MD 0843 CONCERNING TORNADO WATCH 279... FOR CENTRAL OKLAHOMA
Mesoscale Discussion 0843 NWS Storm Prediction Center Norman OK 0435 PM CDT Sat May 17 2025 Areas affected...Central Oklahoma Concerning...Tornado Watch 279... Valid 172135Z - 172300Z The severe weather threat for Tornado Watch 279 continues. SUMMARY...The severe threat for WW 279 is increasing, with an isolated supercell thunderstorm ongoing across central Oklahoma. All hazards are anticipated, including hail larger than 2.00", 65-80 MPH winds, and tornadoes. DISCUSSION...Recent radar imagery shows an ongoing supercell thunderstorm that is undergoing an updraft split. 20Z OUN sounding data and KTLX VAD data show very strong low-level shear and streamwise vorticity that will favor the right split and an eastward storm motion along the warm front, resulting in increased tornado potential this afternoon into the evening. A strong tornado is possible with the right splitting supercell as it approaches and crosses the I-35 corridor in the next 1-2 hours. Echo tops on the right-split of the supercell have increased to 55 kft, suggesting rapid updraft intensification. Any additional thunderstorms that develop and interact with the warm front will be capable of all hazards. ..Halbert.. 05/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TSA...OUN... LAT...LON 34389875 34659956 34919988 35359994 35589951 35769911 35659756 35549688 35279585 34909543 34499561 34259620 34239737 34389875 MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0500 PM CDT Sat May 17 2025 Valid 191200Z - 251200Z An upper-level trough and associated mid-level wind maximum will contribute to ongoing elevated/critical fire weather conditions across portions of southern New Mexico/western Texas for Day 3/Monday. Residual precipitation and higher elevation snow within a cool, post frontal air mass will temporarily mitigate fire weather threat across the Intermountain West north of Interstate 40. Several upper-level embedded short waves should calm fire weather concerns across the Northern Rockies with several opportunities for precipitation through Day 8/Saturday. Dry conditions under a building ridge and suppressed surface pressure gradients will accompany rising temperatures across the Southwest, aiding in drying of fuels. ...Southwest... Persistent critical fire weather conditions are expected for Day 3/Monday across southern New Mexico and far western Texas as mid-level trough and associated jet eject into the Southern Plains. Efficient boundary layer mixing with minimal cloud cover ahead of a cold front will support strong sustained west winds of 20 mph, to locally 30 mph along with critically low relative humidity. Critical probabilities were expanded slightly eastward into west Texas. Overall fire weather conditions are expected to improve from Day 4/Tuesday into Day 8/Saturday across the Southwest. No large scale critical conditions are expected although above normal temperatures will develop as a result of the building upper-level ridge, drying fuels in areas that are already experiencing severe/extreme drought. ...Sacramento/Central Valley... Dry, post-frontal northerly winds of 15-20 mph with relative humidity falling into the 15-20 percent range will promote at least an elevated fire weather threat for Day 3/Monday across the Sacramento/Central Valley. Marginal fuel dryness precludes introduction of Critical probabilities at this time. ..Williams.. 05/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0500 PM CDT Sat May 17 2025 Valid 191200Z - 251200Z An upper-level trough and associated mid-level wind maximum will contribute to ongoing elevated/critical fire weather conditions across portions of southern New Mexico/western Texas for Day 3/Monday. Residual precipitation and higher elevation snow within a cool, post frontal air mass will temporarily mitigate fire weather threat across the Intermountain West north of Interstate 40. Several upper-level embedded short waves should calm fire weather concerns across the Northern Rockies with several opportunities for precipitation through Day 8/Saturday. Dry conditions under a building ridge and suppressed surface pressure gradients will accompany rising temperatures across the Southwest, aiding in drying of fuels. ...Southwest... Persistent critical fire weather conditions are expected for Day 3/Monday across southern New Mexico and far western Texas as mid-level trough and associated jet eject into the Southern Plains. Efficient boundary layer mixing with minimal cloud cover ahead of a cold front will support strong sustained west winds of 20 mph, to locally 30 mph along with critically low relative humidity. Critical probabilities were expanded slightly eastward into west Texas. Overall fire weather conditions are expected to improve from Day 4/Tuesday into Day 8/Saturday across the Southwest. No large scale critical conditions are expected although above normal temperatures will develop as a result of the building upper-level ridge, drying fuels in areas that are already experiencing severe/extreme drought. ...Sacramento/Central Valley... Dry, post-frontal northerly winds of 15-20 mph with relative humidity falling into the 15-20 percent range will promote at least an elevated fire weather threat for Day 3/Monday across the Sacramento/Central Valley. Marginal fuel dryness precludes introduction of Critical probabilities at this time. ..Williams.. 05/17/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0281 Status Updates
