Severe Storms

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun May 19 2024 Valid 191200Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHWEST TO CENTRAL KS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEPARATELY IN EAST-CENTRAL TO SOUTHEAST FL... ...SUMMARY... Severe thunderstorms are expected across parts of Kansas into northwest Oklahoma from late afternoon into mid-evening, including the potential for a derecho. Destructive wind swaths of 80-100 mph may occur, with localized extreme gusts exceeding 100 mph possible. Very large hail and a few tornadoes are also anticipated. ...KS/OK vicinity... An active severe-weather day is expected during the late afternoon to mid-evening. Primary changes this outlook are to increase wind and hail probabilities with above-average guidance agreement regarding the likelihood of supercells evolving into multiple linear bows. Significant severe, from both hail and especially wind, appears likely. How far downstream higher-end intensity threats will persist towards the lower plains is more uncertain. General thunderstorm activity is expected to be ongoing within a low-level warm theta-e advection regime across parts of the central Great Plains. This will probably persist through much of the morning into the afternoon, becoming more centered on the Mid-MO Valley to Upper Midwest. Pronounced differential boundary-layer heating is expected between this early-day activity and full insolation that yields hot surface temperatures across the southern High Plains. With a plume of mid to upper 60s surface dew points overspreading much of western/central OK into central KS, beneath a plume of very steep mid-level lapse rates, a strongly unstable airmass will develop with MLCAPE of 2500-3500 J/kg becoming common. A strengthening upper-level jet across the Southwest, nosing over the southern Rockies, should aid in dryline sharpening by late afternoon. Initial very high-based thunderstorms should form off the Raton Mesa behind the dryline, while other storms form along the dryline near the TX Panhandle/western OK border, and in the north-central KS vicinity near the warm front. The far southern dryline storms in northwest OK and near the warm front in KS should remain semi-discrete longer, and will be most capable of producing very large hail and a couple tornadoes. Between these two corridors, CAM signals are fairly consistent that a mix of outflow-dominated clusters with embedded supercells will move east-northeast during the evening. This includes evolution into linear bowing segments with forecast soundings, indicating potential for intense rear-inflow jet development. Given the highly favorable thermodynamic environment, coupled with the impinging of a mid-level jetlet across the southern High Plains, this scenario appears probable. The southern to central Great Plains low-level jet will strengthen during the evening, which should result in a large MCS with embedded bowing structures persisting after dusk. CAM guidance is fairly quick to indicate diminishing intensity as MLCIN rapidly increases across much of OK into at least southeast KS. But given the potential for prolific, organized severe wind swaths upstream, have increased severe probabilities downstream from the Mid-MO Valley and deeper into OK. ...Western NE to western/central SD... Scattered thunderstorm development is expected along the northern portion of the dryline during the late afternoon to early evening as a narrow plume of mid to upper 50s surface dew points spreads north. With a more confined and more modestly buoyant warm-moist sector relative to KS southward, overall threat should consist of isolated to scattered large hail and severe wind. ...FL... Scattered afternoon thunderstorms appear likely to develop ahead of a slow-moving, positive-tilt shortwave trough over the Southeast. Best potential for a few supercells should be focused along the Atlantic Coast sea breeze across parts the central to south peninsula. Favorable deep-layer shear, in conjunction with large buoyancy, should foster a predominant threat of large hail, with isolated damaging winds possible as well. ..Grams/Bentley.. 