Severe Storms

No watches are valid as of Fri Jul 8 16:31:01 UTC 2022.

No watches are valid as of Fri Jul 8 16:31:01 UTC 2022.

No Mesoscale Discussions are in effect as of Fri Jul 8 16:31:02 UTC 2022.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Fri Jul 08 2022 Valid 081300Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO/TENNESSEE VALLEYS AND NORTHERN ROCKIES/HIGH PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms capable of severe winds and large hail are expected across parts of the northern Rockies and northern Plains this afternoon into tonight. A corridor of severe storms may also develop this afternoon into evening across parts of the Ohio and Tennessee Valleys. ...Ohio Valley and Tennessee Valley... A mid-level shortwave trough/convectively reinforced MCV near the Iowa/Missouri/Illinois border at daybreak will continue east-southeastward today coincident with moderately enhanced (30-40 kt 500-700 mb) westerlies over the Ohio Valley. Some scattered strong storms are ongoing across downstate portions of Illinois/Indiana early today. The persistence of this convection will help to reinforce a slow-moving front across the region. Storms should further develop and intensify into this afternoon within an unstable environment across southern Indiana into central/eastern Kentucky and possibly southwest Ohio, with the moderately strong flow potentially allowing for some weak/transient supercells aside from a more prevalent tendency for organizing bands and linear segments. Damaging winds will likely be the most common risk overall, but some hail may occur as well especially with any storms exhibiting supercellular characteristics, which is most probable across parts of Kentucky and far southern Indiana. Additional severe storms may form by mid/late afternoon through early evening along the southeastward-advancing front across far southern Illinois/southeast Missouri and western Kentucky, and possibly into Tennessee. ...Montana/Northern High Plains... Broad mid-level height rises are expected across much of the central and western CONUS, but a shortwave trough will eject across Montana into southeast Saskatchewan/northwest North Dakota later today. Strong surface heating will remove CINH by mid-afternoon and scattered thunderstorms should once again develop across the mountains of Idaho into southwest Montana by late afternoon. Seasonally strong southwesterly mid-level flow will encourage this activity to spread toward lower elevations where higher moisture/buoyancy will provide an opportunity for upscale growth. Forecast soundings suggest supercells capable of large hail and damaging winds can be expected, while an increasing low-level jet across eastern Montana during the evening should support this activity propagating toward western North Dakota after sunset. ...Southern Plains to Mid-South... A surface front will settle southward across the region through the afternoon and early evening. Strong insolation and heating will allow temperatures to soar above 100F near/south of the front, while PW values will be around 2 inches particularly across parts of Oklahoma/Arkansas. With large temperature/dew point spreads at the surface, isolated severe downbursts may occur across the region this afternoon through around sunset. ...Maine... Isolated strong storms may occur primarily across northern Maine along/ahead of a cold front that will surge southeastward across northern New England this afternoon. Overall buoyancy nor mid-level lapse rates will be robust, but steep low-level lapse rates and strong unidirectional westerlies could yield gusty winds/small hail with the most robust convection. ..Guyer/Leitman.. 07/08/2022 Read more

No watches are valid as of Thu Jul 7 17:07:02 UTC 2022.

No Mesoscale Discussions are in effect as of Thu Jul 7 17:07:02 UTC 2022.

