829 ACUS11 KWNS 270033 SWOMCD SPC MCD 270033 WAZ000-ORZ000-270200- Mesoscale Discussion 0267 NWS Storm Prediction Center Norman OK 0733 PM CDT Wed Mar 26 2025 Areas affected...portions of WA and OR Concerning...Severe Thunderstorm Watch 65... Valid 270033Z - 270200Z The severe weather threat for Severe Thunderstorm Watch 65 continues. SUMMARY...A gradual increase in storm coverage is expected over the next couple of hours in and close to WW65. Severe storms, including a couple of supercells will remain capable of damaging gusts, hail and possibly a tornado or two. DISCUSSION...As of 0030 UTC, regional radar and lightning data indicated a slow increase in convective activity across parts of the Northwest. Likely driven by the local diurnal maximum in surface heating and the arrival of ascent from the broad east Pac trough, this trend should continue over the next few hours. Around 1000 J/kg of MUCAPE and 50-60 kt of deep-layer shear from the RTX VAD are strongly supportive of organized storms, including supercells and linear clusters. Radar echo tops and lightning trends across parts of Cowlitz and Lewis counties do suggest an increase in convective intensity. This matches with recent HRRR runs that suggest a few stronger storms should evolve from northern OR, across the Columbia River Valley, and northward into western WA this evening. This would support a continued risk for damaging wind gusts given the strong lower tropospheric flow. Additionally, hail and a tornado or two will remain possible with the stronger rotating storms and any favorable terrain interactions. Thus, the severe risk continues across WW65. ..Lyons.. 03/27/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PDT...SEW...PQR... LAT...LON 45132375 46802394 47702401 48092287 48162181 47892130 46032158 44382185 44332240 44262282 44522355 45132375 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  514 ACUS01 KWNS 270046 SWODY1 SPC AC 270045 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 PM CDT Wed Mar 26 2025 Valid 270100Z - 271200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE PACIFIC NORTHWEST... ...SUMMARY... Severe thunderstorms remain possible across parts of the Pacific Northwest this evening, with supercells possible west of the Cascades across Oregon into Washington. These storms may produce large hail, perhaps a brief tornado, and severe wind gusts. ...01z Update... Deep convection has struggled to organize across western OR/WA early this evening, possibly due to extensive cloudiness. Even so, temperatures remain warm with readings in the mid 70s from Portland north into Lewis County WA. Westerly boundary-layer flow is increasing and upslope flow may be contributing to gradual uptick in convection from Clark County into central Lewis County WA. This activity is expected to grow upscale over the next few hours and wind profiles favor supercell development. If this occurs, storms will track north-northeast along the higher terrain, and large hail should develop within these storms. Latest trends suggest the greatest risk may be shifting into WA as large-scale forcing is beginning to shift into this region. Across the lower Rio Grande Valley, a lone supercell is tracking southeast along the international border over southern Starr County. Large hail has likely been noted with this storm, most likely along the Mexican side of the border. Some risk for hail will be noted with this storm for the next few hours. ..Darrow.. 03/27/2025 $$  699 ACUS11 KWNS 270335 SWOMCD SPC MCD 270335 WAZ000-270500- Mesoscale Discussion 0268 NWS Storm Prediction Center Norman OK 1035 PM CDT Wed Mar 26 2025 Areas affected...Parts of nwrn WA Concerning...Severe Thunderstorm Watch 65... Valid 270335Z - 270500Z The severe weather threat for Severe Thunderstorm Watch 65 continues. SUMMARY...Widespread convection and embedded weak thunderstorm activity lingers, but the potential for severe weather appears unlikely to increase. Severe Thunderstorm Watch 65 may be allowed to expire at 9 PM PDT. DISCUSSION...Convective development, and embedded weak thunderstorm activity, persists along the western slopes of the Oregon Cascades. However, the primary cluster of thunderstorm activity is now rapidly spreading with the more favorable mid/upper forcing for ascent across and north-northwest of the Puget Sound vicinity. Locally strong surface gusts might still be possible, but thermodynamic profiles characterized by rather modest to weak mid/upper lapse rates, and more limited low-level moisture than some model guidance indicated, appear to have mitigated the severe weather threat. ..Kerr.. 03/27/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SEW... LAT...LON 48802319 48752155 47612133 47162195 47512281 48262387 48802319 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  717 ACUS01 KWNS 270531 SWODY1 SPC AC 270530 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Mar 27 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE LOWER MISSOURI/MID-MISSISSIPPI VALLEY REGION...AND SOUTH