Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Wed Jun 21 2023 Valid 212000Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF EASTERN COLORADO...SOUTHEAST WYOMING...AND THE NEBRASKA PANHANDLE...AND FROM THE EASTERN TEXAS PANHANDLE AND WESTERN OKLAHOMA INTO CENTRAL TEXAS... ...SUMMARY... Intense severe thunderstorms are expected late this afternoon into this evening over parts of the central and southern Plains, where severe gusts, very large hail, and a few tornadoes are possible. ...20Z Update... The Marginal and Slight Risks have been trimmed over parts of OK, in the wake of an earlier storm cluster that has since weakened. Otherwise, the previous forecast reasoning remains valid. ...Eastern CO/Southeast WY Intense supercell development is underway across northeast CO into the NE Panhandle, with additional supercells expected later this afternoon into this evening farther west toward the CO Front Range and southeast WY. Very large hail, severe gusts, and a few tornadoes will be possible in this area. See MCD 1188, WW 349, and WW 350 for more information regarding the threats in this area. ...Extreme southwest KS into the TX/OK Panhandles and northwest TX... A separate zone of intense supercell development is expected late this afternoon from extreme southwest KS into the TX/OK Panhandles, within a region of very rich low-level moisture, steep midlevel lapse rates, and strong to extreme buoyancy. Very large hail, severe wind gusts, and a couple of tornadoes will be possible with initial supercells. Some upscale growth is possible this evening, which may result in a larger swath of destructive wind gusts as storms move southeastward, though the areal extent of MCS development remains somewhat uncertain, as a westward-moving outflow may result in a narrowing of the instability axis with time. See MCD 1189 and WW 351 for more information regarding the short-term threat in this area. ..Dean.. 06/21/2023 .PREV DISCUSSION... /ISSUED 1123 AM CDT Wed Jun 21 2023/ ...TX/OK... Morning water vapor imagery shows a large upper trough over the western states, with moderately strong southwesterly mid-level winds across much of the central and southern High Plains. At the surface, an extremely moist and potentially unstable air mass (dewpoints in the mid 70s) is present from the eastern TX Panhandle eastward into western OK, and extending southeastward into central TX. Full heating will lead to afternoon MLCAPE values of 5000-6000 J/kg and minimal cap. Large scale forcing is weak, but circulations along the surface dryline will lead to rapidly thunderstorm development from extreme southwest KS into the eastern TX Panhandle. These storms are likely to be supercells capable of very large hail and a few tornadoes. These storms are likely to slowly congeal into one or more bowing complexes by mid evening, tracking southeastward into northwest and central TX. Several morning CAM solutions suggest the potential for a corridor of significant wind damage if this scenario unfolds. ...Eastern CO/Southeast WY... An extremely moist and unstable low-level air mass is streaming into the central High Plains, with dewpoints in the 70s being transported westward into the higher elevations of the eastern CO/southeast WY plains. Strong daytime heating and steep mid-level lapse rates will yield afternoon MLCAPE values over 3000 J/kg. All morning CAM solutions agree on the development of scattered thunderstorms by mid-afternoon along the front range and foothills, as well as the DCVZ along the Palmer Ridge. A combination of backed low-level winds and 30+ knots of southwesterly flow aloft will promote supercell structures capable of very large hail and a few tornadoes. The threat of severe storms may persist much of the evening, building southward along the Front Range into southeast CO. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Wed Jun 21 2023 Valid 221200Z - 231200Z The current D2 Outlook remains on track with no updates needed. See previous discussion below for more information. ..Thornton.. 06/21/2023 .PREV DISCUSSION... /ISSUED 0116 AM CDT Wed Jun 21 2023/ ...Synopsis... A shortwave trough is expected to lift through the Four Corners on Thursday into Friday morning. A surface low will develop in the western Great Basin with a surface trough extending eastward into the southern High Plains. ...Southwest... Surface winds will likely be slightly stronger than on Wednesday. 15-20 mph is what is generally expected. However, some pockets of sustained 20 mph winds are possible, particularly within the terrain. RH will again be quite low (10-20%) by the afternoon. With the trough and stronger mid-level winds arriving during the evening/overnight, critical conditions are currently expected to remain spatially limited. ...Great Basin... Surface winds will increase in response to the approaching shortwave and surface low. RH could fall below 10% in some locations with 10-20% occurring more broadly. Fuels at lower elevations in the southern Great Basin have dried, but ERCs within the area are still near normal seasonal levels. Conditions will favor locally elevated fire weather where drier fuels exist. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Wed Jun 21 2023 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF SOUTHEAST WY...EASTERN CO...AND NORTHEAST NM... ...SUMMARY... Severe thunderstorms are possible on Thursday across parts of the central and southern High Plains, with a threat of large hail (possibly in excess of 2 inches in diameter), severe wind gusts, and a tornado or two. ...Synopsis... A seasonably deep upper trough is forecast to begin ejecting northeastward across the southwest CONUS on Friday. Farther east, a shortwave ridge will remain in place across parts of the southern Rockies/High Plains, while a mid/upper-level low will move little over the Southeast and Ohio Valley. An outflow-enhanced surface boundary is forecast to be draped somewhere from the VA Tidewater region southwestward toward the upper TX Coast, then northwestward toward the TX South Plains, and finally northward into the CO Front Range. ...Central/southern High Plains... Favorably moist post-frontal surface flow will again support scattered thunderstorm development across parts of the central/southern High Plains on Thursday. Initial development is expected from near the Raton Mesa vicinity in NM northward along the CO Front Range into southeast WY. Stronger deep-layer flow will remain west of the Rockies through the evening, but in the presence of moderate to locally strong buoyancy, veering wind profiles and 30-40 kt of effective shear will be sufficient for a few supercells. Large hail (possibly in excess of 2 inches in diameter) will be the primary initial hazard, though a tornado or two cannot be ruled out as well. Storm coverage through early evening is currently expected to be somewhat greater from southeast WY into eastern CO and northeast NM, with more isolated development farther south into the remainder of the southern High Plains. Upscale growth into one or more clusters will be possible with time Thursday evening, potentially resulting in a threat for at least isolated severe wind/hail spreading eastward into a larger portion of the High Plains, before diminishing instability with eastward extent results in a weakening trend overnight. ...Gulf Coast into parts of the Southeast... A remnant MCS may be ongoing somewhere near the upper TX or LA Gulf Coast at the start of the period, though most guidance suggests it will already be offshore by 12Z and move across the northern Gulf of Mexico during the day if it persists. If the system tracks farther north, or weakens quickly and allows the effective surface front to move northward, then some isolated severe threat may evolve near the Gulf Coast, but confidence remains too low for probabilities in this area. A more favorable area for at least isolated strong to severe storms may evolve from FL into south GA and parts of the Carolinas, where rich low-level moisture will support the development of moderate buoyancy along/south of the front, despite weak midlevel lapse rates. Modestly enhanced low/midlevel flow along the eastern periphery of the mid/upper-level low may support localized damaging gusts and perhaps a brief tornado will the strongest convection. Farther south across the FL Peninsula, low/midlevel flow will be somewhat weaker, but somewhat stronger buoyancy may support an isolated damaging wind and hail risk. ..Dean.. 06/21/2023 Read more

MD 1178 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEASTERN AND SOUTH-CENTRAL LOUISIANA
Mesoscale Discussion 1178 NWS Storm Prediction Center Norman OK 0501 PM CDT Tue Jun 20 2023 Areas affected...Southeastern and south-central Louisiana Concerning...Severe potential...Watch possible Valid 202201Z - 210000Z Probability of Watch Issuance...40 percent SUMMARY...Damaging winds and isolated large hail will be possible with a storm cluster moving westward into south-central Louisiana. A watch is possible. DISCUSSION...Large buoyancy and modest effective shear values are in place again across parts of southern Louisiana. A cluster of strong to severe storms continues to move westward into the greater buoyancy. Other isolated cellular activity has thus far been slow to become sustained, likely due to warm air aloft present on the observed 12Z LCH sounding. MRMS MESH data has shown some tendency for newer storm cores to have 1-1.5 inch hail signatures. Isolated large hail and damaging winds will continue to be possible into the early evening. The western extent of the severe threat will be limited by the warmer air aloft. A watch is possible this evening should convective trends warrant. ..Wendt/Thompson.. 06/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAN...LIX...LCH...SHV... LAT...LON 29119104 29359187 29559220 30069263 30699309 31239325 31419289 31369232 30949105 30569083 29829035 29319019 29069053 29119104 Read more

WW 0345 Status Updates
STATUS FOR WATCH 0345 HAS NOT BEEN ISSUED YET Read more