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Thu Jul 07 2022 Valid 071700Z - 081200Z The forecast remains on track, and very minor adjustments were made to the Elevated area based on the latest surface observations. For details, see the previous discussion below. ..Weinman.. 07/07/2022 .PREV DISCUSSION... /ISSUED 0129 AM CDT Thu Jul 07 2022/ ...Synopsis... Upper ridging will continue to amplify across the Rockies into the Plains as a mid-level trough remains stationary across the Interior West today. Surface lee-troughing will become established across the Great Basin by afternoon, with modest southwesterly mid-level winds overspreading a deep, dry boundary layer. The net result will be widespread Elevated dry and windy surface conditions across the Great Basin by afternoon peak heating. Modest lee troughing across the southern High Plains may encourage locally dry and breezy conditions over spotty receptive fuels to support a brief, localized wildfire-spread threat. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1123 AM CDT Thu Jul 07 2022 Valid 071630Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS MT AND PARTS OF THE SOUTHEAST TO LOWER MO VALLEY... ...SUMMARY... Scattered damaging winds will be possible from parts of the Southeast to the Lower Missouri Valley this afternoon and evening. Scattered large hail and severe wind gusts are also possible in Montana from late afternoon through the evening. ...MT and vicinity... The continued presence of mid 50s to low 60s surface dew points banked along the northern Rockies will support another round of scattered thunderstorms off the higher terrain by late afternoon. Amid low-amplitude mid-level ridging from the central Rockies to the Prairie Provinces, a belt of moderate southwesterlies/westerlies atop weak low-level easterlies will yield sufficient bulk shear for a few initial supercells centered on central MT that should consolidate into a couple eastward-moving clusters this evening. With 1500-2000 J/kg of MLCAPE becoming common, large hail will be the primary initial hazard transitioning to predominantly severe wind gusts in time. Overall severe threat will gradually diminish overnight as MLCIN strengthens across eastern MT into the western Dakotas. ...Lower OH Valley to the Southeast... To the southeast of a decaying non-severe MCS over IL, robust boundary-layer heating and very rich low-level moisture will support a broad area of scattered thunderstorms this afternoon. This activity should tend to focus along residual outflow boundaries, the higher terrain of the southern Appalachians, and a weak cold front sinking south in VA. Relative maxima of large buoyancy will be centered on middle TN and separately along the Carolina coastal plain, while very poor mid-level lapse rates with 700-500 mb values less than 5 C/km will be prevalent from VA north, east of the Appalachians. Deep-tropospheric flow will be quite weak with effective bulk shear largely around 10-15 kt. This will favor extensive disorganized pulse convection with wet microbursts capable of localized damaging winds. It's plausible that weakly organized multicell clustering may occur within mesoscale corridors, mainly during the late afternoon and early evening, which would temporarily increase the wind damage threat. ...Lower MO Valley... Convective outflow in the wake of a decaying MCS has pushed as far south as southwest MO. This boundary should wash out or effectively consolidate north across northern portions of KS/MO as a warm front by early evening with pronounced differential heating across it. Modest low-level warm advection and an upstream MCV drifting east from central NE should aid in scattered thunderstorm development during the evening. With a confined corridor of large buoyancy expected along and just south of the front, coincident with enhanced 0-3 km SRH along and just north of it, an organized multicell cluster may develop and gradually spread east-southeast. Damaging winds should be the main threat, but a tornado will also be possible before convection weakens overnight. ..Grams/Wendt.. 