Severe Storms

WW 0222 Status Updates
STATUS REPORT ON WW 222 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SW STL TO 15 NE ALN TO 20 NE SPI. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0788 ..THORNTON..05/13/23 ATTN...WFO...LSX...ILX...PAH... STATUS REPORT FOR WS 222 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-021-025-027-049-051-055-065-077-081-115-119-121-133-135- 139-145-157-163-173-189-191-132240- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CHRISTIAN CLAY CLINTON EFFINGHAM FAYETTE FRANKLIN HAMILTON JACKSON JEFFERSON MACON MADISON MARION MONROE MONTGOMERY MOULTRIE PERRY RANDOLPH ST. CLAIR SHELBY WASHINGTON WAYNE MOC055-093-099-123-157-179-186-187-221-132240- MO . MISSOURI COUNTIES INCLUDED ARE CRAWFORD IRON JEFFERSON MADISON PERRY REYNOLDS Read more

WW 0222 Status Updates
STATUS REPORT ON WW 222 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SW STL TO 15 NE ALN TO 20 NE SPI. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0788 ..THORNTON..05/13/23 ATTN...WFO...LSX...ILX...PAH... STATUS REPORT FOR WS 222 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-021-025-027-049-051-055-065-077-081-115-119-121-133-135- 139-145-157-163-173-189-191-132240- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CHRISTIAN CLAY CLINTON EFFINGHAM FAYETTE FRANKLIN HAMILTON JACKSON JEFFERSON MACON MADISON MARION MONROE MONTGOMERY MOULTRIE PERRY RANDOLPH ST. CLAIR SHELBY WASHINGTON WAYNE MOC055-093-099-123-157-179-186-187-221-132240- MO . MISSOURI COUNTIES INCLUDED ARE CRAWFORD IRON JEFFERSON MADISON PERRY REYNOLDS Read more

WW 222 SEVERE TSTM IL MO 131725Z - 140000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 222 NWS Storm Prediction Center Norman OK 1225 PM CDT Sat May 13 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Illinois Far East-Central Missouri * Effective this Saturday afternoon and evening from 1225 PM until 700 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Line of thunderstorms currently moving across far east-central MO is expected to continue eastward into the unstable airmass across southern IL. A threat for damaging gusts and large hail will accompany the strongest storms within this line. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 50 miles northwest of Saint Louis MO to 40 miles northeast of Salem IL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). 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 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Mosier Read more

WW 222 SEVERE TSTM IL MO 131725Z - 140000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 222 NWS Storm Prediction Center Norman OK 1225 PM CDT Sat May 13 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Illinois Far East-Central Missouri * Effective this Saturday afternoon and evening from 1225 PM until 700 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Line of thunderstorms currently moving across far east-central MO is expected to continue eastward into the unstable airmass across southern IL. A threat for damaging gusts and large hail will accompany the strongest storms within this line. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 50 miles northwest of Saint Louis MO to 40 miles northeast of Salem IL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). 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 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Mosier Read more

MD 0789 CONCERNING TORNADO WATCH 223... FOR CENTRAL TO SOUTHEAST IOWA
Mesoscale Discussion 0789 NWS Storm Prediction Center Norman OK 0331 PM CDT Sat May 13 2023 Areas affected...Central to southeast Iowa Concerning...Tornado Watch 223... Valid 132031Z - 132230Z The severe weather threat for Tornado Watch 223 continues. SUMMARY...The tornado threat continues across parts of WW 223. Confidence in the severe threat is highest across parts of central/northwest IA as well as south-central/southeast IA for the next few hours. DISCUSSION...Regional radar imagery over the past couple of hours has shown a broken band of discrete convection across northwest IA as well as more discrete convection across central/southeast IA. Despite a favorable thermodynamic and kinematic environment for supercells (MLCAPE over 1000 J/kg and 40-50 knots of effective bulk shear per latest RAP analyses), convection thus far appears to not be fully realizing the available environment based on the relatively short lifespan of individual cells and rather anemic appearance of most convection in IR imagery. This is likely due to fairly weak low-level forcing for ascent with a notable diminishment of