Severe Storms

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CDT Tue May 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... ...Day 4/Fri - Mid MS Valley/Upper Great Lakes vicinity... An upper shortwave trough over the northern Plains will pivot northeast across the Upper Midwest on Friday. At the surface, low pressure will develop northward across MN/WI and a trailing cold front will push east, becoming positioned from WI to central OK/MO by Saturday morning. Some severe potential is possible ahead of the front from the Mid-MS Valley into the Great Lakes vicinity. However, ongoing convection early Friday and large-scale ascent lifting northeast of the region with time is resulting in uncertainty. Severe probabilities will likely be needed in subsequent outlooks as mesoscale details become better resolved, but confidence is too low to delineate an unconditional 15 percent probability at this time. ...Day 5/Sat - Southern Plains to the Ozarks vicinity... Low-amplitude west/southwest mid/upper flow is forecast across the southern Plains to the Mid-South vicinity for much of the diurnal period on Saturday. By 00z, forecast guidance suggests a shortwave trough will eject from the southern Rockies into the southern Plains, and eventually impinging on the Ozarks/Mid-South area by Sunday morning. A very moist and unstable airmass is forecast over the southern Plains vicinity ahead of this feature as a surface warm front lifts northward through the day. Increasing ascent may not arrive until after 00-03z, limiting convective initiation until the nighttime hours. If storms can develop during the day across portions of OK/TX, all hazards severe potential will exist. Otherwise, thunderstorm potential may be more likely during the evening/overnight from north TX into southeast OK and AR as large-scale ascent increases and a 65-75 kt 500 mb jet overspreads the region. The north and west bounds of severe potential are a bit uncertain, so this area may shift in subsequent outlooks. ...Day 6/Sun - Ozarks to the Lower OH and TN Valleys... An upper shortwave trough will progress across the region on Sunday. Forecast guidance depicts a 50-60 kt southwesterly 700 mb jet overspreading the region during the day. Meanwhile, a surface low will intensify over MO/IL, shifting northeast along the OH River through the period. A very moist and unstable airmass is depicted ahead of the low and attendant south/southeastward-progressing cold front. Intense severe thunderstorms will likely accompany this system. Consistency among deterministic guidance, favorable synoptic pattern, as well as CSU/NSSL ML output, support introduction of 15 percent probabilities for Sunday. ...Days 7-8/Mon-Tue... Spread among forecast guidance increases substantially by the end of the forecast period. However, a pattern shift by Day 8/Tue appears possible, with an amplified upper ridge potentially building over the western half of the CONUS. Overall, predictability is too low to delineate areas of severe potential across the eastern half of the CONUS. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CDT Tue May 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... ...Day 4/Fri - Mid MS Valley/Upper Great Lakes vicinity... An upper shortwave trough over the northern Plains will pivot northeast across the Upper Midwest on Friday. At the surface, low pressure will develop northward across MN/WI and a trailing cold front will push east, becoming positioned from WI to central OK/MO by Saturday morning. Some severe potential is possible ahead of the front from the Mid-MS Valley into the Great Lakes vicinity. However, ongoing convection early Friday and large-scale ascent lifting northeast of the region with time is resulting in uncertainty. Severe probabilities will likely be needed in subsequent outlooks as mesoscale details become better resolved, but confidence is too low to delineate an unconditional 15 percent probability at this time. ...Day 5/Sat - Southern Plains to the Ozarks vicinity... Low-amplitude west/southwest mid/upper flow is forecast across the southern Plains to the Mid-South vicinity for much of the diurnal period on Saturday. By 00z, forecast guidance suggests a shortwave trough will eject from the southern Rockies into the southern Plains, and eventually impinging on the Ozarks/Mid-South area by Sunday morning. A very moist and unstable airmass is forecast over the southern Plains vicinity ahead of this feature as a surface warm front lifts northward through the day. Increasing ascent may not arrive until after 00-03z, limiting convective initiation until the nighttime hours. If storms can develop during the day across portions of OK/TX, all hazards severe potential will exist. Otherwise, thunderstorm potential may be more likely during the evening/overnight from north TX into