05/19/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun May 19 2024 Valid 191200Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHWEST TO CENTRAL KS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEPARATELY IN EAST-CENTRAL TO SOUTHEAST FL... ...SUMMARY... Severe thunderstorms are expected across parts of Kansas into northwest Oklahoma from late afternoon into mid-evening, including the potential for a derecho. Destructive wind swaths of 80-100 mph may occur, with localized extreme gusts exceeding 100 mph possible. Very large hail and a few tornadoes are also anticipated. ...KS/OK vicinity... An active severe-weather day is expected during the late afternoon to mid-evening. Primary changes this outlook are to increase wind and hail probabilities with above-average guidance agreement regarding the likelihood of supercells evolving into multiple linear bows. Significant severe, from both hail and especially wind, appears likely. How far downstream higher-end intensity threats will persist towards the lower plains is more uncertain. General thunderstorm activity is expected to be ongoing within a low-level warm theta-e advection regime across parts of the central Great Plains. This will probably persist through much of the morning into the afternoon, becoming more centered on the Mid-MO Valley to Upper Midwest. Pronounced differential boundary-layer heating is expected between this early-day activity and full insolation that yields hot surface temperatures across the southern High Plains. With a plume of mid to upper 60s surface dew points overspreading much of western/central OK into central KS, beneath a plume of very steep mid-level lapse rates, a strongly unstable airmass will develop with MLCAPE of 2500-3500 J/kg becoming common. A strengthening upper-level jet across the Southwest, nosing over the southern Rockies, should aid in dryline sharpening by late afternoon. Initial very high-based thunderstorms should form off the Raton Mesa behind the dryline, while other storms form along the dryline near the TX Panhandle/western OK border, and in the north-central KS vicinity near the warm front. The far southern dryline storms in northwest OK and near the warm front in KS should remain semi-discrete longer, and will be most capable of producing very large hail and a couple tornadoes. Between these two corridors, CAM signals are fairly consistent that a mix of outflow-dominated clusters with embedded supercells will move east-northeast during the evening. This includes evolution into linear bowing segments with forecast soundings, indicating potential for intense rear-inflow jet development. Given the highly favorable thermodynamic environment, coupled with the impinging of a mid-level jetlet across the southern High Plains, this scenario appears probable. The southern to central Great Plains low-level jet will strengthen during the evening, which should result in a large MCS with embedded bowing structures persisting after dusk. CAM guidance is fairly quick to indicate diminishing intensity as MLCIN rapidly increases across much of OK into at least southeast KS. But given the potential for prolific, organized severe wind swaths upstream, have increased severe probabilities downstream from the Mid-MO Valley and deeper into OK. ...Western NE to western/central SD... Scattered thunderstorm development is expected along the northern portion of the dryline during the late afternoon to early evening as a narrow plume of mid to upper 50s surface dew points spreads north. With a more confined and more modestly buoyant warm-moist sector relative to KS southward, overall threat should consist of isolated to scattered large hail and severe wind. ...FL... Scattered afternoon thunderstorms appear likely to develop ahead of a slow-moving, positive-tilt shortwave trough over the Southeast. Best potential for a few supercells should be focused along the Atlantic Coast sea breeze across parts the central to south peninsula. Favorable deep-layer shear, in conjunction with large buoyancy, should foster a predominant threat of large hail, with isolated damaging winds possible as well. ..Grams/Bentley.. 05/19/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun May 19 2024 Valid 191200Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHWEST TO CENTRAL KS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEPARATELY IN EAST-CENTRAL TO SOUTHEAST FL... ...SUMMARY... Severe thunderstorms are expected across parts of Kansas into northwest Oklahoma from late afternoon into mid-evening, including the potential for a derecho. Destructive wind swaths of 80-100 mph may occur, with localized extreme gusts exceeding 100 mph possible. Very large hail and a few tornadoes are also anticipated. ...KS/OK vicinity... An active severe-weather day is expected during the late afternoon to mid-evening. Primary changes this outlook are to increase wind and hail probabilities with above-average guidance agreement regarding the likelihood of supercells evolving into multiple linear bows. Significant severe, from both hail and especially wind, appears likely. How far downstream higher-end intensity threats will persist towards the lower plains is more uncertain. General thunderstorm activity is expected to be ongoing within a low-level warm theta-e advection regime across parts of the central Great Plains. This will probably persist through much of the morning into the afternoon, becoming more centered on the Mid-MO Valley to Upper Midwest. Pronounced differential