WW 345 SEVERE TSTM ND 202150Z - 210400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 345 NWS Storm Prediction Center Norman OK 450 PM CDT Tue Jun 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central North Dakota * Effective this Tuesday afternoon and evening from 450 PM until 1100 PM CDT. * Primary threats include... Scattered large hail likely with isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph likely A tornado or two possible SUMMARY...Severe thunderstorms will form this afternoon along a slow-moving front and persist through the evening. A mix of multicell clusters and supercells is expected, with the potential for large hail of 1-2 inches in diameter and severe outflow gusts of 60-70 mph. An isolated tornado or two will also be possible with the initial storms. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 65 miles north northwest of Devils Lake ND to 60 miles south of Bismarck ND. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). 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 344... 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 21020. ...Thompson Read more

WW 0344 Status Updates
STATUS FOR WATCH 0344 HAS NOT BEEN ISSUED YET Read more

WW 344 SEVERE TSTM NE SD 202055Z - 210400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 344 NWS Storm Prediction Center Norman OK 255 PM MDT Tue Jun 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Nebraska Central South Dakota * Effective this Tuesday afternoon and evening from 255 PM until 1000 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms will become more numerous through the late afternoon along an axis from northern Nebraska into central South Dakota. The strongest storms will pose a risk of large hail and damaging wind gusts. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 140 miles south of Philip SD to 30 miles north northwest of Mobridge SD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 23025. ...Hart Read more

MD 1177 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN TEXAS AND WESTERN LOUISIANA
Mesoscale Discussion 1177 NWS Storm Prediction Center Norman OK 0343 PM CDT Tue Jun 20 2023 Areas affected...parts of eastern Texas and western Louisiana Concerning...Severe potential...Watch unlikely Valid 202043Z - 202315Z Probability of Watch Issuance...20 percent SUMMARY...Isolated intense thunderstorm development is possible through 5-7 PM CDT. It remains unclear how long any storms that do develop will persist, but they may pose at least a short-lived risk for very large hail and strong downbursts. It does not currently appear that a severe weather watch will be needed, but trends will continue to be monitored. DISCUSSION...Attempts at new thunderstorm development are ongoing near/east-southeast of Longview, TX. This may be supported by forcing for ascent within a focused area of weak low-level warm advection, in the wake of a subtle short wave impulse now digging across Louisiana coastal areas. Due to substantial lingering inhibition associated with warm and dry elevated mixed-layer air, it remains unclear if this convection will be sustained, particularly based on recent model output. However, seasonably moist boundary-layer inflow into the south-southeastward propagating convection appears characterized by very large CAPE. And deep-layer shear beneath moderate northwesterly mid-level flow (on the order of 30 kt) may be marginally sufficient to support supercell structures. So, there appears at least some potential for isolated rapid thunderstorm development and intensification during the next few hours. If this occurs, it probably will be accompanied by a risk for very large hail and occasional strong downbursts as long as it it maintained. ..Kerr/Hart.. 06/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LCH...SHV... LAT...LON 32509427 32399408 31739327 30979343 30869387 31029428 32179455 32529452 32509427 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Tue Jun 20 2023 Valid 202000Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF LOUISIANA AND EAST TEXAS...AND ALSO OVER PORTIONS OF EASTERN MONTANA AND THE DAKOTAS... ...SUMMARY... Isolated to scattered severe thunderstorms will be possible late this afternoon into tonight across parts of the northern Plains, and also from east Texas to the Southeast. Damaging winds and large hail should be the main threats. ...20Z Update... The primary outlook change is to trim the northeastern portion of the southern Slight Risk area across parts of southern MS, in the wake of extensive convection that has recently moved into southeast LA. Otherwise, see the previous discussion below for more information, and MCD 1175 for more information regarding the short-term threat across parts of WY. Outside of the Marginal Risk area, elevated storms may develop late tonight across south-central NE into north-central KS. A hail threat cannot be ruled out with the strongest storms, due to the presence of steep midlevel lapse rates and favorable elevated buoyancy. However, with uncertainty regarding storm placement and coverage, and