Severe Storms

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

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

MD 1377 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR SOUTHWESTERN OHIO...EASTERN KENTUCKY INTO SOUTHWESTERN VIRGINIA
Mesoscale Discussion 1377 NWS Storm Prediction Center Norman OK 1215 PM CDT Tue Jul 05 2022 Areas affected...Far southwestern Ohio...Eastern Kentucky into southwestern Virginia Concerning...Severe potential...Watch possible Valid 051715Z - 051915Z Probability of Watch Issuance...40 percent SUMMARY...Storms in eastern Kentucky into southwest Virginia will continue to move into a increasingly buoyant, but decreasingly sheared, airmass this afternoon. Wind damage will be possible with water-loaded downdrafts. A watch is possible should convective trends in cold-pool organization warrant. DISCUSSION...Outflow from an MCS that moved through Ohio overnight yesterday continues to push southward into the southern Appalachians region. A very moist airmass (70+ F dewpoints) has warmed into the low 90s in eastern Kentucky with slightly lower temperatures to the east. With time, continued heating should support an increase in damaging wind potential. A secondary outflow push is also evident on regional MRMS radar. This could produce an increase in storm coverage/intensity as it interacts with storms farther to the south. However, overall organization is not expected to be high given the southward movement away from greater deep-layer shear. A watch is possible should an area of greater cold-pool organization develop this afternoon. Trends will be monitored. ..Wendt/Grams.. 07/05/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RNK...RLX...MRX...JKL...ILN...LMK... LAT...LON 36608158 37228439 37518490 37738520 38498512 39308480 39468436 39298400 38798327 38208185 38128092 38198017 38127976 37837949 37517945 37048018 36648152 36608158 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1204 PM CDT Tue Jul 05 2022 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF MONTANA...AND FROM PARTS OF THE OHIO VALLEY INTO THE CAROLINAS... ...SUMMARY... Areas of severe thunderstorms may occur Wednesday from parts of the northern/central Rockies/Plains into from the Midwest/Ohio Valley into the Carolinas. Damaging winds and large hail should be the main threats. ...MT into the western Dakotas... Height rises will occur over the region during the day, with ridge axis over central MT/WY at 00Z. At the surface, a ridge will extend from the Upper Great Lakes into the northern Plains, resulting in weak east/southeast surface winds. The air mass will remain sufficiently moist with dewpoints near 60 F over eastern MT, resulting in strong instability when combined with heating and steep lapse rates aloft. Storms are expected to form after 21Z over west-central MT, moving into northern MT by late evening. Additional diurnal activity is likely over northern/eastern WY where the moist air mass will become uncapped and where weak upslope will contribute to ascent. Low-level flow will be weak, but better mid and high level winds may yield some organization potential with outflow-driven clusters or lines producing damaging wind and hail. ...IN/OH/KY into the Carolinas... A modest northwest flow regime will exist across the region with mid and high-level winds around 30 kt. At the surface, an east-west oriented cold front will sink south across IL/IN/OH with high pressure over the Upper Great Lakes. Farther east, a weak surface trough will redevelop from eastern VA into the central Carolinas. Both of these features will provide low-level convergence and lift for a diurnal thunderstorm threat. A few lingering storms are possible Wednesday morning from northern IL into OH, as MLCAPE will be strong and the moist air mass uncapped. This activity could produce a few strong wind gusts or small hail early. The primary risk will develop after 18Z when heating contributes to stronger instability. One or more clusters of southeastward-moving storms will be possible, producing severe gusts and isolated hail. Farther east, storms should be most numerous after 18Z from northern GA into the Carolinas, with moist and tall CAPE profiles favoring locally severe downbursts. Strong heating will also favor vigorous pulsing updrafts capable of hail. Storm coverage from WV into VA is more questionable as some models indicate a bit of drying from the northwest, also reflected in lower HREF thunder probabilities. Isolated strong wind gusts appear most probable over these areas. ..Jewell.. 07/05/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1151 AM CDT Tue Jul 05 2022 Valid 051630Z - 061200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS SOUTHEAST SOUTH DAKOTA...SOUTHWEST MINNESOTA...AND NORTHWEST IOWA... CORRECTED FOR NDFD GRIDDED SIG HAIL ...SUMMARY... A derecho with embedded significant severe wind gusts appears probable from central to eastern South Dakota into southwest Minnesota and northern Iowa into this evening. ...SD to IA and southern MN... An intense cluster over central SD will likely persist east-southeast across southeast SD. This should evolve into a forward-propagating linear MCS, expanding in latitudinal extent as MLCIN further diminishes ahead of it. A large MLCAPE reservoir in excess of 3000 J/kg across southern SD/MN and northern IA will support potential for embedded significant severe wind gusts exceeding 75 kts. While the majority of CAM guidance appears to be egregiously poor (especially the HRW-FV3) with handling the conceptual model for this event, the 12Z HRW-ARW and NSSL are in the ballpark and suggest bowing linear segments will be maintained into southern MN and northern IA before weakening this evening. ...Central/eastern MT to western ND... Air mass recovery is underway across central to eastern MT in the wake of the intense MCS over northwest SD. Residual 50s to low 60s surface dew points in conjunction with pockets of pronounced boundary-layer heating will yield MLCAPE of 1000-1500 J/kg. With 45-55 kt effective bulk shear, at least a few supercells are expected from central to northeast MT during the late afternoon and evening with large hail and isolated severe wind gusts as the primary threats. Some of these cells should consolidate into a cluster that spreads into western ND during the evening. Overall intensity should decrease as activity impinges on the more stable air mass left in the wake of the SD MCS. ...Mid-Atlantic to Midwest... Poor mid-level lapse rates were evident in 12Z observed soundings east of the Appalachians and this will be the main limiting factor to more intense convective development. An MCV over western PA will move east towards the NJ coast, with scattered thunderstorms near and to its south. With 30-40 kt 700-mb westerlies impinging on the region attendant to this MCV and the boundary-layer destabilizing from south to north, an increase in strong gust potential should occur from VA into the Lower DE Valley. Arcing convective bands extend west of the lead MCV across WV and OH/IN. This activity will likely persist through the rest of the afternoon into this evening, building south-southwest in time towards large buoyancy centered on the Lower OH Valley. Moderate deep-layer shear will be further offset as this process occurs, suggesting that loosely organized clusters will dominate with strong to isolated severe gusts as the primary threat. Additional multicell clusters will probably form northwest along the baroclinic zone near the IA/IL/WI border area during the late afternoon into the evening. These will similarly pose a threat for scattered damaging winds and isolated severe hail, although the spatial extent of this threat will likely be limited by this morning's stabilization in OH. ..Grams/Wendt.. 07/05/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1149 AM CDT Tue Jul 05 2022 Valid 051700Z - 061200Z The Elevated area was expanded slightly southward into southern NV and far northwest AZ based on the latest surface observations and high-resolution guidance. Along the western periphery of deeper monsoonal moisture, isolated dry thunderstorms are possible over parts of central UT this afternoon, and a lightning-induced ignition or two cannot be ruled out given near-critical to locally critical fuels. However, this activity looks too isolated/marginal for dry thunderstorm highlights. ..Weinman.. 07/05/2022 .PREV DISCUSSION... /ISSUED 0129 AM CDT Tue Jul 05 2022/ ...Synopsis... Upper ridging will remain in place across the central CONUS as a broad mid-level trough persists over the Interior West today. Broad surface lee troughing across the Great Basin will support Elevated dry and windy conditions by afternoon. Surface troughing to the lee of the southern Rockies may also support a localized, brief wildfire-spread threat over portions of the southern Plains, where fuel ERCs are forecast to rise into the 80th-90th percentile range. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CDT TUE JUL 05 2022 ...Severe thunderstorms expected over parts of the Mid-Missouri Valley and Upper Midwest this afternoon and evening... * LOCATIONS... Southeast South Dakota Southwest Minnesota Northwest Iowa * HAZARDS... Widespread damaging winds, some hurricane force Isolated large hail up to baseball size * SUMMARY... A derecho with embedded significant severe wind gusts appears probable from central to eastern South Dakota into southwest Minnesota and northern Iowa into this evening. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Grams.. 07/05/2022 $$ Read more

WW 0436 Status Updates
STATUS REPORT ON WW 436 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N PIR TO 35 NNE PIR TO 30 SSE MBG. ..KERR..07/05/22 ATTN...WFO...FSD...ABR...UNR... STATUS REPORT FOR WS 436 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS SDC003-005-011-015-017-023-025-029-035-039-043-045-049-053-057- 059-061-065-067-069-071-073-075-077-079-085-087-095-097-107-111- 115-117-119-121-123-129-051740- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE AURORA BEADLE BROOKINGS BRULE BUFFALO CHARLES MIX CLARK CODINGTON DAVISON DEUEL DOUGLAS EDMUNDS FAULK GREGORY HAMLIN HAND HANSON HUGHES HUTCHINSON HYDE JACKSON JERAULD JONES KINGSBURY LAKE LYMAN MCCOOK MELLETTE MINER POTTER SANBORN SPINK STANLEY SULLY TODD TRIPP WALWORTH 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

WW 436 SEVERE TSTM SD 051435Z - 052100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 436 NWS Storm Prediction Center Norman OK 935 AM CDT Tue Jul 5 2022 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central to eastern South Dakota * Effective this Tuesday morning and afternoon from 935 AM until 400 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 90 mph likely Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Intense cluster in northwest South Dakota will likely expand in coverage across central to eastern South Dakota. Embedded bowing linear segments will be conducive to producing significant severe wind gusts. The severe thunderstorm watch area is approximately along and 90 statute miles east and west of a line from 35 miles south southwest of Chamberlain SD to 55 miles north of Huron SD. 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 435... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 80 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29035. ...Grams Read more

WW 0435 Status Updates
STATUS REPORT ON WW 435 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 50 WNW PIR TO 45 NW PIR. REMAINING VALID PORTION OF WW 435 MAY BE ALLOWED TO EXPIRE AT 05/17Z. ..KERR..07/05/22 ATTN...WFO...BYZ...GGW...BIS...UNR...ABR... STATUS REPORT FOR WS 435 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS SDC041-051700- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE DEWEY 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 CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 AM CDT Tue Jul 05 2022 Valid 051300Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF CENTRAL/SOUTHERN SOUTH DAKOTA...NORTHEASTERN NEBRASKA...NORTHWESTERN IOWA...AND SOUTHWESTERN MINNESOTA... ...SUMMARY... Clusters of severe thunderstorms are forecast this afternoon and evening in a broad area from parts of the northern/central Plains into the Midwest, Ohio Valley, and Mid-Atlantic. Severe gusts and large hail are the main threats. The most intense gusts and very large hail are expected across parts of the northern Plains. ...Synopsis... The mid/upper-level pattern will continue to be dominated by a Rex block over northwestern Canada, with the cyclonic component over the Pacific west of BC, WA and OR. As a shortwave trough now over extreme southern BC ejects northeastward, ridging will build through the northern Rockies, connecting the longstanding anticyclones over the Mid-South and northwestern Canada. Downstream, westerly to west-northwest flow will prevail in a belt from the northern Plains to the Mid-Atlantic. In that flow belt, several embedded shortwaves and vorticity maxima are expected, including those related to convection now over the northern Plains and OH. The former will shift southeastward across the Dakotas to eastern IA through the period. The OH activity, and associated MCV, are in the southern part of a longer shortwave trough that extends over Lake Huron and adjoining parts of southern/central ON. That perturbation should move east-southeastward across the Mid-Atlantic today. The surface analysis at 11Z showed a wavy stationary to warm front near Cape Cod, northern NJ, central PA, to a low over northeastern Lower MI. A slow-moving cold to stationary front was drawn from there across central lake Michigan, southern WI, northern IA, southeastern SD, and north-central NE, to another low between AKO-GLD. Outflow boundaries shunted the effective baroclinic zone farther southward over parts of the middle/upper Ohio Valley region and Upper Great Lakes. The front should move slowly southeastward through Lower MI, the Lower Great Lakes, and much of NY through the period, while moving little and being diffused further by more strongly baroclinic convective processes over the Upper Midwest and central Plains regions. ...Northern Plains to IA... Widely scattered to scattered thunderstorms -- some severe -- are moving roughly eastward over parts of eastern MT and the western Dakotas. See SPC severe thunderstorm watch 435 and related mesoscale discussions for near-term coverage of the ongoing activity. As the associated perturbation and area of large-scale ascent pivots southeastward today near the low-level baroclinic zone -- additional development is expected mainly over southern SD. This activity will arise from strong diurnal destabilization, weakening MLCINH, favorable low-level moisture, steep low/middle-level lapse rates, and both orographic (in the Black Hills vicinity) and deep-layer lift. Specifics of the convective evolution remain somewhat uncertain, though a strong and reasonable guidance consensus remains for relatively maximized concentration of convection in and near the "enhanced" area. The immediately preconvective environment this afternoon will contain a parameter space suitable for both organized multicells and a few supercells prior to upscale evolution. Forecast soundings along and northeast of the front show strong veering of winds with height, offsetting modest midlevel flow enough to contribute to effective-shear magnitudes of 40-50 kt. Near the low-level moist axis, surface dew points in the upper 60s to low 70s F will contribute to MLCAPE in the 3000-4000 J/kg range. Farther northwest, additional convective development is likely across parts of southern/central and eastern MT, as warm/moist advection and diurnal heating contribute to recovery behind the current eastern MT complex and near its residual outflow boundary. The environment will become favorable again for supercells and bowing convective clusters, with residual moisture near the theta-e axis, diabatic heating, and steep low/middle-level lapse rates contributing to a corridor of 1000-2000 J/kg MLCAPE, superimposed by 45-55-kt effective-shear magnitudes. The width of this corridor, and coverage of related severe convection, each is in doubt, with surface dew points likely to be less than the previous day, in a narrower zone of relatively maximized but convectively processed moisture. As a result, while at least a few severe thunderstorms are still expected, perhaps even a supercell or two with significant hail/gusts possible, a 30% unconditional wind coverage appears less justified than in previous outlooks. ...Mid-Atlantic to Ohio Valley... A currently non-severe, quasi-linear MCS is moving east- southeastward to southeastward across portions of OH and northwestern PA. The associated clouds/precip and UVV field should impinge on a diurnally destabilizing boundary layer in the Mid-Atlantic from later this morning into afternoon. As that occurs, strengthening and/or additional development is expected, with potential for damaging/isolated severe gusts and isolated large hail to result. Forecast soundings in the preconvective environment indicate weak low-level flow/hodographs, but enough deep shear (effective-shear magnitudes generally 35-40 kt) for a mix of organized storm modes. Diabatic heating and surface dew points in the 60s F at lower elevations will offset modest midlevel lapse rates enough to yield: 1. A well-mixed boundary layer supporting damaging to locally severe gusts, as well as maintenance of any supercell-generated severe hail to the surface, and 2. MLCAPE reaching 500-1000 J/kg in a corridor east of, and parallel to, the Blue Ridge into southeastern PA. Already modest buoyancy should decrease considerably farther northeast, while shear and overall organization diminish southward. However, strong heating and steeper lapse rates aloft will spread across parts of the Ohio Valley region and into the adjoining Appalachians this afternoon, persisting into early evening. This should support additional development near the front and residual outflow boundaries, some of which may become severe, with damaging gusts likely and isolated large hail possible. ..Edwards/Goss.. 07/05/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1144 AM CDT Mon Jul 04 2022 Valid 041700Z - 051200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE EASTERN GREAT BASIN... The forecast remains on track, and only minor adjustments were made to the ongoing Critical area based on the latest surface observations and high-resolution guidance consensus. For details, see the previous discussion below. Of note, fuels continue to dry across parts of the southern Plains where above-average temperatures are forecast. The combination of hot/dry conditions (minimum RH nearing 25 percent) and breezy southerly surface winds of 15-20 mph (with higher gusts) could promote locally elevated conditions generally along and west of the I-35 corridor in parts of OK and TX. However, these conditions appear too localized for Elevated highlights. ..Weinman.. 07/04/2022 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Jul 04 2022/ ...Synopsis... A mid-level short-wave trough positioned over the Pacific Northwest will lift northeast into southwestern portions of Canada, while another short-wave enters in its wake. Consequently, the broader upper-level trough situated over much of the West will remain quasi-stationary throughout the day. Southwesterly mid-level flow within this regime will remain generally light, but approaching 30-35 kt over portions of the Great Basin. ...Portions of the Eastern Great Basin... Diurnal heating/mixing will allow for afternoon sustained winds of 15-20 mph and RH values into the teens over a broad region, extending from southern Nevada into central Wyoming. The region of strongest winds should be confined to parts of southeast Nevada and western Utah, where critical highlights are maintained. Elsewhere, elevated fire-weather conditions will be possible where fuels remain receptive to large-fire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more