boundary-layer heating is expected between this early-day activity and full insolation that yields hot surface temperatures across the southern High Plains. With a plume of mid to upper 60s surface dew points overspreading much of western/central OK into central KS, beneath a plume of very steep mid-level lapse rates, a strongly unstable airmass will develop with MLCAPE of 2500-3500 J/kg becoming common. A strengthening upper-level jet across the Southwest, nosing over the southern Rockies, should aid in dryline sharpening by late afternoon. Initial very high-based thunderstorms should form off the Raton Mesa behind the dryline, while other storms form along the dryline near the TX Panhandle/western OK border, and in the north-central KS vicinity near the warm front. The far southern dryline storms in northwest OK and near the warm front in KS should remain semi-discrete longer, and will be most capable of producing very large hail and a couple tornadoes. Between these two corridors, CAM signals are fairly consistent that a mix of outflow-dominated clusters with embedded supercells will move east-northeast during the evening. This includes evolution into linear bowing segments with forecast soundings, indicating potential for intense rear-inflow jet development. Given the highly favorable thermodynamic environment, coupled with the impinging of a mid-level jetlet across the southern High Plains, this scenario appears probable. The southern to central Great Plains low-level jet will strengthen during the evening, which should result in a large MCS with embedded bowing structures persisting after dusk. CAM guidance is fairly quick to indicate diminishing intensity as MLCIN rapidly increases across much of OK into at least southeast KS. But given the potential for prolific, organized severe wind swaths upstream, have increased severe probabilities downstream from the Mid-MO Valley and deeper into OK. ...Western NE to western/central SD... Scattered thunderstorm development is expected along the northern portion of the dryline during the late afternoon to early evening as a narrow plume of mid to upper 50s surface dew points spreads north. With a more confined and more modestly buoyant warm-moist sector relative to KS southward, overall threat should consist of isolated to scattered large hail and severe wind. ...FL... Scattered afternoon thunderstorms appear likely to develop ahead of a slow-moving, positive-tilt shortwave trough over the Southeast. Best potential for a few supercells should be focused along the Atlantic Coast sea breeze across parts the central to south peninsula. Favorable deep-layer shear, in conjunction with large buoyancy, should foster a predominant threat of large hail, with isolated damaging winds possible as well. ..Grams/Bentley.. 05/19/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun May 19 2024 Valid 191200Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHWEST TO CENTRAL KS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEPARATELY IN EAST-CENTRAL TO SOUTHEAST FL... ...SUMMARY... Severe thunderstorms are expected across parts of Kansas into northwest Oklahoma from late afternoon into mid-evening, including the potential for a derecho. Destructive wind swaths of 80-100 mph may occur, with localized extreme gusts exceeding 100 mph possible. Very large hail and a few tornadoes are also anticipated. ...KS/OK vicinity... An active severe-weather day is expected during the late afternoon to mid-evening. Primary changes this outlook are to increase wind and hail probabilities with above-average guidance agreement regarding the likelihood of supercells evolving into multiple linear bows. Significant severe, from both hail and especially wind, appears likely. How far downstream higher-end intensity threats will persist towards the lower plains is more uncertain. General thunderstorm activity is expected to be ongoing within a low-level warm theta-e advection regime across parts of the central Great Plains. This will probably persist through much of the morning into the afternoon, becoming more centered on the Mid-MO Valley to Upper Midwest. Pronounced differential boundary-layer heating is expected between this early-day activity and full insolation that yields hot surface temperatures across the southern High Plains. With a plume of mid to upper 60s surface dew points overspreading much of western/central OK into central KS, beneath a plume of very steep mid-level lapse rates, a strongly unstable airmass will develop with MLCAPE of 2500-3500 J/kg becoming common. A strengthening upper-level jet across the Southwest, nosing over the southern Rockies, should aid in dryline sharpening by late afternoon. Initial very high-based thunderstorms should form off the Raton Mesa behind the dryline, while other storms form along the dryline near the TX