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WW 250 SEVERE TSTM IA MN NE SD 150635Z - 151400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 250 NWS Storm Prediction Center Norman OK 135 AM CDT Thu May 15 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest Iowa Southwest Minnesota Extreme northeast Nebraska Southeast South Dakota * Effective this Thursday morning from 135 AM until 900 AM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...A line of severe thunderstorms will continue moving northeast across the watch area this morning with a risk for damaging wind gusts and isolated large hail. The severe thunderstorm watch area is approximately along and 35 statute miles east and west of a line from 25 miles east northeast of Brookings SD to 30 miles east southeast of Sioux City IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 249... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Bunting Read more

MD 0784 CONCERNING SEVERE THUNDERSTORM WATCH 250... FOR PARTS OF EASTERN SD INTO SOUTHWEST MN AND FAR NORTHWEST IA
Mesoscale Discussion 0784 NWS Storm Prediction Center Norman OK 0404 AM CDT Thu May 15 2025 Areas affected...Parts of eastern SD into southwest MN and far northwest IA Concerning...Severe Thunderstorm Watch 250... Valid 150904Z - 151030Z The severe weather threat for Severe Thunderstorm Watch 250 continues. SUMMARY...An isolated severe threat may spread northeast out of WW 250 with time this morning. DISCUSSION...A long-lived storm cluster has evolved into a bowing MCS (with embedded cellular elements) from far eastern SD into southwest MN, and strong to locally severe gusts have been reported over the last hour to the northeast of Sioux Falls, SD. Small mesovortices have occasionally been noted along the leading edge of the line, and a threat for localized severe gusts could be maximized with these features, especially where the outflow has not surged ahead of the deeper convection. The northern portion of the line will tend to move into a cooler and less unstable environment with time, though more substantial moisture return above the surface could maintain robust elevated convection through the early morning. The southern portion of the line will be in closer proximity to increasing MLCAPE and weaker MLCINH, though lingering near-surface stability may hamper reintensification potential. An isolated severe threat may spread northeast out of WW 250 with time, though the need for downstream watch issuance is uncertain. ..Dean/Bunting.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...DMX...FSD...ABR... LAT...LON 44179616 45139736 45729686 45619575 45459489 45319442 45059420 44679403 44419403 43999424 43239470 42899540 42889580 43099623 44179616 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu May 15 2025 Valid 181200Z - 231200Z ...DISCUSSION... Medium-range guidance indicates that the persistent, prominent mid/upper ridging across the mid-latitude and subtropical eastern Pacific will become suppressed late this coming weekend into early next week, before breaking down through the remainder of this period. As it does, amplified downstream troughing is forecast to emerge from the Intermountain West. Sunday, this may commence gradually, with one significant lead short wave perturbation pivoting north-northeast of the southern Rockies, accompanied by cyclogenesis across eastern Colorado, as an upstream perturbation continues to dig toward the Four Corners region. It appears that this trailing perturbation will then pivot across the southern Rockies through the central/southern Great Plains by late Monday, perhaps accompanied by renewed cyclogenesis across the Texas Panhandle into central Great Plains. Both days, the dryline and warm front may provide focus for organized severe convective development, including supercells, in the presence of strong deep-layer shear and thermodynamic profiles characterized by steep lapse rates and sizable CAPE. It appears that a substantive risk for strong to severe thunderstorms will persist into at least Tuesday, within a broadening warm sector as the cyclone and associated mid-level troughing shift a bit more rapidly eastward across the middle Mississippi Valley. Convective potential becomes more unclear Wednesday into Thursday as the cyclone likely weakens and synoptic developments become more uncertain across the East. Read more

