Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun May 19 2024 Valid 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF OK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE PLAINS AND SOUTHEAST FLORIDA... ...SUMMARY... Numerous severe thunderstorms capable of widespread damaging winds and giant hail are expected this afternoon and evening across portions of Kansas and northern Oklahoma. Gusts of 75-100 mph are possible, along with very large hail and a few tornadoes. ...20z Update... No consequential changes to forecast reasoning and current Day 1 Outlook. Main severe risk as depicted by MDT/ENH risks appears to be steadily unfolding generally as expected, including intense storm development along the boundary in north-central Kansas, with higher-based storms also steadily increasing across southeast Colorado and the Oklahoma/Texas Panhandles. Semi-discrete supercells are still expected before cell mergers/aggregating cold pools lead to potentially significant severe wind potential across southwest/central Kansas and nearby northern Oklahoma, which is consistent with latest WoFS forecasts. ..Guyer.. 05/19/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 19 2024/ ...KS/OK... Morning water vapor imagery shows a shortwave trough over northern AZ. This feature is expected to accelerate eastward this afternoon, with an associated mid/upper level jet max nosing into the central High Plains. This will lead to scattered high-based thunderstorms over southeast CO by mid-afternoon, capable of locally gusty winds and hail. As this activity builds eastward across the dryline, rapid intensification of supercell storms is expected. Forecast soundings show a relatively deep boundary-layer, but large CAPE values and dry-adiabatic mid-level lapse rates. Deep-layer shear profiles will promote rotating storms capable of very large hail, damaging winds, and a tornado or two across southwest KS and any more isolated cells that form southward along the dryline into western Oklahoma. As this activity moves eastward, congealing outflows will likely result in a fast-moving QLCS capable of widespread significant wind damage for a few hours. It remains unclear how far east this threat will persist, but given current model guidance, will not change the ongoing bounds of the ENH/MDT risk areas in eastern KS. ...Eastern FL... A surface cold front is sagging southward across the central FL peninsula today. Along and ahead of the front, very warm/moist low-level conditions persist with dewpoints in the low-mid 70s and strong daytime heating occurring. It appears likely that at least scattered thunderstorms will form near/along the east-coast sea breeze later this afternoon. Any storm that can intensify before it moves offshore would potentially acquire supercell characteristics and pose a risk of large hail and damaging wind gusts. See mesoscale discussion #829 for further details. ...SD/NE/Northeast CO... Strong heating is occurring across much of western SD/NE, where southerly low-level winds are helping to transport 50s dewpoints in the region. A weak shortwave trough currently over WY will approach the region by mid-afternoon, helping to initiate scattered thunderstorms from the Black Hills region southward into western NE and northeast CO. These storms will be relatively high-based, but in an environment of sufficient vertical shear to promote organized multicell or supercell structures capable of damaging winds and hail. Storms will persist through much of the evening and spread into central SD/NE before weakening. Read more

MD 0831 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS
Mesoscale Discussion 0831 NWS Storm Prediction Center Norman OK 0109 PM CDT Sun May 19 2024 Areas affected...Parts of the central/northern High Plains Concerning...Severe potential...Watch likely Valid 191809Z - 192015Z Probability of Watch Issuance...80 percent SUMMARY...Severe storms capable of producing severe gusts and hail will be possible later this afternoon. Watch issuance is likely. DISCUSSION...Diurnal heating of a modestly moist environment is underway across the central/northern High Plains vicinity, with recent attempts at high-based storm development already noted across the NE Panhandle. Continued heating will support MLCAPE rising to near/above 1000 J/kg across parts of the region later this afternoon, along with decreasing CINH. Scattered thunderstorm development is expected with time as a shortwave trough currently over the northern Rockies approaches the region. Deep-layer shear will generally be supportive of organized convection, especially with northward extent across SD into far southern ND. Initial development could evolve into a few supercells with a threat of large hail and localized severe gusts. With time, consolidating outflows within a relatively warm and well-mixed environment could support some upscale growth and an increasing severe-wind threat. Watch issuance is likely for parts of this region later this afternoon. ..Dean/Hart.. 05/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...BIS...LBF...UNR...GLD...BOU...CYS... LAT...LON 41050399 42330388 44350340 45520223 46250124 46369999 43870038 41100090 39670107 39640228 41050399 Read more