Panhandle/western OK border, and in the north-central KS vicinity near the warm front. The far southern dryline storms in northwest OK and near the warm front in KS should remain semi-discrete longer, and will be most capable of producing very large hail and a couple tornadoes. Between these two corridors, CAM signals are fairly consistent that a mix of outflow-dominated clusters with embedded supercells will move east-northeast during the evening. This includes evolution into linear bowing segments with forecast soundings, indicating potential for intense rear-inflow jet development. Given the highly favorable thermodynamic environment, coupled with the impinging of a mid-level jetlet across the southern High Plains, this scenario appears probable. The southern to central Great Plains low-level jet will strengthen during the evening, which should result in a large MCS with embedded bowing structures persisting after dusk. CAM guidance is fairly quick to indicate diminishing intensity as MLCIN rapidly increases across much of OK into at least southeast KS. But given the potential for prolific, organized severe wind swaths upstream, have increased severe probabilities downstream from the Mid-MO Valley and deeper into OK. ...Western NE to western/central SD... Scattered thunderstorm development is expected along the northern portion of the dryline during the late afternoon to early evening as a narrow plume of mid to upper 50s surface dew points spreads north. With a more confined and more modestly buoyant warm-moist sector relative to KS southward, overall threat should consist of isolated to scattered large hail and severe wind. ...FL... Scattered afternoon thunderstorms appear likely to develop ahead of a slow-moving, positive-tilt shortwave trough over the Southeast. Best potential for a few supercells should be focused along the Atlantic Coast sea breeze across parts the central to south peninsula. Favorable deep-layer shear, in conjunction with large buoyancy, should foster a predominant threat of large hail, with isolated damaging winds possible as well. ..Grams/Bentley.. 05/19/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Sun May 19 2024 Valid 191200Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHWEST TO CENTRAL KS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SEPARATELY IN EAST-CENTRAL TO SOUTHEAST FL... ...SUMMARY... Severe thunderstorms are expected across parts of Kansas into northwest Oklahoma from late afternoon into mid-evening, including the potential for a derecho. Destructive wind swaths of 80-100 mph may occur, with localized extreme gusts exceeding 100 mph possible. Very large hail and a few tornadoes are also anticipated. ...KS/OK vicinity... An active severe-weather day is expected during the late afternoon to mid-evening. Primary changes this outlook are to increase wind and hail probabilities with above-average guidance agreement regarding the likelihood of supercells evolving into multiple linear bows. Significant severe, from both hail and especially wind, appears likely. How far downstream higher-end intensity threats will persist towards the lower plains is more uncertain. General thunderstorm activity is expected to be ongoing within a low-level warm theta-e advection regime across parts of the central Great Plains. This will probably persist through much of the morning into the afternoon, becoming more centered on the Mid-MO Valley to Upper Midwest. Pronounced differential boundary-layer heating is expected between this early-day activity and full insolation that yields hot surface temperatures across the southern High Plains. With a plume of mid to upper 60s surface dew points overspreading much of western/central OK into central KS, beneath a plume of very steep mid-level lapse rates, a strongly unstable airmass will develop with MLCAPE of 2500-3500 J/kg becoming common. A strengthening upper-level jet across the Southwest, nosing over the southern Rockies, should aid in dryline sharpening by late afternoon. Initial very high-based thunderstorms should form off the Raton Mesa behind the dryline, while other storms form along the dryline near the TX Panhandle/western OK border, and in the north-central KS vicinity near the warm front. The far southern dryline storms in northwest OK and near the warm front in KS should remain semi-discrete longer, and will be most capable of producing very large hail and a couple tornadoes. Between these two corridors, CAM signals are fairly consistent that a mix of outflow-dominated clusters with embedded supercells will move east-northeast during the evening. This includes evolution into linear bowing segments with forecast soundings, indicating potential for intense rear-inflow jet development. Given the highly favorable thermodynamic environment, coupled with the impinging of a mid-level jetlet