southeast OK and AR as large-scale ascent increases and a 65-75 kt 500 mb jet overspreads the region. The north and west bounds of severe potential are a bit uncertain, so this area may shift in subsequent outlooks. ...Day 6/Sun - Ozarks to the Lower OH and TN Valleys... An upper shortwave trough will progress across the region on Sunday. Forecast guidance depicts a 50-60 kt southwesterly 700 mb jet overspreading the region during the day. Meanwhile, a surface low will intensify over MO/IL, shifting northeast along the OH River through the period. A very moist and unstable airmass is depicted ahead of the low and attendant south/southeastward-progressing cold front. Intense severe thunderstorms will likely accompany this system. Consistency among deterministic guidance, favorable synoptic pattern, as well as CSU/NSSL ML output, support introduction of 15 percent probabilities for Sunday. ...Days 7-8/Mon-Tue... Spread among forecast guidance increases substantially by the end of the forecast period. However, a pattern shift by Day 8/Tue appears possible, with an amplified upper ridge potentially building over the western half of the CONUS. Overall, predictability is too low to delineate areas of severe potential across the eastern half of the CONUS. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CDT Tue May 21 2024 Valid 241200Z - 291200Z ...DISCUSSION... ...Day 4/Fri - Mid MS Valley/Upper Great Lakes vicinity... An upper shortwave trough over the northern Plains will pivot northeast across the Upper Midwest on Friday. At the surface, low pressure will develop northward across MN/WI and a trailing cold front will push east, becoming positioned from WI to central OK/MO by Saturday morning. Some severe potential is possible ahead of the front from the Mid-MS Valley into the Great Lakes vicinity. However, ongoing convection early Friday and large-scale ascent lifting northeast of the region with time is resulting in uncertainty. Severe probabilities will likely be needed in subsequent outlooks as mesoscale details become better resolved, but confidence is too low to delineate an unconditional 15 percent probability at this time. ...Day 5/Sat - Southern Plains to the Ozarks vicinity... Low-amplitude west/southwest mid/upper flow is forecast across the southern Plains to the Mid-South vicinity for much of the diurnal period on Saturday. By 00z, forecast guidance suggests a shortwave trough will eject from the southern Rockies into the southern Plains, and eventually impinging on the Ozarks/Mid-South area by Sunday morning. A very moist and unstable airmass is forecast over the southern Plains vicinity ahead of this feature as a surface warm front lifts northward through the day. Increasing ascent may not arrive until after 00-03z, limiting convective initiation until the nighttime hours. If storms can develop during the day across portions of OK/TX, all hazards severe potential will exist. Otherwise, thunderstorm potential may be more likely during the evening/overnight from north TX into southeast OK and AR as large-scale ascent increases and a 65-75 kt 500 mb jet overspreads the region. The north and west bounds of severe potential are a bit uncertain, so this area may shift in subsequent outlooks. ...Day 6/Sun - Ozarks to the Lower OH and TN Valleys... An upper shortwave trough will progress across the region on Sunday. Forecast guidance depicts a 50-60 kt southwesterly 700 mb jet overspreading the region during the day. Meanwhile, a surface low will intensify over MO/IL, shifting northeast along the OH River through the period. A very moist and unstable airmass is depicted ahead of the low and attendant south/southeastward-progressing cold front. Intense severe thunderstorms will likely accompany this system. Consistency among deterministic guidance, favorable synoptic pattern, as well as CSU/NSSL ML output, support introduction of 15 percent probabilities for Sunday. ...Days 7-8/Mon-Tue... Spread among forecast guidance increases substantially by the end of the forecast period. However, a pattern shift by Day 8/Tue appears possible, with an amplified upper ridge potentially building over the western half of the CONUS. Overall, predictability is too low to delineate areas of severe potential across the eastern half of the CONUS. Read more

WW 0274 Status Updates
STATUS REPORT ON WW 274 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 NE HLC TO 5 NE BUB. ..GOSS..05/21/24 ATTN...WFO...OAX...GID...LBF... STATUS REPORT FOR WS 274 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC085-129-133-155-165-211040- IA . IOWA COUNTIES INCLUDED ARE HARRISON MILLS MONONA POTTAWATTAMIE SHELBY KSC183-211040- KS . KANSAS COUNTIES INCLUDED ARE SMITH NEC001-003-011-019-021-023-025-035-037-039-053-055-059-061-067- 071-077-079-081-093-095-097-099-109-119-121-125-129-131-139-141- 143-151-153-155-159-163-167-169-173-175-177-179-181-183-185- 211040- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