STATUS FOR WATCH 0281 HAS NOT BEEN ISSUED YET Read more

WW 281 SEVERE TSTM AR LA MS 172200Z - 180300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 281 NWS Storm Prediction Center Norman OK 500 PM CDT Sat May 17 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Arkansas Northeast Louisiana West-Central Mississippi * Effective this Saturday afternoon and evening from 500 PM until 1000 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...Ongoing supercell thunderstorms should persist for several more hours this afternoon and evening while posing a threat for mainly 1-2 inch diameter hail. Isolated damaging winds may also occur. The severe thunderstorm watch area is approximately along and 45 statute miles north and south of a line from 40 miles north of Monroe LA to 30 miles south of Greenwood MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 277...WW 278...WW 279...WW 280... 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 550. Mean storm motion vector 26025. ...Gleason Read more

WW 0280 Status Updates
STATUS REPORT ON WW 280 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..THORNTON..05/17/25 ATTN...WFO...EWX...SJT... STATUS REPORT FOR WS 280 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TXC019-049-053-137-171-265-267-271-299-307-319-323-327-385-411- 435-463-465-172240- TX . TEXAS COUNTIES INCLUDED ARE BANDERA BROWN BURNET EDWARDS GILLESPIE KERR KIMBLE KINNEY LLANO MCCULLOCH MASON MAVERICK MENARD REAL SAN SABA SUTTON UVALDE VAL VERDE 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 280 SEVERE TSTM TX 171955Z - 180300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 280 NWS Storm Prediction Center Norman OK 255 PM CDT Sat May 17 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of West-Central Texas * Effective this Saturday afternoon and evening from 255 PM until 1000 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging wind gusts to 70 mph likely SUMMARY...Thunderstorms will affect the watch area through the afternoon and early evening. Very unstable conditions will promote a risk of large hail and damaging winds in the strongest storms. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 10 miles southwest of Del Rio TX to 45 miles northwest of Temple TX. 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 277...WW 278...WW 279... AVIATION...A few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25025. ...Hart Read more

WW 0278 Status Updates
STATUS REPORT ON WW 278 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..THORNTON..05/17/25 ATTN...WFO...FWD... STATUS REPORT FOR WS 278 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TXC035-085-093-097-099-113-119-121-133-139-143-147-181-193-213- 217-221-223-231-237-251-257-277-281-309-333-337-349-363-367-379- 397-425-429-439-467-497-503-172240- TX . TEXAS COUNTIES INCLUDED ARE BOSQUE COLLIN COMANCHE COOKE CORYELL DALLAS DELTA DENTON EASTLAND ELLIS ERATH FANNIN GRAYSON HAMILTON HENDERSON HILL HOOD HOPKINS HUNT JACK JOHNSON KAUFMAN LAMAR LAMPASAS MCLENNAN MILLS MONTAGUE NAVARRO PALO PINTO PARKER RAINS ROCKWALL SOMERVELL STEPHENS TARRANT VAN ZANDT WISE YOUNG 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 278 SEVERE TSTM TX 171930Z - 180300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 278 NWS Storm Prediction Center Norman OK 230 PM CDT Sat May 17 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest and North-Central Texas * Effective this Saturday afternoon and evening from 230 PM until 1000 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 4 inches in diameter likely Scattered damaging winds likely with isolated significant gusts to 80 mph possible A tornado or two possible SUMMARY...Thunderstorms will rapidly intensify this afternoon. Supercells capable of very large hail and damaging winds will be a concern through the early evening. A tornado or two is also possible. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 60 miles north of Fort Worth TX to 5 miles south of Waco TX. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). 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 277... AVIATION...A few severe thunderstorms with hail surface and aloft to 4 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 600. Mean storm motion vector 27030. ...Hart Read more

WW 0279 Status Updates
STATUS REPORT ON WW 279 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..THORNTON..05/17/25 ATTN...WFO...OUN...TSA... STATUS REPORT FOR WT 279 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OKC005-009-011-013-015-017-019-023-027-029-031-033-039-043-045- 049-051-055-057-063-065-067-069-073-075-077-081-083-085-087-095- 099-107-109-121-123-125-127-129-133-137-141-149-172240- OK . OKLAHOMA COUNTIES INCLUDED ARE ATOKA BECKHAM BLAINE BRYAN CADDO CANADIAN CARTER CHOCTAW CLEVELAND COAL COMANCHE COTTON CUSTER DEWEY ELLIS GARVIN GRADY GREER HARMON HUGHES JACKSON JEFFERSON JOHNSTON KINGFISHER KIOWA LATIMER LINCOLN LOGAN LOVE MCCLAIN MARSHALL MURRAY OKFUSKEE OKLAHOMA PITTSBURG PONTOTOC POTTAWATOMIE PUSHMATAHA ROGER MILLS SEMINOLE STEPHENS TILLMAN WASHITA TXC009-023-077-155-197-275-485-487-172240- Read more

WW 279 TORNADO OK TX 171940Z - 180300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 279 NWS Storm Prediction Center Norman OK 240 PM CDT Sat May 17 2025 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Western and Southern Oklahoma Northwest Texas * Effective this Saturday afternoon and evening from 240 PM until 1000 PM CDT. * Primary threats include... A couple tornadoes possible Scattered large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging wind gusts to 70 mph likely SUMMARY...Widely scattered supercell thunderstorms are expected to develop this afternoon in a very moist and unstable air mass. Very large hail and damaging winds may occur in these storms. A warm front draped across Oklahoma may provide sufficient low-level shear for a few tornadoes as well. The tornado watch area is approximately along and 60 statute miles north and south of a line from 45 miles west northwest of Altus OK to 35 miles east southeast of Mcalester OK. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 277...WW 278... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 25030. ...Hart Read more

WW 0277 Status Updates
STATUS REPORT ON WW 277 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SW ELM TO 20 N BGM TO 15 ESE MSS. ..THORNTON..05/17/25 ATTN...WFO...GYX...ALY...BUF...BGM...BTV... STATUS REPORT FOR WS 277 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NHC005-007-009-019-172240- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE CHESHIRE COOS GRAFTON SULLIVAN NYC001-017-019-031-033-035-041-043-057-077-083-091-093-095-113- 115-172240- NY . NEW YORK COUNTIES INCLUDED ARE ALBANY CHENANGO CLINTON ESSEX FRANKLIN FULTON HAMILTON HERKIMER MONTGOMERY OTSEGO RENSSELAER SARATOGA SCHENECTADY SCHOHARIE WARREN WASHINGTON VTC001-003-005-007-009-011-013-015-017-019-021-023-025-027- 172240- Read more

WW 277 SEVERE TSTM NH NY VT LO 171635Z - 180000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 277 NWS Storm Prediction Center Norman OK 1235 PM EDT Sat May 17 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western New Hampshire Central and Northern New York Vermont Lake Ontario * Effective this Saturday afternoon and evening from 1235 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible Scattered large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Scattered strong to severe thunderstorms will increase in coverage through the afternoon. Locally damaging winds are the main concern, but the strongest cells could also produce large hail and perhaps a tornado. The severe thunderstorm watch area is approximately along and 75 statute miles north and south of a line from 30 miles east southeast of Montpelier VT to 5 miles south of Rochester NY. 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 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Hart Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Sat May 17 2025 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN NEW MEXICO INTO FAR WESTERN TEXAS... Stronger mid-level winds on the southern periphery of a upper-trough will spread over parts of the Southwest and Southern Plains for Tuesday will continue to support a broad fire weather threat across the region. A developing lee trough along with downsloping into the adjacent High Plains will support meteorologically critical fire weather conditions across southeastern Colorado and southwestern Kansas. However, with recent green up and ERCs below the 50th percentile in this area, fire spread potential is reduced. Even so, southwest winds of 25-30 mph and single digit relative humidity should support at least an elevated fire danger concern. ..Williams.. 05/17/2025 .PREV DISCUSSION... /ISSUED 0105 AM CDT Sat May 17 2025/ ...Synopsis... On Sunday, a mid-level trough (and associated wind speed maximum) is forecast to progress across the Four Corners region into the southern High Plains. Deep boundary-layer mixing behind a sharpening dryline and deepening surface cyclone will result in widespread Critical conditions, primarily across southern New Mexico into far West Texas. ...Southern New Mexico into Far West Texas... As the surface cyclone over the southern High Plains deepens and the dryline mixes eastward, surface winds of 20-25 MPH with 5-10% relative humidity are forecast. Fuels will be receptive to rapid wildfire ignition and spread, with ERC percentiles at or exceeding the 80th-90th annual percentiles. There is some suggestion in the 00Z HREF ensemble guidance that winds could reach 30 MPH, though there is not enough confidence at this time to introduce any Extremely Critical highlights. Further east into Texas, meteorological conditions will also reach Critical threshold -- however, current fuels guidance shows fuels are only at or below average, so only Elevated highlights have been maintained at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Sat May 17 2025 Valid 172000Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER NORTHEAST TEXAS...SOUTHEAST OKLAHOMA...SOUTHWEST ARKANSAS...AND NORTHWEST LOUISIANA....... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF UPSTATE NEW YORK AND WESTERN NEW ENGLAND... ...SUMMARY... Severe thunderstorms producing large to very large hail, damaging gusts and a couple of tornadoes are expected across the southern Plains. Additional severe storms are possible across the Northeast. ...20z Update... Adjustments were made to the 20z to remove the Marginal risk across portions of Georgia into South Carolina and across the northeast behind morning convection. The Slight Risk and Moderate Risk were nudged further south in far southern Texas to account for potential for storms to come out of Mexico this evening with potential for large hail and severe winds. Otherwise, the risk areas across the main region of the southern/central Plains were not changed. Thunderstorm development has begun across the dryline from southern/central Texas to the Red River in Oklahoma. See MCD#840 and MCD#838 for more information on the short term risks in these areas. ..Thornton/Hart.. 05/17/2025 .PREV DISCUSSION... /ISSUED 1117 AM CDT Sat May 17 2025/ ...Central TX/Southern OK into the ArkLaTex Region... Morning water vapor loop shows a well-defined shortwave trough over southern AZ tracking northeastward. Ahead of this system, southerly low-level winds and steep lapse rates aloft have established a very moist and extremely unstable air mass from southern OK into central TX. Dewpoints in the low/mid 70s and ample daytime heating will yield afternoon MLCAPE values over 4000 J/kg. As the upper system and associated mid-level jet max approach the dryline, thunderstorms are expected to rapidly develop by mid-afternoon. Splitting supercells capable of very large hail will be the main initial concern, along with damaging winds and a tornado or two. Most model solutions suggest upscale growth of these storms into a bowing MCS by evening, tracking eastward across the ArklaTex region. Have extended the ENH a little farther east to accommodate this scenario, with damaging winds and large hail being the main concerns. This cluster of storms may persist overnight, tracking into central/northern MS. ...Northwest OK... The plume of dense cirrus ahead of the AZ shortwave trough will move east of northwest OK by late afternoon, allowing strong heating and destabilization. This combined with southeasterly low level winds near a retreating warm front will provide a corridor of strong instability and favorable low-level shear for supercell development. The coverage of storms in this area is uncertain and varied between the morning CAM solutions. However, the storms that form will pose a risk of very large hail, damaging winds, and a tornado or two. It is also unclear how far east this threat may persist, with some concern for an MCS tracking into northeast OK overnight. ...NY/New England... A progressive shortwave trough and associated mid-level jet is tracking eastward across the Great Lakes region today. Cooling temperatures aloft and strong daytime heating will lead to pockets of moderate CAPE and steep low/mid level lapse rates. Storms are beginning to form across NY and will move into a progressively more favorable air mass for strong/severe convection (including a few supercells) by mid-afternoon. Locally damaging winds are the main concern, but the strongest cells could also produce hail and perhaps a tornado or two. Refer to MCD #837 for further details. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Sat May 17 2025 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL PLAINS INTO MISSOURI... ...SUMMARY... Severe storms with all severe weather hazards remain likely from portions of the Midwest to the southern Plains on Monday. ...Synopsis... The embedded mid-level impulse (responsible for Day 2 severe) will approach the Great Lakes region as the primary upper trough ejects into the Plains states on Monday. Some surface low strengthening is expected along or just north of the KS/OK border by afternoon, supporting a sharpening dryline along the I-35 corridor, with a warm front draped from eastern NE to the OH River. Scattered to potentially widespread thunderstorm development is likely by mid afternoon along the warm front and ahead of the dryline. With strong vertical wind shear and instability in place over the Plains to the Midwest, severe storms with all convective hazards are likely. Strong thunderstorms may also develop further east along the warm front over the TN Valley as well. ...Portions of the central Plains into the Midwest... Scattered showers and thunderstorms may be ongoing at the start of the period (12Z Monday morning). However, gradual clearing of this precipitation and associated cloud cover should support destabilization along and south of a warm front during the afternoon. Boundary layer heating, along with increasing deep-layer ascent from the approaching upper trough, will encourage the development of several thunderstorms along the warm front during the afternoon, from far eastern NE to the MO/IL border. On the warm side of the front, 70+ F surface dewpoints beneath steep mid-level lapse rates will boost MLCAPE to over 3000 J/kg amid 50 kts of effective bulk shear. NAM forecast soundings depict enlarged hodographs as well. Supercells may develop along the warm front, accompanied by large hail. Storms that can remain surface based, along or just south of the warm front, will have the best chance to produce tornadoes. ...Portions of the central into southern Plains... Modest to considerable cloud cover, perhaps accompanied by showers, may overspread parts of the central and southern Plains Monday morning. Nonetheless, enough clearing should take place ahead of a sharpening dryline by afternoon to support considerable destabilization given steep mid-level lapse rates from an EML. The dryline should be positioned just west of I-35 by mid-afternoon, with surface dewpoints ahead of the dryline exceeding upper 60s to 70 F, supporting well over 3000 J/kg MLCAPE on a widespread basis. Strong southwesterly mid-level flow overspreading southeasterly surface flow ahead of the low will result in over 50 kts of effective bulk shear. By mid afternoon, at least scattered supercell development is expected all along the dryline, from southeast NE to central OK, with more isolated supercell coverage likely over northern into central TX. Given ample buoyancy and deep-layer shear, large hail is expected, with very large hail over 2 inches in diameter likely with the more dominant supercell structures. By late afternoon into early evening, the strengthening of the low-level jet over central and eastern KS/OK will support substantial low-level veering of the vertical wind profile, with notable low-level hodograph size/curvature in forecast soundings. As such, the more dominant, right-moving supercells will have the potential to produce tornadoes, and at least a few strong tornadoes are possible. ...Portions of the TN Valley... Multiple rounds of thunderstorms are possible along a residual baroclinic boundary across the TN Valley, both during the morning hours, and later in the evening. While not quite as unstable as points farther to the west, modest mid-level lapse rates amid elongated hodographs should support multicells, supercells, and short line segments. The stronger storms may be capable of isolated instances of large hail, gusty winds, and perhaps a brief tornado. ..Squitieri.. 05/17/2025 Read more

MD 0838 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR 2CENTRAL TO SOUTHERN TEXAS
Mesoscale Discussion 0838 NWS Storm Prediction Center Norman OK 0132 PM CDT Sat May 17 2025 Areas affected...2central to southern Texas Concerning...Severe potential...Watch possible Valid 171832Z - 172030Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorm development appears likely based on recent satellite trends, and will develop in an environment very conducive for severe convection. Watch issuance is probable as thunderstorm coverage/intensity begins to increase. DISCUSSION...Latest GOES visible imagery shows steadily growing congestus along a confluence axis/differential heating boundary draped from central TX to the Rio Grande and on the northern slopes of the Sierra Del Carmen range in northern Mexico. Ahead of the building cumulus field, high-quality moisture (dewpoints in the mid 70s) and temperatures warming into the low to mid 90s are supporting MLCAPE values upwards of 3000 J/kg. Despite weak low-level winds, increasing mid-level flow ahead of an approaching speed max is supporting effective shear values on the order of 45 to 55 knots. This convective environment is very favorable for organized supercells and may support severe gusts and hail as large as 2 to 3 inches in diameter. Weak forcing for ascent casts some uncertainty on storm coverage, but recent high-res guidance continues to suggest rapid thunderstorm development is likely between 20-22 UTC both along the boundary and off the northern Mexico mountains. Convective trends will continue to be monitored and watch issuance is probable as deep convection begin to develop. ..Moore/Hart.. 05/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...EWX...SJT... LAT...LON 29710143 31070032 31749947 31909895 31789848 31509813 31159803 30839807 30579821 30469832 30189866 29069998 28870030 28760048 28900066 29120076 29340098 29450116 29540133 29630148 29710143 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN Read more

MD 0839 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHERN UTAH AND ADJACENT PORTIONS OF FAR SOUTHEAST IDAHO AND SOUTHWEST WYOMING
Mesoscale Discussion 0839 NWS Storm Prediction Center Norman OK 0156 PM CDT Sat May 17 2025 Areas affected...Northern Utah and adjacent portions of far southeast Idaho and southwest Wyoming Concerning...Severe potential...Watch unlikely Valid 171856Z - 172100Z Probability of Watch Issuance...5 percent SUMMARY...Isolated thunderstorms developing across northern/northeast Utah into far southeast Idaho and southwest Wyoming may be capable of severe gusts through late afternoon. Watch issuance is not expected. DISCUSSION...Over the past hour, temperatures have warmed into the mid to upper 60s across northeast UT on the eastern fringe of a dense cirrus canopy. Based on forecast soundings, temperatures in the 65-70 F range are required for surface-based convective initiation, which appears to be ongoing based on recent convective trends. Although buoyancy will remain very modest across the region (250-500 J/kg), a 2-3 km deep, well-mixed boundary layer will enhance convective downdrafts and support the potential for strong to severe wind gusts (most likely between 55-70 mph). This threat will likely persist through early evening as lift ahead of an approaching upper wave increases and low-level temperatures continue to warm across the region. Convective coverage should gradually increase through late afternoon, but storm longevity and the overall convective environment should remain sufficiently limited to preclude watch issuance. ..Moore/Hart.. 05/17/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RIW...GJT...SLC...PIH... LAT...LON 41230942 40200947 39690973 39281044 39041097 39081136 39351165 39901206 40621230 41611241 42101231 42231212 42341180 42521083 42360991 41900959 41230942 MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1238 PM CDT Sat May 17 2025 Valid 181200Z - 191200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL KS INTO NORTHERN OK...AND FAR NORTHEAST COLORADO INTO WESTERN NEBRASKA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are still expected on Sunday across portions of the central and southern Plains, as well as parts of the central High Plains. ...Synopsis... A negatively tilted mid-level trough will traverse the central Rockies and eject into the Plains states, encouraging rapid surface low development along the CO/KS tomorrow (Sunday). Ahead of the surface low and sharpening dryline, rapid north-northwestward advection of relatively rich low-level moisture beneath a pronounced EML will result in strong buoyancy across much of the central and southern Plains. Furthermore, a low-level jet will overspread the Plains states, beneath strong southwesterly 500 mb flow associated with the ejecting upper trough, resulting in strong vertical speed and directional shear coinciding with the aforementioned unstable environment. Multiple clusters of strong to severe thunderstorms are expected to develop near, and to the north of the surface low, ahead of the dryline, and along an effective warm front across the central Plains, with all convective hazards possible. Lastly, isolated strong storms are possible along a diffuse baroclinic boundary across the Southeast tomorrow afternoon. ...Portions of the central High Plains... A narrow corridor of mid to upper 50s F surface dewpoints may advect to the north of the surface low by afternoon, ahead of an arching dryline, where scattered thunderstorms should develop. 8-9 C/km mid-level lapse rates will overspread this moisture ahead of the dryline, supporting well over 1000 J/kg MLCAPE amid 50+ kts of effective bulk shear. Forecast soundings show very long hodographs, with a subset of these forecast soundings also depicting enlarged/curved low-level hodographs. Supercells are expected to be the dominant mode, with large hail the main threat. At least a few instances of 2+ inch diameter hail and severe gusts may also occur, along with a few tornadoes. If a mature, discrete supercell can materialize and achieve substantial residence time within the narrow warm sector, the storm may become cyclic tornadic in nature. However, confidence in this scenario is not overly high at this time. ...Kansas into central Texas... At least scattered thunderstorms are expected to develop along the leading edge of greater moisture return along the KS/OK border by early afternoon. With strong shear/instability already in place, supercells are likely, accompanied by a large hail threat. Questions remain how far north the better moisture will return into KS given possible stabilizing impacts of these storms. However, by mid to late afternoon, some eastward advancement of the dryline should encourage a second round of supercell development along the KS/OK border. Ahead of these storms and south of the effective warm front, surface dewpoints should exceed 70 F in spots, beneath 8 C/km mid-level lapse rates, boosting MLCAPE to over 3000 J/kg on a widespread basis. Substantial veering/strengthening of the vertical wind fields with height will also result in enlarged, curved hodographs and over 300 m2/s2 effective SRH sometime between 21-00Z. Any supercells that can mature and sustain themselves in this environment will have the potential to produce very large hail (perhaps exceeding 3 inches in diameter) and tornadoes (some possibly EF2+). Storm coverage is expected to be less across central OK into central TX owing to less low-level convergence along the dryline. However, 3000+ J/kg MLCAPE amid 300+ m2/s2 effective SRH will support supercells capable of producing very large hail and tornadoes should storms develop farther south along the dryline. ...Portions of the Southeast... Scattered strong storms should develop along the baroclinic boundary across the Southeast by afternoon peak heating tomorrow (Sunday). Rich low-level moisture beneath modest mid-level lapse rates will support over 2000 J/kg SBCAPE, with strong flow aloft also contributing to elongated, mainly straight hodographs. Stronger storms that develop in this environment will be capable of large hail and gusty winds. ..Squitieri.. 