across the southern High Plains, this scenario appears probable. The southern to central Great Plains low-level jet will strengthen during the evening, which should result in a large MCS with embedded bowing structures persisting after dusk. CAM guidance is fairly quick to indicate diminishing intensity as MLCIN rapidly increases across much of OK into at least southeast KS. But given the potential for prolific, organized severe wind swaths upstream, have increased severe probabilities downstream from the Mid-MO Valley and deeper into OK. ...Western NE to western/central SD... Scattered thunderstorm development is expected along the northern portion of the dryline during the late afternoon to early evening as a narrow plume of mid to upper 50s surface dew points spreads north. With a more confined and more modestly buoyant warm-moist sector relative to KS southward, overall threat should consist of isolated to scattered large hail and severe wind. ...FL... Scattered afternoon thunderstorms appear likely to develop ahead of a slow-moving, positive-tilt shortwave trough over the Southeast. Best potential for a few supercells should be focused along the Atlantic Coast sea breeze across parts the central to south peninsula. Favorable deep-layer shear, in conjunction with large buoyancy, should foster a predominant threat of large hail, with isolated damaging winds possible as well. ..Grams/Bentley.. 05/19/2024 Read more

WW 0257 Status Updates
STATUS REPORT ON WW 257 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NW OSH TO 35 NW GRB. REMAINING VALID PORTION OF WW 257 MAY BE ALLOWED TO EXPIRE AT 19/03Z. ..KERR..05/19/24 ATTN...WFO...MQT...DLH...ARX...GRB... STATUS REPORT FOR WS 257 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS WIC037-075-135-137-190300- WI . WISCONSIN COUNTIES INCLUDED ARE FLORENCE MARINETTE WAUPACA WAUSHARA 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 257 SEVERE TSTM MI MN WI LS 182030Z - 190300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 257 NWS Storm Prediction Center Norman OK 330 PM CDT Sat May 18 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Upper Michigan Minnesota Arrowhead Central and Northern Wisconsin Lake Superior * Effective this Saturday afternoon and evening from 330 PM until 1000 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms are developing along a cold front over western Wisconsin and northeast Minnesota. These storms will track eastward through the early evening, posing a risk of hail and damaging winds. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 30 miles north northeast of Grand Marais MN to 35 miles south of Mosinee WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart Read more

WW 0257 Status Updates
STATUS REPORT ON WW 257 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 S CWA TO 35 WNW IMT. ..KERR..05/19/24 ATTN...WFO...MQT...DLH...ARX...GRB... STATUS REPORT FOR WS 257 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS WIC037-041-075-097-135-137-190240- WI . WISCONSIN COUNTIES INCLUDED ARE FLORENCE FOREST MARINETTE PORTAGE WAUPACA WAUSHARA 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 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 PM CDT Sat May 18 2024 Valid 190100Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN TO SOUTHERN WI...THE CENTRAL HIGH PLAINS...AND NORTH FL TO SOUTHEAST GA... ...SUMMARY... Isolated severe thunderstorms remain possible this evening in parts of eastern to southern Wisconsin and the central High Plains. Isolated severe storms may develop over parts of north Florida and far southeast Georgia during the early morning. ...01Z Update... Overall severe potential has diminished across much of the CONUS. Strong to marginally severe storms may linger for another hour or two across parts of eastern to southern WI. Increasing MLCIN within the modestly buoyant warm sector and diminishing low-level convergence should result in storms further weakening through late evening. High-based, low-topped convection persists across east-central to southeast CO. This activity may still produce locally strong wind gusts and small hail as storms spread east into western KS while impinging on a more buoyant air mass in KS. But with increasing nocturnal MLCIN, the overall severe threat should remain marginal. Finally, across north FL into far southeast GA, recent guidance still suggests renewed warm-advection-driven storms should develop within the lingering low-level baroclinic zone over the northeast Gulf. While overall instability will be more limited in the wake of earlier D1 convection, a low-probability severe threat might develop within the mid-level jetlet that is downstream of the positive-tilt shortwave trough across the Deep South and Southeast. ..Grams.. 