MD 0865 CONCERNING SEVERE THUNDERSTORM WATCH 274... FOR SOUTHERN AND EASTERN NEBRASKA...NORTH-CENTRAL KANSAS...AND INTO PARTS OF WESTERN IOWA
Mesoscale Discussion 0865 NWS Storm Prediction Center Norman OK 0204 AM CDT Tue May 21 2024 Areas affected...southern and eastern Nebraska...north-central Kansas...and into parts of western Iowa Concerning...Severe Thunderstorm Watch 274... Valid 210704Z - 210900Z The severe weather threat for Severe Thunderstorm Watch 274 continues. SUMMARY...Strong/locally severe storms continue in/near WW 274. DISCUSSION...Latest radar loop shows widespread convection across eastern Nebraska and eastward into western and central Iowa. While a relatively favorable thermodynamic environment is in place, rather paltry shear is indicated, with only 20 to 30 kt flow through most of the troposphere, per model output and confirmed via KDMX WSR-88d VWP. With this area to remain east of the low-level jet, and associated enhancement to the wind profile thereby provided, expect only isolated risk for marginal hail/wind with the strongest multicell storms. Greater severe potential is expected to evolve across southwestern portions of the watch over the next 1 to 2 hours, as a bowing cluster of storms with a fairly well-developed cold pool moves eastward across southwestern Nebraska/northwestern Kansas. The convection is progressing eastward near and just north of the surface front, within the surface-based CAPE gradient. With the MCS roughly co-located with the nose of a 60-kt southerly low-level jet, a much more favorably sheared environment should sustain this convection -- and attendant, more substantial severe potential, over the next few hours. ..Goss.. 05/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DMX...FSD...OAX...GID...LBF...GLD... LAT...LON 41340010 41889822 42519580 41719507 40989534 40739667 39660003 41340010 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 AM CDT Tue May 21 2024 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OKLAHOMA AND KANSAS INTO THE ARKLATEX VICINITY... ...SUMMARY... Severe thunderstorms are possible across portions Kansas and Oklahoma into the Arklatex region on Thursday. Damaging gusts, hail and a couple of tornadoes will be possible. Isolated strong to severe thunderstorms also will be possible across the central Plains into South Dakota, and across the Mid-Atlantic and Northeast coastal areas. ...Mid-Atlantic and Northeast... Broad, low-amplitude southwesterly flow will persist across much of the eastern CONUS on Thursday. Some enhancement of mid/upper flow is forecast across from the Northeast states as a compact upper shortwave trough glances the international border. At the surface, a cold front will move east across the Northeast. This will focus thunderstorm activity during the afternoon from VA northeast along the Atlantic coastal vicinity amid a seasonally moist airmass. Modest destabilization and steepening low-level lapse rates are forecast. Strong gusts will be possible with thunderstorms during the late morning into the afternoon. A plume of modest midlevel lapse rate also will overspread the region, and vertical shear will be sufficient, especially from NJ northward, to support sporadic marginal hail as well. ...Plains Vicinity... A subtle upper shortwave trough is forecast to migrate across the southern Plains and Mid-South vicinity, while another deepening shortwave trough overspreads the northern/central Plains. Both of these features will result in increasing mid/upper southwesterly flow (30-50 kt) on Thursday. At the surface, lee cyclogenesis is forecast over the central High Plains. A surface low will progress east across SD/NE to IA/MN, with a cold front developing east/southeast across the northern/central Plains during the evening/overnight. Meanwhile, a dryline will extend southward from a secondary low over western KS into central TX. Strengthening low-level southerly flow in response to the deepening low will transport Gulf moisture northward ahead of the front, with near-60 F dewpoints as far north as NE. Richer boundary-layer moisture (mid 60s to low 70s F) will remain farther south. Strong destabilization ahead of the dryline and increasing large-scale ascent will support thunderstorm development during the afternoon across the southern Plains vicinity. One or more clusters will track southeast through the evening into the ArkLaTex region. All severe hazards appear possible. Severe potential may be less with northward extent into NE/SD and vicinity given more modest moisture, but at least isolated strong/severe storms appear possible given an otherwise favorable environment. ..Leitman.. 