cumulus depth and westward retrograde of the warm front noted in surface obs across central IA. Despite this limitation, a few brief tornadoes have been reported since 18 UTC, and the KDMX VWP continues to sample 0-1 km SHR on the order of 100-150 m2/s2. Given the aforementioned environmental characteristics, a conditional tornado threat continues across the entire watch area. Over the next couple of hours, a relatively higher severe threat will likely be focused within two corridors to the northwest and southeast of the Des Moines area. Within these corridors, visible satellite imagery has shown persistent agitated cumulus and multiple attempts at more robust convection. This supports recent RAP analyses that depict locally enhanced low-level convergence and ambient vorticity along the frontal boundary that may be conducive for tornadogenesis with any stronger updraft. Recent hi-res guidance continues to hint that the greatest potential for long-lived tornadic supercells resides across south-central IA, which matches environmental trends (higher buoyancy and stronger baroclinicity along the warm front) and recent radar/satellite observations. ..Moore.. 05/13/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...DMX...EAX...FSD... LAT...LON 41489446 41689472 42009506 42309534 42639551 42809541 42899506 42779454 42389404 41949339 41739279 41559216 41369180 41089158 40679172 40589204 40599254 40769304 40979355 41079378 41489446 Read more

MD 0789 CONCERNING TORNADO WATCH 223... FOR CENTRAL TO SOUTHEAST IOWA
Mesoscale Discussion 0789 NWS Storm Prediction Center Norman OK 0331 PM CDT Sat May 13 2023 Areas affected...Central to southeast Iowa Concerning...Tornado Watch 223... Valid 132031Z - 132230Z The severe weather threat for Tornado Watch 223 continues. SUMMARY...The tornado threat continues across parts of WW 223. Confidence in the severe threat is highest across parts of central/northwest IA as well as south-central/southeast IA for the next few hours. DISCUSSION...Regional radar imagery over the past couple of hours has shown a broken band of discrete convection across northwest IA as well as more discrete convection across central/southeast IA. Despite a favorable thermodynamic and kinematic environment for supercells (MLCAPE over 1000 J/kg and 40-50 knots of effective bulk shear per latest RAP analyses), convection thus far appears to not be fully realizing the available environment based on the relatively short lifespan of individual cells and rather anemic appearance of most convection in IR imagery. This is likely due to fairly weak low-level forcing for ascent with a notable diminishment of cumulus depth and westward retrograde of the warm front noted in surface obs across central IA. Despite this limitation, a few brief tornadoes have been reported since 18 UTC, and the KDMX VWP continues to sample 0-1 km SHR on the order of 100-150 m2/s2. Given the aforementioned environmental characteristics, a conditional tornado threat continues across the entire watch area. Over the next couple of hours, a relatively higher severe threat will likely be focused within two corridors to the northwest and southeast of the Des Moines area. Within these corridors, visible satellite imagery has shown persistent agitated cumulus and multiple attempts at more robust convection. This supports recent RAP analyses that depict locally enhanced low-level convergence and ambient vorticity along the frontal boundary that may be conducive for tornadogenesis with any stronger updraft. Recent hi-res guidance continues to hint that the greatest potential for long-lived tornadic supercells resides across south-central IA, which matches environmental trends (higher buoyancy and stronger baroclinicity along the warm front) and recent radar/satellite observations. ..Moore.. 05/13/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...DMX...EAX...FSD... LAT...LON 41489446 41689472 42009506 42309534 42639551 42809541 42899506 42779454 42389404 41949339 41739279 41559216 41369180 41089158 40679172 40589204 40599254 40769304 40979355 41079378 41489446 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Sat May 13 2023 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM IOWA INTO CENTRAL ILLINOIS... ...SUMMARY... Thunderstorms associated with a few tornadoes, wind damage and large hail remain possible this afternoon and evening from Iowa into central Illinois. Isolated strong to severe storms are also possible across southern Oklahoma and East Texas as well as the eastern Virginia/North Carolina border vicinity. ...IA into the mid MS Valley... The