TEXAS... ...SUMMARY... Multiple rounds of severe thunderstorms are possible in south Texas with hail and wind as the primary hazards. Across parts of the Lower Missouri/Mid-Mississippi Valleys, isolated to scattered large hail and localized severe gusts are possible, mainly during the late afternoon and evening. ...South Texas... Complex, slow-moving upper trough will eject across northern Mexico toward deep South TX by the end of the period. Strongest mid-level flow will translate through the base of the trough, south of the international border into the lower Valley of TX by early evening. LLJ will remain focused across south TX and multiple rounds of deep convection are expected during the day1 period. Adequately buoyant, and modestly steep lapse rate environment favors robust updrafts, as deep layer shear will support storm organization. Hail/wind appear to be the main threats with this activity, though a brief tornado or two can not be ruled out. ...Lower MO/Mid-MS Valleys... Upper ridge is forecast to flatten a bit by the end of the period, though heights will remain neutral to slight rises. As a result, mid-level flow should back to a more westerly orientation with a few weak disturbances expected to translate across the northern Plains toward the mid/upper MS Valley. This flow regime will maintain a notable, but veered, LLJ from western KS into eastern IA through the period. Primary corridor of low-level warm advection will thus be oriented across the upper Red River region into the lower OH Valley. This corridor will likely experience multiple bouts of elevated convection, driven in large part by the aforementioned LLJ. Steep mid-level lapse rates will overspread this region and thermodynamic profiles will prove at least somewhat supportive of robust updrafts capable of generating hail at times. However, of potentially more concern will be convection that develops during the late afternoon along the eastern-most plume of steep low-level lapse rates, from northeast KS/southeast NE into southwest IA. Latest model guidance suggests inhibition will weaken such that isolated thunderstorms may try to initiate by 23-00z. Wind profiles favor organized updrafts and potential supercell development. However, additional thunderstorm activity should be noted downstream within the stronger warm advection corridor during the overnight hours, though updrafts will be elevated in nature. ..Darrow/Lyons.. 03/27/2025 $$  739 ACUS02 KWNS 270601 SWODY2 SPC AC 270600 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Mar 27 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MISSOURI VALLEY AND INTO THE UPPER GREAT LAKES...AND FROM THE EASTERN HALF OF TEXAS TO THE LOWER MISSISSIPPI VALLEY AREA... ...SUMMARY... Isolated severe thunderstorms are possible across portions of eastern and southern Texas and into southern Arkansas and Louisiana Friday, and from Nebraska into parts of the Upper Midwest on Friday evening/night. ...Synopsis... A slow-moving southern-stream short-wave trough will continue shifting across the southern Plains Friday, toward the Lower Mississippi Valley. Farther north, a series of vorticity maxima will move east-northeastward across the north-central U.S. within background west-southwesterly northern-stream flow. At the surface, a low initially over the northern Plains is forecast to move eastward along a surface warm front, reaching the Upper Mississippi Valley by evening, and then continuing across the Great Lakes through the end of the period. ...Southern and eastern Texas east to southwestern Arkansas and Louisiana... As the upper trough moves slowly eastward across Texas through the day, heating beneath the cool air aloft will result in moderate destabilization. As such, ongoing convection early in the period will likely increase during the afternoon, particularly in areas relatively undisturbed by prior convection/cloud cover. While mid-level flow will remain somewhat modest, low level flow veering and increasing with height will provide ample shear for organized storms and occasional rotation. Along with potential for large hail and damaging winds locally, with a few of the strongest storms, a tornado or two will also be possible. Once locations of more concentrated afternoon/evening storms can be identified in future outlooks, an upgrade to SLGT may be required. ...Portions of Nebraska northeastward to the Upper Great Lakes... Late afternoon/evening thunderstorms are forecast to evolve in the vicinity of a baroclinic zone stretching from Nebraska to the Upper Great Lakes, as modest airmass destabilization occurs. With ample mid-level flow aloft supporting organized storms, hail and locally damaging gusts will be possible with a couple of the stronger storms over the Mid Missouri Valley area. Farther east, ahead of the low, most of the convection will be elevated north of the warm front, with hail possible with stronger storms into the overnight hours. ..Goss.. 03/27/2025 $$  946 ACUS03 KWNS 270737 SWODY3 SPC AC 270736 