05/21/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0222 AM CDT Tue May 21 2024 Valid 221200Z - 231200Z ...Synopsis... A broad upper trough will encompass the central and western CONUS Wednesday. The strongest mid-level flow is expected to extend from the Southern Plains through the Upper Midwest and Great Lakes regions, and across the Pacific Northwest near the base of mid-level cyclone. A deeply mixed air mass will remain present over the Desert Southwest, while a cold front dives southward into portions of the Southern and High Plains. Further west across portions of NM and AZ, sustained westerly surface winds near 15 mph are expected where increasingly receptive fuels and single-digit RH will be present. Localized wind speeds may briefly approach or exceed 20 mph across southern NM Wednesday afternoon, but the probability of this occurring for more than 3 hours across a broad region is too low to introduce a Critical area at this time. ..Barnes.. 05/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0222 AM CDT Tue May 21 2024 Valid 221200Z - 231200Z ...Synopsis... A broad upper trough will encompass the central and western CONUS Wednesday. The strongest mid-level flow is expected to extend from the Southern Plains through the Upper Midwest and Great Lakes regions, and across the Pacific Northwest near the base of mid-level cyclone. A deeply mixed air mass will remain present over the Desert Southwest, while a cold front dives southward into portions of the Southern and High Plains. Further west across portions of NM and AZ, sustained westerly surface winds near 15 mph are expected where increasingly receptive fuels and single-digit RH will be present. Localized wind speeds may briefly approach or exceed 20 mph across southern NM Wednesday afternoon, but the probability of this occurring for more than 3 hours across a broad region is too low to introduce a Critical area at this time. ..Barnes.. 05/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0222 AM CDT Tue May 21 2024 Valid 221200Z - 231200Z ...Synopsis... A broad upper trough will encompass the central and western CONUS Wednesday. The strongest mid-level flow is expected to extend from the Southern Plains through the Upper Midwest and Great Lakes regions, and across the Pacific Northwest near the base of mid-level cyclone. A deeply mixed air mass will remain present over the Desert Southwest, while a cold front dives southward into portions of the Southern and High Plains. Further west across portions of NM and AZ, sustained westerly surface winds near 15 mph are expected where increasingly receptive fuels and single-digit RH will be present. Localized wind speeds may briefly approach or exceed 20 mph across southern NM Wednesday afternoon, but the probability of this occurring for more than 3 hours across a broad region is too low to introduce a Critical area at this time. ..Barnes.. 05/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0222 AM CDT Tue May 21 2024 Valid 221200Z - 231200Z ...Synopsis... A broad upper trough will encompass the central and western CONUS Wednesday. The strongest mid-level flow is expected to extend from the Southern Plains through the Upper Midwest and Great Lakes regions, and across the Pacific Northwest near the base of mid-level cyclone. A deeply mixed air mass will remain present over the Desert Southwest, while a cold front dives southward into portions of the Southern and High Plains. Further west across portions of NM and AZ, sustained westerly surface winds near 15 mph are expected where increasingly receptive fuels and single-digit RH will be present. Localized wind speeds may briefly approach or exceed 20 mph across southern NM Wednesday afternoon, but the probability of this occurring for more than 3 hours across a broad region is too low to introduce a Critical area at this time. ..Barnes.. 05/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0222 AM CDT Tue May 21 2024 Valid 221200Z - 231200Z ...Synopsis... A broad upper trough will encompass the central and western CONUS Wednesday. The strongest mid-level flow is expected to extend from the Southern Plains through the Upper Midwest and Great Lakes regions, and across the Pacific Northwest near the base of mid-level cyclone. A deeply mixed air mass will remain present over the Desert Southwest, while a cold front dives southward into portions of the Southern and High Plains. Further west across portions of NM and AZ, sustained westerly surface winds near 15 mph are expected where increasingly receptive fuels and single-digit RH will be present. Localized wind speeds may briefly approach or exceed 20 mph across southern NM Wednesday afternoon, but the probability of this occurring for more than 3 hours across a broad region is too low to introduce a Critical area at this time. ..Barnes.. 05/21/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more