165 ACUS01 KWNS 120101 SWODY1 SPC AC 120100 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Wed Jun 11 2025 Valid 120100Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF NORTHEASTERN IOWA INTO ADJACENT SOUTHWESTERN WISCONSIN AND NORTHWESTERN ILLINOIS... ...SUMMARY... Thunderstorm activity may still increase across parts of central Texas, toward the upper Texas coastal plain, tonight accompanied by at least some risk for severe weather. Otherwise, ongoing thunderstorm development elsewhere is expected to generally wane by mid to late evening. ...01Z Update... ...Midwest... Convection with small cluster which has evolved along a stalled frontal zone across northeastern Iowa remains strong. However, it appears that forcing associated with a supporting mid-level perturbation is beginning to shift east of the Upper Midwest into Great Lakes, where the environment along the frontal zone becomes less unstable and will trend more stable with the loss of daytime heating. As this occurs, storms are expected to generally diminish in intensity this evening across northeastern Iowa through southern Wisconsin/northern Illinois. ...Northern Intermountain Region and Rockies... Downstream of a weak mid-level trough progressing eastward into the northern Rockies, stronger convection is now spreading in a swath across south central Montana and northern Wyoming. Instability is weak due to limited low-level moisture, but steep lower/mid-tropospheric lapse rates, including a modestly heated and deeply mixed boundary layer, are contributing to the generation of strong to severe gusts with the most vigorous storms. This should begin to wane as low-level lapse rates stabilize with the onset of boundary-layer cooling. ...Texas... Within slow moving, weak mid-level troughing, a digging smaller-scale perturbation is supporting increasing thunderstorm development near/west of the I-35 corridor of central Texas. In the presence of 10-20 kt westerly to southwesterly deep-layer mean flow, it appears that instability and large-scale forcing for ascent will be sufficient to support a further increase in convection through 04-06Z, which probably will tend to slowly advect across and east of the I-35 corridor. It appears that low-level warm advection/convergence focused along a remnant frontal zone near/north of the San Antonio/Austin area could support an upscale growing cluster, perhaps aided by inflow of seasonably moist air becoming characterized by CAPE in excess of 2000 J/kg. This may be accompanied by at least some increase in potential for strong to severe gusts associated with a developing cold pool while spreading toward the upper Texas coast overnight. However, given the initial weakness of the ambient mean flow/shear and lack of steeper lower/mid-tropospheric lapse rates, the severe threat appears conditioned on strong convective augmentation of the wind fields, which seems relatively low in probability. ..Kerr.. 06/12/2025 $$  291 ACUS11 KWNS 120105 SWOMCD SPC MCD 120105 ILZ000-WIZ000-IAZ000-120230- Mesoscale Discussion 1258 NWS Storm Prediction Center Norman OK 0805 PM CDT Wed Jun 11 2025 Areas affected...portions of eastern Iowa into extreme southwest Wisconsin and far northwestern Illinois Concerning...Severe Thunderstorm Watch 408... Valid 120105Z - 120230Z The severe weather threat for Severe Thunderstorm Watch 408 continues. SUMMARY...Severe winds may continue with an ongoing cluster of thunderstorms for at least a couple more hours, east of Severe Thunderstorm Watch 408. It is unclear how much longer/far downstream the threat will persist. DISCUSSION...A cluster of thunderstorms continues to produce mainly severe gusts while propagating along a baroclinic boundary. Along this boundary, 8+ C/km low-level lapse rates and 30 kts of effective bulk shear remain, with the DVN 00Z observed sounding showing a deep, dry boundary layer in place (extending up to 700 mb). Such conditions favor the continuance of an organized severe gust threat, with the primary negating factor likely being nocturnal cooling. It is unclear how quickly nocturnal stabilization of the boundary layer will begin limiting severe gust potential, but at least a couple of severe gusts may occur as far east as far northwestern IL. ..Squitieri.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...MKX...DVN...ARX...DMX... LAT...LON 42109278 42559240 42829200 42939141 42458947 42238911 41988903 41678931 41548979 41569052 41729155 41879226 41959245 42109278 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  694 ACUS02 KWNS 120519 SWODY2 SPC AC 120518 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 AM CDT Thu Jun 12 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN MONTANA INTO MUCH OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered severe storms may occur Friday from Montana into the central Plains, with hail and corridors of damaging winds possible. ...Synopsis... A shortwave trough will move across the Pacific Northwest during the day and into the northern Rockies late, with an upper ridge building from northern Mexico into AZ/NM. Meanwhile, modest westerly flow aloft will exist over the Northeast as a weak disturbance moves across AR/MO and into the mid MS/Lower OH Valleys. At the surface, low pressure will exist across the Great Basin with a southwest flow regime south of the upper trough, with a lee trough along the length of the High