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0236 AM CDT Thu Mar 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF OKLAHOMA TO PARTS OF IOWA AND ILLINOIS... ...SUMMARY... Thunderstorms developing Saturday evening may pose local risk for hail and potentially strong wind gusts. ...portions of Oklahoma northeastward into Iowa/Illinois... Substantial uncertainty exists regarding the forecast for Saturday across the central U.S. -- with models exhibiting notable differences with respect to evolution of the surface pattern. Additionally, the NAM in particular maintains strong capping across the warm sector, which will likely hinder convective development for much of the period -- and potentially limiting convective to being primarily elevated/nocturnal. At this time, it appears that a corridor for initial storm development will be over the eastern Kansas vicinity, as a cold front moves across the area trailing from a frontal wave/low shifting eastward across roughly the Kansas City area during the evening. Convection may evolve mainly to the cool side of this boundary as a strong south-southwesterly low-level jet develops, though a few at least nearly surface-based storms are expected. Though mid-level flow will not be particularly strong, shear will be sufficient for a few stronger storms to evolve -- aided by steep lapse rates aloft. Large hail will likely be the primary risk, though a strong gusty or two may also occur. Expect adjustments to the risk area and/or risk level, as greater certainty evolves with time in this complex scenario. ..Goss.. 03/27/2025 $$  995 ACUS48 KWNS 270859 SWOD48 SPC AC 270857 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Thu Mar 27 2025 Valid 301200Z - 041200Z ...DISCUSSION... Predictability remains a concern during the medium-range period. Models reveal notable differences even in the Day 4-5 time frame with respect to strength of the eastern U.S. upper trough, and associated evolution/development of the surface pattern. As the initial surface system moves offshore late in the Day 5 period (Tuesday morning), substantial divergence in solutions is evident with the next trough moving into/across the western CONUS. Given these differences, any severe potential beyond Day 5 cannot be quantified with any degree of confidence. With that said, a fairly widespread area of severe potential remains evident Day 4/Sunday, ahead of a cold front moving eastward across the Mississippi and Ohio and eventually the Tennessee Valleys. Northward advection of 60s dewpoints is expected ahead of this front, which will combine with daytime heating to boost mixed-layer CAPE into the 1000 to 1500 J/kg range, and potentially above 2000 J/kg farther southwestward along the front from East Texas into the lower Mississippi Valley. As a belt of strong southwesterly flow aloft overspreads the moistening/destabilizing pre-frontal boundary layer, development of strong/severe storms is expected near and ahead of the boundary during the afternoon -- potentially extending as far southwestward as East Texas. Along with potential for large hail and damaging winds, likelihood for supercell storms suggests potential for a few tornadoes as well. Risk will spread eastward through the evening across portions of the Midwest/Ohio Valley and Mid/Lower Mississippi Valley, and southeastward into the Tennessee Valley and central Gulf Coast states overnight -- likely persisting through the end of the period. Day 5/Monday, models begin to differ more substantially with respect to surface frontal location -- particularly with northern extent. The GFS depicts the front as extending from New England southwestward to the Texas Coast Monday morning, while the ECMWF places it from Lower Michigan to coastal Texas. By late afternoon, the GFS shows the front reaching the New England coastal area and Mid-Atlantic region, focusing the primary severe threat from the Mid-Atlantic area southwestward. Meanwhile, some risk could extend as far north as the Lower Great Lakes region/central Appalachians per the ECMWF's deterministic forecast. At this time, will keep the Day 5 risk area focused from the Mid-Atlantic region to the lower Mississippi Valley, though adjustments/refinements to the area over the next several days will likely be required. ..Goss.. 03/27/2025  871 ACUS01 KWNS 271258 SWODY1 SPC AC 271256 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0756 AM CDT Thu Mar 27 2025 Valid 271300Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE LOWER MISSOURI/MID-MISSISSIPPI VALLEY REGION...AND SOUTH TEXAS... ...SUMMARY... Multiple rounds of severe thunderstorms are possible in south Texas. Across parts of the Lower Missouri/Mid-Mississippi Valleys, isolated to scattered large hail and localized severe wind gusts are possible, mainly during the late afternoon and evening. ...South Texas... The slow-moving upper trough will eject across northern Mexico toward deep South Texas by the end of the period. Strongest mid-level flow will translate through the base of the trough, south of the international border into the lower Valley of Texas by early evening. A low-level jet will remain focused across south Texas and multiple rounds of deep convection are expected. While regenerative convection and outflow will limit the northern extent of more appreciable destabilization, adequate buoyancy, a modestly steep lapse rate environment, and deep-layer shear will support robust updrafts and storm organization. Hail/wind appear to be the main threats, although a tornado or two can not be ruled out. ...Central Plains to Lower Missouri/Middle Mississippi Valleys... Scattered thunderstorms, including a few lingering strong storms, continue early this morning mainly across northwest Missouri and far southern Iowa. These storms will continue to transition east-southeastward, with severe-storm potential remaining limited as the low-level jet/warm advection abate this morning. As the regional upper ridge tends to flatten later today into tonight, steep mid-level lapse rates will overspread this region. Convective inhibition may become sufficiently weak by late afternoon/early for isolated thunderstorm development near the warm front/wind shift including a corridor across northern Kansas, southeast Nebraska to southwest Iowa/northwest Missouri. Supercellular development could occur in the presence of moderate instability and favorable wind profiles featuring around 35-40 kt effective shear magnitudes. A greater coverage of elevated storms will occur tonight as the low-level jet reestablishes and storms expand eastward regionally. Large hail is the most probable hazard in both regimes. ..Guyer/Bentley.. 03/27/2025 $$  008 ACUS11 KWNS 271504 SWOMCD SPC MCD 271503 MOZ000-IAZ000-KSZ000-NEZ000-271700- Mesoscale Discussion 0269 NWS Storm Prediction Center Norman OK 1003 AM CDT Thu Mar 27 2025 Areas affected...Northeast KS into northern MO and far southern IA Concerning...Severe potential...Watch unlikely Valid 271503Z - 271700Z Probability of Watch Issuance...20 percent SUMMARY...Isolated hail and strong to locally severe wind gusts will remain possible into late morning. DISCUSSION...Elevated convection has persisted this morning from southern IA/northern MO into eastern KS, within a low-level warm-advection regime. While this convection has generally been sub-severe, some intensification has recently been noted near/south of Topeka, in closer proximity to the leading edge of very steep midlevel lapse rates (as noted on the 00Z DDC sounding). With the low-level jet expected to veer and weaken with time, the longevity of the ongoing elevated storms remains uncertain, but some threat for isolated hail and strong to locally severe wind gusts may continue into late morning, given steep midlevel lapse rates, MUCAPE of 500-1000 J/kg, and sufficient effective shear for some storm organization. ..Dean/Smith.. 03/27/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...DMX...EAX...OAX...TOP...ICT... LAT...LON 38999229 38839314 38539453 38009629 38119636 38749622 39329602 40509518 40899433 40539277 39979247 39399239 38999229 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  854 ACUS01 KWNS 271630 SWODY1 SPC AC 271628 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Thu Mar 27 2025 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE LOWER MISSOURI VALLEY... ...SUMMARY... Isolated to scattered large hail and localized severe wind gusts are possible across parts of the Lower Missouri/Mid-Mississippi Valleys. ...Central Plains to Lower Missouri/Middle Mississippi Valleys... Scattered thunderstorms, including a few lingering strong storms, continue late this morning from eastern KS into northern MO within a warm-air advection regime. Morning raob data over the central Great Plains indicated the northeastern periphery of the EML is located over the lower MO Valley. Strong heating in wake of the early day convection will result in moderate buoyancy developing into northeastern KS later this afternoon. Models show a flattening mid- to upper-level ridge through tonight. Nebulous/weak forcing at best is expected in the vicinity of a warm front/outflow intersection later this afternoon. However, the erosion of CINH may enable a few isolated thunderstorms to develop late this afternoon into the evening. Recent HRRR runs and the 12 UTC model-run members of the HREF show a dearth of storm development. Confidence in appreciable storm coverage is lowering for diurnally based storm initiation and casting uncertainty in terms of the potential severe threat. Nonetheless, supercellular development could occur in the presence of moderate instability and favorable wind profiles featuring around 35-40 kt effective shear magnitudes. A greater coverage of elevated storms may occur tonight as the low-level jet reestablishes and storms expand eastward regionally. Large hail is the most probable hazard in both regimes. ...South Texas... Visible-satellite imagery shows an extensive cloud shield and convective cloud debris across much of south TX into the upper