Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 AM CDT Fri May 03 2024 Valid 031300Z - 041200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NEAR THE WEST TEXAS CAPROCK ONTO ADJOINING LOW ROLLING PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE ENHANCED AREA...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail and damaging gusts are possible over parts of the central/southern Great Plains from southern Nebraska to west Texas, along with some tornado potential over parts of west Texas. ...Synopsis... Today's transitional mid/upper-level synoptic pattern is a tale of two cyclones -- one astride the Upper Midwest/Canadian border, and another digging southeastward out of the Gulf of Alaska. The broad, complex leading cyclone will eject northeastward over MB and northwestern ON through the period. A trailing shortwave trough -- apparent in moisture-channel imagery over parts of southern ID and northern NV -- will move east-northeastward to eastern SD and central NE by 12Z tomorrow. The strong, well-developed Pacific cyclone will proceed southeastward to just off the coast of OR by the end of the period. Southwest flow aloft will be maintained with weak synoptic-scale height rises over most of the central/southern Plains. Still, sufficient moisture, buoyancy, lift and shear are apparent for a couple relative maxima in severe potential as discussed below. At the surface, 11Z analysis showed a low attached to a cold front over south-central WY. The front should proceed southeastward through the day, extending from southeastern SD to western NE an central CO by 00Z, with the low over northeastern CO. By 12Z tomorrow, the front should extend from a low over IA to south- central KS, the northern TX Panhandle, and north-central NM. This front will overtake a developing dryline over the central High Plains from north-south, with the dryline position at 00Z over eastern CO, the western TX Panhandle, and Permian Basin. A weak/ residual, nearly stationary front extended from a low near FST northeastward across northwest TX, eastern OK and the Ozarks, and should continue to lose definition amidst considerable convective outflow. The southern rim of that outflow was evident from southeast TX (between GLS-BPT) across the HOU metro then west- northwestward to near SJT. The western part will shift northward slowly through the day toward the front, which itself should drift northward up the Caprock. ...West/southwest TX... Widely scattered to scattered thunderstorms are expected to form this afternoon near the dryline and the residual outflow boundary over the South Plains to Low Rolling Plains/Concho Valley regions. Isolated to widely scattered convection possible farther south off the dryline past the Rio Grande, and into strongly heated/CINH- minimized higher terrain of the Serranias del Burro range in northern Coahuila. This activity should move eastward across areas below the Caprock and around the Big Country to Edwards Plateau, with potential for some of the Mexican convection to cross the Rio Grande this evening as well. Supercells -- with large to very large hail and at least isolated potential for tornadoes -- will be more probable in and near the 30%/"enhanced" hail area. Dryline and orographic activity to the south will be an early hail/wind threat. Some of this activity may aggregate into clusters offering mainly strong-severe gusts, with one or two small MCSs possible this evening into the early overnight hours. Despite multiple days of MCS and smaller-scale convective activity to the east and southeast, a reservoir of rich low-level moisture remains not far upstream across south-central TX and into the southern Edwards Plateau, where upper 60s to low 70s F surface dewpoints and PW commonly 1-1.5 inches. When advected northwestward amid diurnal heating and beneath steep midlevel lapse rates, 3000-4000 J/kg MLCAPE should become common. Though low-level flow should not be particularly strong, it will be backed, contributing to elongated hodographs ad around 30-40 kt effective-shear magnitudes. Splitting storms may be common early, offering the greatest hail potential (size and coverage). The damaging-wind threat will be maximized on the mesoscale where organized cold pools can develop, and should extend farther east at greater density than the hail potential this evening into tonight. In the absence of substantial large-scale support, tornado potential will be locally maximized with any supercells that can interact favorably with outflow boundaries or each other. ...Central Plains... Large hail and severe gusts are possible from mid/late afternoon into tonight, from thunderstorms shifting eastward across portions of the central Plains. Though nowhere nearly as moist as the TX outlook area, a diurnally destabilized plume of moist advection should support a secondary relative max in severe potential along/ahead of the cold front and dryline from parts of eastern CO to western/northern KS and southern NE. Convection should develop by mid/late afternoon in a regional convergence maximum near and northeast of the surface low, with MLCINH weakened by favorable diurnal heating. Surface dewpoints in the 40s to low 50s F should be common, with steep surface-500-mb lapse rates, 500-1000 J/kg MLCAPE and well-mixed subcloud layers. Effective-shear magnitudes around 40-50 kt indicate potential for organized convection -- both in quasi-linear form near the front and initially discrete (but later merging upscale) off the dryline. Though activity will encounter a more-stable boundary layer with time and eastward extent across KS/NE, at least marginal severe-gust potential may last overnight as far eastward as parts of the Missouri Valley region. ..Edwards/Broyles.. 05/03/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 AM CDT Fri May 03 2024 Valid 031300Z - 041200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NEAR THE WEST TEXAS CAPROCK ONTO ADJOINING LOW ROLLING PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE ENHANCED AREA...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail and damaging gusts are possible over parts of the central/southern Great Plains from southern Nebraska to west Texas, along with some tornado potential over parts of west Texas. ...Synopsis... Today's transitional mid/upper-level synoptic pattern is a tale of two cyclones -- one astride the Upper Midwest/Canadian border, and another digging southeastward out of the Gulf of Alaska. The broad, complex leading cyclone will eject northeastward over MB and northwestern ON through the period. A trailing shortwave trough -- apparent in moisture-channel imagery over parts of southern ID and northern NV -- will move east-northeastward to eastern SD and central NE by 12Z tomorrow. The strong, well-developed Pacific cyclone will proceed southeastward to just off the coast of OR by the end of the period. Southwest flow aloft will be maintained with weak synoptic-scale height rises over most of the central/southern Plains. Still, sufficient moisture, buoyancy, lift and shear are apparent for a couple relative maxima in severe potential as discussed below. At the surface, 11Z analysis showed a low attached to a cold front over south-central WY. The front should proceed southeastward through the day, extending from southeastern SD to western NE an central CO by 00Z, with the low over northeastern CO. By 12Z tomorrow, the front should extend from a low over IA to south- central KS, the northern TX Panhandle, and north-central NM. This front will overtake a developing dryline over the central High Plains from north-south, with the dryline position at 00Z over eastern CO, the western TX Panhandle, and Permian Basin. A weak/ residual, nearly stationary front extended from a low near FST northeastward across northwest TX, eastern OK and the Ozarks, and should continue to lose definition amidst considerable convective outflow. The southern rim of that outflow was evident from southeast TX (between GLS-BPT) across the HOU metro then west- northwestward to near SJT. The western part will shift northward slowly through the day toward the front, which itself should drift northward up the Caprock. ...West/southwest TX... Widely scattered to scattered thunderstorms are expected to form this afternoon near the dryline and the residual outflow boundary over the South Plains to Low Rolling Plains/Concho Valley regions. Isolated to widely scattered convection possible farther south off the dryline past the Rio Grande, and into strongly heated/CINH- minimized higher terrain of the Serranias del Burro range in northern Coahuila. This activity should move eastward across areas below the Caprock and around the Big Country to Edwards Plateau, with potential for some of the Mexican convection to cross the Rio Grande this evening as well. Supercells -- with large to very large hail and at least isolated potential for tornadoes -- will be more probable in and near the 30%/"enhanced" hail area. Dryline and orographic activity to the south will be an early hail/wind threat. Some of this activity may aggregate into clusters offering mainly strong-severe gusts, with one or two small MCSs possible