Plains. Increasing boundary layer theta-e will spread into the High Plains via southeast winds, resulting in an elongated area of scattered severe storm potential during the afternoon and evening. ...MT into the central High Plains... Strong heating will occur over much of west-central/southwest MT, and extending into WY CO and NM, as well as western NE/KS/TX-OK Panhandles, resulting in steep lapse rates. Meanwhile, southeast surface winds will bring moisture northwestward into the High Plains, with a large area of moderate instability developing. Storms are expected to form by 21Z over western MT, with additional storms into eastern WY/northeast CO. These will likely produce hail and areas of damaging wind. Other isolated storms are likely all the way south into eastern NM/western TX. Elsewhere, strong instability and ample moisture may result in scattered strong storms over much of MO, AR, LA, MS and vicinity, though the likelihood of ongoing early storms and outflows results in low predictability at this time. Locally strong gusts may occur. ..Jewell.. 06/12/2025 $$  501 ACUS01 KWNS 120552 SWODY1 SPC AC 120550 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Thu Jun 12 2025 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TODAY INTO TONIGHT ACROSS PARTS OF THE GREAT PLAINS...THE UPPER MIDWEST...SOUTHEASTERN TEXAS INTO THE LOWER MISSISSIPPI VALLEY AND PARTS OF THE NORTHERN MID ATLANTIC... ...SUMMARY... Scattered areas of strong thunderstorm development are possible today into tonight, accompanied by potential for severe hail and wind across parts of the Great Plains, the Upper Midwest, the Texas coastal plains into lower Mississippi Valley and a small portion of the northern Mid Atlantic. ...Discussion... Split westerlies across the mid- and higher latitudes of the eastern Pacific into North America include broad, weak troughing across the northeastern Pacific into British Columbia and the Pacific Northwest. Models suggest that this cyclonic flow may undergo some amplification later today through tonight, as an embedded short wave perturbation pivots into the Pacific Northwest, to the south of a slow moving low near/offshore of the northern British Columbia coast. Downstream, short wave ridging is forecast to shift across the Canadian Prairies and east of the northern U.S. Rockies. However, it appears a residual belt of (relatively) stronger flow will linger above a stalled frontal zone across parts of the middle Missouri Valley, into a confluent regime across the northern Mid Atlantic, to the south of large-scale mid/upper troughing across the eastern Canadian provinces. It appears that seasonably high moisture content will largely remain confined to the southern mid- and subtropical latitudes, where ridging will remain suppressed, but westerlies will remain modest to weak. One larger-scale trough within this regime is forecast to slowly shift east of the southern Great Plains and northwest Gulf coast, toward the Mississippi Valley today through tonight. ...Northern Rockies into Upper Midwest... Despite seasonably modest boundary-layer moisture, models indicate that lower/mid-tropospheric lapse will become sufficiently steep to support at least pockets of mixed-layer CAPE in excess of 1000 J/kg, along/south of the stalled frontal zone across the Big Horns and Black Hills vicinity into the Upper Midwest, and within lee surface troughing across/northeast of the Cheyenne Ridge. Aided by forcing for ascent and shear associated with a couple of smaller scale mid-level perturbations/speed maxima (40-50+ kt at 500 mb) progressing through the belt of westerly flow, the environment may become conducive to organized convective development this afternoon and evening. This may include widely scattered supercells and small upscale growing clusters posing a risk for severe hail and wind. ...Northern Mid Atlantic... The development of mixed-layer CAPE on the order of 1000-2000 J/kg also appears possible with daytime heating of a moistening boundary-layer, along the southern slopes of the higher terrain of north central through northeastern Pennsylvania by late this afternoon. Although forcing for ascent to support thunderstorm initiation remains unclear, deep-layer shear beneath the southern fringe of seasonably strong westerlies will likely be conditionally supportive of organized convection capable of producing severe hail and wind, before the instability wanes late this evening. ...Southern Rockies into adjacent Great Plains... Downstream of the large-scale mid/upper troughing developing inland of the Pacific coast, models indicate a generally weak but difluent downstream flow will prevail across the southern Rockies. There is a notable signal within the model output that forcing for ascent will become supportive of widespread thunderstorm development along the Front Range and Sangre de Cristo Mountains by mid to late afternoon. Although propagation off the higher terrain will probably be initially slow, due to modest downstream destabilization, model forecast soundings indicate that a warm and deeply mixed boundary layer will become supportive of a few strong downbursts to the lee of the higher terrain. Consolidating and strengthening outflow may support strengthening surface cold pools with a continuing risk of strong to severe gusts into portions of the adjacent high plains through this evening. ...Texas Coastal Plains into lower