coast, and farther west into the Big Bend region. This is in response to a slow-moving upper trough which is forecast to move across northern Mexico toward Deep South Texas by Friday morning. This episodic convection across northern Mexico into adjacent portions of TX should limit heating during the day. Forecast soundings show seasonably moist profiles from the surface through the mid levels subduing lapse rate magnitudes. Mid-level flow will translate through the base of the trough, south of the international border into the lower Valley of Texas by early evening. However, considerably weaker flow with north extent (i.e., Edwards Plateau) and uncertainty regarding destabilization farther north cast uncertainty on storm intensity across south-central TX. The low-level jet will remain focused across south Texas aiding in regenerative storm development and an occasional isolated severe threat may occur with the stronger storms. ..Smith/Jewell.. 03/27/2025 $$  555 ACUS02 KWNS 271721 SWODY2 SPC AC 271719 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1219 PM CDT Thu Mar 27 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE CENTRAL STATES... ...SUMMARY... A low-probability tornado and wind threat remains forecast for Friday morning through evening across portions of the western Gulf Coast States. Isolated severe hail is possible from the Upper Midwest into Nebraska on Friday evening/night. ...TX Coastal Plain to LA... After extensive preceding convection yesterday through today, poor mid-level lapse rates will be prevalent across much the region ahead of a low-amplitude mid-level trough characterized by embedded convectively modified impulses. This trough should drift east-northeast across south to east TX during the period. Within the rich western Gulf airmass, surface-based destabilization will be tempered and deep-layer shear appears modest. But belts of moderately enhanced low-level flow could support low-probability tornado and wind potential, mainly during the morning to evening. These may linger along the southwest LA coast through Friday night. ...Upper Midwest to NE.. Very steep mid-level lapse rates around 8.5-9 C/km will be prevalent atop a pronounced surface warm front over WI/MN to a lee trough in the central High Plains. Elevated convective potential appears most prominent by Friday evening near the Upper Great Lakes, downstream of a low-amplitude shortwave impulse progressing east near the international border. Surface temperatures may be close to freezing, but small to marginally severe hail is possible with fast-moving, highly elevated cells along the northern periphery of the EML plume. Farther southwest, the degree of low-level moisture relative to the stout EML should mitigate appreciable convective potential until evening. Convective coverage will probably be sparse as large-scale ascent may be limited, but should eventually increase across NE as the low-level jet strengthens Friday night. Overall severe potential appears likely to remain marginal. ..Grams.. 03/27/2025 $$  367 ACUS11 KWNS 271841 SWOMCD SPC MCD 271841 TXZ000-272115- Mesoscale Discussion 0270 NWS Storm Prediction Center Norman OK 0141 PM CDT Thu Mar 27 2025 Areas affected...far southern Texas / Lower Rio Grande Valley Concerning...Severe potential...Watch unlikely Valid 271841Z - 272115Z Probability of Watch Issuance...5 percent SUMMARY...A couple strong gusts cannot be ruled out eventually over parts of the Lower Rio Grande Valley. DISCUSSION...A large, heavy-rain producing convective system continues to slowly propagate eastward, with newer development upstream into Mexico (see WPC MPD #0088). Midday soundings reveal deep, moist profiles with poor lapse rates and a high LFC. While the 18Z BRO sounding shows winds veering with height and substantial 0-1 SRH, the combination of poor low-level lapse rates and lack of any baroclinic boundary (outflow) thus far suggests little brief tornado risk. In addition, overall wind potential remains low as the deep moist profiles mitigate downdraft/evaporation potential. Although radar indicates little outflow at this time, a few strong gusts may eventually be generated as heating persist. For any brief/QLCS type tornado potential, this appears highly conditional on a substantial outflow boundary first materializing. ..Jewell/Smith.. 03/27/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BRO... LAT...LON 26089895 26349865 26589849 26679815 26889783 27099759 26929732 26389710 25989705 25829741 25879797 25959850 26089895 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH  382 ACUS03 KWNS 271928 SWODY3 SPC AC 271927 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Thu Mar 27 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHERN OK TO NORTHERN MO... ...SUMMARY... Scattered severe thunderstorms are possible from northern Oklahoma into the Lower Missouri Valley on Saturday evening/night. Large to very large hail could be the primary hazard, but severe gusts and a couple tornadoes may occur. ...Central States... Primary changes with this outlook are to add a level 2-SLGT risk and expand the level 1-MRGL along the dryline through TX. A broad negative-tilt mid/upper trough, with at least a few embedded shortwave impulses, will shift east from the West into the Central States by early Sunday. A northern/leading impulse will aid in cyclogenesis into Saturday evening over the Lower MO Valley. A southern/basal impulse will yield a separate cyclone over the eastern TX Panhandle/western OK border area. Boundary-layer moisture will be richer ahead of the southern cyclone beneath a stout EML. Guidance consensus suggests early evening thunderstorm development should occur along the northwest edge of the low to mid 60s surface dew point plume, centered on south-central KS/north-central OK. Additional storms will probably form northeastward along the front into the Lower MO Valley. The degree of convective coverage with southern extent is more nebulous, but there are signals for isolated cells as far south as the Edwards Plateau. Convection along much of the front northeast of OK should tend to grow upscale into clusters given the flow orientation relative to the boundary and initially moderate mid-level winds. A more favorable discrete supercell wind profile exists in OK, posing a conditional very large hail and tornado threat along this portion of the dryline Saturday evening. ..Grams.. 03/27/2025 $$  529 ACUS01 KWNS 271948 SWODY1 SPC AC 271947 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Thu Mar 27 2025 Valid 272000Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE CENTRAL PLAINS TO LOWER MISSOURI/MIDDLE MISSISSIPPI VALLEYS AND SOUTH TEXAS... ...SUMMARY... Isolated to scattered large hail and localized severe wind gusts are possible across parts of the Lower Missouri/Mid-Mississippi Valleys. ...20z Update... The Slight Risk was removed from portions of northeastern Kansas into southwestern Iowa and northwestern Missouri. It appears there remains a conditional risk of a storm or two redeveloping in this region through the afternoon/late evening, but overall coverage of severe risk will remain low. Within this region, a pseudo stationary front/warm front is located, with large scale forcing weak in the absence of any pronounced upper-level trough. Through the afternoon and evening, low-level jet response is expected which will help augment weaker forcing and aid in thunderstorm development but consensus is mainly for storms across far western Missouri into central Iowa. Within this region, storms are expected to be largely elevated, with potential primarily being large hail and a severe gust or two. Overall, the severe threat is appropriately covered with a Marginal Risk given the likely low coverage of the severe threat. Across southern Texas, the Marginal Risk removed across the upper Texas Coast region to mainly encompass the area from Corpus Christi to Brownsville westward. The northern extent of the Marginal Risk continues along the Rio Grande into Big Bend. Damaging wind risk will continue across south Texas through the afternoon before redevelopment is expected across Mexico through the evening. This secondary round of convection will pose a risk for damaging wind and large hail. ..Thornton/Smith.. 03/27/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Mar 27 2025/ ...Central Plains to Lower Missouri/Middle Mississippi Valleys... Scattered thunderstorms, including a few lingering strong storms, continue late this morning from eastern KS into northern MO within a warm-air advection regime. Morning raob data over the central Great Plains indicated the northeastern periphery of the EML is located over the lower MO Valley. Strong heating in wake of the early day convection will result in moderate buoyancy developing into northeastern KS later this afternoon. Models show a flattening mid- to upper-level ridge through tonight. Nebulous/weak forcing at best is expected in the vicinity of a warm front/outflow intersection later this afternoon. However, the erosion of CINH may enable a few isolated thunderstorms to develop late this afternoon into the evening. Recent HRRR runs and the 12 UTC model-run members of the HREF show a dearth of storm development. Confidence in appreciable storm coverage is lowering for diurnally based storm initiation and casting uncertainty in terms of the potential severe threat. Nonetheless, supercellular development could occur in the presence of moderate instability and favorable wind profiles featuring around 35-40 kt effective shear magnitudes. A greater coverage of elevated storms may occur tonight as the low-level jet reestablishes and storms expand eastward regionally. Large hail is the most probable hazard in both regimes. ...South Texas... Visible-satellite imagery shows an extensive cloud shield and convective cloud debris across much of south TX into the upper coast, and farther west into the Big Bend region. This is in response to a slow-moving upper trough which is forecast to move across northern Mexico