Slight Risk across IA has been expanded slightly to the west and trimmed from the northeast, based on the location of ongoing convection and an outflow-reinforced surface boundary that is expected to move little during the rest of the afternoon. The environment remains only marginally favorable for supercells, but storms near the boundary may continue to pose a threat for at least brief tornadoes, in addition to isolated hail and gusty winds. Farther south, a storm cluster is ongoing from near St. Louis into parts of central IL. This cluster may continue to pose a threat for isolated severe hail/wind and possibly a brief tornado as it moves eastward this afternoon, and the Slight Risk has been expanded slightly southeastward. Renewed development along the remnant outflow cannot be ruled out back into east-central/northeast MO, which could also pose at least an isolated severe threat later this afternoon into the evening. ...Central/southern OK...ArkLaTex...East TX... 2% tornado probabilities have been confined to parts of southwest/central OK and north TX, in closer proximity to ambient surface vorticity near an MCV and associated weak surface low. Otherwise, no changes have been made to the Marginal Risk. See the previous discussion below. ...VA Tidewater into northern NC... No changes have been made to this area, see the previous discussion below for more information. ..Dean.. 05/13/2023 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat May 13 2023/ ...IA into the Mid MS Valley... Recent surface analysis places a low about 30 miles northwest of OFK in far northeast NE. A cold front extends southward from this low through central KS and then back southwestward from north-central trough southwest OK. Surface pattern east of the low is a bit more complex, with a warm front extending from the low southeastward across southwest IA and into north-central MO. This warm front intersects a residual stationary boundary near DSM, with this stationary boundary continuing eastward across the OH Valley. The surface low is forecast to make modest eastward progress throughout the day, with the warm front continuing to move northward as well. However, the presence of the stationary boundary may impeded the northern progression of the warm front somewhat. Expectation is a corridor or mid to upper 60s dewpoints to extend from east-central MO/southern IL northwestward through central IA. This corridor will likely be south of the warm front, but east of dryline-like boundary that is expected to mix eastward with time. Moderate buoyancy is anticipated within this corridor as well, contributing to likely thunderstorm development as the boundary moves eastward. Southeasterly surface winds will beneath modest westerlies will contribute to moderate deep-layer vertical shear and the potential for more organized storm structures capable of all severe hazards across IA. Strong low-level buoyancy (i.e. 0-3 km MLCAPE greater than 150 J/kg) and low-level vorticity throughout the corridor of southeasterly winds could increase what would otherwise be a low probability tornado risk given anticipated shear magnitudes. Farther south, surface winds will be weaker with a more outflow-dominant storm structure anticipated. Here, some clustering is also possible, with storms then forward-propagating into west-central IL. ...Central/Southern OK...Arklatex...East TX... Widespread thunderstorm development is anticipated this afternoon from central OK eastward into the Arklatex and East TX amid the tropical air mass in place. Vertical shear is weak, limiting storm organization and the overall severe potential. Even so, a few water-loaded downbursts and maybe even a tornado or two remain possible. This low-probability tornado threat appears maximized across southern OK, where greater low-level vorticity is expected. ...VA Tidewater...Northeast NC... An upper trough is rotating quickly southeastward into New England, with a cold front sagging southward across WV/VA. This boundary will move into a relatively moist airmass over southern VA this afternoon, resulting in thunderstorm development. Strengthening westerly flow aloft and relatively steep boundary-layer lapse rates may result in a few strong wind gusts in the more intense cells. Activity will move into northern NC this evening before weakening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Sat May 13 2023 Valid 132000Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM IOWA INTO CENTRAL ILLINOIS... ...SUMMARY... Thunderstorms associated with a few tornadoes, wind damage and large hail remain