Mississippi Valley... An increase in thunderstorm development gradually continues across and east of the I-35 corridor of central Texas, aided by forcing for ascent associated with a short wave impulse progressing through the weak larger-scale mid-level trough. It appears that this will continue into the Texas coastal plain, where inflow of seasonably high moisture content characterized by sizable CAPE may support considerable gradual further intensification through 12Z. To differing degrees, the various model output suggests that this may be accompanied by a developing lower/mid-tropospheric cyclonic circulation, and associated augmentation of the wind fields, that will tend to advect north-northeastward toward the Ozark Plateau/Mid South today. Preceded by a developing corridor of moderately large CAPE with daytime heating, it is possible that the environment could become conducive to organizing convection with potential to produce strong to severe surface gusts, and perhaps potential for a couple of brief tornadoes. ..Kerr/Squitieri.. 06/12/2025 $$  278 ACUS11 KWNS 120715 SWOMCD SPC MCD 120714 TXZ000-120945- Mesoscale Discussion 1259 NWS Storm Prediction Center Norman OK 0214 AM CDT Thu Jun 12 2025 Areas affected...parts of south-central and southeast Texas Concerning...Severe potential...Watch unlikely Valid 120714Z - 120945Z Probability of Watch Issuance...20 percent SUMMARY...Numerous storms with some transient supercells expected through the early morning hours. DISCUSSION...A modest strengthening of a southeasterly low-level jet has resulted in widespread storm development across southeast Texas over the past hour. Relatively warm temperatures aloft and moist conditions through the column should be a limiting factor to large hail. However, intense water loading within these updrafts could result in some strong downbursts capable of strong to severe wind gusts. In addition, small but strongly curved low-level hodographs, as sampled by the KHGX VWP, will support some tornado threat. The lack of stronger deep-layer shear will likely limit the overall threat and thus the need for a watch. ..Bentley/Hart.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LCH...HGX...CRP...EWX... LAT...LON 28119666 28209701 29219877 29479892 29779845 30069772 30589638 30769586 30699526 30529464 30099437 29659432 29479438 29079480 28489569 28259625 28179643 28119666 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  308 ACUS03 KWNS 120715 SWODY3 SPC AC 120714 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0214 AM CDT Thu Jun 12 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE BLACK HILLS SOUTHWARD ACROSS THE CENTRAL PLAINS AND INTO THE SOUTHERN HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms may occur on Saturday over parts of the central Plains. ...Synopsis and Discussion... Moderate southwest flow aloft will persist over the northwestern states on Saturday, with an upper high over northern Mexico, AZ and NM. Modest west/northwest winds aloft will exist along the US/CN border and into the Great Lakes, with generally weak shear across the remainder of the CONUS. At the surface, a quasi-stationary front will stretch roughly from the Black Hills eastward toward the Mid Atlantic, with a large area of 60s to 70s F dewpoints over most of the southern and central Plains, mid to lower MS Valley, and across the Southeast. ...Plains... Areas of early day storms may be ongoing over parts of NE, KS and OK, depending on what survives the previous night. Otherwise, a lee trough will develop over the central and southern High Plains during the afternoon, with strong heating contributing to 2000-3000 J/kg MUCAPE. Although shear will remain weak, little if any capping will be present during peak heating, and the very moist air mass should yield areas of storm development from the Black Hills southward into eastern NM. Additional activity may redevelop, or even persist, in association with any robust early activity or residual outflows. Given weak shear, strong outflow and damaging gusts appears to be the primary concern, although sporadic hail may occur with initial development over the high Plains. Uncertainties exist in this weak forcing setup, but local corridors of higher probabilities may be needed in later outlook updates. ..Jewell.. 06/12/2025 $$  744 ACUS48 KWNS 120835 SWOD48 SPC AC 120833 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0333 AM CDT Thu Jun 12 2025 Valid 151200Z - 201200Z ...DISCUSSION... During the Sunday/D4 to Monday/D5 period, an upper ridge is forecast to remain over the Plains, with modest southwest flow aloft over the West. Models suggest that around Tuesday/D6, the upper ridge will break down over the central/northern Plains, although the amplitude and track of the wave is in question. Ample low-level moisture will be in place from the Plains to the East Coast, with mid to upper 60s F as far north as southern parts of the Great Lakes. As a result of this large area of moisture and instability, widely scattered thunderstorms will be common each day. The northern Plains appears to have the greatest change of organized severe storms includes MCS/s, but predictability is clearly low at this time with the uncertain wave. However, it appears that the Tuesday/D6 to Wednesday/D7 time frame may yield a corridor of organized damaging wind potential over parts of the northern and central plains to Midwest, and these trends will continue to be monitored. ..Jewell.. 