Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...Synopsis... Moderate mid-level flow will remain across the Southwest on Tuesday with single-digit relative humidity across New Mexico. As deep mixing develops during the afternoon, some of this stronger flow will mix to the surface. In addition, a secondary lee cyclone is expected to develop in the TX/OK Panhandle vicinity. This will also aid in stronger surface winds. 15 to 25 mph sustained surface winds are expected across much of New Mexico. Locally critical conditions are probable and a Critical delineation may be needed at a later time, but for now, it is unclear where within the broader Elevated area, the greater threat may be. ..Bentley.. 05/20/2024 ...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 0202 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...Synopsis... Moderate mid-level flow will remain across the Southwest on Tuesday with single-digit relative humidity across New Mexico. As deep mixing develops during the afternoon, some of this stronger flow will mix to the surface. In addition, a secondary lee cyclone is expected to develop in the TX/OK Panhandle vicinity. This will also aid in stronger surface winds. 15 to 25 mph sustained surface winds are expected across much of New Mexico. Locally critical conditions are probable and a Critical delineation may be needed at a later time, but for now, it is unclear where within the broader Elevated area, the greater threat may be. ..Bentley.. 05/20/2024 ...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 0202 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...Synopsis... Moderate mid-level flow will remain across the Southwest on Tuesday with single-digit relative humidity across New Mexico. As deep mixing develops during the afternoon, some of this stronger flow will mix to the surface. In addition, a secondary lee cyclone is expected to develop in the TX/OK Panhandle vicinity. This will also aid in stronger surface winds. 15 to 25 mph sustained surface winds are expected across much of New Mexico. Locally critical conditions are probable and a Critical delineation may be needed at a later time, but for now, it is unclear where within the broader Elevated area, the greater threat may be. ..Bentley.. 05/20/2024 ...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 0202 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...Synopsis... Moderate mid-level flow will remain across the Southwest on Tuesday with single-digit relative humidity across New Mexico. As deep mixing develops during the afternoon, some of this stronger flow will mix to the surface. In addition, a secondary lee cyclone is expected to develop in the TX/OK Panhandle vicinity. This will also aid in stronger surface winds. 15 to 25 mph sustained surface winds are expected across much of New Mexico. Locally critical conditions are probable and a Critical delineation may be needed at a later time, but for now, it is unclear where within the broader Elevated area, the greater threat may be. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Mon May 20 2024 Valid 201200Z - 211200Z ...Synopsis... A mid-level jet streak will overspread the Southwest this afternoon as a mid-level trough amplifies across the western CONUS. A deeply mixed boundary layer is expected across Arizona and New Mexico with temperatures in the 90s. Some of this stronger flow will mix to the surface amid the deep boundary layer. In addition, lee cyclogenesis will tighten the pressure gradient in the region and aid in stronger surface winds. Sustained surface winds of 25 to 30 mph are expected across New Mexico with some sustained winds over 30 mph in northern Arizona. Single-digit relative humidity is also expected across most of the region. Fuels have started to dry to critical levels across portions of eastern and northern Arizona. Therefore, a Critical delineation is warranted. ..Bentley.. 05/20/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0266 Status Updates
STATUS REPORT ON WW 266 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..GOSS..05/20/24 ATTN...WFO...TSA...OUN... STATUS REPORT FOR WS 266 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OKC035-037-041-047-071-097-103-105-113-115-117-119-131-143-145- 147-200740- OK . OKLAHOMA COUNTIES INCLUDED ARE CRAIG CREEK DELAWARE GARFIELD KAY MAYES NOBLE NOWATA OSAGE OTTAWA PAWNEE PAYNE ROGERS TULSA WAGONER WASHINGTON THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0266 Status Updates
STATUS REPORT ON WW 266 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..GOSS..05/20/24 ATTN...WFO...TSA...OUN... STATUS REPORT FOR WS 266 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OKC035-037-041-047-071-097-103-105-113-115-117-119-131-143-145- 147-200740- OK . OKLAHOMA COUNTIES INCLUDED ARE CRAIG CREEK DELAWARE GARFIELD KAY MAYES NOBLE NOWATA OSAGE OTTAWA PAWNEE PAYNE ROGERS TULSA WAGONER WASHINGTON THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSOURI VALLEY TO CENTRAL WISCONSIN... ...SUMMARY... A broad area of severe-thunderstorm potential is expected from the southern Plains to the upper Great Lakes. The highest concentration of severe storms is expected from eastern Kansas to southwest Wisconsin. Tornadoes (a few strong), damaging gusts, and large hail are possible through Monday night. ...Lower Missouri Valley to the Upper Great Lakes... An upper shortwave trough over the central High Plains Tuesday morning will spread northeast to the upper Great Lakes through the forecast period. This will result in strong height falls (particularly across IA/MN/WI) and strengthening surface cyclogenesis. An elongated surface low over eastern NE Tuesday morning will deepen and lift northeast to northern WI/Upper MI by evening. A surface warm