this evening into the early overnight hours. Despite multiple days of MCS and smaller-scale convective activity to the east and southeast, a reservoir of rich low-level moisture remains not far upstream across south-central TX and into the southern Edwards Plateau, where upper 60s to low 70s F surface dewpoints and PW commonly 1-1.5 inches. When advected northwestward amid diurnal heating and beneath steep midlevel lapse rates, 3000-4000 J/kg MLCAPE should become common. Though low-level flow should not be particularly strong, it will be backed, contributing to elongated hodographs ad around 30-40 kt effective-shear magnitudes. Splitting storms may be common early, offering the greatest hail potential (size and coverage). The damaging-wind threat will be maximized on the mesoscale where organized cold pools can develop, and should extend farther east at greater density than the hail potential this evening into tonight. In the absence of substantial large-scale support, tornado potential will be locally maximized with any supercells that can interact favorably with outflow boundaries or each other. ...Central Plains... Large hail and severe gusts are possible from mid/late afternoon into tonight, from thunderstorms shifting eastward across portions of the central Plains. Though nowhere nearly as moist as the TX outlook area, a diurnally destabilized plume of moist advection should support a secondary relative max in severe potential along/ahead of the cold front and dryline from parts of eastern CO to western/northern KS and southern NE. Convection should develop by mid/late afternoon in a regional convergence maximum near and northeast of the surface low, with MLCINH weakened by favorable diurnal heating. Surface dewpoints in the 40s to low 50s F should be common, with steep surface-500-mb lapse rates, 500-1000 J/kg MLCAPE and well-mixed subcloud layers. Effective-shear magnitudes around 40-50 kt indicate potential for organized convection -- both in quasi-linear form near the front and initially discrete (but later merging upscale) off the dryline. Though activity will encounter a more-stable boundary layer with time and eastward extent across KS/NE, at least marginal severe-gust potential may last overnight as far eastward as parts of the Missouri Valley region. ..Edwards/Broyles.. 05/03/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 AM CDT Fri May 03 2024 Valid 031300Z - 041200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NEAR THE WEST TEXAS CAPROCK ONTO ADJOINING LOW ROLLING PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE ENHANCED AREA...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail and damaging gusts are possible over parts of the central/southern Great Plains from southern Nebraska to west Texas, along with some tornado potential over parts of west Texas. ...Synopsis... Today's transitional mid/upper-level synoptic pattern is a tale of two cyclones -- one astride the Upper Midwest/Canadian border, and another digging southeastward out of the Gulf of Alaska. The broad, complex leading cyclone will eject northeastward over MB and northwestern ON through the period. A trailing shortwave trough -- apparent in moisture-channel imagery over parts of southern ID and northern NV -- will move east-northeastward to eastern SD and central NE by 12Z tomorrow. The strong, well-developed Pacific cyclone will proceed southeastward to just off the coast of OR by the end of the period. Southwest flow aloft will be maintained with weak synoptic-scale height rises over most of the central/southern Plains. Still, sufficient moisture, buoyancy, lift and shear are apparent for a couple relative maxima in severe potential as discussed below. At the surface, 11Z analysis showed a low attached to a cold front over south-central WY. The front should proceed southeastward through the day, extending from southeastern SD to western NE an central CO by 00Z, with the low over northeastern CO. By 12Z tomorrow, the front should extend from a low over IA to south- central KS, the northern TX Panhandle, and north-central NM. This front will overtake a developing dryline over the central High Plains from north-south, with the dryline position at 00Z over eastern CO, the western TX Panhandle, and Permian Basin. A weak/ residual, nearly stationary front extended from a low near FST northeastward across northwest TX, eastern OK and the Ozarks, and should continue to lose definition amidst considerable convective outflow. The southern rim of that outflow was evident from southeast TX (between GLS-BPT) across the HOU metro then west- northwestward to near SJT. The western part will shift northward slowly through the day toward the front, which itself should drift northward up the Caprock. ...West/southwest TX... Widely scattered to scattered thunderstorms are expected to form this afternoon near the dryline and the residual outflow boundary over the South Plains to Low Rolling Plains/Concho Valley regions. Isolated to widely scattered convection possible farther south off the dryline past the Rio Grande, and into strongly heated/CINH- minimized higher terrain of the Serranias del Burro range in northern Coahuila. This activity should move eastward across areas below the Caprock and around the Big Country to Edwards Plateau, with potential for some of the Mexican convection to cross the Rio Grande this evening as well. Supercells -- with large to very large hail and at least isolated potential for tornadoes -- will be more probable in and near the 30%/"enhanced" hail area. Dryline and orographic activity to the south will be an early hail/wind threat. Some of this activity may aggregate into clusters offering mainly strong-severe gusts, with one or two small MCSs possible this evening into the early overnight hours. Despite multiple days of MCS and smaller-scale convective activity to the east and southeast, a reservoir of rich low-level moisture remains not far upstream across south-central TX and into the southern Edwards Plateau, where upper 60s to low 70s F surface dewpoints and PW commonly 1-1.5 inches. When advected northwestward amid diurnal heating and beneath steep midlevel lapse rates, 3000-4000 J/kg MLCAPE should become common. Though low-level flow should not be particularly strong, it will be backed, contributing to elongated hodographs ad around 30-40 kt effective-shear magnitudes. Splitting storms may be common early, offering the greatest hail potential (size and coverage). The damaging-wind threat will be maximized on the mesoscale where organized cold pools can develop, and should extend farther east at greater density than the hail potential this evening into tonight. In the absence of substantial large-scale support, tornado potential will be locally maximized with any supercells that can interact favorably with outflow boundaries or each other. ...Central Plains... Large hail and severe gusts are possible from mid/late afternoon into tonight, from thunderstorms shifting eastward across portions of the central Plains. Though nowhere nearly as moist as the TX outlook area, a diurnally destabilized plume of moist advection should support a secondary relative max in severe potential along/ahead of the cold front and dryline from parts of eastern CO to western/northern KS and southern NE. Convection should develop by mid/late afternoon in a regional convergence maximum near and northeast of the surface low, with MLCINH weakened by favorable diurnal heating. Surface dewpoints in the 40s to low 50s F should be common, with steep surface-500-mb lapse rates, 500-1000 J/kg MLCAPE and well-mixed subcloud layers. Effective-shear magnitudes around 40-50 kt indicate potential for organized convection -- both in quasi-linear form near the front and initially discrete (but later merging upscale) off the dryline. Though activity will encounter a more-stable boundary layer with time and eastward extent across KS/NE, at least marginal severe-gust potential may last overnight as far eastward as parts of the Missouri Valley region. ..Edwards/Broyles.. 