WW 0249 Status Updates
STATUS REPORT ON WW 249 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NNE OFK TO 25 SSW YKN TO 20 WSW FSD TO 30 W BKX TO 10 NNE HON. ..DEAN..05/15/25 ATTN...WFO...OAX...LBF...GID...FSD... STATUS REPORT FOR WS 249 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC051-150840- NE . NEBRASKA COUNTIES INCLUDED ARE DIXON SDC027-150840- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE CLAY 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 0249 Status Updates
STATUS REPORT ON WW 249 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NNE OFK TO 25 SSW YKN TO 20 WSW FSD TO 30 W BKX TO 10 NNE HON. ..DEAN..05/15/25 ATTN...WFO...OAX...LBF...GID...FSD... STATUS REPORT FOR WS 249 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC051-150840- NE . NEBRASKA COUNTIES INCLUDED ARE DIXON SDC027-150840- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE CLAY 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 0249 Status Updates
STATUS REPORT ON WW 249 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NNE OFK TO 25 SSW YKN TO 20 WSW FSD TO 30 W BKX TO 10 NNE HON. ..DEAN..05/15/25 ATTN...WFO...OAX...LBF...GID...FSD... STATUS REPORT FOR WS 249 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC051-150840- NE . NEBRASKA COUNTIES INCLUDED ARE DIXON SDC027-150840- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE CLAY 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 0249 Status Updates
STATUS REPORT ON WW 249 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NNE OFK TO 25 SSW YKN TO 20 WSW FSD TO 30 W BKX TO 10 NNE HON. ..DEAN..05/15/25 ATTN...WFO...OAX...LBF...GID...FSD... STATUS REPORT FOR WS 249 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC051-150840- NE . NEBRASKA COUNTIES INCLUDED ARE DIXON SDC027-150840- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE CLAY 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 0249 Status Updates
STATUS REPORT ON WW 249 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 NNE OFK TO 25 SSW YKN TO 20 WSW FSD TO 30 W BKX TO 10 NNE HON. ..DEAN..05/15/25 ATTN...WFO...OAX...LBF...GID...FSD... STATUS REPORT FOR WS 249 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC051-150840- NE . NEBRASKA COUNTIES INCLUDED ARE DIXON SDC027-150840- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE CLAY 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 249 SEVERE TSTM NE SD 150100Z - 150800Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 249 NWS Storm Prediction Center Norman OK 800 PM CDT Wed May 14 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of East-Central and Northeast Nebraska Southeast South Dakota * Effective this Wednesday night and Thursday morning from 800 PM until 300 AM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter likely Scattered damaging winds likely with isolated significant gusts to 75 mph possible A tornado or two possible SUMMARY...Thunderstorms over central Nebraska will becoming increasingly organized and track northeastward through the evening and overnight period. Damaging wind gusts and large hail will be through across the watch area. A tornado or two is also possible. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 5 miles west northwest of Mitchell SD to 25 miles west southwest of Grand Island NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 247...WW 248... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25035. ...Hart Read more

WW 0250 Status Updates
STATUS REPORT ON WW 250 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..05/15/25 ATTN...WFO...FSD... STATUS REPORT FOR WS 250 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-141-143-149-167-193-150840- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON O'BRIEN OSCEOLA PLYMOUTH SIOUX WOODBURY MNC033-063-081-083-101-105-117-133-150840- MN . MINNESOTA COUNTIES INCLUDED ARE COTTONWOOD JACKSON LINCOLN LYON MURRAY NOBLES PIPESTONE ROCK NEC043-150840- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

WW 0250 Status Updates
STATUS REPORT ON WW 250 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..05/15/25 ATTN...WFO...FSD... STATUS REPORT FOR WS 250 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-141-143-149-167-193-150840- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON O'BRIEN OSCEOLA PLYMOUTH SIOUX WOODBURY MNC033-063-081-083-101-105-117-133-150840- MN . MINNESOTA COUNTIES INCLUDED ARE COTTONWOOD JACKSON LINCOLN LYON MURRAY NOBLES PIPESTONE ROCK NEC043-150840- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

WW 0250 Status Updates
STATUS REPORT ON WW 250 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..DEAN..05/15/25 ATTN...WFO...FSD... STATUS REPORT FOR WS 250 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC021-035-041-059-093-119-141-143-149-167-193-150840- IA . IOWA COUNTIES INCLUDED ARE BUENA VISTA CHEROKEE CLAY DICKINSON IDA LYON O'BRIEN OSCEOLA PLYMOUTH SIOUX WOODBURY MNC033-063-081-083-101-105-117-133-150840- MN . MINNESOTA COUNTIES INCLUDED ARE COTTONWOOD JACKSON LINCOLN LYON MURRAY NOBLES PIPESTONE ROCK NEC043-150840- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

MD 0783 CONCERNING SEVERE THUNDERSTORM WATCH 249... FOR NORTHEAST NE...SOUTHEAST SD...NORTHWEST IA...SOUTHWEST MN
Mesoscale Discussion 0783 NWS Storm Prediction Center Norman OK 0108 AM CDT Thu May 15 2025 Areas affected...Northeast NE...southeast SD...northwest IA...southwest MN Concerning...Severe Thunderstorm Watch 249... Valid 150608Z - 150745Z The severe weather threat for Severe Thunderstorm Watch 249 continues. SUMMARY...Some severe threat could spread northeast overnight. DISCUSSION...A long-lived storm cluster is moving northeastward across northeast NE and southeast SD early this morning, downstream of a midlevel shortwave trough and possible MCV over north-central NE. A rather strong low-level jet (evident on the KOAX and KFSD VWPs) and favorable upper-level difluence will help to maintain convection through the overnight hours. Moderate buoyancy will spread into a larger portion of eastern SD and southwest MN overnight, while modestly favorable deep-layer shear will continue to support organized convection. The strongest storms within this cluster will continue to be capable of producing isolated large hail and strong to locally severe gusts. Some increase in severe-wind potential is possible if more organized upscale growth occurs overnight, though this potential remains uncertain. Also, while the bulk of convection may remain somewhat elevated, there remains some conditional potential for near-surface-based supercells within the southern part of the cluster, and a tornado cannot be ruled out. With WW 249 scheduled to expire at 3 AM CDT, new watch issuance is possible overnight, depending on short-term observational trends. ..Dean/Bunting.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...FSD...OAX...ABR...GID...LBF... LAT...LON 41569836 42179845 43439770 44719794 44939635 44539570 44009534 43049538 42369564 41699654 41569748 41569788 41569836 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more