front will lift north ahead of the surface low, becoming positioned across central WI by 00z. Meanwhile, a trailing cold front will surge east across IA/eastern KS/northern MO from mid-afternoon into the evening. The cold front will continue east overnight, becoming positioned from western Lower MI to central MO and northwest OK by Wednesday morning. One point of uncertainty on Tuesday is expected morning convection across IA into southeast MN and WI. Most guidance quickly moves this activity northeast with airmass recovery occurring quickly in a strong warm advection regime and progressive/dynamic large-scale pattern. An EML plume, characterized by midlevel lapse rates greater than 8 C/km, will overspread the region along with an increase 850-700 mb jet (50-70 kt) by afternoon and into the evening. This should support airmass recovery in the wake of morning convection. A broad warm sector, with surface dew points in the mid/upper 60s F will be in place. The moist boundary layer beneath steep to very steep midlevel lapse rates will result in a corridor of strong instability (greater than 2000 J/kg MLCAPE) from eastern KS into southwest WI. Large and favorably curved low-level shear profiles will be present as indicated by forecast hodographs. While supercell wind profiles are evident, a mixed mode scenario is possible with discrete supercells developing initially with potentially rapid upscale growth into a QLCS given both strong large-scale ascent and frontal forcing. Regardless, tornadoes will be possible with either convective mode, and a few strong tornadoes are possible. Severe-gust potential will increase a upscale growth ensues, with some potential for significant gusts (greater than 65 kt). Large hail will also be possible with any more discrete or line-embedded supercells. Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast OK/northwest AR by late afternoon/evening, and more conditionally with southwest extent near a dryline from central OK into central TX. Large hail and severe gusts will be possible with this activity. A QLCS will likely continue through the overnight hours into parts of Lower MI, northern IN, and central IL/MO. Damaging gusts will become the primary risk overnight, but a couple of tornadoes also will be possible. ...Northeast... A weak upper shortwave trough will move across southern Quebec and northern New England through Wednesday evening. This will result in a band of enhanced westerly deep-layer flow from northern NY into ME. A seasonally moist airmass will be in place with surface dewpoints into the low 60s. Strong heating will result in steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging gusts. ..Leitman.. 05/20/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSOURI VALLEY TO CENTRAL WISCONSIN... ...SUMMARY... A broad area of severe-thunderstorm potential is expected from the southern Plains to the upper Great Lakes. The highest concentration of severe storms is expected from eastern Kansas to southwest Wisconsin. Tornadoes (a few strong), damaging gusts, and large hail are possible through Monday night. ...Lower Missouri Valley to the Upper Great Lakes... An upper shortwave trough over the central High Plains Tuesday morning will spread northeast to the upper Great Lakes through the forecast period. This will result in strong height falls (particularly across IA/MN/WI) and strengthening surface cyclogenesis. An elongated surface low over eastern NE Tuesday morning will deepen and lift northeast to northern WI/Upper MI by evening. A surface warm front will lift north ahead of the surface low, becoming positioned across central WI by 00z. Meanwhile, a trailing cold front will surge east across IA/eastern KS/northern MO from mid-afternoon into the evening. The cold front will continue east overnight, becoming positioned from western Lower MI to central MO and northwest OK by Wednesday morning. One point of uncertainty on Tuesday is expected morning convection across IA into southeast MN and WI. Most guidance quickly moves this activity northeast with airmass recovery occurring quickly in a strong warm advection regime and progressive/dynamic large-scale pattern. An EML plume, characterized by midlevel lapse rates greater than 8 C/km, will overspread the region along with an increase 850-700 mb jet (50-70 kt) by afternoon and into the evening. This should support airmass recovery in the wake of morning convection. A broad warm sector, with surface dew points in the mid/upper 60s F will be in place. The moist boundary layer beneath steep to very steep midlevel lapse rates will result in a corridor of strong instability (greater than 2000 J/kg MLCAPE) from eastern KS into southwest WI. Large and favorably curved low-level shear profiles will be present as indicated by forecast hodographs. While supercell wind profiles are evident, a mixed mode scenario is possible with discrete supercells developing initially with potentially rapid upscale growth into a QLCS given both strong large-scale ascent and frontal forcing. Regardless, tornadoes will be possible with either convective mode, and a few strong tornadoes are possible. Severe-gust potential will increase a upscale growth ensues, with some potential for significant gusts (greater than 65 kt). Large hail will also be possible with any more discrete or line-embedded supercells. Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast OK/northwest AR by late afternoon/evening, and more conditionally with southwest extent near a dryline from central OK into central TX. Large hail and severe gusts will be possible with this activity. A QLCS will likely continue through the overnight hours into parts of Lower MI, northern IN, and central IL/MO. Damaging gusts will become the primary risk overnight, but a couple of tornadoes also will be possible. ...Northeast... A weak upper shortwave trough will move across southern Quebec and northern New England through Wednesday evening. This will result in a band of enhanced westerly deep-layer flow from northern NY into ME. A seasonally moist airmass will be in place with surface dewpoints into the low 60s. Strong heating will result in steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging gusts. ..Leitman.. 05/20/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSOURI VALLEY TO CENTRAL WISCONSIN... ...SUMMARY... A broad area of severe-thunderstorm potential is expected from the southern Plains to the upper Great Lakes. The highest concentration of severe storms is expected from eastern Kansas to southwest Wisconsin. Tornadoes (a few strong), damaging gusts, and large hail are possible through Monday night. ...Lower Missouri Valley to the Upper Great Lakes... An upper shortwave trough over the central High Plains Tuesday morning will spread northeast to the upper Great Lakes through the forecast period. This will result in strong height falls (particularly across IA/MN/WI) and strengthening surface cyclogenesis. An elongated surface low over eastern NE Tuesday morning will deepen and lift northeast to northern WI/Upper MI by evening. A surface warm front will lift north ahead of the surface low, becoming positioned across central WI by 00z. Meanwhile, a trailing cold front will surge east across IA/eastern KS/northern MO from mid-afternoon into the evening. The cold front will continue east overnight, becoming positioned from western Lower MI to central MO and northwest OK by Wednesday morning. One point of uncertainty on Tuesday is expected morning convection across IA into southeast MN and WI. Most guidance quickly moves this activity northeast with airmass recovery occurring quickly in a strong warm advection regime and progressive/dynamic large-scale pattern. An EML plume, characterized by midlevel lapse rates greater than 8 C/km, will overspread the region along with an increase 850-700 mb jet (50-70 kt) by afternoon and into the evening. This should support airmass recovery in the wake of morning convection. A broad warm sector, with surface dew points in the mid/upper 60s F will be in place. The moist boundary layer beneath steep to very steep midlevel lapse rates will result in a corridor of strong instability (greater than 2000 J/kg MLCAPE) from eastern KS into southwest WI. Large and favorably curved low-level shear profiles will be present as indicated by forecast hodographs. While supercell wind profiles are evident, a mixed mode scenario is possible with discrete supercells developing initially with potentially rapid upscale growth into a QLCS given both strong large-scale ascent and frontal forcing. Regardless, tornadoes will be possible with either convective mode, and a few strong tornadoes are possible. Severe-gust potential will increase a upscale growth ensues, with some potential for significant gusts (greater than 65 kt). Large hail will also be possible with any more discrete or line-embedded supercells. Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast OK/northwest AR by late afternoon/evening, and more conditionally with southwest extent near a dryline from central OK into central TX. Large hail and severe gusts will be possible with this activity. A QLCS will likely continue through the overnight hours into parts of Lower MI, northern IN, and central IL/MO. Damaging gusts will become the primary risk overnight, but a couple of tornadoes also will be possible. ...Northeast... A weak upper shortwave trough will move across southern Quebec and northern New England through Wednesday evening. This will result in a band of enhanced westerly deep-layer flow from northern NY into ME. A seasonally moist airmass will be in place with surface dewpoints into the low 60s. Strong heating will result in steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging gusts. ..Leitman.. 05/20/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSOURI VALLEY TO CENTRAL WISCONSIN... ...SUMMARY... A broad area of severe-thunderstorm potential is expected from the southern Plains to the upper Great Lakes. The highest concentration of severe storms is expected from eastern Kansas to southwest Wisconsin. Tornadoes (a few strong), damaging gusts, and large hail are possible through Monday night. ...Lower Missouri Valley to the Upper Great Lakes... An upper shortwave trough over the central High Plains Tuesday morning will spread northeast to the upper Great Lakes through the forecast period. This will result in strong height falls (particularly across IA/MN/WI) and strengthening surface cyclogenesis. An elongated surface low over eastern NE Tuesday morning will deepen and lift northeast to northern WI/Upper MI by evening. A surface warm front will lift north ahead of the surface low, becoming positioned across central WI by 00z. Meanwhile, a trailing cold front will surge east across IA/eastern KS/northern MO from mid-afternoon into the evening. The cold front will continue east overnight, becoming positioned from western Lower MI to central MO and northwest OK by Wednesday morning. One point of uncertainty on Tuesday is expected morning convection across IA into southeast MN and WI. Most guidance quickly moves this activity northeast with airmass recovery occurring quickly in a strong warm advection regime and progressive/dynamic large-scale pattern. An EML plume, characterized by midlevel lapse rates greater than 8 C/km, will overspread the region along with an increase 850-700 mb jet (50-70 kt) by afternoon and into the evening. This should support airmass recovery in the wake of morning convection. A broad warm