05/03/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 AM CDT Fri May 03 2024 Valid 031300Z - 041200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NEAR THE WEST TEXAS CAPROCK ONTO ADJOINING LOW ROLLING PLAINS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE ENHANCED AREA...AND OVER PORTIONS OF THE CENTRAL PLAINS... ...SUMMARY... Large hail and damaging gusts are possible over parts of the central/southern Great Plains from southern Nebraska to west Texas, along with some tornado potential over parts of west Texas. ...Synopsis... Today's transitional mid/upper-level synoptic pattern is a tale of two cyclones -- one astride the Upper Midwest/Canadian border, and another digging southeastward out of the Gulf of Alaska. The broad, complex leading cyclone will eject northeastward over MB and northwestern ON through the period. A trailing shortwave trough -- apparent in moisture-channel imagery over parts of southern ID and northern NV -- will move east-northeastward to eastern SD and central NE by 12Z tomorrow. The strong, well-developed Pacific cyclone will proceed southeastward to just off the coast of OR by the end of the period. Southwest flow aloft will be maintained with weak synoptic-scale height rises over most of the central/southern Plains. Still, sufficient moisture, buoyancy, lift and shear are apparent for a couple relative maxima in severe potential as discussed below. At the surface, 11Z analysis showed a low attached to a cold front over south-central WY. The front should proceed southeastward through the day, extending from southeastern SD to western NE an central CO by 00Z, with the low over northeastern CO. By 12Z tomorrow, the front should extend from a low over IA to south- central KS, the northern TX Panhandle, and north-central NM. This front will overtake a developing dryline over the central High Plains from north-south, with the dryline position at 00Z over eastern CO, the western TX Panhandle, and Permian Basin. A weak/ residual, nearly stationary front extended from a low near FST northeastward across northwest TX, eastern OK and the Ozarks, and should continue to lose definition amidst considerable convective outflow. The southern rim of that outflow was evident from southeast TX (between GLS-BPT) across the HOU metro then west- northwestward to near SJT. The western part will shift northward slowly through the day toward the front, which itself should drift northward up the Caprock. ...West/southwest TX... Widely scattered to scattered thunderstorms are expected to form this afternoon near the dryline and the residual outflow boundary over the South Plains to Low Rolling Plains/Concho Valley regions. Isolated to widely scattered convection possible farther south off the dryline past the Rio Grande, and into strongly heated/CINH- minimized higher terrain of the Serranias del Burro range in northern Coahuila. This activity should move eastward across areas below the Caprock and around the Big Country to Edwards Plateau, with potential for some of the Mexican convection to cross the Rio Grande this evening as well. Supercells -- with large to very large hail and at least isolated potential for tornadoes -- will be more probable in and near the 30%/"enhanced" hail area. Dryline and orographic activity to the south will be an early hail/wind threat. Some of this activity may aggregate into clusters offering mainly strong-severe gusts, with one or two small MCSs possible this evening into the early overnight hours. Despite multiple days of MCS and smaller-scale convective activity to the east and southeast, a reservoir of rich low-level moisture remains not far upstream across south-central TX and into the southern Edwards Plateau, where upper 60s to low 70s F surface dewpoints and PW commonly 1-1.5 inches. When advected northwestward amid diurnal heating and beneath steep midlevel lapse rates, 3000-4000 J/kg MLCAPE should become common. Though low-level flow should not be particularly strong, it will be backed, contributing to elongated hodographs ad around 30-40 kt effective-shear magnitudes. Splitting storms may be common early, offering the greatest hail potential (size and coverage). The damaging-wind threat will be maximized on the mesoscale where organized cold pools can develop, and should extend farther east at greater density than the hail potential this evening into tonight. In the absence of substantial large-scale support, tornado potential will be locally maximized with any supercells that can interact favorably with outflow boundaries or each other. ...Central Plains... Large hail and severe gusts are possible from mid/late afternoon into tonight, from thunderstorms shifting eastward across portions of the central Plains. Though nowhere nearly as moist as the TX outlook area, a diurnally destabilized plume of moist advection should support a secondary relative max in severe potential along/ahead of the cold front and dryline from parts of eastern CO to western/northern KS and southern NE. Convection should develop by mid/late afternoon in a regional convergence maximum near and northeast of the surface low, with MLCINH weakened by favorable diurnal heating. Surface dewpoints in the 40s to low 50s F should be common, with steep surface-500-mb lapse rates, 500-1000 J/kg MLCAPE and well-mixed subcloud layers. Effective-shear magnitudes around 40-50 kt indicate potential for organized convection -- both in quasi-linear form near the front and initially discrete (but later merging upscale) off the dryline. Though activity will encounter a more-stable boundary layer with time and eastward extent across KS/NE, at least marginal severe-gust potential may last overnight as far eastward as parts of the Missouri Valley region. ..Edwards/Broyles.. 05/03/2024 Read more

MD 0612 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EAST/SOUTHEAST TEXAS
Mesoscale Discussion 0612 NWS Storm Prediction Center Norman OK 0423 AM CDT Fri May 03 2024 Areas affected...East/Southeast Texas Concerning...Severe potential...Watch unlikely Valid 030923Z - 031200Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms associated with isolated large hail and strong gusts are expected across parts of east Texas over the next few hours. The threat should remain marginal, and weather watch issuance appears unlikely. DISCUSSION...The latest high-resolution radar from Houston shows a cluster of strong thunderstorms over east Texas. The storms are developing in response to a large-scale ascent ahead of a shortwave trough, evident on water vapor imagery. RAP forecast soundings near the ongoing storms in east Texas early this morning have a low-level temperature inversion, with MUCAPE above the inversion generally around 1500 J/kg. Effective shear is in the 45 to 50 knot range, and 700-500 mb lapse rates are between 7.0 and 7.5 C/km. This environment will support elevated storms with isolated large-hail potential. The severe threat is expected to move into far east Texas by daybreak, but should remain too marginal for watch issuance. ..Broyles/Edwards.. 05/03/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LCH...SHV...HGX...FWD... LAT...LON 29629577 29399562 29229534 29219497 29659405 29959378 30669363 31079360 31569371 31919395 32199425 32179499 31929531 31189558 30519569 29909583 29629577 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri May 03 2024 Valid 061200Z - 111200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON... ...DISCUSSION... A multi-day period of organized severe thunderstorm potential appears likely across parts of the central to eastern CONUS next week, beginning on Day 4/Monday across the Plains, and continuing through at least Day 6/Wednesday. ...Day 4/Monday... A negatively tilted upper trough will eject northeastward over the northern/central Plains on Monday. Pronounced low-level mass response will encourage rich low-level moisture to advect northward over the southern/central Plains, as a surface low rapidly deepens over the northern High Plains. Strong deep-layer shear and at least moderate instability are expected to be in place ahead of a surface dryline extending across the southern/central Plains. Thunderstorms will likely erupt along the length of the dryline by late Monday afternoon from southern NE into central KS and north-central OK. Supercells are likely to be the dominant mode initially given the strength of the deep-layer shear. Both very large hail and tornadoes will be possible with these supercells as they spread eastward across the southern/central Plains through Monday evening. With a southerly low-level jet forecast to strengthen to at least 50-60 kt Saturday evening, a corresponding rapid increase in low-level shear will likely support a continued threat for tornadoes with any discrete convection. Some of these tornadoes could be strong. The severe threat will likely continue Monday night with eastward extent across the Plains, before convection possibly weakens some towards early Tuesday morning. Given increased confidence in high-end severe potential, a 30% severe area has been introduced from parts of southern NE into central KS and north-central OK. ...Day 5/Tuesday... The large-scale upper trough/low is forecast to gradually occlude over the northern Plains on Tuesday. But, an enhanced mid-level jet and embedded vorticity maximum will likely overspread parts of the Upper Midwest, mid MS Valley, and OH Valley through Tuesday evening. An expansive warm sector will likely be in place across these regions ahead of a surface cold front/dryline. Robust convection should develop along/ahead of these boundaries through the day. Sufficient instability and deep-layer shear will likely exist to support organized severe thunderstorms, including supercells posing a threat for all severe hazards. The northeastward extent of the warm sector remains somewhat uncertain into the OH Valley. Still, some severe risk will probably persist into Tuesday evening/night with eastward extent across the mid MS Valley and lower OH Valley/Midwest. Expansion of the 15% severe area may be needed in later outlooks, pending better model agreement and increased confidence in the eastward extent of rich low-level moisture and related instability. ...Day 6/Wednesday... The upper trough/low should gradually evolve