05/19/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 PM CDT Sat May 18 2024 Valid 190100Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN TO SOUTHERN WI...THE CENTRAL HIGH PLAINS...AND NORTH FL TO SOUTHEAST GA... ...SUMMARY... Isolated severe thunderstorms remain possible this evening in parts of eastern to southern Wisconsin and the central High Plains. Isolated severe storms may develop over parts of north Florida and far southeast Georgia during the early morning. ...01Z Update... Overall severe potential has diminished across much of the CONUS. Strong to marginally severe storms may linger for another hour or two across parts of eastern to southern WI. Increasing MLCIN within the modestly buoyant warm sector and diminishing low-level convergence should result in storms further weakening through late evening. High-based, low-topped convection persists across east-central to southeast CO. This activity may still produce locally strong wind gusts and small hail as storms spread east into western KS while impinging on a more buoyant air mass in KS. But with increasing nocturnal MLCIN, the overall severe threat should remain marginal. Finally, across north FL into far southeast GA, recent guidance still suggests renewed warm-advection-driven storms should develop within the lingering low-level baroclinic zone over the northeast Gulf. While overall instability will be more limited in the wake of earlier D1 convection, a low-probability severe threat might develop within the mid-level jetlet that is downstream of the positive-tilt shortwave trough across the Deep South and Southeast. ..Grams.. 05/19/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 PM CDT Sat May 18 2024 Valid 190100Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN TO SOUTHERN WI...THE CENTRAL HIGH PLAINS...AND NORTH FL TO SOUTHEAST GA... ...SUMMARY... Isolated severe thunderstorms remain possible this evening in parts of eastern to southern Wisconsin and the central High Plains. Isolated severe storms may develop over parts of north Florida and far southeast Georgia during the early morning. ...01Z Update... Overall severe potential has diminished across much of the CONUS. Strong to marginally severe storms may linger for another hour or two across parts of eastern to southern WI. Increasing MLCIN within the modestly buoyant warm sector and diminishing low-level convergence should result in storms further weakening through late evening. High-based, low-topped convection persists across east-central to southeast CO. This activity may still produce locally strong wind gusts and small hail as storms spread east into western KS while impinging on a more buoyant air mass in KS. But with increasing nocturnal MLCIN, the overall severe threat should remain marginal. Finally, across north FL into far southeast GA, recent guidance still suggests renewed warm-advection-driven storms should develop within the lingering low-level baroclinic zone over the northeast Gulf. While overall instability will be more limited in the wake of earlier D1 convection, a low-probability severe threat might develop within the mid-level jetlet that is downstream of the positive-tilt shortwave trough across the Deep South and Southeast. ..Grams.. 05/19/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 PM CDT Sat May 18 2024 Valid 190100Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN TO SOUTHERN WI...THE CENTRAL HIGH PLAINS...AND NORTH FL TO SOUTHEAST GA... ...SUMMARY... Isolated severe thunderstorms remain possible this evening in parts of eastern to southern Wisconsin and the central High Plains. Isolated severe storms may develop over parts of north Florida and far southeast Georgia during the early morning. ...01Z Update... Overall severe potential has diminished across much of the CONUS. Strong to marginally severe storms may linger for another hour or two across parts of eastern to southern WI. Increasing MLCIN within the modestly buoyant warm sector and diminishing low-level convergence should result in storms further weakening through late evening. High-based, low-topped convection persists across east-central to southeast CO. This activity may still produce locally strong wind gusts and small hail as storms spread east into western KS while impinging on a more buoyant air mass in KS. But with increasing nocturnal MLCIN, the overall severe threat should remain marginal. Finally, across north FL into far southeast GA, recent guidance still suggests renewed warm-advection-driven storms should develop within the lingering low-level baroclinic zone over the northeast Gulf. While overall instability will be more limited in the wake of earlier D1 convection, a low-probability severe threat might develop within the mid-level jetlet that is downstream of the positive-tilt shortwave trough across the Deep South and Southeast. ..Grams.. 