possible this afternoon and evening from Iowa into central Illinois. Isolated strong to severe storms are also possible across southern Oklahoma and East Texas as well as the eastern Virginia/North Carolina border vicinity. ...IA into the mid MS Valley... The Slight Risk across IA has been expanded slightly to the west and trimmed from the northeast, based on the location of ongoing convection and an outflow-reinforced surface boundary that is expected to move little during the rest of the afternoon. The environment remains only marginally favorable for supercells, but storms near the boundary may continue to pose a threat for at least brief tornadoes, in addition to isolated hail and gusty winds. Farther south, a storm cluster is ongoing from near St. Louis into parts of central IL. This cluster may continue to pose a threat for isolated severe hail/wind and possibly a brief tornado as it moves eastward this afternoon, and the Slight Risk has been expanded slightly southeastward. Renewed development along the remnant outflow cannot be ruled out back into east-central/northeast MO, which could also pose at least an isolated severe threat later this afternoon into the evening. ...Central/southern OK...ArkLaTex...East TX... 2% tornado probabilities have been confined to parts of southwest/central OK and north TX, in closer proximity to ambient surface vorticity near an MCV and associated weak surface low. Otherwise, no changes have been made to the Marginal Risk. See the previous discussion below. ...VA Tidewater into northern NC... No changes have been made to this area, see the previous discussion below for more information. ..Dean.. 05/13/2023 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sat May 13 2023/ ...IA into the Mid MS Valley... Recent surface analysis places a low about 30 miles northwest of OFK in far northeast NE. A cold front extends southward from this low through central KS and then back southwestward from north-central trough southwest OK. Surface pattern east of the low is a bit more complex, with a warm front extending from the low southeastward across southwest IA and into north-central MO. This warm front intersects a residual stationary boundary near DSM, with this stationary boundary continuing eastward across the OH Valley. The surface low is forecast to make modest eastward progress throughout the day, with the warm front continuing to move northward as well. However, the presence of the stationary boundary may impeded the northern progression of the warm front somewhat. Expectation is a corridor or mid to upper 60s dewpoints to extend from east-central MO/southern IL northwestward through central IA. This corridor will likely be south of the warm front, but east of dryline-like boundary that is expected to mix eastward with time. Moderate buoyancy is anticipated within this corridor as well, contributing to likely thunderstorm development as the boundary moves eastward. Southeasterly surface winds will beneath modest westerlies will contribute to moderate deep-layer vertical shear and the potential for more organized storm structures capable of all severe hazards across IA. Strong low-level buoyancy (i.e. 0-3 km MLCAPE greater than 150 J/kg) and low-level vorticity throughout the corridor of southeasterly winds could increase what would otherwise be a low probability tornado risk given anticipated shear magnitudes. Farther south, surface winds will be weaker with a more outflow-dominant storm structure anticipated. Here, some clustering is also possible, with storms then forward-propagating into west-central IL. ...Central/Southern OK...Arklatex...East TX... Widespread thunderstorm development is anticipated this afternoon from central OK eastward into the Arklatex and East TX amid the tropical air mass in place. Vertical shear is weak, limiting storm organization and the overall severe potential. Even so, a few water-loaded downbursts and maybe even a tornado or two remain possible. This low-probability tornado threat appears maximized across southern OK, where greater low-level vorticity is expected. ...VA Tidewater...Northeast NC... An upper trough is rotating quickly southeastward into New England, with a cold front sagging southward across WV/VA. This boundary will move into a relatively moist airmass over southern VA this afternoon, resulting in thunderstorm development. Strengthening westerly flow aloft and relatively steep boundary-layer lapse rates may result in a few strong wind gusts in the more intense cells. Activity will move into northern NC this evening before