eastward across the northern Plains on Wednesday. While there are still some differences in model guidance regarding the evolution of an embedded shortwave trough, there appears to be enough agreement in the synoptic pattern to include a 15% severe delineation for Wednesday for parts of the southern Plains into the ArkLaTex/Ozarks and towards the mid MS Valley. Across these areas, strong instability is forecast to develop east of a front/dryline. With enhanced mid-level flow persisting with a westerly mid/upper-level jet, organized severe thunderstorms should once again develop Wednesday afternoon. Supercells posing a threat for all severe hazards may occur. The northern/eastern extent of the severe threat is unclear, as the convection from Tuesday may tend to limit better low-level moisture return into the OH/TN Valleys. Depending on model trends over the next few days, the 15% severe area may need to be expanded to include these regions. ...Day 7/Thursday and Day 8/Friday... Some severe threat may continue on Thursday from parts of TX into the lower MS Valley/Southeast, generally along/south of a front and any convection that develops Wednesday. Too much uncertainty currently exists to include a 15% severe area at this time, but trends will be monitored. A severe risk also appears possible next Friday across the same general regions, but confidence in the placement of the front and convection is even lower than Thursday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri May 03 2024 Valid 061200Z - 111200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON... ...DISCUSSION... A multi-day period of organized severe thunderstorm potential appears likely across parts of the central to eastern CONUS next week, beginning on Day 4/Monday across the Plains, and continuing through at least Day 6/Wednesday. ...Day 4/Monday... A negatively tilted upper trough will eject northeastward over the northern/central Plains on Monday. Pronounced low-level mass response will encourage rich low-level moisture to advect northward over the southern/central Plains, as a surface low rapidly deepens over the northern High Plains. Strong deep-layer shear and at least moderate instability are expected to be in place ahead of a surface dryline extending across the southern/central Plains. Thunderstorms will likely erupt along the length of the dryline by late Monday afternoon from southern NE into central KS and north-central OK. Supercells are likely to be the dominant mode initially given the strength of the deep-layer shear. Both very large hail and tornadoes will be possible with these supercells as they spread eastward across the southern/central Plains through Monday evening. With a southerly low-level jet forecast to strengthen to at least 50-60 kt Saturday evening, a corresponding rapid increase in low-level shear will likely support a continued threat for tornadoes with any discrete convection. Some of these tornadoes could be strong. The severe threat will likely continue Monday night with eastward extent across the Plains, before convection possibly weakens some towards early Tuesday morning. Given increased confidence in high-end severe potential, a 30% severe area has been introduced from parts of southern NE into central KS and north-central OK. ...Day 5/Tuesday... The large-scale upper trough/low is forecast to gradually occlude over the northern Plains on Tuesday. But, an enhanced mid-level jet and embedded vorticity maximum will likely overspread parts of the Upper Midwest, mid MS Valley, and OH Valley through Tuesday evening. An expansive warm sector will likely be in place across these regions ahead of a surface cold front/dryline. Robust convection should develop along/ahead of these boundaries through the day. Sufficient instability and deep-layer shear will likely exist to support organized severe thunderstorms, including supercells posing a threat for all severe hazards. The northeastward extent of the warm sector remains somewhat uncertain into the OH Valley. Still, some severe risk will probably persist into Tuesday evening/night with eastward extent across the mid MS Valley and lower OH Valley/Midwest. Expansion of the 15% severe area may be needed in later outlooks, pending better model agreement and increased confidence in the eastward extent of rich low-level moisture and related instability. ...Day 6/Wednesday... The upper trough/low should gradually evolve eastward across the northern Plains on Wednesday. While there are still some differences in model guidance regarding the evolution of an embedded shortwave trough, there appears to be enough agreement in the synoptic pattern to include a 15% severe delineation for Wednesday for parts of the southern Plains into the ArkLaTex/Ozarks and towards the mid MS Valley. Across these areas, strong instability is forecast to develop east of a front/dryline. With enhanced mid-level flow persisting with a westerly mid/upper-level jet, organized severe thunderstorms should once again develop Wednesday afternoon. Supercells posing a threat for all severe hazards may occur. The northern/eastern extent of the severe threat is unclear, as the convection from Tuesday may tend to limit better low-level moisture return into the OH/TN Valleys. Depending on model trends over the next few days, the 15% severe area may need to be expanded to include these regions. ...Day 7/Thursday and Day 8/Friday... Some severe threat may continue on Thursday from parts of TX into the lower MS Valley/Southeast, generally along/south of a front and any convection that develops Wednesday. Too much uncertainty currently exists to include a 15% severe area at this time, but trends will be monitored. A severe risk also appears possible next Friday across the same general regions, but confidence in the placement of the front and convection is even lower than Thursday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri May 03 2024 Valid 061200Z - 111200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON... ...DISCUSSION... A multi-day period of organized severe thunderstorm potential appears likely across parts of the central to eastern CONUS next week, beginning on Day 4/Monday across the Plains, and continuing through at least Day 6/Wednesday. ...Day 4/Monday... A negatively tilted upper trough will eject northeastward over the northern/central Plains on Monday. Pronounced low-level mass response will encourage rich low-level moisture to advect northward over the southern/central Plains, as a surface low rapidly deepens over the northern High Plains. Strong deep-layer shear and at least moderate instability are expected to be in place ahead of a surface dryline extending across the southern/central Plains. Thunderstorms will likely erupt along the length of the dryline by late Monday afternoon from southern NE into central KS and north-central OK. Supercells are likely to be the dominant mode initially given the strength of the deep-layer shear. Both very large hail and tornadoes will be possible with these supercells as they spread eastward across the southern/central Plains through Monday evening. With a southerly low-level jet forecast to strengthen to at least 50-60 kt Saturday evening, a corresponding rapid increase in low-level shear will likely support a continued threat for tornadoes with any discrete convection. Some of these tornadoes could be strong. The severe threat will likely continue Monday night with eastward extent across the Plains, before convection possibly weakens some towards early Tuesday morning. Given increased confidence in high-end severe potential, a 30% severe area has been introduced from parts of southern NE into central KS and north-central OK. ...Day 5/Tuesday... The large-scale upper trough/low is forecast to gradually occlude over the northern Plains on Tuesday. But, an enhanced mid-level jet and embedded vorticity maximum will likely overspread parts of the Upper Midwest, mid MS Valley, and OH Valley through Tuesday evening. An expansive warm sector will likely be in place across these regions ahead of a surface cold front/dryline. Robust convection should develop along/ahead of these boundaries through the day. Sufficient instability and deep-layer shear will likely exist to support organized severe thunderstorms, including supercells posing a threat for all severe hazards. The northeastward extent of the warm sector remains somewhat uncertain into the OH Valley. Still, some severe risk will probably persist into Tuesday evening/night with eastward extent across the mid MS Valley and lower OH Valley/Midwest. Expansion of the 15% severe area may be needed in later outlooks, pending better model agreement and increased confidence in the eastward extent of rich low-level moisture and related instability. ...Day 6/Wednesday... The upper trough/low should gradually evolve eastward across the northern Plains on Wednesday. While there are still some differences in model guidance regarding the evolution of an embedded shortwave trough, there appears to be enough agreement in the synoptic pattern to include a 15% severe delineation for Wednesday for parts of the southern Plains into the ArkLaTex/Ozarks