05/19/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 PM CDT Sat May 18 2024 Valid 190100Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN TO SOUTHERN WI...THE CENTRAL HIGH PLAINS...AND NORTH FL TO SOUTHEAST GA... ...SUMMARY... Isolated severe thunderstorms remain possible this evening in parts of eastern to southern Wisconsin and the central High Plains. Isolated severe storms may develop over parts of north Florida and far southeast Georgia during the early morning. ...01Z Update... Overall severe potential has diminished across much of the CONUS. Strong to marginally severe storms may linger for another hour or two across parts of eastern to southern WI. Increasing MLCIN within the modestly buoyant warm sector and diminishing low-level convergence should result in storms further weakening through late evening. High-based, low-topped convection persists across east-central to southeast CO. This activity may still produce locally strong wind gusts and small hail as storms spread east into western KS while impinging on a more buoyant air mass in KS. But with increasing nocturnal MLCIN, the overall severe threat should remain marginal. Finally, across north FL into far southeast GA, recent guidance still suggests renewed warm-advection-driven storms should develop within the lingering low-level baroclinic zone over the northeast Gulf. While overall instability will be more limited in the wake of earlier D1 convection, a low-probability severe threat might develop within the mid-level jetlet that is downstream of the positive-tilt shortwave trough across the Deep South and Southeast. ..Grams.. 05/19/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 PM CDT Sat May 18 2024 Valid 190100Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF EASTERN TO SOUTHERN WI...THE CENTRAL HIGH PLAINS...AND NORTH FL TO SOUTHEAST GA... ...SUMMARY... Isolated severe thunderstorms remain possible this evening in parts of eastern to southern Wisconsin and the central High Plains. Isolated severe storms may develop over parts of north Florida and far southeast Georgia during the early morning. ...01Z Update... Overall severe potential has diminished across much of the CONUS. Strong to marginally severe storms may linger for another hour or two across parts of eastern to southern WI. Increasing MLCIN within the modestly buoyant warm sector and diminishing low-level convergence should result in storms further weakening through late evening. High-based, low-topped convection persists across east-central to southeast CO. This activity may still produce locally strong wind gusts and small hail as storms spread east into western KS while impinging on a more buoyant air mass in KS. But with increasing nocturnal MLCIN, the overall severe threat should remain marginal. Finally, across north FL into far southeast GA, recent guidance still suggests renewed warm-advection-driven storms should develop within the lingering low-level baroclinic zone over the northeast Gulf. While overall instability will be more limited in the wake of earlier D1 convection, a low-probability severe threat might develop within the mid-level jetlet that is downstream of the positive-tilt shortwave trough across the Deep South and Southeast. ..Grams.. 05/19/2024 Read more

MD 0828 CONCERNING SEVERE THUNDERSTORM WATCH 257... FOR PARTS OF CENTRAL/NORTHEASTERN WISCONSIN INTO ADJACENT PORTIONS OF UPPER MICHIGAN
Mesoscale Discussion 0828 NWS Storm Prediction Center Norman OK 0546 PM CDT Sat May 18 2024 Areas affected...parts of central/northeastern Wisconsin into adjacent portions of Upper Michigan Concerning...Severe Thunderstorm Watch 257... Valid 182246Z - 190045Z The severe weather threat for Severe Thunderstorm Watch 257 continues. SUMMARY...Strong to severe thunderstorm development, including a few supercells posing a risk for severe hail and wind, probably will be maintained while spreading eastward across the region through around 8-9 PM CDT. DISCUSSION...Multiple discrete thunderstorms, including evolving supercells, are ongoing, emanating from a zone of stronger pre-frontal confluence across west central Wisconsin into the western Upper Peninsula of Michigan vicinity. Boundary-layer instability appears maximized along this corridor with mixed-layer CAPE on the order of 1000-1500 J/kg and renewed convective initiation remains possible another couple of hours as this zone shifts slowly eastward. Embedded within strongly sheared, 30-40 kt southwesterly deep-layer mean flow, storms have tended to propagate northeastward and eastward away from the initiating zone. Aided by the strong shear, these storms may continue to pose a risk for severe hail and locally strong gusts while spreading toward the Iron Mountain, Green Bay and Oshkosh vicinities through 00-01Z. While forecast soundings exhibit low-level hodographs potentially conducive to a a risk for tornadoes, it still appears this risk will be limited by sizable boundary-layer temperature/dew point spreads. ..Kerr.. 05/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MQT...GRB...MKX...ARX... LAT...LON 45868902 46428861 46008744 44678817 43778901 43609009 44288998 45358935 45868902 Read more