weakening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0128 PM CDT Sat May 13 2023 Valid 141200Z - 151200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 05/13/2023 .PREV DISCUSSION... /ISSUED 0146 AM CDT Sat May 13 2023/ ...Synopsis... Similar to Day 1/Saturday, boundary-layer mixing into strong west-northwesterly flow aloft could favor dry/gusty conditions across parts of the Northeast during the afternoon. While locally elevated conditions are possible, the fire-weather threat appears too marginal/localized for Elevated highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sat May 13 2023 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF MO/IL SOUTHEASTWARD INTO THE TN VALLEY... ...SUMMARY... A few strong/locally severe storms are forecast to affect portions of the Midwest, lower Ohio Valley, and Tennessee Valley, mainly Sunday afternoon and evening. Isolated hail and locally damaging winds are expected to be the primary threats. ...Parts of MO/IL into the lower OH Valley and TN Valley... An occluded cyclone is expected to continue decaying on Sunday, with the surface remnant of this system expected to move southward across MO in conjunction with a cold front. South of the cold front, relatively rich low-level moisture and diurnal heating will support moderate destabilization during the afternoon, with MLCAPE generally increasing into the 1000-2000 J/kg range. Widely scattered thunderstorm development is expected within the weakly capped environment along/south of the front. Stronger mid/upper-level flow will remain mostly displaced north of the warm sector, but modest midlevel west/northwesterly flow will support effective shear in the 25-35 kt range, sufficient for a few stronger multicells and perhaps a supercell or two, with an attendant risk of isolated hail and strong/damaging gusts. Some upscale growth into one or more clusters is possible during the evening, which would maintain an isolated damaging wind risk. Farther south into the TN Valley, a remnant MCS may move through the region in the morning, with potential redevelopment of isolated storms along outflow during the afternoon, and potential for additional clusters spreading southeastward into the area later Sunday evening. With generally modest instability and weak deep-layer shear in place, convection will likely remain mostly disorganized, but isolated damaging wind cannot be ruled out with any stronger rounds of convection. ...Parts of NV/UT... Scattered thunderstorms are expected across parts of the Great Basin on Sunday, associated with a retrograding upper low. Modest southerly midlevel flow on the east side of the upper low may weakly augment deep-layer shear, and isolated strong gusts cannot be ruled out, but any severe wind potential is expected to remain quite isolated. ..Dean.. 05/13/2023 Read more

WW 0216 Status Updates
STATUS REPORT ON WW 216 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..THORNTON..05/12/23 ATTN...WFO...MAF...SJT...EWX...LUB... STATUS REPORT FOR WS 216 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TXC033-043-059-081-083-095-103-105-135-137-151-173-207-227-235- 253-263-267-271-301-317-323-327-329-335-353-371-383-389-399-413- 415-417-431-433-435-441-443-447-451-461-465-475-495-122240- TX . TEXAS COUNTIES INCLUDED ARE BORDEN BREWSTER CALLAHAN COKE COLEMAN CONCHO CRANE CROCKETT ECTOR EDWARDS FISHER GLASSCOCK HASKELL HOWARD IRION JONES KENT KIMBLE KINNEY LOVING MARTIN MAVERICK MENARD MIDLAND MITCHELL NOLAN PECOS REAGAN REEVES RUNNELS SCHLEICHER SCURRY SHACKELFORD STERLING STONEWALL SUTTON TAYLOR TERRELL THROCKMORTON TOM GREEN UPTON VAL VERDE WARD WINKLER THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL Read more

WW 216 SEVERE TSTM TX 121950Z - 130300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 216 NWS Storm Prediction Center Norman OK 250 PM CDT Fri May 12 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of West and Southwest Texas * Effective this Friday afternoon and evening from 250 PM until 1000 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorm coverage is expected to increase this afternoon across west and southwest Texas. A very unstable air mass is in place, supporting robust updrafts capable of producing large hail. Strong downbursts are also possible, along with the potential for a few forward-propagating clusters which could also produce damaging gusts. A few strong storms could move off the higher terrain of northeast Mexico into Edwards Plateau as well. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 100 miles southwest of Del Rio TX to 70 miles north northwest of Abilene TX. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). 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 215... 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 27020. ...Mosier Read more