and towards the mid MS Valley. Across these areas, strong instability is forecast to develop east of a front/dryline. With enhanced mid-level flow persisting with a westerly mid/upper-level jet, organized severe thunderstorms should once again develop Wednesday afternoon. Supercells posing a threat for all severe hazards may occur. The northern/eastern extent of the severe threat is unclear, as the convection from Tuesday may tend to limit better low-level moisture return into the OH/TN Valleys. Depending on model trends over the next few days, the 15% severe area may need to be expanded to include these regions. ...Day 7/Thursday and Day 8/Friday... Some severe threat may continue on Thursday from parts of TX into the lower MS Valley/Southeast, generally along/south of a front and any convection that develops Wednesday. Too much uncertainty currently exists to include a 15% severe area at this time, but trends will be monitored. A severe risk also appears possible next Friday across the same general regions, but confidence in the placement of the front and convection is even lower than Thursday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri May 03 2024 Valid 061200Z - 111200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON... ...DISCUSSION... A multi-day period of organized severe thunderstorm potential appears likely across parts of the central to eastern CONUS next week, beginning on Day 4/Monday across the Plains, and continuing through at least Day 6/Wednesday. ...Day 4/Monday... A negatively tilted upper trough will eject northeastward over the northern/central Plains on Monday. Pronounced low-level mass response will encourage rich low-level moisture to advect northward over the southern/central Plains, as a surface low rapidly deepens over the northern High Plains. Strong deep-layer shear and at least moderate instability are expected to be in place ahead of a surface dryline extending across the southern/central Plains. Thunderstorms will likely erupt along the length of the dryline by late Monday afternoon from southern NE into central KS and north-central OK. Supercells are likely to be the dominant mode initially given the strength of the deep-layer shear. Both very large hail and tornadoes will be possible with these supercells as they spread eastward across the southern/central Plains through Monday evening. With a southerly low-level jet forecast to strengthen to at least 50-60 kt Saturday evening, a corresponding rapid increase in low-level shear will likely support a continued threat for tornadoes with any discrete convection. Some of these tornadoes could be strong. The severe threat will likely continue Monday night with eastward extent across the Plains, before convection possibly weakens some towards early Tuesday morning. Given increased confidence in high-end severe potential, a 30% severe area has been introduced from parts of southern NE into central KS and north-central OK. ...Day 5/Tuesday... The large-scale upper trough/low is forecast to gradually occlude over the northern Plains on Tuesday. But, an enhanced mid-level jet and embedded vorticity maximum will likely overspread parts of the Upper Midwest, mid MS Valley, and OH Valley through Tuesday evening. An expansive warm sector will likely be in place across these regions ahead of a surface cold front/dryline. Robust convection should develop along/ahead of these boundaries through the day. Sufficient instability and deep-layer shear will likely exist to support organized severe thunderstorms, including supercells posing a threat for all severe hazards. The northeastward extent of the warm sector remains somewhat uncertain into the OH Valley. Still, some severe risk will probably persist into Tuesday evening/night with eastward extent across the mid MS Valley and lower OH Valley/Midwest. Expansion of the 15% severe area may be needed in later outlooks, pending better model agreement and increased confidence in the eastward extent of rich low-level moisture and related instability. ...Day 6/Wednesday... The upper trough/low should gradually evolve eastward across the northern Plains on Wednesday. While there are still some differences in model guidance regarding the evolution of an embedded shortwave trough, there appears to be enough agreement in the synoptic pattern to include a 15% severe delineation for Wednesday for parts of the southern Plains into the ArkLaTex/Ozarks and towards the mid MS Valley. Across these areas, strong instability is forecast to develop east of a front/dryline. With enhanced mid-level flow persisting with a westerly mid/upper-level jet, organized severe thunderstorms should once again develop Wednesday afternoon. Supercells posing a threat for all severe hazards may occur. The northern/eastern extent of the severe threat is unclear, as the convection from Tuesday may tend to limit better low-level moisture return into the OH/TN Valleys. Depending on model trends over the next few days, the 15% severe area may need to be expanded to include these regions. ...Day 7/Thursday and Day 8/Friday... Some severe threat may continue on Thursday from parts of TX into the lower MS Valley/Southeast, generally along/south of a front and any convection that develops Wednesday. Too much uncertainty currently exists to include a 15% severe area at this time, but trends will be monitored. A severe risk also appears possible next Friday across the same general regions, but confidence in the placement of the front and convection is even lower than Thursday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri May 03 2024 Valid 061200Z - 111200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON... ...DISCUSSION... A multi-day period of organized severe thunderstorm potential appears likely across parts of the central to eastern CONUS next week, beginning on Day 4/Monday across the Plains, and continuing through at least Day 6/Wednesday. ...Day 4/Monday... A negatively tilted upper trough will eject northeastward over the northern/central Plains on Monday. Pronounced low-level mass response will encourage rich low-level moisture to advect northward over the southern/central Plains, as a surface low rapidly deepens over the northern High Plains. Strong deep-layer shear and at least moderate instability are expected to be in place ahead of a surface dryline extending across the southern/central Plains. Thunderstorms will likely erupt along the length of the dryline by late Monday afternoon from southern NE into central KS and north-central OK. Supercells are likely to be the dominant mode initially given the strength of the deep-layer shear. Both very large hail and tornadoes will be possible with these supercells as they spread eastward across the southern/central Plains through Monday evening. With a southerly low-level jet forecast to strengthen to at least 50-60 kt Saturday evening, a corresponding rapid increase in low-level shear will likely support a continued threat for tornadoes with any discrete convection. Some of these tornadoes could be strong. The severe threat will likely continue Monday night with eastward extent across the Plains, before convection possibly weakens some towards early Tuesday morning. Given increased confidence in high-end severe potential, a 30% severe area has been introduced from parts of southern NE into central KS and north-central OK. ...Day 5/Tuesday... The large-scale upper trough/low is forecast to gradually occlude over the northern Plains on Tuesday. But, an enhanced mid-level jet and embedded vorticity maximum will likely overspread parts of the Upper Midwest, mid MS Valley, and OH Valley through Tuesday evening. An expansive warm sector will likely be in place across these regions ahead of a surface cold front/dryline. Robust convection should develop along/ahead of these boundaries through the day. Sufficient instability and deep-layer shear will likely exist to support organized severe thunderstorms, including supercells posing a threat for all severe hazards. The northeastward extent of the warm sector remains somewhat uncertain into the OH Valley. Still, some severe risk will probably persist into Tuesday evening/night with eastward extent across the mid MS Valley and lower OH Valley/Midwest. Expansion of the 15% severe area may be needed in later outlooks, pending better model agreement and increased confidence in the eastward extent of rich low-level moisture and related instability. ...Day 6/Wednesday... The upper trough/low should gradually evolve eastward across the northern Plains on Wednesday. While there are still some differences in model guidance regarding the evolution of an embedded shortwave trough, there appears to be enough agreement in the synoptic pattern to include a 15% severe delineation for Wednesday for parts of the southern Plains into the ArkLaTex/Ozarks and towards the mid MS Valley. Across these areas, strong instability is forecast to develop east of a front/dryline. With enhanced mid-level flow persisting with a westerly mid/upper-level jet, organized severe thunderstorms should once again develop Wednesday afternoon. Supercells posing a threat for all severe hazards may occur. The northern/eastern extent of the severe threat is unclear, as the convection from Tuesday may tend to limit better low-level moisture return into the OH/TN Valleys. Depending on model trends over the next few days, the 15% severe area may need to be expanded to include these regions. ...Day 7/Thursday and Day 8/Friday... Some severe threat may continue on Thursday from parts of TX into the lower MS Valley/Southeast, generally along/south of a front and any convection that develops Wednesday. Too much uncertainty currently exists to include a 15% severe area at this time, but trends will be monitored. A severe risk also appears possible next Friday across the same general regions, but confidence in the placement of the front and convection is even lower than Thursday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri May 03 2024 Valid 061200Z - 111200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON... ...DISCUSSION... A multi-day period of organized severe thunderstorm potential appears likely across parts of the central to eastern CONUS next week, beginning on Day 4/Monday across the Plains, and continuing through at least Day 6/Wednesday. ...Day 4/Monday... A negatively tilted upper trough will eject northeastward over the northern/central Plains on Monday. Pronounced low-level mass response will encourage rich low-level moisture to advect northward over the southern/central Plains, as a surface low rapidly deepens over the northern High Plains. Strong deep-layer shear and at least moderate instability are expected to be in place ahead of a surface dryline extending across the southern/central Plains. Thunderstorms will likely erupt along the length of the dryline by late Monday afternoon from southern NE into central KS and north-central OK. Supercells are likely to be the dominant mode initially given the strength of the deep-layer shear. Both very large hail and tornadoes will be possible with these supercells as they spread eastward across the southern/central Plains through Monday evening. With a southerly low-level jet forecast to strengthen to at least 50-60 kt Saturday evening, a corresponding rapid increase in low-level shear will likely support a continued threat for tornadoes with any discrete convection. Some of these tornadoes could be strong. The severe threat will likely continue Monday night with eastward extent across the Plains, before convection possibly weakens some towards early Tuesday morning. Given increased confidence in high-end severe potential, a 30% severe area has been introduced from parts of southern NE into central KS and north-central OK. ...Day 5/Tuesday... The large-scale upper trough/low is forecast to gradually occlude over the northern Plains on Tuesday. But, an enhanced mid-level jet and embedded vorticity maximum will likely overspread parts of the Upper Midwest, mid MS Valley, and OH Valley through Tuesday evening. An expansive warm sector will likely be in place across these regions ahead of a surface cold front/dryline. Robust convection should develop along/ahead of these boundaries through the day. Sufficient instability and deep-layer shear will likely exist to support organized severe thunderstorms, including supercells posing a threat for all severe hazards. The northeastward extent of the warm sector remains somewhat uncertain into the OH Valley. Still, some severe risk will probably persist into Tuesday evening/night with eastward extent across the mid MS Valley and lower OH Valley/Midwest. Expansion of the 15% severe area may be needed in later outlooks, pending better model agreement and increased confidence in the eastward extent of rich low-level moisture and related instability. ...Day 6/Wednesday... The upper trough/low should gradually evolve eastward across the northern Plains on Wednesday. While there are still some differences in model guidance regarding the evolution of an embedded shortwave trough, there appears to be enough agreement in the synoptic pattern to include a 15% severe delineation for Wednesday for parts of the southern Plains into the ArkLaTex/Ozarks and towards the mid MS Valley. Across these areas, strong instability is forecast to develop east of a front/dryline. With enhanced mid-level flow persisting with a westerly mid/upper-level jet, organized severe thunderstorms should once again develop Wednesday afternoon. Supercells posing a threat for all severe hazards may occur. The northern/eastern extent of the severe threat is unclear, as the convection from Tuesday may tend to limit better low-level moisture return into the OH/TN Valleys. Depending on model trends over the next few days, the 15% severe area may need to be expanded to include these regions. ...Day 7/Thursday and Day 8/Friday... Some severe threat may continue on Thursday from parts of TX into the lower MS Valley/Southeast, generally along/south of a front and any convection that develops Wednesday. Too much uncertainty currently exists to include a 15% severe area at this time, but trends will be monitored. A severe risk also appears possible next Friday across the same general regions, but confidence in the placement of the front and convection is even lower than Thursday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Fri May 03 2024 Valid 061200Z - 111200Z ...SEVERE WEATHER OUTBREAK POSSIBLE ON D4/MON... ...DISCUSSION... A multi-day period of organized severe thunderstorm potential appears likely across parts of the central to eastern CONUS next week, beginning on Day 4/Monday across the Plains, and continuing through at least Day 6/Wednesday. ...Day 4/Monday... A negatively tilted upper trough will eject northeastward over the northern/central Plains on Monday. Pronounced low-level mass response will encourage rich low-level moisture to advect northward over the southern/central Plains, as a surface low rapidly deepens over the northern High Plains. Strong deep-layer shear and at least moderate instability are expected to be in place ahead of a surface dryline extending across the southern/central Plains. Thunderstorms will likely erupt along the length of the dryline by late Monday afternoon from southern NE into central KS and north-central OK. Supercells are likely to be the dominant mode initially given the strength of the deep-layer shear. Both very large hail and tornadoes will be possible with these supercells as they spread eastward across the southern/central Plains through Monday evening. With a southerly low-level jet forecast to strengthen to at least 50-60 kt Saturday evening, a corresponding rapid increase in low-level shear will likely support a continued threat for tornadoes with any discrete convection. Some of these tornadoes could be strong. The severe threat will likely continue Monday night with eastward extent across the Plains, before convection possibly weakens some towards early Tuesday morning. Given increased confidence in high-end severe potential, a 30% severe area has been introduced from parts of southern NE into central KS and north-central OK. ...Day 5/Tuesday... The large-scale upper trough/low is forecast to gradually occlude over the northern Plains on Tuesday. But, an enhanced mid-level jet and embedded vorticity maximum will likely overspread parts of the Upper Midwest, mid MS Valley, and OH Valley through Tuesday evening. An expansive warm sector will likely be in place across these regions ahead of a surface cold front/dryline. Robust convection should develop along/ahead of these boundaries through the day. Sufficient instability and deep-layer shear will likely exist to support organized severe thunderstorms, including supercells posing a threat for all severe hazards. The northeastward extent of the warm sector remains somewhat uncertain into the OH Valley. Still, some severe risk will probably persist into Tuesday evening/night with eastward extent across the mid MS Valley and lower OH Valley/Midwest. Expansion of the 15% severe area may be needed in later outlooks, pending better model agreement and increased confidence in the eastward extent of rich low-level moisture and related instability. ...Day 6/Wednesday... The upper trough/low should gradually evolve eastward across the northern Plains on Wednesday. While there are still some differences in model guidance regarding the evolution of an embedded shortwave trough, there appears to be enough agreement in the synoptic pattern to include a 15% severe delineation for Wednesday for parts of the southern Plains into the ArkLaTex/Ozarks and towards the mid MS Valley. Across these areas, strong instability is forecast to develop east of a front/dryline. With enhanced mid-level flow persisting with a westerly mid/upper-level jet, organized severe thunderstorms should once again develop Wednesday afternoon. Supercells posing a threat for all severe hazards may occur. The northern/eastern extent of the severe threat is unclear, as the convection from Tuesday may tend to limit better low-level moisture return into the OH/TN Valleys. Depending on model trends over the next few days, the 15% severe area may need to be expanded to include these regions. ...Day 7/Thursday and Day 8/Friday... Some severe threat may continue on Thursday from parts of TX into the lower MS Valley/Southeast, generally along/south of a front and any convection that develops Wednesday. Too much uncertainty currently exists to include a 15% severe area at this time, but trends will be monitored. A severe risk also appears possible next Friday across the same general regions, but confidence in the placement of the front and convection is even lower than Thursday. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri May 03 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS TO THE ARKLATEX... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the southern Plains to the ArkLaTex. ...Synopsis... A strong upper trough/low over the western CONUS is expected to advance eastward towards the northern/central Rockies on Sunday while evolving into a negatively tilted open wave. A weak southern-stream upper trough should continue to move across the southern Plains into the lower MS Valley through the day. At the surface, lee cyclogenesis will occur through the period over the northern/central High Plains as large-scale ascent preceding the upper trough overspreads this region. Rich low-level will return northward over much of the Plains in response. ...Southern Plains to the ArkLaTex... Multiple rounds of convection will likely have occurred across much of the southern Plains prior to the start of the Day 3 period Sunday morning. It appears possible that one or more thunderstorm clusters may be ongoing Sunday morning over parts of OK/TX in association with a low-amplitude shortwave trough over the southern Plains. Some regeneration/strengthening of convection may occur on the eastern fringes of this morning activity as gradual destabilization occurs with filtered daytime heating, with an isolated threat for mainly damaging winds across the ArkLaTex and vicinity. In the wake of the shortwave trough passage, the airmass across much of the southern Plains may tend to remain capped. One exception may be along trailing outflow from the morning thunderstorms. If convection can initiate, a moderately to strongly unstable airmass across central/north TX, along with sufficient deep-layer shear, would support robust thunderstorms with some hail/wind threat. Still, large-scale forcing appears nebulous at best across this region, and overall convective coverage across OK/TX remains rather uncertain. Have therefore included a fairly broad Marginal Risk to account for this somewhat conditional/unfocused severe potential. ..Gleason.. 05/03/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri May 03 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS TO THE ARKLATEX... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the southern Plains to the ArkLaTex. ...Synopsis... A strong upper trough/low over the western CONUS is expected to advance eastward towards the northern/central Rockies on Sunday while evolving into a negatively tilted open wave. A weak southern-stream upper trough should continue to move across the southern Plains into the lower MS Valley through the day. At the surface, lee cyclogenesis will occur through the period over the northern/central High Plains as large-scale ascent preceding the upper trough overspreads this region. Rich low-level will return northward over much of the Plains in response. ...Southern Plains to the ArkLaTex... Multiple rounds of convection will likely have occurred across much of the southern Plains prior to the start of the Day 3 period Sunday morning. It appears possible that one or more thunderstorm clusters may be ongoing Sunday morning over parts of OK/TX in association with a low-amplitude shortwave trough over the southern Plains. Some regeneration/strengthening of convection may occur on the eastern fringes of this morning activity as gradual destabilization occurs with filtered daytime heating, with an isolated threat for mainly damaging winds across the ArkLaTex and vicinity. In the wake of the shortwave trough passage, the airmass across much of the southern Plains may tend to remain capped. One exception may be along trailing outflow from the morning thunderstorms. If convection can initiate, a moderately to strongly unstable airmass across central/north TX, along with sufficient deep-layer shear, would support robust thunderstorms with some hail/wind threat. Still, large-scale forcing appears nebulous at best across this region, and overall convective coverage across OK/TX remains rather uncertain. Have therefore included a fairly broad Marginal Risk to account for this somewhat conditional/unfocused severe potential. ..Gleason.. 05/03/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri May 03 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS TO THE ARKLATEX... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the southern Plains to the ArkLaTex. ...Synopsis... A strong upper trough/low over the western CONUS is expected to advance eastward towards the northern/central Rockies on Sunday while evolving into a negatively tilted open wave. A weak southern-stream upper trough should continue to move across the southern Plains into the lower MS Valley through the day. At the surface, lee cyclogenesis will occur through the period over the northern/central High Plains as large-scale ascent preceding the upper trough overspreads this region. Rich low-level will return northward over much of the Plains in response. ...Southern Plains to the ArkLaTex... Multiple rounds of convection will likely have occurred across much of the southern Plains prior to the start of the Day 3 period Sunday morning. It appears possible that one or more thunderstorm clusters may be ongoing Sunday morning over parts of OK/TX in association with a low-amplitude shortwave trough over the southern Plains. Some regeneration/strengthening of convection may occur on the eastern fringes of this morning activity as gradual destabilization occurs with filtered daytime heating, with an isolated threat for mainly damaging winds across the ArkLaTex and vicinity. In the wake of the shortwave trough passage, the airmass across much of the southern Plains may tend to remain capped. One exception may be along trailing outflow from the morning thunderstorms. If convection can initiate, a moderately to strongly unstable airmass across central/north TX, along with sufficient deep-layer shear, would support robust thunderstorms with some hail/wind threat. Still, large-scale forcing appears nebulous at best across this region, and overall convective coverage across OK/TX remains rather uncertain. Have therefore included a fairly broad Marginal Risk to account for this somewhat conditional/unfocused severe potential. ..Gleason.. 05/03/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri May 03 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS TO THE ARKLATEX... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the southern Plains to the ArkLaTex. ...Synopsis... A strong upper trough/low over the western CONUS is expected to advance eastward towards the northern/central Rockies on Sunday while evolving into a negatively tilted open wave. A weak southern-stream upper trough should continue to move across the southern Plains into the lower MS Valley through the day. At the surface, lee cyclogenesis will occur through the period over the northern/central High Plains as large-scale ascent preceding the upper trough overspreads this region. Rich low-level will return northward over much of the Plains in response. ...Southern Plains to the ArkLaTex... Multiple rounds of convection will likely have occurred across much of the southern Plains prior to the start of the Day 3 period Sunday morning. It appears possible that one or more thunderstorm clusters may be ongoing Sunday morning over parts of OK/TX in association with a low-amplitude shortwave trough over the southern Plains. Some regeneration/strengthening of convection may occur on the eastern fringes of this morning activity as gradual destabilization occurs with filtered daytime heating, with an isolated threat for mainly damaging winds across the ArkLaTex and vicinity. In the wake of the shortwave trough passage, the airmass across much of the southern Plains may tend to remain capped. One exception may be along trailing outflow from the morning thunderstorms. If convection can initiate, a moderately to strongly unstable airmass across central/north TX, along with sufficient deep-layer shear, would support robust thunderstorms with some hail/wind threat. Still, large-scale forcing appears nebulous at best across this region, and overall convective coverage across OK/TX remains rather uncertain. Have therefore included a fairly broad Marginal Risk to account for this somewhat conditional/unfocused severe potential. ..Gleason.. 05/03/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri May 03 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS TO THE ARKLATEX... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the southern Plains to the ArkLaTex. ...Synopsis... A strong upper trough/low over the western CONUS is expected to advance eastward towards the northern/central Rockies on Sunday while evolving into a negatively tilted open wave. A weak southern-stream upper trough should continue to move across the southern Plains into the lower MS Valley through the day. At the surface, lee cyclogenesis will occur through the period over the northern/central High Plains as large-scale ascent preceding the upper trough overspreads this region. Rich low-level will return northward over much of the Plains in response. ...Southern Plains to the ArkLaTex... Multiple rounds of convection will likely have occurred across much of the southern Plains prior to the start of the Day 3 period Sunday morning. It appears possible that one or more thunderstorm clusters may be ongoing Sunday morning over parts of OK/TX in association with a low-amplitude shortwave trough over the southern Plains. Some regeneration/strengthening of convection may occur on the eastern fringes of this morning activity as gradual destabilization occurs with filtered daytime heating, with an isolated threat for mainly damaging winds across the ArkLaTex and vicinity. In the wake of the shortwave trough passage, the airmass across much of the southern Plains may tend to remain capped. One exception may be along trailing outflow from the morning thunderstorms. If convection can initiate, a moderately to strongly unstable airmass across central/north TX, along with sufficient deep-layer shear, would support robust thunderstorms with some hail/wind threat. Still, large-scale forcing appears nebulous at best across this region, and overall convective coverage across OK/TX remains rather uncertain. Have therefore included a fairly broad Marginal Risk to account for this somewhat conditional/unfocused severe potential. ..Gleason.. 05/03/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri May 03 2024 Valid 051200Z - 061200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS TO THE ARKLATEX... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the southern Plains to the ArkLaTex. ...Synopsis... A strong upper trough/low over the western CONUS is expected to advance eastward towards the northern/central Rockies on Sunday while evolving into a negatively tilted open wave. A weak southern-stream upper trough should continue to move across the southern Plains into the lower MS Valley through the day. At the surface, lee cyclogenesis will occur through the period over the northern/central High Plains as large-scale ascent preceding the upper trough overspreads this region. Rich low-level will return northward over much of the Plains in response. ...Southern Plains to the ArkLaTex... Multiple rounds of convection will likely have occurred across much of the southern Plains prior to the start of the Day 3 period Sunday morning. It appears possible that one or more thunderstorm clusters may be ongoing Sunday morning over parts of OK/TX in association with a low-amplitude shortwave trough over the southern Plains. Some regeneration/strengthening of convection may occur on the eastern fringes of this morning activity as gradual destabilization occurs with filtered daytime heating, with an isolated threat for mainly damaging winds across the ArkLaTex and vicinity. In the wake of the shortwave trough passage, the airmass across much of the southern Plains may tend to remain capped. One exception may be along trailing outflow from the morning thunderstorms. If convection can initiate, a moderately to strongly unstable airmass across central/north TX, along with sufficient deep-layer shear, would support robust thunderstorms with some hail/wind threat. Still, large-scale forcing appears nebulous at best across this region, and overall convective coverage across OK/TX remains rather uncertain. Have therefore included a fairly broad Marginal Risk to account for this somewhat conditional/unfocused severe potential. ..Gleason.. 05/03/2024 Read more

MD 0611 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL AND EAST-CENTRAL OK INTO FAR WEST-CENTRAL AR
Mesoscale Discussion 0611 NWS Storm Prediction Center Norman OK 1134 PM CDT Thu May 02 2024 Areas affected...Central and East-Central OK into Far West-Central AR Concerning...Severe potential...Watch unlikely Valid 030434Z - 030630Z Probability of Watch Issuance...20 percent SUMMARY...Isolated hail and/or damaging gusts possible for the next few hours across central and east-central Oklahoma. DISCUSSION...The combination of modest ascent along a southward-moving cold front and weak warm-air advection has lead to the increase in predominantly multicellular thunderstorm across central and east-central OK. Deep-layer vertical shear is modest, which is expected to keep updraft organization minimal. Even so, relatively cold mid-level temperatures, helping support max lapse rates in the 2-6 km layer around 7 deg C per km. These are steep enough to support moderate buoyancy and the potential for a few updrafts strong enough to produce small hail. Elevated character to most of the storms should limit the wind gusts threat, but interaction with the front and/or with other storms could lead to a few stronger gusts (as recently observed with the storm over Wagoner and Cherokee Counties). ..Mosier/Guyer.. 05/03/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SHV...TSA...OUN... LAT...LON 34699640 35399761 35909713 36189602 35789415 34819427 34489471 34489562 34699640 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri May 03 2024 Valid 041200Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF WEST TEXAS AND SOUTHEASTERN NEW MEXICO... ...SUMMARY... Scattered severe thunderstorms posing a threat for very large hail, damaging winds, and perhaps a few tornadoes should occur across parts of the southern High Plains Saturday afternoon and evening. Isolated strong to severe thunderstorms may occur across a broader portion of the southern Plains into the Ozarks, mid Mississippi Valley, and Midwest. ...Synopsis... A closed upper low will move east-southeastward over the western states on Saturday. Downstream, a shortwave trough will advance quickly east-northeastward across the Upper Midwest through the day. A related weak surface low should develop from IA towards IL in the same time frame. A cold front will extend southwestward from this low across parts of the mid MS Valley into the southern Plains. A subtle/low-amplitude shortwave trough is forecast to move across northern Mexico and the southern High Plains by late Saturday afternoon. This feature may provide sufficient lift to support isolated to scattered severe thunderstorms across parts of the southern High Plains Saturday afternoon/evening. ...Southern High Plains... A weak surface low should be in place over parts of far west TX and north-central Mexico through the day, with a dryline extending southward from this low. A southward-moving cold front should eventually intersect the dryline by late Saturday afternoon. Diurnal heating of a very moist low-level airmass and steep mid-level lapse rates will contribute to moderate/locally strong instability across west TX and southeastern NM. Convective initiation appears likely along both boundaries Saturday afternoon and evening. Although low-level flow should remain rather weak through the day, a favorably veering and slowly strengthening wind profile with height through mid levels will support around 35-45 kt of deep-layer shear. Robust thunderstorms that develop should quickly become supercellular and pose a threat for very large hail. Occasional severe/damaging downdraft winds may also occur. The tornado threat should be modulated to some extent by weak low-level flow and modest 0-1 km shear through much of the afternoon. Still, a few tornadoes appear possible towards Saturday evening with any persistent supercell as an easterly low-level jet strengthens. A Slight Risk has been introduced across parts of west TX and southeastern NM where confidence is greatest in supercells occurring. ...Midwest/Mid Mississippi Valley to the Ozarks/Southern Plains... A line of strong to locally severe thunderstorms may be ongoing at the start of the period Saturday morning along or just ahead of the cold front, extending from IA into eastern KS. Even with a nocturnal minimum in instability, occasional damaging winds may occur with this line before it eventually weakens by late morning. Eventual redevelopment appears probable across parts of the mid MS Valley/Midwest by Saturday afternoon, as daytime heating ahead of the front fosters weak to moderate MLCAPE. Deep-layer shear appears marginal to support organized convection (around 25-30 kt). But, some small clusters may consolidate and pose an isolated threat for damaging winds and hail as they spread eastward across parts of the Midwest through Saturday afternoon, before slowly weakening Saturday evening with the loss of daytime heating. There also appears to be some chance for convection across west TX to spread eastward across much of OK/TX Saturday evening/night as the weak shortwave trough continues eastward across these areas. With moderate to strong MUCAPE present along/south of the cold front, some of this activity could pose a continued threat for isolated severe hail and gusty winds. ..Gleason.. 05/03/2024 Read more