07/07/2022 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0755 AM CDT Thu Jul 07 2022 Valid 071300Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS MAINLY ACROSS PARTS OF MONTANA...AND FROM THE LOWER MISSOURI VALLEY INTO THE CAROLINAS... ...SUMMARY... Scattered thunderstorms, some severe, will be possible today mainly across parts of Montana, and from the lower Missouri Valley into the Carolinas. Damaging winds are possible over all areas, with large hail also expected over Montana. ...Synopsis... The large-scale pattern in mid/upper levels will continue to feature troughing off the West Coast, mean ridging across the south-central CONUS and Rockies, and west-northwest to northwest flow across much of the Upper Midwest, Great Lakes and Appalachians. The Rockies ridging is expected to amplify through the period, leading to a net westward displacement of the main/anchoring 500-mb high across the southern Plains and toward NM. An embedded shortwave trough -- now evident in moisture-channel imagery over eastern portions of CO/WY and central NM -- should pivot eastward over the central Plains, closely following a smaller, MCV-reinforced shortwave trough now over north-central/west-central KS. Downstream, a series of mostly low-amplitude/mesoscale perturbations will cross the Ohio Valley and Southeast. At the surface 11Z analysis showed a wavy/quasistationary front from a low over the Delmarva Peninsula, across west-central VA, WV, southern IN, and northern MO, with a diffuse segment northwestward to a low over central SD. A cold front was drawn from a low over west-central KS across the TX Panhandle and northeastern NM. The main foci for convection this period should be boundaries south of the front over the eastern outlook area, and north of the front across the northern Rockies/northern High Plains regions. ...MT and vicinity... Isolated to scattered thunderstorms are expected to develop this afternoon -- mainly over higher terrain of southern/western MT -- and move northeastward while offering the potential for sporadic severe gusts and large hail. Any supercells that survive into the more-suitable moisture profiles of central/northern MT will be capable of significant hail, and depending on storm-scale processes and boundary interactions, a marginal/conditional tornado threat. Large-scale support will be more nebulous today compared to previous days, with net height rises forecast across the region. Convection will be focused largely by heating of elevated terrain, preferentially weakening MLCINH sooner compared to lower elevations in the northern/eastern areas, and secondarily along boundaries left from prior activity. A drier and more deeply mixed boundary layer is expected with southwestward extent (and increasing elevation) across MT, away from a low-level moist/theta-e axis extending from central SD to north-central/northeastern MT. This should contribute to MLCAPE ranging from around 2000-2500 J/kg near that axis to 1000 J/kg over southern/western MT near the main, orographically aided convective initiation zones. Forecast soundings also suggest strong veering of winds with height, though modest low-level wind speeds will keep hodographs and SRH marginal in magnitude. Some of the diurnal activity may aggregate upscale into an evening cluster across eastern MT into the western Dakotas, nearer to the moist axis, with severe gusts being the main concern until convection encounters progressively more-stable boundary layer and stronger MLCINH tonight in the Dakotas. ...KY/TN to Carolinas... Again today, a large swath of the area from the Ohio Valley to Southeast will have thunderstorm potential, with the greatest concentration likely in and near the "slight"/15%-wind outlook area. Multicell clusters and pulse storms will be common and locally numerous, offering the threat of damaging gusts, with a few severe/50+ kt gusts possible. Development should be focused mainly along higher terrain, a surface trough east of the mountains, and especially any number of outflow boundaries south of the synoptic front -- both from prior convection and generated throughout today's event. Strong surface heating in a richly moist air mass (dewpoints commonly in the upper 60s to mid 70s F), along with a deep troposphere, will offset modest midlevel lapse rates enough to yield MLCAPE in the 1500-2500 J/kg (locally higher) over much of the outlook area. Deep-tropospheric flow and vertical shear each will be weak, but oriented such that southeastward-propagating clusters will be favored. Potential should wane after dark as the boundary layer stabilizes from a combination of outflows and nocturnal/diabatic cooling. ...Central Plains to mid Mississippi Valley... Scattered thunderstorms are possible today over parts of IL as an eastward extension of ongoing activity in northeastern MO, as well as near a diurnally heated/modified version of the trailing outflow boundary across parts of northern MO to eastern KS. Damaging gusts and isolated large hail will be the main concerns, and at least a marginal tornado threat may develop with any supercell that can take advantage of favorable low-level vorticity/SRH along