WW 0217 Status Updates
STATUS REPORT ON WW 217 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..THORNTON..05/12/23 ATTN...WFO...OUN...TSA...FWD... STATUS REPORT FOR WS 217 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OKC015-017-019-027-029-031-033-037-049-051-063-067-069-071-073- 081-083-085-087-095-099-103-105-107-109-111-113-117-119-123-125- 131-133-137-141-143-145-147-122240- OK . OKLAHOMA COUNTIES INCLUDED ARE CADDO CANADIAN CARTER CLEVELAND COAL COMANCHE COTTON CREEK GARVIN GRADY HUGHES JEFFERSON JOHNSTON KAY KINGFISHER LINCOLN LOGAN LOVE MCCLAIN MARSHALL MURRAY NOBLE NOWATA OKFUSKEE OKLAHOMA OKMULGEE OSAGE PAWNEE PAYNE PONTOTOC POTTAWATOMIE ROGERS SEMINOLE STEPHENS TILLMAN TULSA WAGONER WASHINGTON TXC009-023-077-097-237-275-337-485-487-497-503-122240- TX . TEXAS COUNTIES INCLUDED ARE Read more

WW 217 SEVERE TSTM OK TX 122040Z - 130400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 217 NWS Storm Prediction Center Norman OK 340 PM CDT Fri May 12 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest/Central/Northeast Oklahoma Northwest Texas * Effective this Friday afternoon and evening from 340 PM until 1100 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms are expected to increase in coverage and intensity this afternoon and evening across northwest Texas and southwest/central/northeast Oklahoma. Strong instability will support robust updrafts capable of large hail. Damaging downbursts are possible as well. Storms may grow upscale into a convective line, which could also produce damaging wind gusts as it moves southeastward. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 45 miles south of Wichita Falls TX to 30 miles west northwest of Tulsa OK. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 215...WW 216... 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. ...Mosier Read more

WW 0215 Status Updates
STATUS REPORT ON WW 215 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 E HSI TO 20 WNW OLU TO 30 SSE ONL TO 30 NNW BUB TO 30 E MHN. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0775 ..THORNTON..05/12/23 ATTN...WFO...OAX...FSD...LBF...GID...ABR...UNR... STATUS REPORT FOR WT 215 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC071-085-093-129-133-137-145-149-155-165-193-122240- IA . IOWA COUNTIES INCLUDED ARE FREMONT HARRISON IDA MILLS MONONA MONTGOMERY PAGE PLYMOUTH POTTAWATTAMIE SHELBY WOODBURY NEC003-015-017-021-023-025-027-037-039-043-051-053-055-067-089- 097-103-107-109-119-127-131-133-139-141-147-149-153-155-159-167- 173-177-179-122240- NE . NEBRASKA COUNTIES INCLUDED ARE ANTELOPE BOYD BROWN BURT BUTLER CASS CEDAR COLFAX CUMING DAKOTA DIXON DODGE DOUGLAS GAGE HOLT Read more

WW 215 TORNADO IA NE SD 121810Z - 130200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 215 NWS Storm Prediction Center Norman OK 110 PM CDT Fri May 12 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Far Western Iowa Central and Eastern Nebraska South-Central South Dakota * Effective this Friday afternoon and evening from 110 PM until 900 PM CDT. * Primary threats include... A couple tornadoes possible Scattered large hail and isolated very large hail events to 2 inches in diameter likely Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms are expected to develop across portions of the central Plains this afternoon. Environmental conditions will support strong to severe thunderstorms, including some supercells capable of tornadoes and very large hail (i.e. greater than 2 inches in diameter). The tornado watch area is approximately along and 70 statute miles north and south of a line from 40 miles north northwest of Ainsworth NE to 40 miles northeast of Shenandoah IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && AVIATION...Tornadoes and 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 19025. ...Mosier Read more

MD 0776 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN KANSAS