only modest deep-layer shear in place, confidence remains too low to extend severe probabilities into the region at this time. ..Dean.. 06/20/2023 .PREV DISCUSSION... /ISSUED 1124 AM CDT Tue Jun 20 2023/ ...LA/TX... Morning water vapor imagery shows a dominant ridge aloft extending from the southern Plains into the upper Midwest, with a band of relatively fast northwesterly mid-level flow from MO/AR into LA/MS. An extremely moist low-level air mass is present beneath the southwesterly fringe of the strong winds aloft, with dewpoints in the upper 70s to near 80F over parts of east TX and much of LA. Strong heating will yield very large CAPE values this afternoon and promote scattered thunderstorm development. Storms will mainly develop along/ahead of a southwestward sagging surface boundary that currently extends from northern LA into southern MS. A few of the cells will likely be severe, with hail and damaging winds possible through the evening. ...SD/ND... A weak surface cold front currently extends from north central ND into southeast SD. Substantial low-level moisture along and east of the front, coupled with full sunshine, will result in moderate CAPE by afternoon. Large scale forcing for ascent associated with a shortwave trough currently over northwest CO will overspread the area this afternoon, promoting scattered thunderstorms along the front. Low-level winds are relatively weak, but sufficient deep layer shear will promote organized multicell or a few supercell storms capable of large hail and damaging winds. ...Eastern MT/western ND... Model guidance shows a well-defined 60-70kt mid-level jet over northern NV. Forcing associated with this feature is moving across western WY and is expected to result in a scattered thunderstorms over the Big Horn mountains by mid-afternoon. These storms will track northeastward into southeast MT and eventually western ND tonight. A cluster of fast-moving supercells or bowing structures (similar to yesterday) is possible, capable of damaging winds and hail. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Tue Jun 20 2023 Valid 211200Z - 221200Z The Elevated region was expanded slightly into northern Arizona to account for Elevated fire weather conditions in the Little Colorado River Valley. In this region, sustained downslope winds around 15-20 will overlap modestly dry fuels and relative humidity reductions to 10-15 percent. Otherwise, the forecast remains on track. See previous discussion below for more information. ..Thornton.. 06/20/2023 .PREV DISCUSSION... /ISSUED 0100 AM CDT Tue Jun 20 2023/ ...Synopsis... A similar upper-level pattern to Tuesday will continue into Wednesday. The trough in the West and ridge in the Plains will make little progress. A similarly situated High Plains lee trough will also be present once again during the afternoon. ...Southwest... Dry and windy conditions are expected during the afternoon from southeastern Arizona into northeastern New Mexico. RH of 15-20% will be most common; however, broader areas of RH near 10% may occur as compared to Tuesday. Winds of 15-20 mph will again occur in most areas. Some terrain-enhancement will promote locally stronger winds. Elevated fire weather will occur for a few hours. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Tue Jun 20 2023 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible on Wednesday across portions of the Plains. Large hail and severe gusts will be the main hazards with this activity. Isolated strong storms also will be possible across parts of the Southeast, with an accompanying risk for damaging gusts. ...Synopsis... Little change to the large-scale pattern is expected on Wednesday, with a deep upper trough remaining in place over much of the west into the northern High Plains, an upper ridge from the southern Rockies into parts of the southern High Plains, and a persistent upper low/trough over the Southeast. At the surface, an initially stationary front will extend from the Gulf Coast northwestward toward the ArkLaTex and into the southern High Plains. This front may tend to move westward across the southern Plains Wednesday evening. Another weak cold front will become nearly stationary across the northern Plains. ...CO Front Range into parts of the central/southern Plains... Guidance varies regarding the placement (if any) of ongoing storm clusters Wednesday morning across the central Plains. Some CAM solutions take an ongoing storm cluster and intensify it through the day as it moves south-southeastward along the periphery of the upper ridge, which would potentially result in a notable severe-wind risk across parts of OK into central/east TX as the downstream environment becomes strongly unstable during the afternoon. Other guidance suggests little to no threat in these areas during the day, as the severe threat focuses farther west toward the High Plains by late afternoon/evening. Even if no substantial MCS development occurs during the day, widely scattered strong storms may be possible along the front, and also emerging from a hot and well-mixed environment across parts of southwest TX. Uncertainty remains quite high, but severe probabilities have been expanded southeastward to cover these potential threats. Otherwise, moist post-frontal low-level flow will support thunderstorm development across parts of the central High Plains and the CO Front Range during the afternoon and evening. Midlevel flow will remain rather modest, but favorably veering wind profiles will result in effective shear of 30-40 kt, supporting the potential for a few supercells with an initial threat of large (possibly golfball-size or larger) hail. A tornado or two will also be possible, especially across parts of southeast WY, where a the most favorable overlap of instability and stronger low-level shear is currently forecast. With time, upscale growth into one or more clusters will be possible, with an increasing severe-wind risk. There is some potential for an organized MCS to develop and move southeastward across the southern High Plains Wednesday night, though this scenario will depend in part on the extent of convective overturning that occurs downstream earlier in the day. ...Northern Plains... Some uncertainty remains regarding the convective evolution on Wednesday across the Dakotas, with morning storms potentially leading to a complex evolution later in the day. Stronger midlevel flow will remain displaced well northwest of the effective warm sector, but a few strong storms may develop during the afternoon near a weakening frontal boundary, with a threat of isolated hail and strong gusts. Farther west, a few stronger cells/clusters may develop across parts of northeast WY, within a modestly moist post-frontal regime. Deep-layer flow/shear will be stronger in this area, but buoyancy may tend to remain somewhat limited. Isolated hail and severe gusts cannot be ruled out in this area. One or more clusters may eventually move northeastward into the Dakotas Wednesday night, which could pose a threat of isolated strong/severe gusts, depending on the magnitude of buoyancy in the wake of potential convection earlier in the day. ...Southeast... To the south and east of the persistent upper low across the Southeast, widespread convection is expected during the day on Wednesday, which may persist into Wednesday night near the immediate Gulf Coast. Modest deep-layer flow/shear and moderate buoyancy will support some stronger cells/clusters, with a primary threat of locally damaging gusts. Weak midlevel lapse rates will tend to limit the hail threat, though small to near-severe hail cannot be ruled out with the strongest storms. ..Dean.. 06/20/2023 Read more

MD 1169 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEASTERN LOUISIANA
Mesoscale Discussion 1169 NWS Storm Prediction Center Norman OK 0503 PM CDT Mon Jun 19 2023 Areas affected...Southeastern Louisiana Concerning...Severe potential...Watch possible Valid 192203Z - 200000Z Probability of Watch Issuance...40 percent SUMMARY...Large hail and damaging winds would be possible should storms develop westward into southeastern Louisiana. A watch is not certain at this time, but convective trends will be monitored. DISCUSSION...Cumulus near Lake Pontchartrain have steadily become more vertically developed late this afternoon. Forcing for ascent remains rather weak with minimal surface convergence and the upper low farther to the northeast. However, temperatures near 100 F and dewpoints in the mid-upper 70s F is supportive of minimal MLCIN. Development along westward-moving outflow from southern Alabama/Mississippi may provide a trigger for additional storm development into southeastern Louisiana. Very large buoyancy and enhanced mid-level northwesterly flow around the upper low (25-35 kts of effective shear) would mean organized supercell structures would be possible. Large hail up to 2 inches and damaging wind gusts would be the main threats. Low-level shear is sufficient for weak low-level rotation (per KLIX VAD). The strongest discrete storms could produce a brief tornado. There is some uncertainty how many storms and how far west development will occur. A watch is possible should convective trends warrant. ..Wendt/Thompson.. 06/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LIX... LAT...LON 29769005 30159120 30699135 30809116 30839069 30778990 30608922 30118888 29608922 29769005 Read more

MD 1168 CONCERNING SEVERE THUNDERSTORM WATCH 340... FOR CENTRAL TEXAS
Mesoscale Discussion 1168 NWS Storm Prediction Center Norman OK 0458 PM CDT Mon Jun 19 2023 Areas affected...Central Texas Concerning...Severe Thunderstorm Watch 340... Valid 192158Z - 200000Z The severe weather threat for Severe Thunderstorm Watch 340 continues. SUMMARY...A severe threat is expected to continue into this evening with large hail and wind damage possible across parts of central Texas. As the severe threat moves toward the edge of weather watch, new watch issuance will need to be considered. DISCUSSION...The latest high-resolution radar imagery from San Angelo shows a severe convective cluster over the Texas Hill Country. These storms are located near a thermal axis extending southeastward across central Texas, where surface temperatures are well above 100 F. Large temperature-dewpoint spreads are resulting in high-based storms with damaging outflow potential. The WSR-88D VWP at Fort Hood has a supercell wind profile, with 0-6 km shear near 40 knots. This, combined with 700-500 mb lapse rates near 8.5 C/km, will also support a large hail threat. The severe threat will move toward the edge of weather watch 340 over the next hour, and could affect areas to the east of the watch later this evening. For this reason, a new watch could be needed across central Texas by 00Z. ..Broyles.. 06/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...EWX...SJT... LAT...LON 31859793 32129830 32209880 31979921 31479951 30839983 30400008 29939996 29679936 29689900 29889866 30749807 31489781 31859793 Read more

MD 1167 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF SOUTHEAST MONTANA INTO FAR NORTHEAST WYOMING
Mesoscale Discussion 1167 NWS Storm Prediction Center Norman OK 0351 PM CDT Mon Jun 19 2023 Areas affected...portions of southeast Montana into far northeast Wyoming Concerning...Severe potential...Watch possible Valid 192051Z - 192315Z Probability of Watch Issuance...60 percent SUMMARY...The severe threat is increasing across portions of the northern High Plains. Severe winds and hail are the greatest threats with any of the stronger storms that develop. An organized convective cluster may ultimately materialize and a WW issuance may become necessary at some point this afternoon. DISCUSSION...Several hours of clearing skies have supported surface temperatures to warm into the upper 70s F amid upper 40s to 50s F dewpoints, resulting in 2000+ J/kg SBCAPE/MUCAPE given the presence of 7-8 C/km low- and mid-level lapse rates. Cumulus are increasing in depth and coverage across northeast WY, likely driven by the strong surface heating. However, the approach of the mid-level trough will result in increasing deep-layer ascent and stronger flow aloft, which will also support 60+ kts of effective bulk shear/elongated hodographs. As storms develop, cellular modes are possible, with a mix of severe hail/gusts the hazards of concern. However, as potential upscale growth of an MCS occurs later this afternoon or early evening, severe winds will become the prevalent threat. ..Squitieri/Hart.. 06/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS...UNR...BYZ...GGW...RIW... LAT...LON 44830940 46360734 47190573 47520432 46950344 46150319 45340368 44920436 44680518 44470625 44090753 44130847 44830940 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Mon Jun 19 2023 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST...NORTHERN PLAINS...AND CENTRAL TEXAS... ...SUMMARY... Severe thunderstorms are possible today over parts of the Southeast, central Texas, Arklatex, and northern Plains. ...20Z Update... The only meaningful change to the outlook has been to introduce a small Slight Risk across parts of central TX. Temperatures have soared into the low to mid 100s amid upper 60s to low 70s surface dewpoints to the east of a dryline. Recent visible satellite imagery shows convective initiation occurring east of San Angelo TX. Even though large-scale ascent will remain weak, any thunderstorms that can form and be sustained may become supercellular given 35-40 kt of deep-layer shear due to modestly enhanced mid/upper-level northwesterly winds. An associated threat for very large hail should exist given the presence of very strong instability and steep mid-level lapse rates. Severe downdraft winds may also occur. For more details, see recently issued Mesoscale Discussion 1166 and Severe Thunderstorm Watch 340. Across the Southeast, tornado potential will likely remain focused along/very near the Gulf Coast in MS/AL and the FL Panhandle. Multiple areas of low-level rotation, with occasional debris signatures, have been noted with convection occurring across these areas given favorable low-level shear noted on recent VWPs from KMOB/KEVX, etc... In the wake of earlier thunderstorms, a separate area of convection has also developed this afternoon across south-central AL. This activity may pose an isolated threat for damaging winds and hail through the rest of the afternoon into this evening as the boundary layer attempts to re-destabilize. See Mesoscale Discussion 1165 for more details on the near-term severe threat across the central Gulf Coast states. No changes have been made to the Slight Risk across parts of eastern MT into ND. ..Gleason.. 06/19/2023 .PREV DISCUSSION... /ISSUED 1112 AM CDT Mon Jun 19 2023/ ...Southern MS/AL to FL Panhandle... A large upper trough is present today over much of the eastern states, with a corridor of 30-40 knot mid-level winds extending from AR into the central Gulf Coast region. Ample low-level moisture remains across much of the southeast, but multiple bouts of convection have pushed the main outflow boundary southward into southern MS/AL and the FL Panhandle. Strong afternoon heating will help to establish moderate to strong instability along this axis where re-development of widely scattered strong/severe storms are expected. Weak forcing mechanisms suggest limited coverage of intense storms, but sufficient deep-layer vertical shear and proximity to boundaries may result in isolated supercells capable of hail, damaging wind gusts, and perhaps a tornado. ...Southeast GA/Northeast FL... A persistent linear MCS continues to track eastward across southern GA and northern FL. Strong heating ahead of the line has resulted in moderate CAPE values and sufficient westerly flow aloft to pose a risk of locally gusty/damaging winds for a few more hours until the line moves offshore. Cooler temperatures in the wake of the line should limit the redevelopment of severe storms later today. ...MT/ND... Fast southwesterly flow aloft extends across the northern Rockies and High Plains today. A band of mid/high clouds lies from northern WY into eastern MT and western ND. A consensus of morning model solutions indicate that strong heating along and east of the eastern edge of this cloud cover will result in a corridor of steep low-level lapse rates and sufficient CAPE for scattered thunderstorm development. Fast-moving supercell and bowing structures appear likely this afternoon and evening as storms track from eastern MT into western ND. Damaging winds and hail are the main risks. ...Central TX... Hot/humid conditions along the surface dryline over central TX will pose some risk of isolated thunderstorms by mid/late afternoon. While coverage of these storms may be quite limited, any storm that forms in the extremely unstable air will pose a risk of large hail and damaging winds. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Mon Jun 19 2023 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR OF NORTHEASTERN AZ AND NORTHWESTERN NM... The current D2 Fire Weather Outlook remains on track with no updates needed. See previous discussion for more information. ..Thornton.. 06/19/2023 .PREV DISCUSSION... /ISSUED 0133 AM CDT Mon Jun 19 2023/ ...Synopsis... The overall weather pattern will remain fairly stationary on Tuesday as a large trough and associated mid-level speed maximum rotate through the western U.S. Farther east, a cutoff mid-level low will develop over the Southeast, yielding a narrow blocking pattern throughout the Central Plains. A smaller zone of mid-level flow is forecast to move through the Desert Southwest Tuesday afternoon and evening. This is expected to contribute to critical fire-weather conditions across portions of AZ and NM on Tuesday. At the surface, sustained winds of 15-20 mph are expected across the Elevated area by late morning. This will be associated with deep boundary-layer mixing, yielding relative humidities below 15 percent across the region. Single-digit humidities are expected in northeastern AZ and northwestern NM which -- along with locally stronger flow around 20 mph -- should contribute to critical fire-weather conditions. Sustained drying and critical-level fuels in this area will contribute to a higher threat for large fire attack and spread. A second belt of stronger surface flow is expected in the lee of the Sandia and Sacramento Mountains, where ERCs in the 90-95th percentiles will support broad elevated, and perhaps locally critical, fire-weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0340 Status Updates
STATUS FOR WATCH 0340 HAS NOT BEEN ISSUED YET Read more

WW 340 SEVERE TSTM TX 191950Z - 200300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 340 NWS Storm Prediction Center Norman OK 250 PM CDT Mon Jun 19 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central Texas * Effective this Monday afternoon and evening from 250 PM until 1000 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 3 inches in diameter possible Isolated significant damaging wind gusts to 75 mph possible SUMMARY...Isolated intense thunderstorms are expected to form this afternoon over the watch area. Very large hail and damaging wind gusts are possible with the strongest cells. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 15 miles south southwest of Junction TX to 50 miles northwest of Brownwood 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 28025. ...Hart Read more

WW 0339 Status Updates
STATUS REPORT ON WW 339 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 ENE CTY TO 10 NNE SGJ TO 40 NE SSI. REMAINING VALID PORTION OF WW MAY BE ALLOWED TO EXPIRE AT 19/18Z. ..KERR..06/19/23 ATTN...WFO...JAX... STATUS REPORT FOR WS 339 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC001-035-041-107-109-191800- FL . FLORIDA COUNTIES INCLUDED ARE ALACHUA FLAGLER GILCHRIST PUTNAM ST. JOHNS AMZ452-454-191800- CW . ADJACENT COASTAL WATERS INCLUDED ARE COASTAL WATERS FROM FERNANDINA BEACH TO ST. AUGUSTINE FL OUT 20 NM COASTAL WATERS FROM ST. AUGUSTINE TO FLAGLER BEACH FL OUT 20 NM 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 Read more