume being negligible again as boundary-layer moisture becomes limited over the Gulf until around late next week. Read more