MD 0830 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST GEORGIA AND FAR SOUTHERN SOUTH CAROLINA
Mesoscale Discussion 0830 NWS Storm Prediction Center Norman OK 0101 PM CDT Sun May 19 2024 Areas affected...Southeast Georgia and far southern South Carolina Concerning...Severe potential...Watch unlikely Valid 191801Z - 192000Z Probability of Watch Issuance...5 percent SUMMARY...Sporadic damaging winds and severe hail will remain possible through the late afternoon hours as thunderstorms spread southward into southeast Georgia. Watch issuance is not expected. DISCUSSION...Scattered thunderstorms continue to develop in the vicinity of a weak upper-level disturbance that is slowly meandering southeastwards towards the GA coast. Although a consolidated cold pool has become established at this point (based on radar velocity data and surface observations), MRMS echo top data and GOES IR imagery have shown several intense updraft pulses within the last half hour, even behind the primary outflow boundary. This thunderstorm cluster is expected to slowly push southward into southeast GA through late afternoon. Weak deep-layer wind shear (20-25 knots) downstream will continue to limit the longevity and organization of the more robust updraft pulses; however, the thermodynamic environment is favorable for strong to severe downbursts given moderate SBCAPE (2500-3000 J/kg), steep low-level lapse rates, and theta-e deficits between 25-30 K. One such downburst has already been observed in southern SC and resulted in a 68 mph wind gust. While winds of this magnitude should be fairly infrequent with these storms, damaging winds appear probable. Similarly, sporadic severe hail has been observed and will continue to be a threat given cool temperatures aloft and surface-based lifted indices between -8 to -10 K. Due to the short-lived nature of this activity, instances of severe wind/hail should be sufficiently sporadic to preclude the need for watch issuance. ..Moore/Hart.. 05/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...JAX...FFC... LAT...LON 30768161 31048218 31388262 31738276 32218265 32618239 32748192 32718144 32648097 32558061 32468046 32178051 31988084 31738108 31448118 31168126 30948131 30838133 30768161 Read more

WW 0259 Status Updates
STATUS REPORT ON WW 259 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..MOORE..05/19/24 ATTN...WFO...BOU...LBF...CYS...UNR...ABR... STATUS REPORT FOR WS 259 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC075-095-115-121-192040- CO . COLORADO COUNTIES INCLUDED ARE LOGAN PHILLIPS SEDGWICK WASHINGTON NEC005-007-013-029-031-033-045-049-063-069-075-085-091-101-105- 111-113-117-123-135-157-161-165-171-192040- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BANNER BOX BUTTE CHASE CHERRY CHEYENNE DAWES DEUEL FRONTIER GARDEN GRANT HAYES HOOKER KEITH KIMBALL LINCOLN LOGAN MCPHERSON MORRILL PERKINS SCOTTS BLUFF SHERIDAN SIOUX THOMAS SDC007-021-031-033-041-047-055-065-071-075-085-093-095-102-103- Read more

WW 0258 Status Updates
STATUS REPORT ON WW 258 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0834 ..MOORE..05/19/24 ATTN...WFO...MFL...MLB... STATUS REPORT FOR WS 258 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC011-061-085-086-093-099-111-192040- FL . FLORIDA COUNTIES INCLUDED ARE BROWARD INDIAN RIVER MARTIN MIAMI-DADE OKEECHOBEE PALM BEACH ST. LUCIE AMZ555-610-630-650-651-192040- CW . ADJACENT COASTAL WATERS INCLUDED ARE SEBASTIAN INLET TO JUPITER INLET 0-20 NM LAKE OKEECHOBEE BISCAYNE BAY COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH FL OUT 20 NM Read more