06/12/2025  393 ACUS01 KWNS 121242 SWODY1 SPC AC 121241 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 AM CDT Thu Jun 12 2025 Valid 121300Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING FOR PARTS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered areas of strong thunderstorm development are possible today into tonight, accompanied by potential for severe hail and wind across parts of the Great Plains, the Upper Midwest, the Texas coastal plains into lower Mississippi Valley and a small portion of the northern Mid Atlantic. ...NE/SD... Morning water vapor imagery shows a shortwave trough over eastern MT, with a mid-level speed max tracking across WY. Large-scale lift associated with the jet max will overspread parts of NE/SD by late afternoon along a stalled surface boundary. At least widely scattered thunderstorm activity is expected for a few hours (mainly 21-03z), with forecast soundings suggesting sufficient deep-layer shear for a few organized/rotating cells. Locally damaging winds and hail are possible. Overnight CAM guidance has shown consistency on the corridor most likely to see storms, so have added a narrow SLGT to cover this threat. ...East TX/LA/AR... An upper trough is located over central TX, where widespread thunderstorms are ongoing this morning. A few of these storms have shown supercell tendencies overnight. Model guidance and local VAD data suggest a region of enhanced low/mid level flow to the east of the upper trough, extending from central into northeast TX. As the trough moves northeastward today, the combination of a very moist and modestly unstable air mass, sufficient low/deep layer shear, and considerable coverage of thunderstorms, will contribute to a risk of a few locally damaging wind gusts and/or tornadoes. Will maintain MRGL risk for today due to widespread clouds and limited opportunity for heating. ...GA/SC/NC... Strong heating is expected today across parts of GA/SC/NC, where temperatures in the upper 80s and dewpoints near 70F are forecast. This will lead to widespread moderate CAPE values and the development scattered afternoon thunderstorms. Vertical shear is weak, but a few weakly organized thunderstorm clusters may reach severe intensity with gusty/damaging winds. ..Hart/Bentley.. 06/12/2025 $$  433 ACUS01 KWNS 121652 SWODY1 SPC AC 121651 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1151 AM CDT Thu Jun 12 2025 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTH-CENTRAL PLAINS... ...SUMMARY... Scattered areas of severe thunderstorm development are possible today into tonight, accompanied by potential for severe hail and wind across parts of the Great Plains, the Upper Midwest, the Texas coastal plain into the Lower Mississippi Valley, as well as a portion of the northern Mid-Atlantic. ...North-central Plains including Nebraska/South Dakota... A low-amplitude shortwave trough and associated speed max will progress eastward over the northern High Plains, from southeast Montana/northeast Wyoming toward the Dakotas. Related forcing for ascent and a moderate belt of mid-level westerlies will overlie a wavy frontal zone across southern South Dakota and western Nebraska. At least widely scattered thunderstorms are expected into mid/late afternoon, with moderate buoyancy and 35-45 kt effective shear (especially northern Nebraska northward) supportive of supercells. Large hail and severe-caliber wind gusts are the primary hazards. ...South/East Texas to Lower Mississippi Valley/Mid-South... An extensive MCS and prominent outflow remain primary forecast factors today, with outflow now having progressed off the middle/upper Texas coast. An enhanced low/mid-level wind field on the eastern periphery of the convectively augmented upper low will continue to contribute to some supercell/tornado risk within a moist environment, although cloud cover and thermodynamic limitations may persist. Damaging winds may also occur on a sporadic/relatively limited basis regionally. ...Southeast/southern Appalachians... Strong heating is expected today across parts of Georgia into the Carolinas, where temperatures in the upper 80s F and dewpoints near 70F are forecast. This will lead to widespread moderate CAPE values and the development of scattered afternoon thunderstorms. Vertical shear is weak, but a few weakly organized thunderstorm clusters may reach severe intensity with gusty/damaging winds. ...Northern Mid-Atlantic/Northeast... With full insolation, moderate destabilization will steadily develop this afternoon near/south of a southward-moving front. While ingredients are severe-storm supportive, the extent of deep convective development may be limited by modest overall forcing/low-level convergence, but at least isolated damaging winds/hail will be possible where storms do develop. Favorable deep-layer shear (40+ kt effective) is conditionally supportive of well-organized storms including supercells. In a relative sense, severe storm development currently appears most probable across eastern Pennsylvania, northern New Jersey, and potentially toward the Great NYC Metro vicinity/far southeast New York. ..Guyer/Thornton.. 