toward Deep South Texas by Friday morning. This episodic convection across northern Mexico into adjacent portions of TX should limit heating during the day. Forecast soundings show seasonably moist profiles from the surface through the mid levels subduing lapse rate magnitudes. Mid-level flow will translate through the base of the trough, south of the international border into the lower Valley of Texas by early evening. However, considerably weaker flow with north extent (i.e., Edwards Plateau) and uncertainty regarding destabilization farther north cast uncertainty on storm intensity across south-central TX. The low-level jet will remain focused across south Texas aiding in regenerative storm development and an occasional isolated severe threat may occur with the stronger storms. $$  002 ACUS11 KWNS 272051 SWOMCD SPC MCD 272051 MOZ000-KSZ000-IAZ000-NEZ000-272245- Mesoscale Discussion 0271 NWS Storm Prediction Center Norman OK 0351 PM CDT Thu Mar 27 2025 Areas affected...Parts of central/northern KS into extreme southeast NE/northwest MO/southwest IA Concerning...Severe potential...Watch unlikely Valid 272051Z - 272245Z Probability of Watch Issuance...20 percent SUMMARY...Isolated strong to severe storms may develop by late afternoon or early evening. DISCUSSION...High-based cumulus is deepening this afternoon across west-central KS, in the vicinity of a diffuse surface boundary. Some increase in shallow cumulus has also been noted across northeast KS into far southeast NE, where airmass recovery is underway in the wake of morning convection. In the short term, the greater chance for storm development may reside within the very warm and well-mixed environment from west-central into northern KS, in the vicinity of the surface boundary where CINH is diminishing. Any development in this area would be high-based, but MLCAPE of 1000-1500 J/kg, steep low/midlevel lapse rates, and modest effective shear (generally 25-30 kt) could support a few stronger storms capable of isolated severe gusts and hail by early evening. Farther northeast into northeast KS/southeast NE and vicinity, a more favorable conditional environment may evolve by early evening, with relatively backed flow, moderate deep-layer shear, and somewhat richer boundary-layer moisture. However, in the absence of stronger large-scale ascent, potential for surface-based storm development within the initially capped environment is uncertain and could remain relatively limited. Should robust convection develop in this area, a supercell or two could evolve and pose an organized severe threat. Watch issuance is currently considered unlikely, due to the potentially limited coverage of the severe threat across the region. However, a watch would become increasingly possible if observational trends begin to support development of multiple severe storms by early evening. ..Dean/Smith.. 03/27/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...OAX...TOP...ICT...GID...DDC... LAT...LON 38800010 39399914 40539650 40939562 40889524 40609501 40409501 39959506 39579513 39159556 38389793 38099910 38069958 38159983 38469994 38800010 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  909 ACUS11 KWNS 272321 SWOMCD SPC MCD 272321 MOZ000-KSZ000-NEZ000-280115- Mesoscale Discussion 0272 NWS Storm Prediction Center Norman OK 0621 PM CDT Thu Mar 27 2025 Areas affected...northeastern Kansas and adjacent southern Nebraska/northwestern Missouri Concerning...Severe potential...Watch unlikely Valid 272321Z - 280115Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms are undergoing a period of intensification which may persist at least through 8-9 PM CDT. An upscale growing cluster accompanied by increasing potential for strong surface gusts is possible, in addition to a continuing risk for severe hail. DISCUSSION...Embedded within 20-30 kt west-southwesterly deep-layer mean flow, initially high-based thunderstorm development is undergoing intensification as it acquires more moist and potentially unstable southeasterly inflow near/northwest through north of Salina KS. Mid/upper 50s F surface dew points, along and north of the Interstate 70 corridor into the Nebraska state border vicinity of northeastern Kansas, appear to be contributing to mixed-layer CAPE in excess of 2000 J/kg. Although objective analysis and forecast soundings indicate the continuing presence of mid-level inhibition, forcing along convective outflow may maintain and perhaps support a further increase in convection through the 00-02Z time frame. Coupled with strengthening low-level warm advection, aided by an intensifying low-level jet (30-50 kt around 850 mb), an upscale growing cluster with increasing potential to produce strong surface gusts might not be entirely out of the question into this evening. ..Kerr/Hart.. 03/27/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...EAX...OAX...TOP...ICT... LAT...LON 39589793 39969709 40009602 39569456 38699482 38629633 38609750 38859782 39589793 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN