Severe Storms

WW 454 SEVERE TSTM CO 062050Z - 070400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 454 NWS Storm Prediction Center Norman OK 250 PM MDT Thu Jul 6 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of North-central and northeast Colorado * Effective this Thursday afternoon and evening from 250 PM until 1000 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 3 inches in diameter likely Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A couple supercells may develop initially along and just east of the Front Range across the I-25 corridor. Additional supercells will likely form later this evening into northeast Colorado and these will have the greatest hail and brief tornado threat. The severe thunderstorm watch area is approximately along and 65 statute miles east and west of a line from 40 miles northeast of Fort Collins CO to 25 miles west southwest of Limon CO. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 452... AVIATION...A few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 29030. ...Grams Read more

WW 0452 Status Updates
STATUS FOR WATCH 0452 HAS NOT BEEN ISSUED YET Read more

WW 452 SEVERE TSTM WY 062020Z - 070300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 452 NWS Storm Prediction Center Norman OK 220 PM MDT Thu Jul 6 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Wyoming * Effective this Thursday afternoon and evening from 220 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A few supercells should develop off the higher terrain and move east into this evening, potentially consolidating into a cluster as they approach the South Dakota-Nebraska border area. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 35 miles east northeast of Sheridan WY to 50 miles east of Laramie WY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28030. ...Grams Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0246 PM CDT Thu Jul 06 2023 Valid 062000Z - 071200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR NORTHEAST COLORADO INTO SOUTHWEST KANSAS... ...SUMMARY... The most concentrated corridor of severe storms is expected across a portion of eastern Colorado and western Kansas, centered on this evening. These storms will be capable of producing very large hail, a few tornadoes, and significant severe wind gusts as they likely evolve into a cluster tracking towards northwest Oklahoma overnight. ...20Z Update... The primary change to this outlook was to disconnect Marginal risk probabilities from the southern Plains to the Lower MS Valley. The probabilities in the Lower MS Valley were adjusted to address the shorter-term large hail/strong gust threat with storms intensifying over the Arklatex toward MS. Meanwhile, the marginal risk probabilities in the southern Plains were terminated southeast into central OK, where an MCS should be positioned at the end of the period (12Z Friday morning). Finally, the 30 percent hail probabilities (and associated Enhanced Risk line) have been extended slightly northwest into northern CO, where persistent insolation may promote locally higher buoyancy and subsequent supercell hail threat. Otherwise, the previous forecast (see below) remains on track. ..Squitieri.. 07/06/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Thu Jul 06 2023/ ...Eastern CO to northwest OK... Decaying remnants of a morning MCS and elevated clusters persist across parts of OK, the far eastern TX Panhandle, and western KS. Abundant cloud coverage from convective debris and a broken stratus canopy will modulate boundary-layer heating, with more robust insolation expected over much of the TX Panhandle and in pockets along the southern Rockies. With a southeasterly component to low-level flow confined to the lowest 1 km and pronounced veering of the wind profile with height to separate confluent belts of enhanced mid-level westerlies centered on the WY/CO border and the CO/NM border, late afternoon thunderstorm development should be focused near the Denver cyclone with capping potentially limiting development over the Raton Mesa. Initial updrafts in northeast CO will likely evolve into one or two slow-moving supercells with very large hail as the main threat early. A strengthening low-level jet this evening should support maintaining these supercells after dusk and/or yield additional development east along the Palmer Divide in east-central CO. Despite increasing MLCIN, low-level hodographs will become quite enlarged, supporting potential for a long-track intense supercell or two moving southeast across a portion of eastern CO and western KS. Overnight, elevated convective development should occur downstream of these long-track supercells, which may yield a small bowing MCS focused on southwest KS to northwest OK. The overall tornado and significant severe wind threat should be modulated to an extent by relatively weak low-level lapse rates. But the highly sheared and steep mid-level lapse rate environment renders concern for a narrow swath of significant severe persisting into early morning. ...Lee of the Big Horns to the Black Hills vicinity... Farther north, a separate region of more concentrated thunderstorm development is expected during the late afternoon to evening downstream of a low-amplitude shortwave trough moving east from the northern Rockies towards the Big Horns. Low-level shear will be weak across this area, but an elongated nearly straight-line hodograph will foster a few splitting supercells capable of very large hail. These should consolidate into an east-southeast moving cluster/small MCS across western SD and the NE Panhandle with a threat for severe wind gusts peaking during the mid-late evening and becoming more isolated overnight. ...Ark-La-Tex to Ark-La-Miss vicinity.. An MCV over east-central OK should drift east with regeneration of thunderstorms downstream to its south and southeast impinging on a confined plume of MLCAPE from 2000-3000 J/kg. Despite relatively weak shear, semi-organized multicell clusters should form and offer a risk for isolated damaging winds through this evening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0205 PM CDT Thu Jul 06 2023 Valid 071200Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN ARIZONA AND ADJACENT AREAS... The forecast for critical fire-weather conditions on Friday remains unchanged in this update for northern Arizona. Similarly, the forecast for isolated dry thunderstorms remains on track across Oregon with the potential for the greatest number/density of cloud-to-ground lightning flashes across Lake and Klamath Counties in southern Oregon. See the previous discussion below for more details. ..Jirak.. 07/06/2023 .PREV DISCUSSION... /ISSUED 0200 AM CDT Thu Jul 06 2023/ ...Synopsis... ...Wind/RH... Similar to Day 1/Thursday, enhanced west-southwesterly deep-layer flow will persist across the Southwest into the central Rockies -- where a dry antecedent air mass will be in place. Boundary-layer mixing into the enhanced flow aloft will favor 20-25 mph sustained west-southwesterly surface winds (with higher gusts) amid 10-15 percent RH across portions of the Southwest and central Rockies. As a result, critical fire-weather conditions are expected across northern AZ -- where 90th percentile ERCs exist. While critical meteorological conditions may spread northward into southern UT, current indications are that fuels are less receptive here (outside of extreme southern UT). ...Dry Thunderstorms... Midlevel moisture will increase atop a diurnally deepening boundary layer over portions of OR on Day 2/Friday. This will favor isolated high-based thunderstorms along/east of the Cascades in OR from the afternoon into late evening. Inverted-V thermodynamic profiles and around 0.7 inch PW will support dry thunderstorms capable of new fire starts given increasingly dry fuels over the area. ...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 1228 PM CDT Thu Jul 06 2023 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CENTRAL AND SOUTHERN HIGH PLAINS INTO THE SOUTHERN PLAINS... ...SUMMARY... Severe wind and hail producing storms are expected across the central and southern High Plains into the southern Plains tomorrow/Friday. A couple of damaging gusts are also possible across the Upper Hudson Valley. ...Synopsis... A pronounced mid-level trough will traverse the central CONUS while a secondary mid-level perturbation crosses the southern Rockies and ejects into the southern Plains tomorrow/Friday. Meanwhile, the approach of the mid-level trough over the Midwest will also support weak surface troughing along and to the lee of the central and northern Appalachians during the afternoon hours. Multiple rounds of organized strong to severe storm potential should occur across the central U.S., including at the start of the period. The most robust severe storm development should occur across the southern Plains with the ejection of the mid-level perturbation, with all severe hazards possible. Scattered strong thunderstorm development may also occur across the northeast in tandem with the weak surface lee trough. ...Southern High Plains into the southern Plains... One or more loosely organized MCSs will likely be in progress over portions of the southern Plains at the start of the period (12Z Friday morning), perhaps accompanied by a marginal severe wind threat. With time, as the low-level jet weakens, the MCSs should dissipate through the late morning/early afternoon hours. Similar to Day 1, residual showers and cloud cover will gradually clear, allowing for surface temperatures to rise over 90 F in the TX Panhandle, to over 80F points north. These temperatures, along with surface dewpoints into the low to mid 60s F, overspread by 8.5+ C/km mid-level lapse rates, will support strong buoyancy (i.e. 3000+ J/kg SBCAPE), especially in the northern TX Panhandle. By late afternoon into early evening, a 20-30 kt southwesterly low-level jet, overspread by 40-50 kts of 500 mb westerly flow, will support 40-50 kts of effective bulk shear, characterized by hodographs with some low-level curvature and mid-level elongation. Questions remain regarding initial storm coverage (especially north of the TX Panhandle) due to capping. However, at least isolated supercells should initiate by late afternoon with a large hail threat. A few 2+ inch stones and a couple of tornadoes cannot be ruled out. Later in the evening, upscale growth into a severe-wind producing MCS is possible. The overall coverage and severity of this MCS is predicated on the number and intensity of initial merging supercells. The isolated nature of the initial supercells and lack of higher confidence in robust MCS development precludes greater severe wind/hail coverage probabilities this outlook. ...Northern Plains... Behind the progressing mid-level trough, a weak cold front will sag southward across the northern Plains during the day. Insolation and boundary-layer mixing, overspread by 7 C/km mid-level lapse rates, will foster 1000-2000 J/kg SBCAPE by afternoon peak heating. Deep-layer shear will not be overly strong (i.e. generally under 30 kts of effective bulk shear). Nonetheless, enough hodograph curvature/elongation may exist to support stronger pulse-cellular storms or loosely organized multicell clusters with an isolated severe gust threat along with some small hail. ...Midwest... Thunderstorm clusters, potentially in the form of loosely organized MCSs, may be ongoing at the start of the period across eastern portions of the central Plains toward the central MS Valley region. These storms will be supported at the terminus of a 30+ kt low-level jet, accompanied by a marginal severe hail/wind threat. Airmass modification behind the initial storms will be modest and gradual due to lingering clouds and precipitation, limiting instability later during the afternoon. Nonetheless, the passage of the upper trough atop a southward-sagging baroclinic zone may serve as a focus for some renewed convective development by late afternoon. Given modest instability (relatively poor mid-level lapse rates fostering 500-1500 J/kg MUCAPE - most of which may be elevated), later severe potential should not be widespread. Nonetheless, given elongated hodographs (and 40-50 kts of effective bulk/speed shear) multicellular storms (and perhaps a brief, transient supercell) are possible by late afternoon, with a couple of severe gusts/large hail stones possible. ...Upper Hudson Valley... Adequate surface heating of a moist boundary layer will support surface temperatures warming well into the 70s F amid mid to upper 60s F dewpoints, resulting in MLCAPE over 1000 J/kg (perhaps approaching 2000 J/kg in spots). The combination of weak ascent associated with the surface lee trough and insolation will support the initiation of scattered thunderstorms by early afternoon. Deep-layer shear should not be overly strong, though point forecast soundings suggest modest hodograph elongation, especially closer to the international border. As such, a few longer lived multicells and pulse single-cells may organize, capable of supporting wet downbursts, a couple of which may approach severe limits. As such, damaging gusts may accompany the stronger storms, warranting the introduction of Category 1/Marginal risk-driven wind probabilities. ..Squitieri.. 07/06/2023 Read more

MD 1434 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN TEXAS PANHANDLE INTO FAR WESTERN OKLAHOMA
Mesoscale Discussion 1434 NWS Storm Prediction Center Norman OK 0355 PM CDT Wed Jul 05 2023 Areas affected...eastern Texas Panhandle into far western Oklahoma Concerning...Severe potential...Watch unlikely Valid 052055Z - 052230Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe storms will remain possible for a few hours over a small area from the eastern Texas Panhandle into far western Oklahoma. Large hail will be the primary threat. DISCUSSION...Storms persist near the intersection of a modified outflow boundary and surface trough over the northeast TX Panhandle. Other attempts at initiation have failed farther east into OK where capping is a bit stronger. However, additional heating and air mass modification may yield isolated cells into that area as well as backed low-level winds favor rightward propagation. If the zone can destabilize further, a small corridor of damaging hail may materialize. At this time, the overall size and duration of the severe risk appears too short/small for a watch, although trends will continue to be monitored. ..Jewell/Grams.. 07/05/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...AMA... LAT...LON 35210108 35810076 36130050 36170020 36019990 35849975 35269903 34969894 34769946 34770010 34810069 34950102 35210108 Read more

WW 0449 Status Updates
STATUS FOR WATCH 0449 HAS NOT BEEN ISSUED YET Read more

WW 449 SEVERE TSTM CO NM 052055Z - 060500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 449 NWS Storm Prediction Center Norman OK 255 PM MDT Wed Jul 5 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Colorado Northeast New Mexico * Effective this Wednesday afternoon and evening from 255 PM until 1100 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 3 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A couple supercells will initially be slow-moving adjacent to the Sangre de Cristos. With time this evening, additional supercells should develop across southeast Colorado. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 45 miles east southeast of Las Vegas NM to 45 miles north northwest of La Junta CO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30025. ...Grams Read more

MD 1433 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR MUCH OF SOUTHEAST COLORADO INTO NORTHEAST NEW MEXICO AND THE FAR WESTERN OK/TX PANHANDLES
Mesoscale Discussion 1433 NWS Storm Prediction Center Norman OK 0335 PM CDT Wed Jul 05 2023 Areas affected...much of southeast Colorado into northeast New Mexico and the far western OK/TX Panhandles Concerning...Severe potential...Watch likely Valid 052035Z - 052230Z Probability of Watch Issuance...80 percent SUMMARY...At least isolated supercells capable of very large hail, damaging gusts and a brief tornado threat are expected to form in the next few hours. DISCUSSION...A very moist yet cool air mass currently exists across much of the central Plains, with easterly surface winds over the High Plains of CO/NM. Visible satellite imagery shows breaks in the cloud fields, with temperatures gradually rising. Of note are the upper 70s F temperatures now into the Raton/Trinidad area, which when combined with mid 50s dewpoints results in very strong instability. Farther north toward Colorado Springs, stratus has locked in cool temperatures for much of the day, but recent observations indicate mixing is underway with winds out of the south around 15 mph. The moist upslope flow combined with heating will lead to at least isolated supercells forming off the high terrain, with initial hail threat. Continued heating as well as persistent moist easterly flow will support the hail/wind/tor threat extending eastward perhaps toward the Panhandles tonight. ..Jewell/Grams.. 07/05/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AMA...PUB...BOU...ABQ... LAT...LON 36310503 36680489 37090479 37410488 37660495 37940491 38260500 38950483 38960468 38880426 38510337 38230253 37900226 37510218 37160219 36700231 36280263 35900298 35820325 35800359 36130465 36310503 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Wed Jul 05 2023 Valid 052000Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS INTO THE SOUTHERN PLAINS... ...SUMMARY... Scattered large hail and damaging winds are possible across a portion of eastern Colorado and northeast New Mexico to northwest Oklahoma through tonight. Scattered damaging winds are also possible over northern Illinois and southeast Wisconsin through early evening. ...20Z Update... No major changes have been made to the Day 1 Convective Outlook. Relatively cool, cloudy conditions persist from the southern Plains to the Colorado Front Range due to the passage of an earlier MCS. Nonetheless, steep mid-level lapse rates should overspread the gradually warming boundary layer through the day to support supercell development off of the higher terrain. Severe hail and the chance of a tornado are the initial concerns, before upscale growth into an MCS supports a severe wind threat across southwest KS, northwest OK, and the TX Panhandle later this evening. Otherwise, pulse cellular storms and multicells will continue to pose a damaging gust threat across the MS Valley into the Southeast through the remainder of the afternoon. ..Squitieri.. 07/05/2023 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 05 2023/ ...Southern Rockies to south KS and OK... Composite outflow/effective surface cold front attendant to a decaying MCS extends from southern OK to the TX Panhandle. Rather pronounced differential heating will occur and yield an intense surface temperature gradient from around 100 along the Red River to upper 60s holding in parts of eastern CO/northwest KS. Late afternoon thunderstorm development should largely be focused along the higher terrain of CO to northeast NM with a fair amount of MLCIN likely holding over the adjacent High Plains north of the Raton Mesa. A few supercells should form with a primary threat of large hail but may struggle to move off the terrain north of the Panhandles early. Additional storms may also form near the outflow/front intersection in the eastern TX Panhandle vicinity along the fringe of the mid-level flow. This evening, a strengthening low-level jet atop the robust baroclinic zone will yield increasing storm coverage as inhibition becomes minimized for slightly elevated parcels. This should favor a mix of supercells and clusters over eastern CO and southwest KS that may grow upscale into a southeast-moving MCS overnight into parts of the TX Panhandle and northwest OK. Large hail will be a threat mainly early, with strong to severe wind gust potential lingering into the overnight. ...AR to WI/MI... A well-defined MCV is evident across northeast MO with a separate MCV approaching the Ozark Plateau attendant to a decaying MCS in OK. The northern one should remain coincident near a slow-moving cold front that arcs from the Mid-MS Valley to eastern WI. While there is flow enhancement evident on the backside of the Ozarks MCV, effective bulk shear downstream of both MCVs should remain weak up to around 20 kts (south of south WI). In addition, mid-level lapse rates will be weak, but nearly full insolation will support a plume of MLCAPE from 2000-3000 J/kg. Morning CAM guidance is consistent in indicating scattered to widespread storms later this afternoon. But the weakly sheared environment suggest clusters will only be loosely organized, suggesting severe gust potential will be relatively sporadic and ill-defined across much of the region. One exception may be across northern IL to southeast WI where slightly stronger deep-layer shear is expected. ...GA and the Carolinas... An MCV over the southern Appalachians drifting east and differential boundary-layer heating owing to its attendant cloud canopy should help focus scattered thunderstorm development to its south in GA and east-southeast across parts of the Carolinas. Relatively greater heating will occur across the coastal plain and parts of the Piedmont, yielding a pronounced MLCAPE gradient from west to east amid weak mid-level lapse rates. Flow enhancement appears minor, resulting in effective bulk shear only up to around 20 kts. This may be adequate for loosely organized, slow-moving multicell clusters that may produce isolated damaging winds. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 PM CDT Wed Jul 05 2023 Valid 061200Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN ARIZONA... The forecast for critical fire weather conditions remains on track for northern Arizona on Thursday (see previous discussion below). The only change to the outlook was to expand the elevated area into portions of western Colorado, where fuels are becoming more receptive for the spread of wildfires, and meteorological conditions (surface RH <15% and sustained winds >15 mph) will likely elevate fire-weather concerns during the afternoon. Regarding dry-thunderstorm potential, the forecast for isolated dry thunderstorms across the southern Cascades in Oregon into northeastern Oregon on Thursday also remains on track (see previous discussion below). ..Jirak.. 07/05/2023 .PREV DISCUSSION... /ISSUED 0200 AM CDT Wed Jul 05 2023/ ...Synopsis... ...Wind/RH... Midlevel west-southwesterly flow will strengthen across the Southwest into the central/southern Rockies on Day 2/Thursday. Over northern AZ, efficient diurnal heating/mixing amid a dry antecedent air mass will yield 10-15 percent minimum RH during the afternoon. Forecast soundings over this area depict around 30 kt of flow in the middle/upper-portions of the diurnally deepening boundary layer -- supporting sustained west-southwesterly surface winds near 25 mph (with higher gusts). Given increasingly dry fuels over this area, critical fire-weather conditions are expected. While critical meteorological conditions may also expand northward into southern UT, fuels are not as supportive of large fires. ...Isolated Dry Thunderstorms... Midlevel ascent preceding a low-amplitude shortwave trough will glance southern OR during the afternoon. This, combined with terrain circulations along the Cascades, could support isolated high-based thunderstorm development given weak instability. Inverted-V thermodynamic profiles and around 0.6 inch PW suggest dry thunderstorms capable of lightning-induced ignitions will be possible. ...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 1227 PM CDT Wed Jul 05 2023 Valid 061200Z - 071200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN COLORADO INTO WESTERN KANSAS AND FAR NORTHWEST OKLAHOMA... ...SUMMARY... Severe storms capable of producing large hail, damaging gusts, and a couple of tornadoes, are forecast from the northern High Plains southeastward to Kansas and Oklahoma. ...Synopsis... Thunderstorms will be ongoing tomorrow (Thursday) morning across parts of the central Plains and are expected to drift into the Lower MS Valley by afternoon, supporting an isolated severe threat. An embedded mid-level impulse will traverse the central Rockies and eject into the central Plains during the afternoon, providing enough deep-layer ascent over a moist, unstable airmass to support severe thunderstorm development (with all hazards possible) across the central High Plains. Organized storm clusters may persist with some severe threat into the central and southern Plains into the evening hours. ...Central High Plains into the central and southern Plains... Guidance consensus depicts considerable cloud cover across the High Plains (especially around the WY/NE border) during the morning/early afternoon hours, suggesting that surface temperatures should only reach the 70s to perhaps 80 F by afternoon peak heating. Despite the modest surface temperatures, upper 50s F surface dewpoints should extend westward to the immediate lee of the central Rockies, with 60+ F dewpoints likely along the NE/CO/KS border and points east. 8+ C/km mid-level lapse rates will overspread this relatively moist low-level airmass, supporting 2000+ J/kg SBCAPE by mid afternoon along the High Plains. Considerable veering and strengthening winds with height will support elongated hodographs with modest low-level curvature, suggesting supercells as the likely initial storm mode. Large hail is the greatest threat with the supercells. The longest-lived supercells may produce instances of 2+ inch hail and/or a tornado. This is especially the case in eastern CO, where a Category 3/Enhanced risk has been introduced. During the evening hours, upscale growth into one or more MCSs is likely, with severe gusts becoming the dominant severe hazard. Latest guidance consensus suggests that a longer-lived MCS may develop across KS and progress to the OK border during the night, where a couple of 65+ kt gusts also cannot be ruled out. ...Southern High Plains... Surface lee troughing across parts of southeast NM, along with strong surface heating of a deep, dry/well-mixed boundary layer, may aid in the initiation of isolated high-based thunderstorms along/ahead of a diffuse dryline by mid to late afternoon. Given some stronger speed shear in the mid-levels (and associated hodograph elongation), a couple of multicellular storm structures may materialize, supporting a couple of severe downbursts given 9+ C/km low-level lapse rates. ...Arklatex into the Lower MS Valley... MCS remnants will slowly drift southeast into the Arklatex region at the start of the period (12Z Thursday morning), posing a limited damaging gust threat. By afternoon though, strong surface heating will promote surface temperatures approaching 90 F in spots, amid 70+ F dewpoints, contributing to 2000-3000 J/kg of tall, thin SBCAPE (given mediocre mid-level lapse rates). Deep-layer shear is also expected to be quite poor, which should limit storm organization. However, convergence along outflow boundaries left behind by preceding convection may serve as the impetus for the initiation of thunderstorm clusters. Water loaded downdrafts associated with these clusters may support brief instances of damaging to potentially severe downburst winds, warranting the introduction of a Category 1/Marginal Risk. ..Squitieri.. 07/05/2023 Read more

No Mesoscale Discussions are in effect as of Tue Jul 4 21:46:17 UTC 2023.

WW 0444 Status Updates
STATUS REPORT ON WW 444 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..07/04/23 ATTN...WFO...BOU...PUB...GLD...CYS... STATUS REPORT FOR WS 444 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-011-013-014-017-019-025-031-035-039-041-047-059-061- 063-069-073-075-087-089-095-099-101-115-121-123-125-042240- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE BENT BOULDER BROOMFIELD CHEYENNE CLEAR CREEK CROWLEY DENVER DOUGLAS ELBERT EL PASO GILPIN JEFFERSON KIOWA KIT CARSON LARIMER LINCOLN LOGAN MORGAN OTERO PHILLIPS PROWERS PUEBLO SEDGWICK WASHINGTON WELD YUMA NEC007-033-105-157-042240- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER CHEYENNE KIMBALL SCOTTS BLUFF Read more

WW 444 SEVERE TSTM CO NE WY 042005Z - 050500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 444 NWS Storm Prediction Center Norman OK 205 PM MDT Tue Jul 4 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Southwest Nebraska Panhandle Southeast Wyoming * Effective this Tuesday afternoon and evening from 205 PM until 1100 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 80 mph likely Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Initial supercells should evolve into a cluster across the eastern Colorado plains, with renewed development expected along the Front Range later this evening. Large hail will be the main threat early and late, with the greatest severe wind threat during the early evening. The severe thunderstorm watch area is approximately along and 80 statute miles east and west of a line from 30 miles west northwest of Scottsbluff NE to 5 miles east southeast of La Junta CO. 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 2.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 29030. ...Grams Read more

WW 0445 Status Updates
STATUS REPORT ON WW 445 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..07/04/23 ATTN...WFO...OAX...FSD...GID... STATUS REPORT FOR WS 445 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC085-093-129-133-155-165-193-042240- IA . IOWA COUNTIES INCLUDED ARE HARRISON IDA MILLS MONONA POTTAWATTAMIE SHELBY WOODBURY KSC089-123-141-147-163-183-042240- KS . KANSAS COUNTIES INCLUDED ARE JEWELL MITCHELL OSBORNE PHILLIPS ROOKS SMITH NEC001-003-011-019-021-023-025-027-035-037-039-043-051-053-055- 059-061-065-073-077-079-081-083-093-099-109-119-121-125-129-137- 139-141-143-151-153-155-159-163-167-169-173-177-179-181-185- 042240- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

WW 0446 Status Updates
STATUS REPORT ON WW 446 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..07/04/23 ATTN...WFO...GLD...DDC... STATUS REPORT FOR WS 446 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC023-039-051-055-063-065-067-071-075-093-101-109-135-137-153- 165-171-179-181-187-193-195-199-203-042240- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE DECATUR ELLIS FINNEY GOVE GRAHAM GRANT GREELEY HAMILTON KEARNY LANE LOGAN NESS NORTON RAWLINS RUSH SCOTT SHERIDAN SHERMAN STANTON THOMAS TREGO WALLACE WICHITA NEC057-087-145-042240- NE . NEBRASKA COUNTIES INCLUDED ARE DUNDY HITCHCOCK RED WILLOW THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL Read more

WW 445 SEVERE TSTM IA KS NE 042030Z - 050300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 445 NWS Storm Prediction Center Norman OK 330 PM CDT Tue Jul 4 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Iowa North-central Kansas South-central to eastern Nebraska * Effective this Tuesday afternoon and evening from 330 PM until 1000 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Initial cells will pose a threat for large hail but should quickly cluster and likely spread east-southeast this evening. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 55 miles west southwest of Concordia KS to 15 miles west northwest of Sioux City IA. 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 444... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 28025. ...Grams Read more

WW 446 SEVERE TSTM KS NE 042040Z - 050500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 446 NWS Storm Prediction Center Norman OK 340 PM CDT Tue Jul 4 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Kansas Far southwest Nebraska * Effective this Tuesday afternoon from 340 PM until Midnight CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 80 mph possible Isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Multicell clusters will develop along a quasi-stationary front, as well as spread east from eastern Colorado later this evening. The severe thunderstorm watch area is approximately along and 85 statute miles north and south of a line from 50 miles south southwest of Goodland KS to 25 miles east northeast of Hill City KS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 444...WW 445... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27030. ...Grams Read more