06/12/2025 $$  187 ACUS02 KWNS 121730 SWODY2 SPC AC 121728 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Thu Jun 12 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN MONTANA INTO MUCH OF THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered severe storms may occur Friday from Montana into the central Plains, with hail and corridors of damaging winds possible. ...Synopsis... A weak shortwave trough will move through the Ozarks into the mid Mississippi Valley region on Friday. This feature will likely lose amplitude with time. Farther west, a stronger shortwave trough will move into the northern Rockies by late afternoon/evening while surface ridging will build into the Southwest and southern High Plains. ...Montana into the central High Plains... Strong surface heating and a lee trough promoting moisture influx into these regions will lead to an elongated region of greater confidence in severe storm coverage from Montana into the northern Texas Panhandle. With the trough approaching the northern Rockies, the highest storm coverage will likely be in Montana into parts of Wyoming. Effective shear in these areas (particularly near the Big Horns) will range from 45-55 kts. Large hail, including some potential for stones around 2 inches in diameter, and severe wind gusts are probable. Farther to the south, storm coverage will gradually become more limited, especially away from terrain initiation sources. Even so, clusters of initial supercells or small linear segments will pose some risk for large hail and severe wind gusts as well. ...Mid-Atlantic... Along the southern fringe of stronger mid-level flow, a few storms are possible along a weak surface boundary near the Maryland/Pennsylvania border. Some model guidance shows a weak shortwave perturbation moving into the region, but timing and strength of the feature are variable. Mid-level lapse rates are expected to be weak and buoyancy will largely depend on surface heating. Given the uncertainty in cloud cover, it appears any severe will be conditional. A few stronger storms are possible and trends in guidance will be monitored with regard to areas of sufficient surface heating. ...Southeast/Mid-South/Lower Ohio Valley... Scattered thunderstorms are likely near and ahead of the weak upper-level shortwave trough that will be slowly lifting northeast through the Ozarks. Areas of precipitation and cloud cover are likely during the morning/afternoon. This increases the uncertainty as to where the greatest amount of destabilization will occur. Some modest flow enhancement appears probable for the Mid-South/lower Ohio Valley vicinity, though mid-level winds will weaken through the day. Greater buoyancy is expected in Mississippi, but deep-layer shear will be much weaker. There is certainly potential for isolated wind damage from the stronger storms tomorrow afternoon, but confidence in highlighting an area of greater coverage of organized severe storms is low at this point. ..Wendt.. 06/12/2025 $$  632 ACUS11 KWNS 121828 SWOMCD SPC MCD 121827 MSZ000-LAZ000-ARZ000-122030- Mesoscale Discussion 1260 NWS Storm Prediction Center Norman OK 0127 PM CDT Thu Jun 12 2025 Areas affected...central/northern Louisiana...southern Arkansas...western Mississippi Concerning...Severe potential...Watch unlikely Valid 121827Z - 122030Z Probability of Watch Issuance...20 percent SUMMARY...Marginal severe threat to continue through the afternoon. DISCUSSION...Thunderstorm activity continues near an MCV across eastern TX into portion so LA/AR. Largely, this has remained below severe limits. Echo tops have increased over the last hour or so with daytime heating and increasing instability across southern LA. Overall, flow remains weak except in association with the MCV where around 20-30 kts of deep layer shear are noted on the eastern periphery. Some organization may occur with deeper updrafts with potential for damaging wind and perhaps a tornado. This corridor will shift north and eastward into AR through time this afternoon. Overall, this risk will likely remain too localized for watch issuance. ..Thornton/Guyer.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAN...LIX...LZK...LCH...SHV... LAT...LON 30599338 31889300 33029326 34289337 34579311 34379197 34039141 33499071 32299018 30779102 30499168 30139225 30219294 30599338 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH  207 ACUS03 KWNS 121927 SWODY3 SPC AC 121927 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Thu Jun 12 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE HIGH PLAINS INTO THE PLAINS... ...SUMMARY... Scattered strong to severe storms may occur on Saturday over parts of the central Plains. Isolated to widely scattered storms may occur from southern Montana into the southern High Plains. ...Central/Northern Plains... The highest storm coverage in this area appears to be within eastern Wyoming into western South Dakota and Nebraska given a shortwave perturbation moving through during the afternoon. With around 30-40 kts of effective shear and strong surface heating, scattered storms capable of large hail and severe wind gusts are possible. A low-level jet will develop during the evening and focus in Nebraska/South Dakota. Some activity may be able to last into the evening. Some guidance develops elevated storms farther east in South Dakota as the low-level jet strengthens. Elevated buoyancy will be large and shear will be sufficient for some storm organization. Though development is conditional, low severe probabilities have been extended into this area given the hail/isolated wind damage