Mesoscale Discussion 0776 NWS Storm Prediction Center Norman OK 0357 PM CDT Fri May 12 2023 Areas affected...Eastern Kansas Concerning...Severe potential...Watch possible Valid 122057Z - 122300Z Probability of Watch Issuance...40 percent SUMMARY...Isolated, but intense, thunderstorms are possible across eastern Kansas within the next few hours. Storm coverage remains uncertain, but trends will be monitored for possible watch issuance. DISCUSSION...Visible satellite imagery across eastern KS shows a deepening trend of cumulus congestus along a dryline over the past hour. A 19 UTC sounding from TOP shows residual capping in place over the region, and forcing for ascent along this portion of the boundary remains somewhat weaker given some displacement from stronger synoptic ascent to the north. Additional daytime heating over the next couple of hours should allow temperatures to warm further into the mid 80s, combined with adequate residence time within the dryline circulation based on the TOP wind profile, may be sufficient for isolated convection. While the number of storms remains uncertain, the environment is characterized by strong buoyancy (MLCAPE near 3000 J/kg) and favorable deep-layer shear for organized supercells with an attendant risk of large hail and severe winds (and perhaps a tornado closer to the I-70 corridor where low-level flow is more backed to the southeast compared to locations further south). Trends will continue to be monitored for thunderstorm initiation, and a watch may be needed. ..Moore/Mosier.. 05/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN... LAT...LON 37139712 37899669 38959638 39019640 39309574 39269520 38929476 38449466 37729477 37209518 36959569 36919647 36929687 37139712 Read more

MD 0775 CONCERNING TORNADO WATCH 215... FOR NORTHEAST NEBRASKA TO NORTHEAST KANSAS
Mesoscale Discussion 0775 NWS Storm Prediction Center Norman OK 0323 PM CDT Fri May 12 2023 Areas affected...Northeast Nebraska to northeast Kansas Concerning...Tornado Watch 215... Valid 122023Z - 122230Z The severe weather threat for Tornado Watch 215 continues. SUMMARY...The severe threat across WW 215 will continue for the next several hours. The tornado threat will likely be maximized in the near-term across northeast Nebraska, while the severe threat is expected to increase across eastern Nebraska to northeast Kansas over the next couple of hours as storms mature. DISCUSSION...Over the past 1-2 hours, regional reflectivity/velocity imagery has shown several organized splitting supercells developing along and ahead of a northward migrating dryline. Splitting supercells have been observed within the arcing band of convection, with the right moving cells exhibiting strong mesocyclones capable of producing tornadoes (with a few tornadoes already reported). This is likely due to enhanced low-level SRH along a subtle confluence axis noted in recent surface observations. The storms associated with recent tornado reports appear to be residing along this boundary as they move to the northwest. This will maintain the tornado threat for the next hour or so. Beyond this time frame, increasing storm interactions casts some uncertainty into the longevity of any one cell. Further the southeast across eastern NE into far northeast KS, cell development is noted along the dryline where richer boundary-layer moisture is supporting MLCAPE values in excess of 1500-3000 J/kg. Additionally, VWP observations from KOAX, supported by recent 19 UTC soundings from OAX and TOP, suggest low-level SRH is on the order of 100-150 m2/s2, which should support an increasing tornado threat over the next couple of hours as cells mature, but prior to gradual upscale growth this evening. An additional watch may be needed in the near-term for parts of northeast KS to address this concern. ..Moore.. 05/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...FSD...OAX...TOP...GID...LBF... LAT...LON 41009818 41499940 41690014 41920067 42340072 42810024 42979928 42739761 42149664 41329612 40349557 39689548 39449625 39409667 40359731 41009818 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0308 PM CDT Fri May 12 2023 Valid 122000Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST NE/FAR SOUTHEAST SD INTO EAST-CENTRAL NE/WESTERN IA... ...SUMMARY... Strong to severe thunderstorms are expected to continue into this evening across northeast Nebraska and vicinity, where a few tornadoes, very large hail and wind damage will be possible. Strong to severe storms are also expected to develop from eastern Kansas southward to Texas later this afternoon, with a potential for damaging winds and large hail. ...20Z Update... A 10% tornado area has been added from north-central into east-central NE. An arc of several potentially tornadic storms is ongoing across central/northern NE, in association with an occluded cyclone centered near North Platte. Favorable low-level shear within an environment characterized by enhanced low-level CAPE and ambient vorticity near the surface cyclone will continue to support the potential