sector, with surface dew points in the mid/upper 60s F will be in place. The moist boundary layer beneath steep to very steep midlevel lapse rates will result in a corridor of strong instability (greater than 2000 J/kg MLCAPE) from eastern KS into southwest WI. Large and favorably curved low-level shear profiles will be present as indicated by forecast hodographs. While supercell wind profiles are evident, a mixed mode scenario is possible with discrete supercells developing initially with potentially rapid upscale growth into a QLCS given both strong large-scale ascent and frontal forcing. Regardless, tornadoes will be possible with either convective mode, and a few strong tornadoes are possible. Severe-gust potential will increase a upscale growth ensues, with some potential for significant gusts (greater than 65 kt). Large hail will also be possible with any more discrete or line-embedded supercells. Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast OK/northwest AR by late afternoon/evening, and more conditionally with southwest extent near a dryline from central OK into central TX. Large hail and severe gusts will be possible with this activity. A QLCS will likely continue through the overnight hours into parts of Lower MI, northern IN, and central IL/MO. Damaging gusts will become the primary risk overnight, but a couple of tornadoes also will be possible. ...Northeast... A weak upper shortwave trough will move across southern Quebec and northern New England through Wednesday evening. This will result in a band of enhanced westerly deep-layer flow from northern NY into ME. A seasonally moist airmass will be in place with surface dewpoints into the low 60s. Strong heating will result in steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging gusts. ..Leitman.. 05/20/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon May 20 2024 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MISSOURI VALLEY TO CENTRAL WISCONSIN... ...SUMMARY... A broad area of severe-thunderstorm potential is expected from the southern Plains to the upper Great Lakes. The highest concentration of severe storms is expected from eastern Kansas to southwest Wisconsin. Tornadoes (a few strong), damaging gusts, and large hail are possible through Monday night. ...Lower Missouri Valley to the Upper Great Lakes... An upper shortwave trough over the central High Plains Tuesday morning will spread northeast to the upper Great Lakes through the forecast period. This will result in strong height falls (particularly across IA/MN/WI) and strengthening surface cyclogenesis. An elongated surface low over eastern NE Tuesday morning will deepen and lift northeast to northern WI/Upper MI by evening. A surface warm front will lift north ahead of the surface low, becoming positioned across central WI by 00z. Meanwhile, a trailing cold front will surge east across IA/eastern KS/northern MO from mid-afternoon into the evening. The cold front will continue east overnight, becoming positioned from western Lower MI to central MO and northwest OK by Wednesday morning. One point of uncertainty on Tuesday is expected morning convection across IA into southeast MN and WI. Most guidance quickly moves this activity northeast with airmass recovery occurring quickly in a strong warm advection regime and progressive/dynamic large-scale pattern. An EML plume, characterized by midlevel lapse rates greater than 8 C/km, will overspread the region along with an increase 850-700 mb jet (50-70 kt) by afternoon and into the evening. This should support airmass recovery in the wake of morning convection. A broad warm sector, with surface dew points in the mid/upper 60s F will be in place. The moist boundary layer beneath steep to very steep midlevel lapse rates will result in a corridor of strong instability (greater than 2000 J/kg MLCAPE) from eastern KS into southwest WI. Large and favorably curved low-level shear profiles will be present as indicated by forecast hodographs. While supercell wind profiles are evident, a mixed mode scenario is possible with discrete supercells developing initially with potentially rapid upscale growth into a QLCS given both strong large-scale ascent and frontal forcing. Regardless, tornadoes will be possible with either convective mode, and a few strong tornadoes are possible. Severe-gust potential will increase a upscale growth ensues, with some potential for significant gusts (greater than 65 kt). Large hail will also be possible with any more discrete or line-embedded supercells. Convective coverage will likely decrease with southward extent as large-scale ascent focuses northward toward the Great Lakes. Nevertheless isolated storms are possible into northeast OK/northwest AR by late afternoon/evening, and more conditionally with southwest extent near a dryline from central OK into central TX. Large hail and severe gusts will be possible with this activity. A QLCS will likely continue through the overnight hours into parts of Lower MI, northern IN, and central IL/MO. Damaging gusts will become the primary risk overnight, but a couple of tornadoes also will be possible. ...Northeast... A weak upper shortwave trough will move across southern Quebec and northern New England through Wednesday evening. This will result in a band of enhanced westerly deep-layer flow from northern NY into ME. A seasonally moist airmass will be in place with surface dewpoints into the low 60s. Strong heating will result in steepening low-level lapse rates. MLCAPE to around 1000 J/kg and effective shear magnitudes around 35 kt will support organized cells. Elongated hodographs and favorable vertical shear suggest marginally severe hail will be possible along with locally damaging gusts. ..Leitman.. 05/20/2024 Read more