threat. ...Central/Southeast Montana... With the upper-level trough generally remaining in the Northwest, the strongest mid-level winds should remain over parts of the northern Rockies into the northern Plains. Lingering, sufficient low-level moisture should allow for isolated to widely scattered storms to develop within the higher terrain and spread into central/southeast Montana. Hail and severe gusts are the likely hazards with this activity. ...Southern Plains... There remains some potential for activity from overnight Friday activity to persist into Saturday morning. Guidance varies in the location of where storms may intensify as the surface heats, but the general theme is that a continuation of overnight activity or perhaps development along an outflow boundary is possible. Shear will not be overly strong, particularly with eastward extent, but large MLCAPE in a moist, uncapped environment could support a corridor of damaging wind potential. Low severe probabilities have been extended east to account for this possibility, though uncertainty is still high. ...Mid-South into Mid-Atlantic... Another day of scattered convection is possible in these regions as a low-amplitude, diffuse upper-level trough shifts eastward. Poor lapse rates and weak shear should limit the overall severe threat. Isolated damaging winds are possible, but, again, highlighting an area of greater organization is quite uncertain at this time. ..Wendt.. 06/12/2025 $$  358 ACUS01 KWNS 121953 SWODY1 SPC AC 121952 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jun 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTH-CENTRAL PLAINS... ...SUMMARY... Scattered areas of severe thunderstorm development are possible today into tonight, accompanied by potential for severe hail and wind across parts of the Great Plains, the Upper Midwest, the Texas coastal plain into the Lower Mississippi Valley, as well as a portion of the northern Mid-Atlantic. ...20z Update... The primary change for this update is to remove risk probabilities across parts of eastern TX and western LA in the wake of a gradually strengthening convective band/MCS where conditions have stabilized. Low-end risk probabilities have been expanded slightly across south TX to account for the southeastward propagation of a convective cluster developing on the outflow of the prior MCS. Recent RAP mesoanalysis estimates/forecast soundings suggest the downstream convective environment may be supportive of organized convection through early evening. Elsewhere, the forecast largely remains on track with few adjustments required. Convection developing within the upslope flow regime across the central High Plains should increase in coverage and intensity as ascent associated with a weak mid-level perturbation (currently over northern UT) overspreads the region. Across the Northern Mid-Atlantic/Northeast, temperatures have warmed into the mid-80s, which should minimize inhibition based on forecast soundings; however, satellite imagery continues to show meager vertical development of cumulus along the frontal zone, which limits confidence in convective initiation and the overall severe threat. See the previous discussion (below) and MCD #1260 for additional details. ..Moore.. 06/12/2025 .PREV DISCUSSION... /ISSUED 1151 AM CDT Thu Jun 12 2025/ ...North-central Plains including Nebraska/South Dakota... A low-amplitude shortwave trough and associated speed max will progress eastward over the northern High Plains, from southeast Montana/northeast Wyoming toward the Dakotas. Related forcing for ascent and a moderate belt of mid-level westerlies will overlie a wavy frontal zone across southern South Dakota and western Nebraska. At least widely scattered thunderstorms are expected into mid/late afternoon, with moderate buoyancy and 35-45 kt effective shear (especially northern Nebraska northward) supportive of supercells. Large hail and severe-caliber wind gusts are the primary hazards. ...South/East Texas to Lower Mississippi Valley/Mid-South... An extensive MCS and prominent outflow remain primary forecast factors today, with outflow now having progressed off the middle/upper Texas coast. An enhanced low/mid-level wind field on the eastern periphery of the convectively augmented upper low will continue to contribute to some supercell/tornado risk within a moist environment, although cloud cover and thermodynamic limitations may persist. Damaging winds may also occur on a sporadic/relatively limited basis regionally. ...Southeast/southern Appalachians... Strong heating is expected today across parts of Georgia into the Carolinas, where temperatures in the upper 80s F and dewpoints near 70F are forecast. This will lead to widespread moderate CAPE values and the development of scattered afternoon thunderstorms. Vertical shear is weak, but a few weakly organized thunderstorm clusters may reach severe intensity with gusty/damaging winds. ...Northern Mid-Atlantic/Northeast... With full insolation, moderate destabilization will steadily develop this afternoon near/south of a southward-moving front. While ingredients are severe-storm supportive, the extent of deep convective development may be limited by modest overall forcing/low-level convergence, but at least isolated damaging winds/hail will be possible where storms do develop. Favorable deep-layer shear (40+ kt effective) is conditionally supportive of well-organized