the boundary. In addition to the northern KS MCV, others are evident in west-central to central NE and over northeastern KS/southeastern NE. Mesoscale enhancements to both large-scale lift aloft, and vertical shear, are possible east and south of these features as they move eastward today, while the outflow boundary moves/diffuses somewhat northward. Relatively undisturbed, richly moist boundary-layer air over the mid Mississippi Valley, central/southern MO and eastern KS will be available as inflow to convection developing today, and over IL for convection moving in from MO. By midafternoon, 2500-3500 J/kg MLCAPE and negligible CINH are expected. Weak mid/upper flow over most areas suggests modes could become clustered and messy, but favorable low-level shear may persist along or north of the outflow boundary for support of at least transient supercellular characteristics. Overall coverage/intensity should diminish from late evening into tonight. ..Edwards/Goss.. 07/07/2022 Read more

MD 1396 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN KENTUCKY...EASTERN TENNESSEE...FAR SOUTHWEST VIRGINIA
Mesoscale Discussion 1396 NWS Storm Prediction Center Norman OK 1219 PM CDT Wed Jul 06 2022 Areas affected...Parts of eastern Kentucky...eastern Tennessee...far southwest Virginia Concerning...Severe potential...Watch unlikely Valid 061719Z - 061915Z Probability of Watch Issuance...20 percent SUMMARY...Scattered storm development is expected across eastern Kentucky into eastern Tennessee. A few damaging downbursts will be possible. A watch is not currently expected for this regime. DISCUSSION...Storms have developed in eastern Kentucky as a high-PWAT airmass has destabilized. Though MLCAPE is 2500-3500 J/kg, shear is quite weak as noted on the KJKL and KMRX VAD. Storms will likely develop and become briefly intense. Localized damaging downbursts will be the primary concern with this activity. There is some potential for storms to move into the region from the northwest later this afternoon. However, the track of the MCV is such that shear is not expected to improve today. A watch is not expected for these generally disorganized storms. ..Wendt/Grams.. 07/06/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RLX...MRX...JKL...LMK...OHX... LAT...LON 36778240 36038324 35698434 36118539 36578552 36758537 37348485 37788445 38258388 38218360 38078315 37228214 36778240 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1201 PM CDT Wed Jul 06 2022 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF MONTANA...AND FROM KENTUCKY AND TENNESSEE INTO THE CAROLINAS... ...SUMMARY... Scattered storms, some severe, will be possible Thursday mainly across Montana, and from the Ohio/Tennessee Valleys into the Carolinas. Damaging winds will be possible over all areas, with hail also expected over Montana. ...MT into the northern and central High Plains... A region of 30-40 kt southwesterly winds at 500 mb will remain over the Pacific Northwest, with neutral to slightly rising heights through the period. Midlevel temperatures will remain cool despite the ridging, and heating will lead to MUCAPE of 1500-2000 J/kg. Storms are expected to form over southwest and central MT after 21Z, with primarily outflow-driven convection spreading northeastward during the evening. The steep lapse rates may support damaging hail in the stronger storms, with severe outflow expected as well. Additional isolated activity is anticipated farther east into the western Dakotas southward into eastern WY/northeast CO/western NE. Here, sporadic hail or wind reports will also be possible, with minimal organization due to weak shear. ...KY/TN into the Carolinas... An upper high will be centered over AR, with gradually rising heights across much of the Southeast. Weak northwest flow aloft will exist across the region (15-20 kt at 500 mb), with warm temperatures aloft as well. Despite these factors, robust moisture with 70s F dewpoints will remain widespread, with strong heating resulting in MUCAPE averaging 2000-3000 J/kg from KY/TN into the Carolinas. Weak surface convergence centered over NC may provide a focus for clusters of storms and locally damaging gusts, with another area across KY and TN coincident with a region of steeper low-level lapse rates. ..Jewell.. 07/06/2022 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1201 PM CDT Wed Jul 06 2022 Valid 071200Z - 081200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF MONTANA...AND FROM KENTUCKY AND TENNESSEE INTO THE CAROLINAS... ...SUMMARY... Scattered storms, some severe, will be possible Thursday mainly across Montana, and from the Ohio/Tennessee Valleys into the Carolinas. Damaging winds will be possible over all areas, with hail also expected over Montana. ...MT into the northern and central High Plains... A region of 30-40 kt southwesterly winds at 500 mb will remain over the Pacific Northwest, with neutral to slightly rising heights through the period. Midlevel temperatures will remain cool despite the ridging, and heating will lead to MUCAPE of 1500-2000 J/kg. Storms are expected to form over southwest and central MT after 21Z, with primarily outflow-driven convection spreading northeastward during the evening. The steep lapse rates may support damaging hail in the stronger storms, with severe outflow expected as well. Additional isolated activity is anticipated farther east into the western Dakotas southward into eastern WY/northeast CO/western NE. Here, sporadic hail or wind reports will also be possible, with minimal organization due to weak shear. ...KY/TN into the Carolinas... An upper high will be centered over AR, with gradually rising heights across much of the Southeast. Weak northwest flow aloft will exist across the region (15-20 kt at 500 mb), with warm temperatures aloft as well. Despite these factors, robust moisture with 70s F dewpoints will remain widespread, with strong heating resulting in MUCAPE averaging 2000-3000 J/kg from KY/TN into the Carolinas. Weak surface convergence centered over NC may provide a focus for clusters of storms and locally damaging gusts, with another area across KY and TN coincident with a region of steeper low-level lapse rates. ..Jewell.. 07/06/2022 Read more

WW 0442 Status Updates
STATUS FOR WATCH 0442 HAS NOT BEEN ISSUED YET Read more

WW 442 SEVERE TSTM IN KY OH WV 061635Z - 062300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 442 NWS Storm Prediction Center Norman OK 1235 PM EDT Wed Jul 6 2022 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Far southeast Indiana Far northern Kentucky Southern Ohio Southern West Virginia * Effective this Wednesday afternoon and evening from 1235 PM until 700 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible SUMMARY...A few multicell clusters should develop east-southeast from southern Ohio and southeast Indiana towards southern West Virginia this afternoon. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 40 miles west northwest of Cincinnati OH to 35 miles north northeast of Beckley WV. 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 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 30025. ...Grams Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Wed Jul 06 2022 Valid 061700Z - 071200Z The forecast remains on track, and very minimal adjustments were made with this update. For details, see the previous discussion below. ..Weinman.. 07/06/2022 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Jul 06 2022/ ...Synopsis... Upper ridging will remain in place across the central U.S. as broad mid-level troughing will persist across the Interior West today. Surface lee troughing will encourage Elevated dry and breezy conditions across portions of the Great Basin, where fuels will remain receptive to wildfire spread and devoid of meaningful precipitation accumulations. Otherwise, occasional dry and breezy surface conditions may overlap patchy areas of marginally receptive fuels across portions of the southern Plains, promoting localized wildfire-spread potential. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1122 AM CDT Wed Jul 06 2022 Valid 061700Z - 071200Z The forecast remains on track, and very minimal adjustments were made with this update. For details, see the previous discussion below. ..Weinman.. 07/06/2022 .PREV DISCUSSION... /ISSUED 0202 AM CDT Wed Jul 06 2022/ ...Synopsis... Upper ridging will remain in place across the central U.S. as broad mid-level troughing will persist across the Interior West today. Surface lee troughing will encourage Elevated dry and breezy conditions across portions of the Great Basin, where fuels will remain receptive to wildfire spread and devoid of meaningful precipitation accumulations. Otherwise, occasional dry and breezy surface conditions may overlap patchy areas of marginally receptive fuels across portions of the southern Plains, promoting localized wildfire-spread potential. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CDT Wed Jul 06 2022 Valid 061630Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE NORTHWEST...CENTRAL...AND EASTERN STATES... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the northern High Plains/Rockies, central High Plains, and the Ohio Valley to Virginia and the Carolinas. ...Northern High Plains/Rockies... Scattered thunderstorms will develop during the late afternoon off the higher terrain of western/southern MT into northeast WY, with a plume of 50s to low 60s surface dew points being maintained over the adjacent High Plains. The largest buoyancy with MLCAPE of 2000-2500 J/kg will be present across parts of central to eastern MT within a plume of moist, low-level east-southeasterlies. Deep-layer shear will be weakest in the northeast WY vicinity around the north rim of a minor mid-level impulse drifting across the central High Plains. Farther northwest, weaknesses in the hodograph from 700-500 mb should result in more transient supercell structures and tendency for outflow-dominant cells to consolidate into clusters from central to northeast MT. A mix of large hail and severe wind gusts are anticipated, likely becoming more dominated by wind with time before convection weakens tonight. ...Central High Plains... Scattered thunderstorms will develop off the Front Range later this afternoon and gradually spread east across the adjacent High Plains during the late afternoon and early evening. With 500-mb temperatures around -6 C, severe potential will largely be driven by the degree of boundary-layer heating/moisture. Stratus has persisted across northeast CO and vicinity, but has gradually been eroding. Moderate buoyancy with MLCAPE of 1000-2000 J/kg is eventually expected by late afternoon. Weak low-level northeasterlies beneath modest mid to upper-level southwesterlies will provide sufficient deep-layer shear for multicell clusters with embedded supercells consolidating into a slow-moving MCS this evening. A mix of severe hail and wind transitioning to mainly wind is expected before weakening later tonight. ...OH Valley to VA and the Southeast... At least a trio of MCVs are evident in a train from the Mid-Atlantic region to the Mid-MO Valley. The most substantial of which for severe potential is drifting east across OH with deep convection ongoing to its south. With peak buoyancy at present over TN/KY, further destabilization is expected to the south of this ongoing activity. Intensification and expansion of convective development along outflows should yield multicell clusters spreading east-southeast across parts of the central/upper OH Valley, Cumberland Plateau, and central Appalachians into early evening. Scattered damaging winds will be the primary threat. Scattered to numerous pulse thunderstorms will likely develop farther south across the southern Appalachians and vicinity where localized downbursts producing tree damage will be the main threat. Thunderstorms are also anticipated farther north into VA where a belt of 25-35 kt 700-500 mb winds would support greater potential for multicell clustering and transient/low-end supercell structures. Primary uncertainties in this area are the degree of destabilization and convective coverage in the wake of a decaying MCV near the southeast PA/northeast MD border. ..Grams/Wendt.. 07/06/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CDT Wed Jul 06 2022 Valid 061630Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE NORTHWEST...CENTRAL...AND EASTERN STATES... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the northern High Plains/Rockies, central High Plains, and the Ohio Valley to Virginia and the Carolinas. ...Northern High Plains/Rockies... Scattered thunderstorms will develop during the late afternoon off the higher terrain of western/southern MT into northeast WY, with a plume of 50s to low 60s surface dew points being maintained over the adjacent High Plains. The largest buoyancy with MLCAPE of 2000-2500 J/kg will be present across parts of central to eastern MT within a plume of moist, low-level east-southeasterlies. Deep-layer shear will be weakest in the northeast WY vicinity around the north rim of a minor mid-level impulse drifting across the central High Plains. Farther northwest, weaknesses in the hodograph from 700-500 mb should result in more transient supercell structures and tendency for outflow-dominant cells to consolidate into clusters from central to northeast MT. A mix of large hail and severe wind gusts are anticipated, likely becoming more dominated by wind with time before convection weakens tonight. ...Central High Plains... Scattered thunderstorms will develop off the Front Range later this afternoon and gradually spread east across the adjacent High Plains during the late afternoon and early evening. With 500-mb temperatures around -6 C, severe potential will largely be driven by the degree of boundary-layer heating/moisture. Stratus has persisted across northeast CO and vicinity, but has gradually been eroding. Moderate buoyancy with MLCAPE of 1000-2000 J/kg is eventually expected by late afternoon. Weak low-level northeasterlies beneath modest mid to upper-level southwesterlies will provide sufficient deep-layer shear for multicell clusters with embedded supercells consolidating into a slow-moving MCS this evening. A mix of severe hail and wind transitioning to mainly wind is expected before weakening later tonight. ...OH Valley to VA and the Southeast... At least a trio of MCVs are evident in a train from the Mid-Atlantic region to the Mid-MO Valley. The most substantial of which for severe potential is drifting east across OH with deep convection ongoing to its south. With peak buoyancy at present over TN/KY, further destabilization is expected to the south of this ongoing activity. Intensification and expansion of convective development along outflows should yield multicell clusters spreading east-southeast across parts of the central/upper OH Valley, Cumberland Plateau, and central Appalachians into early evening. Scattered damaging winds will be the primary threat. Scattered to numerous pulse thunderstorms will likely develop farther south across the southern Appalachians and vicinity where localized downbursts producing tree damage will be the main threat. Thunderstorms are also anticipated farther north into VA where a belt of 25-35 kt 700-500 mb winds would support greater potential for multicell clustering and transient/low-end supercell structures. Primary uncertainties in this area are the degree of destabilization and convective coverage in the wake of a decaying MCV near the southeast PA/northeast MD border. ..Grams/Wendt.. 07/06/2022 Read more

MD 1395 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR PARTS OF MID/UPPER OHIO VALLEY
Mesoscale Discussion 1395 NWS Storm Prediction Center Norman OK 1115 AM CDT Wed Jul 06 2022 Areas affected...Parts of mid/upper Ohio Valley Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 061615Z - 061815Z Probability of Watch Issuance...80 percent SUMMARY...A severe thunderstorm watch is likely for parts of the mid/upper Ohio Valley this afternoon. An MCV should foster scattered storms capable of wind damage. DISCUSSION...The remnant MCV from yesterdays severe MCS is currently moving through the southern Great Lakes region per water vapor imagery. Convection ahead of this feature has deepened over the past hour in western/central Ohio and this trend should continue this afternoon. The airmass ahead of this activity is quite moist and temperature range from the low 80s F in southern Ohio to around 90 F in southern Indiana. Enhanced wind fields with the MCV will promote 25-35 kts of effective shear. Scattered storms should eventually develop this afternoon with a primary risk of damaging wind gusts. The primary uncertainty is how convection will evolve. The activity in Ohio will likely intensify as it ingest more buoyant air through time. There is also additional development possible along the outflow boundary in southern Indiana. It is likely that parts of the mid/upper Ohio Valley region will need a severe thunderstorm watch this within the next hour or two. ..Wendt/Grams.. 07/06/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RLX...JKL...ILN...LMK...IND... LAT...LON 39348664 40148511 40318447 39558192 39148132 38648112 38118164 37978253 38398503 38898630 39348664 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 AM CDT Wed Jul 06 2022 Valid 061300Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN HIGH PLAINS/ROCKIES REGION...CENTRAL PLAINS...AND PARTS OF THE OHIO VALLEY TO CAROLINAS... ...SUMMARY... Severe-thunderstorm potential (mainly gusts and hail) appears most concentrated today over parts of the northern High Plains/Rockies region, central Plains, and parts of the Ohio Valley to Carolinas. ...Synopsis... The mid/upper-level pattern will be dominated by troughing offshore from the West Coast, with a cyclone offshore from the Pacific Northwest, mean ridging from the Gulf Coast states across the central/northern Rockies, and belt of west-northwesterly to northwesterly flow from the mid/upper Mississippi Valley to the coastal Carolinas and Tidewater regions. The following shortwave troughs influencing convective potential were evident in moisture- channel imagery. 1. Western/central NV, forecast to move northeastward to eastern ID and western MT by 00Z, through the mean ridge position, then pivoting eastward to eastern MT with some convective reinforcement overnight. 2. Western parts of CO/NM, forecast to pivot northeastward and eastward, also through the mean ridge, then across the central Plains by 12Z tomorrow. 3. Southern Lower MI, northwestern IN and IL, convectively reinforced by the previous day's severe MCS, with an MCV apparent near the southern end of Lake Michigan. This feature should move southeastward to WV by 00Z, the over parts of VA and the Carolinas by 12Z. At the surface, 11Z analysis showed a wavy, slow-moving cold front, with several weak lows attached, from southeastern NY across northern portions of OH/IN/IL to central/southwestern KS. Most of the front east of the Mississippi River should sag southward through the period, while a low initially near DDC moves slowly toward central KS along the boundary. Several outflow boundaries from earlier MCS activity also exist south of the front over the Ohio Valley States. ...Northern High Plains/Rockies region... Widely scattered thunderstorms are expected to develop initially over higher terrain of western/southern MT and northeastern WY this afternoon, where diabatic heating and orographic lift will weaken and overcome MLCINH first, beneath increasing large-scale ascent related to the approaching perturbation. Resulting convection should move east-northeastward to eastward over the nearby northern High Plains this afternoon and evening, offering occasional severe hail and gusts, with isolated significant severe possible. A roughly zonal corridor of relatively maximized moisture/theta-e will be in place over eastern and central MT into western SD, with dewpoints commonly in the 50s over western areas to mid 60s in the east by around 00Z. In tandem with diurnal surface heating and steep low/middle-level lapse rates, corridor of MLCAPE around 1500-2000 J/kg should develop. Strong veering of flow with height will offset modest low/midlevel wind speeds enough to yield effective-shear magnitudes commonly in the 35-45-kt range, supporting both supercells and organized multicells (including bowing structures). Some clustering and related, localized cold-pool growth may occur for a few hours to support wind potential into the evening. The severe threat should diminish with time tonight as both ambient/antecedent MLCINH from the EML base, and nocturnal surface cooling, become increasingly hostile to convective growth. ...Central Plains... Widely scattered to scattered thunderstorms should develop from midday into this afternoon over the foothills, Cheyenne Ridge and Palmer Divide, then move eastward over the adjoining High Plains. Severe hail and gusts are possible. Some of this activity may coalesce into a forward-propagational thunderstorm cluster this evening into tonight. Strong diurnal surface heating of the higher elevations will erode MLCINH quickly today, amidst favorable moisture (with surface dew points commonly in the 50s to low 60s F and areas of 1.25-1.5-inch PW). Being removed from the stronger mid/upper winds aloft, deep shear will be limited, though strong veering with height of weak low-level flow will exist to support 30-40 kt effective-shear magnitudes. Peak/preconvective MLCAPE should range from around 1000 J/kg near the foothills to around 2000 J/kg near the latitude of the eastern border of CO. Well-mixed subcloud layers will support gust potential. ...Parts of the Ohio Valley to Carolinas... Widely scattered to scattered thunderstorms are expected to develop through this afternoon along any of several plausible foci: higher terrain in the Appalachians, the prefrontal/lee-side surface trough, sea breezes, and outflow/differential-heating boundaries from antecedent/ongoing convection. This includes boundaries related to non-severe convection now crossing portions of WV and OH. Thunderstorm coverage should increase through the afternoon, with a few clusters potentially aggregating upscale and offering concentrations of damaging winds. Isolated large hail also is possible. The air mass along and south of the composite front/outflow boundary will remain richly moist, with lower-elevation dewpoints commonly in the upper 60s to mid-70s F, and strong diurnal heating. These factors should offset modest midlevel lapse rates enough to contribute to MLCAPE in the 1000-2000 J/kg range over most of the area, with 2000-3000 J/kg possible over parts of the Ohio Valley region not substantially altered by prior convection. With the area displaced south of strong mid/upper-level winds, vertical shear generally will be weak, with small hodographs and effective-shear magnitudes. As such, the dominant mode should be multicellular and clustered, with activity moving generally southeastward amidst difluent/northwesterly mid/upper-level winds. ..Edwards/Goss.. 07/06/2022 Read more