WW 0260 Status Updates
STATUS FOR WATCH 0260 HAS NOT BEEN ISSUED YET Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0233 PM CDT Sun May 19 2024 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN AND WEST-CENTRAL NM INTO FAR SOUTHEAST AZ... The primary change with this update was to expand the Critical area north into west-central NM. Here, critical meteorological conditions are expected, and given a lack of appreciable rainfall over this area during the last 15-30 days, fuels should become increasingly receptive to large-fire spread (aided by continued drying today). Elsewhere, the forecast remains on track. For details, see the previous discussion below. ..Weinman.. 05/19/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Sun May 19 2024/ ...Synopsis... Mid-level flow will start to strengthen on Monday as a subtropical shortwave trough approaches the region. A very deeply mixed airmass (near 500mb) will be in place on Monday. Therefore, some of this stronger mid-level flow should transport to the surface relatively easily. A large portion of the Southwest and into the central Rockies will experience Critical meteorological conditions on Monday. The current Critical outline represents where the driest fuels are present. Some expansion of this Critical area may be needed if guidance comes in stronger with winds and/or if fuels dry significantly in the next 36 hours. Elsewhere, fire weather concerns remain low at this time due to moist fuels and high relative humidity. ...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 0233 PM CDT Sun May 19 2024 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN AND WEST-CENTRAL NM INTO FAR SOUTHEAST AZ... The primary change with this update was to expand the Critical area north into west-central NM. Here, critical meteorological conditions are expected, and given a lack of appreciable rainfall over this area during the last 15-30 days, fuels should become increasingly receptive to large-fire spread (aided by continued drying today). Elsewhere, the forecast remains on track. For details, see the previous discussion below. ..Weinman.. 05/19/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Sun May 19 2024/ ...Synopsis... Mid-level flow will start to strengthen on Monday as a subtropical shortwave trough approaches the region. A very deeply mixed airmass (near 500mb) will be in place on Monday. Therefore, some of this stronger mid-level flow should transport to the surface relatively easily. A large portion of the Southwest and into the central Rockies will experience Critical meteorological conditions on Monday. The current Critical outline represents where the driest fuels are present. Some expansion of this Critical area may be needed if guidance comes in stronger with winds and/or if fuels dry significantly in the next 36 hours. Elsewhere, fire weather concerns remain low at this time due to moist fuels and high relative humidity. ...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 0233 PM CDT Sun May 19 2024 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN AND WEST-CENTRAL NM INTO FAR SOUTHEAST AZ... The primary change with this update was to expand the Critical area north into west-central NM. Here, critical meteorological conditions are expected, and given a lack of appreciable rainfall over this area during the last 15-30 days, fuels should become increasingly receptive to large-fire spread (aided by continued drying today). Elsewhere, the forecast remains on track. For details, see the previous discussion below. ..Weinman.. 05/19/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Sun May 19 2024/ ...Synopsis... Mid-level flow will start to strengthen on Monday as a subtropical shortwave trough approaches the region. A very deeply mixed airmass (near 500mb) will be in place on Monday. Therefore, some of this stronger mid-level flow should transport to the surface relatively easily. A large portion of the Southwest and into the central Rockies will experience Critical meteorological conditions on Monday. The current Critical outline represents where the driest fuels are present. Some expansion of this Critical area may be needed if guidance comes in stronger with winds and/or if fuels dry significantly in the next 36 hours. Elsewhere, fire weather concerns remain low at this time due to moist fuels and high relative humidity. ...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 0233 PM CDT Sun May 19 2024 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN AND WEST-CENTRAL NM INTO FAR SOUTHEAST AZ... The primary change with this update was to expand the Critical area north into west-central NM. Here, critical meteorological conditions are expected, and given a lack of appreciable rainfall over this area during the last 15-30 days, fuels should become increasingly receptive to large-fire spread (aided by continued drying today). Elsewhere, the forecast remains on track. For details, see the previous discussion below. ..Weinman.. 05/19/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Sun May 19 2024/ ...Synopsis... Mid-level flow will start to strengthen on Monday as a subtropical shortwave trough approaches the region. A very deeply mixed airmass (near 500mb) will be in place on Monday. Therefore, some of this stronger mid-level flow should transport to the surface relatively easily. A large portion of the Southwest and into the central Rockies will experience Critical meteorological conditions on Monday. The current Critical outline represents where the driest fuels are present. Some expansion of this Critical area may be needed if guidance comes in stronger with winds and/or if fuels dry significantly in the next 36 hours. Elsewhere, fire weather concerns remain low at this time due to moist fuels and high relative humidity. ...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 0233 PM CDT Sun May 19 2024 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN AND WEST-CENTRAL NM INTO FAR SOUTHEAST AZ... The primary change with this update was to expand the Critical area north into west-central NM. Here, critical meteorological conditions are expected, and given a lack of appreciable rainfall over this area during the last 15-30 days, fuels should become increasingly receptive to large-fire spread (aided by continued drying today). Elsewhere, the forecast remains on track. For details, see the previous discussion below. ..Weinman.. 05/19/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Sun May 19 2024/ ...Synopsis... Mid-level flow will start to strengthen on Monday as a subtropical shortwave trough approaches the region. A very deeply mixed airmass (near 500mb) will be in place on Monday. Therefore, some of this stronger mid-level flow should transport to the surface relatively easily. A large portion of the Southwest and into the central Rockies will experience Critical meteorological conditions on Monday. The current Critical outline represents where the driest fuels are present. Some expansion of this Critical area may be needed if guidance comes in stronger with winds and/or if fuels dry significantly in the next 36 hours. Elsewhere, fire weather concerns remain low at this time due to moist fuels and high relative humidity. ...Please see www.spc.noaa.gov/fire for graphic product... Read more