WW 0257 Status Updates
STATUS REPORT ON WW 257 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NNE VOK TO 30 NE IWD TO 25 SW CMX. ..KERR..05/19/24 ATTN...WFO...MQT...DLH...ARX...GRB... STATUS REPORT FOR WS 257 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MIC013-053-061-071-131-190140- MI . MICHIGAN COUNTIES INCLUDED ARE BARAGA GOGEBIC HOUGHTON IRON ONTONAGON WIC037-041-067-069-073-075-083-085-097-125-135-137-141-190140- WI . WISCONSIN COUNTIES INCLUDED ARE FLORENCE FOREST LANGLADE LINCOLN MARATHON MARINETTE OCONTO ONEIDA PORTAGE VILAS WAUPACA WAUSHARA WOOD LSZ247-190140- CW Read more

MD 0828 CONCERNING SEVERE THUNDERSTORM WATCH 257... FOR PARTS OF CENTRAL/NORTHEASTERN WISCONSIN INTO ADJACENT PORTIONS OF UPPER MICHIGAN
Mesoscale Discussion 0828 NWS Storm Prediction Center Norman OK 0546 PM CDT Sat May 18 2024 Areas affected...parts of central/northeastern Wisconsin into adjacent portions of Upper Michigan Concerning...Severe Thunderstorm Watch 257... Valid 182246Z - 190045Z The severe weather threat for Severe Thunderstorm Watch 257 continues. SUMMARY...Strong to severe thunderstorm development, including a few supercells posing a risk for severe hail and wind, probably will be maintained while spreading eastward across the region through around 8-9 PM CDT. DISCUSSION...Multiple discrete thunderstorms, including evolving supercells, are ongoing, emanating from a zone of stronger pre-frontal confluence across west central Wisconsin into the western Upper Peninsula of Michigan vicinity. Boundary-layer instability appears maximized along this corridor with mixed-layer CAPE on the order of 1000-1500 J/kg and renewed convective initiation remains possible another couple of hours as this zone shifts slowly eastward. Embedded within strongly sheared, 30-40 kt southwesterly deep-layer mean flow, storms have tended to propagate northeastward and eastward away from the initiating zone. Aided by the strong shear, these storms may continue to pose a risk for severe hail and locally strong gusts while spreading toward the Iron Mountain, Green Bay and Oshkosh vicinities through 00-01Z. While forecast soundings exhibit low-level hodographs potentially conducive to a a risk for tornadoes, it still appears this risk will be limited by sizable boundary-layer temperature/dew point spreads. ..Kerr.. 05/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MQT...GRB...MKX...ARX... LAT...LON 45868902 46428861 46008744 44678817 43778901 43609009 44288998 45358935 45868902 Read more

WW 0257 Status Updates
STATUS REPORT ON WW 257 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N VOK TO 25 NNE IWD TO 30 SW CMX. ..KERR..05/18/24 ATTN...WFO...MQT...DLH...ARX...GRB... STATUS REPORT FOR WS 257 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MIC013-053-061-071-131-190040- MI . MICHIGAN COUNTIES INCLUDED ARE BARAGA GOGEBIC HOUGHTON IRON ONTONAGON WIC037-041-067-069-073-085-097-125-141-190040- WI . WISCONSIN COUNTIES INCLUDED ARE FLORENCE FOREST LANGLADE LINCOLN MARATHON ONEIDA PORTAGE VILAS WOOD LSZ247-190040- CW . ADJACENT COASTAL WATERS INCLUDED ARE Read more

WW 257 SEVERE TSTM MI MN WI LS 182030Z - 190300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 257 NWS Storm Prediction Center Norman OK 330 PM CDT Sat May 18 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Upper Michigan Minnesota Arrowhead Central and Northern Wisconsin Lake Superior * Effective this Saturday afternoon and evening from 330 PM until 1000 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms are developing along a cold front over western Wisconsin and northeast Minnesota. These storms will track eastward through the early evening, posing a risk of hail and damaging winds. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 30 miles north northeast of Grand Marais MN to 35 miles south of Mosinee WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart Read more

WW 0257 Status Updates
STATUS REPORT ON WW 257 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 S ASX TO 20 SW GNA TO 40 NNW CMX. ..KERR..05/18/24 ATTN...WFO...MQT...DLH...ARX...GRB... STATUS REPORT FOR WS 257 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MIC013-053-061-071-083-131-182340- MI . MICHIGAN COUNTIES INCLUDED ARE BARAGA GOGEBIC HOUGHTON IRON KEWEENAW ONTONAGON WIC003-019-037-041-051-067-069-073-085-097-099-119-125-141- 182340- WI . WISCONSIN COUNTIES INCLUDED ARE ASHLAND CLARK FLORENCE FOREST IRON LANGLADE LINCOLN MARATHON ONEIDA PORTAGE PRICE TAYLOR VILAS WOOD LSZ121-147-148-150-240-241-242-243-244-245-246-247-263-182340- CW Read more