a few tornadoes. Severe potential is expected to expand into parts of southeast NE and western IA later this afternoon, with all severe hazards possible. Farther south, a substantial increase in thunderstorm coverage is expected later this afternoon and evening from OK into much of TX, along/east of a weak surface boundary. While deep-layer shear is marginal at best, large buoyancy will support a threat of hail and severe gusts with outflow-driven cells/clusters through the evening and potentially into the overnight hours. See the previous discussion below for more information. ..Dean.. 05/12/2023 .PREV DISCUSSION... /ISSUED 1119 AM CDT Fri May 12 2023/ ...Eastern NE into the Mid MO Valley ... Morning satellite imagery and surface observations show a stacked cyclone centered over western KS/NE border vicinity. Occluded surface low associated with this cyclone is forecast to further occlude as it lifts northward throughout the day. Warm sector to the north and east of the surface low is characterized by temperatures and dewpoints in the mid to upper 60s. Modest heating within this moist low-level environment is expected to result in moderate to strong buoyancy by the early afternoon. Thunderstorm development is then anticipated as a cold front associated with the low pushes into the region during the early afternoon. Ample buoyancy will exist for storms to persist as the move northward/northeastward off the boundary. Vertical shear is sufficient for storm organization, but is not overly strong, owing to the weakening mid-level flow. This weakening is somewhat countered by the modest southeasterly low-level flow, and resulting low-level veering with height. However, the overall wind profile leads to some questions regarding overall supercell coverage, with a somewhat clustered storm mode currently anticipated. Even so, a few supercells capable of all severe hazards, including very large hail and tornadoes, are still possible. Additionally, ambient low-level vorticity should enhance the tornado potential along and north of the front. ...Eastern KS into southern OK/northwest TX... Ample low-level moisture exists east of a Pacific front/dryline extending from the surface low over the western KS/NE border vicinity southward through central KS and then back southwestward through northwest TX. This dryline may make modest eastward progress across KS today (and even less across OK) before then retreating back westward later this evening. Large-scale forcing for ascent is nebulous, but mesoscale ascent along this dryline combined with a destabilized airmass with moderate to strong buoyancy is expected to result in thunderstorm development. Modest deep-layer flow and resultant modest shear suggests a potential outflow-dominant storm mode, but a few transient supercell structures could still occur. Strong gusts and large hail are the primary severe threats. ...West TX into the TX Hill Country... Current satellite imagery shows a weak shortwave trough moving through northern Mexico. This shortwave is expected to continue northeastward into Trans-Pecos, interacting with the warm, moist, and strongly buoyant air mass across the region. Widespread thunderstorm development is anticipated, with an outflow-dominant, multicellular mode favored. Some amalgamation along outflows is expected, with resulting clusters also capable of damaging gusts. Storm interactions may also result in updrafts strong enough to produce large hail. ...Portions of the Southeast... Weak convective cluster continues to gradually push southeastward from the Mid-South into MS. 12Z JAN sounding sampled over 7 deg C per km from 700 to 500 mb and recent observations show upper 60s to low 70s dewpoints ahead of the cluster across MS. These conditions, coupled with diurnal heating, is expected to result in strong buoyancy this afternoon. Redevelopment along this outflow could result in a few stronger storms capable of water-loaded downbursts. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 PM CDT Fri May 12 2023 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 05/12/2023 .PREV DISCUSSION... /ISSUED 0143 AM CDT Fri May 12 2023/ ...Synopsis... A broad midlevel low will be centered over portions of the Great Basin. On the backside of this feature, enhanced northerly midlevel flow will overspread a relatively warm/dry airmass over the western CONUS. While locally dry/breezy conditions are possible (primarily focused along/east of the Cascades), these conditions will be too marginal/localized for any highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more