storms including supercells. In a relative sense, severe storm development currently appears most probable across eastern Pennsylvania, northern New Jersey, and potentially toward the Great NYC Metro vicinity/far southeast New York. $$  865 ACUS11 KWNS 122004 SWOMCD SPC MCD 122004 COZ000-NEZ000-WYZ000-122200- Mesoscale Discussion 1261 NWS Storm Prediction Center Norman OK 0304 PM CDT Thu Jun 12 2025 Areas affected...South-Central/Southeast WY...NE Panhandle...Northeast/East-Central CO Concerning...Severe potential...Watch possible Valid 122004Z - 122200Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorms are expected to evolve into one or more convective lines capable of damaging gusts over the next several hours. Some isolated hail is possible as well. DISCUSSION...Thunderstorm coverage continues to increase across the higher terrain of south-central WY and north-central CO, supported by large-scale ascent attendant to an approaching shortwave trough. Persisting westerly flow aloft should result in these storms eventually moving off the terrain into the High Plains, where strong heating has resulted in a deeply mixed and modest buoyant airmass. Expectation is for storms to evolve into one or more outflow-dominant convective lines over the next few hours, with an associated threat for damaging gusts. Some isolated hail is also possible, particularly if storms can maintain a more cellular mode. This appears most likely across southeast WY in the vicinity of a weak surface low. Uncertainty regarding the coverage of severe limits forecast confidence, but convective trends will be monitored closely. ..Mosier/Guyer.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS...RIW... LAT...LON 39590513 40900554 41200709 41670732 42170675 42540599 42840498 42840391 42310311 40220230 39020304 38720453 39590513 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  371 ACUS11 KWNS 122020 SWOMCD SPC MCD 122019 SDZ000-NEZ000-122215- Mesoscale Discussion 1262 NWS Storm Prediction Center Norman OK 0319 PM CDT Thu Jun 12 2025 Areas affected...Northern NE...Southern SD Concerning...Severe potential...Watch likely Valid 122019Z - 122215Z Probability of Watch Issuance...80 percent SUMMARY...Thunderstorms capable of large hail and damaging gusts are possible across northern NE and southern SD this afternoon and evening. DISCUSSION...Convective initiation is underway along a modest frontal boundary that extends from east-central SD through the NE Panhandle to a low over southeast WY. Despite lingering mid-level warm air, strong diurnal heating has largely eroded any convective inhibition, and low-level convergence along the boundary has fostered deepening cumulus (and at least one storm capable of lightning). Expectation is for thunderstorm coverage to increase within a narrow corridor along this boundary. Wind profiles, which are characterized by low-level south-southeasterlies and mid/upper-level westerlies, support the potential for supercells initially capable of large hail. The thermodynamic profiles become more conducive for strong outflow with western extent, and there is some potential for outflow-dominant storms to progress southward (or even southwestward) into more of north-central NE. Overall severe coverage is expected to be high enough to merit watch issuance. ..Mosier/Guyer.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR...LBF...UNR...CYS... LAT...LON 42580293 43720169 44359949 44609767 43579769 41820093 41690248 42580293 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  888 ACUS11 KWNS 122046 SWOMCD SPC MCD 122045 TXZ000-122145- Mesoscale Discussion 1263 NWS Storm Prediction Center Norman OK 0345 PM CDT Thu Jun 12 2025 Areas affected...portions of deep south Texas Concerning...Severe potential...Watch unlikely Valid 122045Z - 122145Z Probability of Watch Issuance...5 percent SUMMARY...Marginal risk for severe wind through the afternoon. DISCUSSION...A broken line of storms continues across deep south Texas, producing occasional gusts 40-50 mph. Outflow has largely moved out ahead of the storms on the western flank. However, portions of the line moving through Corpus Christi appear to be more aligned with the outflow. This will gradually shift offshore in the next hour. Agitated cumulus can be seen on visible in the vicinity of the southward moving outflow. Additional storms my develop along the boundary with potential for gusty winds. Overall, the temporal and limited spatial area of the threat will preclude the need for watch issuance. ..Thornton/Guyer.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CRP...BRO... LAT...LON 26439883 27659911 28169848 28229750 28119716 27759721 27239738 27039739 26789736 26459750 26249769 26169794 26199823 26379882 26439883 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH  314 ACUS11 KWNS 122057 SWOMCD SPC MCD 122057 CTZ000-NYZ000-NJZ000-PAZ000-122300- Mesoscale Discussion 1264 NWS Storm Prediction Center Norman OK 0357 PM CDT Thu Jun 12 2025 Areas affected...central/eastern Pennsylvania...portions of northern New Jersey Concerning...Severe potential...Watch possible Valid 122057Z - 122300Z Probability of Watch Issuance...40 percent SUMMARY...Conditional risk for severe hail and wind possible this afternoon. DISCUSSION...Thunderstorm development is possible across portions of central PA this afternoon near the southward moving cold front. Visible satellite shows deepening cumulus across the area, with a few echos now on radar, as MLCIN has eroded over the last few hours. MLCAPE around 500-1000 J/kg is in place with deep layer shear around 40 kts. Should thunderstorm development occur along the front, a supercell or two could be possible with potential for damaging wind and hail. This threat will be monitored for watch potential. ..Thornton/Guyer.