05/17/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1238 PM CDT Sat May 17 2025 Valid 181200Z - 191200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF CENTRAL KS INTO NORTHERN OK...AND FAR NORTHEAST COLORADO INTO WESTERN NEBRASKA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are still expected on Sunday across portions of the central and southern Plains, as well as parts of the central High Plains. ...Synopsis... A negatively tilted mid-level trough will traverse the central Rockies and eject into the Plains states, encouraging rapid surface low development along the CO/KS tomorrow (Sunday). Ahead of the surface low and sharpening dryline, rapid north-northwestward advection of relatively rich low-level moisture beneath a pronounced EML will result in strong buoyancy across much of the central and southern Plains. Furthermore, a low-level jet will overspread the Plains states, beneath strong southwesterly 500 mb flow associated with the ejecting upper trough, resulting in strong vertical speed and directional shear coinciding with the aforementioned unstable environment. Multiple clusters of strong to severe thunderstorms are expected to develop near, and to the north of the surface low, ahead of the dryline, and along an effective warm front across the central Plains, with all convective hazards possible. Lastly, isolated strong storms are possible along a diffuse baroclinic boundary across the Southeast tomorrow afternoon. ...Portions of the central High Plains... A narrow corridor of mid to upper 50s F surface dewpoints may advect to the north of the surface low by afternoon, ahead of an arching dryline, where scattered thunderstorms should develop. 8-9 C/km mid-level lapse rates will overspread this moisture ahead of the dryline, supporting well over 1000 J/kg MLCAPE amid 50+ kts of effective bulk shear. Forecast soundings show very long hodographs, with a subset of these forecast soundings also depicting enlarged/curved low-level hodographs. Supercells are expected to be the dominant mode, with large hail the main threat. At least a few instances of 2+ inch diameter hail and severe gusts may also occur, along with a few tornadoes. If a mature, discrete supercell can materialize and achieve substantial residence time within the narrow warm sector, the storm may become cyclic tornadic in nature. However, confidence in this scenario is not overly high at this time. ...Kansas into central Texas... At least scattered thunderstorms are expected to develop along the leading edge of greater moisture return along the KS/OK border by early afternoon. With strong shear/instability already in place, supercells are likely, accompanied by a large hail threat. Questions remain how far north the better moisture will return into KS given possible stabilizing impacts of these storms. However, by mid to late afternoon, some eastward advancement of the dryline should encourage a second round of supercell development along the KS/OK border. Ahead of these storms and south of the effective warm front, surface dewpoints should exceed 70 F in spots, beneath 8 C/km mid-level lapse rates, boosting MLCAPE to over 3000 J/kg on a widespread basis. Substantial veering/strengthening of the vertical wind fields with height will also result in enlarged, curved hodographs and over 300 m2/s2 effective SRH sometime between 21-00Z. Any supercells that can mature and sustain themselves in this environment will have the potential to produce very large hail (perhaps exceeding 3 inches in diameter) and tornadoes (some possibly EF2+). Storm coverage is expected to be less across central OK into central TX owing to less low-level convergence along the dryline. However, 3000+ J/kg MLCAPE amid 300+ m2/s2 effective SRH will support supercells capable of producing very large hail and tornadoes should storms develop farther south along the dryline. ...Portions of the Southeast... Scattered strong storms should develop along the baroclinic boundary across the Southeast by afternoon peak heating tomorrow (Sunday). Rich low-level moisture beneath modest mid-level lapse rates will support over 2000 J/kg SBCAPE, with strong flow aloft also contributing to elongated, mainly straight hodographs. Stronger storms that develop in this environment will be capable of large hail and gusty winds. ..Squitieri.. 05/17/2025 Read more