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...BGM...CTP... LAT...LON 41467754 41707641 41607493 41127363 40597364 40047399 40547679 40937776 41467754 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  259 ACUS11 KWNS 122214 SWOMCD SPC MCD 122214 NMZ000-COZ000-130015- Mesoscale Discussion 1265 NWS Storm Prediction Center Norman OK 0514 PM CDT Thu Jun 12 2025 Areas affected...portions of southeast Colorado and eastern New Mexico Concerning...Severe potential...Watch unlikely Valid 122214Z - 130015Z Probability of Watch Issuance...5 percent SUMMARY...Occasional severe gusts and large hail may occur this afternoon across portions of southeast Colorado and eastern New Mexico. A watch is not anticipated. DISCUSSION...Convection has developed in weak upslope surface flow along the lee of the higher terrain across portions of central Colorado and New Mexico. Strong mixing on the High Plains has resulted in inverted-V thermodynamic profiles with approximately 1000 J/kg MLCAPE per mesoanalysis and short-term RAP forecast profiles. Generally, low-level and deep-layer shear are marginal for supercells, particularly across northeast New Mexico and southeast Colorado, and some transient mid-level mesocyclones are apparent on WSR-88D radar. Some clustering of storms may occur with time given strong cold pools, and this may result in a risk for severe gusts. Additionally, given the weak low-level shear and low freezing levels, some marginally severe hail may be possible. Due to the expected sparse coverage of severe weather, a watch is not anticipated. ..Supinie/Smith.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MAF...PUB...BOU...ABQ...EPZ... LAT...LON 37570523 38560477 38590381 38110350 36160348 34310369 33160418 32870473 32990530 33860555 35790556 37570523 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  525 ACUS11 KWNS 122217 SWOMCD SPC MCD 122217 MNZ000-IAZ000-122345- Mesoscale Discussion 1266 NWS Storm Prediction Center Norman OK 0517 PM CDT Thu Jun 12 2025 Areas affected...Parts of extreme southern MN into far northern IA Concerning...Severe potential...Watch unlikely Valid 122217Z - 122345Z Probability of Watch Issuance...20 percent SUMMARY...Isolated strong to locally severe storms are possible into this evening. DISCUSSION...Isolated storms have developed in the vicinity of a surface front across far southern MN. Frontal convergence and weak low-level warm advection may continue to support development of an additional strong storm or two near the front into this evening. MLCAPE of 1000-1500 J/kg near/south of the front combined with effective shear of 30-35 kt could support marginal supercell potential with a threat for isolated hail and damaging wind, and possibly a brief tornado if any supercell can persist in the vicinity of the surface boundary. ..Dean/Smith.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ARX...MPX...DMX...FSD... LAT...LON 44029536 44009358 43839286 43619285 43259321 43129425 43189522 43259545 43429556 43529559 43599558 43899556 44029536 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  627 ACUS11 KWNS 122308 SWOMCD SPC MCD 122308 SDZ000-NEZ000-COZ000-WYZ000-130045- Mesoscale Discussion 1267 NWS Storm Prediction Center Norman OK 0608 PM CDT Thu Jun 12 2025 Areas affected...Southeast WY/northeast CO into western/north-central NE and south-central SD Concerning...Severe Thunderstorm Watch 410... Valid 122308Z - 130045Z The severe weather threat for Severe Thunderstorm Watch 410 continues. SUMMARY...A threat for primarily large hail and severe gusts will continue this evening. DISCUSSION...Two clusters of potentially severe storms are ongoing as of 23 UTC across WW 410. One is a backbuilding supercell cluster near the NE/SD border north of Valentine, NE, in the vicinity of a quasi-stationary surface front. Given the orientation of the instability gradient, this cluster may attempt to propagate southward with time, with continued backbuilding possible along its western flank. Moderate to strong buoyancy (MLCAPE in excess of 2000 J/kg near/south of the front) and sufficient deep-layer shear will continue to support potential for hail in the 1.5-2.5 inch range, along with localized severe gusts. Also, while low-level flow is not particularly strong, a tornado cannot be ruled out, given the presence of supercell structures in the vicinity of the surface boundary. Farther southwest, more loosely organized convection is ongoing near the NE/WY border. Moderate to strong buoyancy will continue to support an isolated hail threat in the short term. Consolidating outflows may eventually result in an outflow-driven cluster with a threat of severe gusts spreading eastward across the NE Panhandle later this evening. ..Dean.. 06/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR...LBF...UNR...GLD...BOU...CYS... LAT...LON 41970508 42640468 43000225 43400117 43889995 44119924 43929871 43329896 42479959 41630008 40270183 40360383 40550415 40780437 41210483 41970508 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN