Severe Storms

No watches are valid as of Fri Jul 15 17:56:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1219 PM CDT Fri Jul 15 2022 Valid 161200Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS CENTERED ACROSS THE CENTRAL PLAINS AREA... ...SUMMARY... Isolated severe thunderstorms are possible over the central Plains vicinity on Saturday. ...Synopsis... A relatively stagnant upper flow regime will persist across the U.S. Saturday, as a ridge remains dominant across the western and south-central states. Meanwhile, a trough will shift slowly eastward across western Canada and the Pacific Northwest, while a second trough over eastern North America continues making gradual eastward progress. Within the northwesterly flow between the western ridge and eastern trough, a series of vorticity maxima -- loosely functioning as a broader-scale short-wave trough -- will move southeastward out of the northern Plains and across the Upper Midwest through the period. At the surface, a cold front will move slowly across the Pacific Northwest, while a second/weaker front sags slowly southeastward across the Midwest and central Plains. ...Central High Plains to northern Missouri... Scattered showers and thunderstorms are forecast to be ongoing at the start of the period across portions of the northern and central Plains, with lingering convection and associated boundaries a complicating factor with respect to storm evolution/severe potential later in the day Saturday. While limited severe risk may linger across the Dakotas and Minnesota during the day, uncertainty prevails, precluding any severe-weather probabilities across this region in this update. From a larger-scale perspective, a surface front progged to extend east-to-west across the central Plains will be a focus for convective development. Isolated storms may initially develop across the central High Plains, while warm advection to the cool side of the boundary also suggests late afternoon storm development, as daytime heating contributes to a corridor of moderate destabilization. As a south-southwesterly low-level jet develops during the evening, isolated storms moving eastward across the High Plains may interact/congeal with convection farther east, potentially yielding an eastward-/southeastward-moving MCS across Kansas. While this scenario remains uncertain, the strengthening low-level jet beneath 40 kt west-northwesterly mid-level flow suggests this potential. In any case, gusty/locally damaging winds will be possible from afternoon into the overnight hours, with any stronger storms. ..Goss.. 07/15/2022 Read more

MD 1486 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PARTS OF WESTERN INTO CENTRAL MONTANA
Mesoscale Discussion 1486 NWS Storm Prediction Center Norman OK 1221 PM CDT Fri Jul 15 2022 Areas affected...Parts of western into central Montana Concerning...Severe potential...Watch likely Valid 151721Z - 151915Z Probability of Watch Issuance...80 percent SUMMARY...A developing cluster of thunderstorms is expected to intensify and become better organized east of the Continental Divide. This may be accompanied by a developing swath of strong to severe wind gusts across and south of the Great Falls vicinity into central Montana (north through south of Lewistown) by 2-4 PM MDT. DISCUSSION...Downstream of one notable short wave perturbation progressing northeast of the Oregon Cascades, forcing for ascent has supported a sustained cluster of thunderstorms now spreading into and across the Continental Divide vicinity of western Montana. This activity appears to be focused near the nose of a 40-50 kt jet streak around 500 mb, with associated momentum contributing to a current forward propagation up to 40-45 kt. As forcing for ascent spread east of the higher terrain into areas near and south of the Great Falls vicinity within the next few hours, the environment appears likely to become increasingly conducive to renewed, intensifying thunderstorm development along an associated strengthening surface cold pool. In advance of the cold pool, forecast soundings suggest that further insolation will contribute to a seasonably warm and well-mixed boundary layer, including large surface temperature/dew point spreads up to around 40 F, but also characterized by CAPE on the order of 1000-1500 J/kg. Coupled with strengthening deep-layer shear, the evolution of an increasingly organized convective system seems possible, accompanied by increasing potential to produce strong to severe wind gusts while spreading into central Montana by 20-22Z. ..Kerr/Hart.. 07/15/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW...TFX... LAT...LON 47601241 48121135 48380993 47750874 46800882 46250920 45451212 46481174 47601241 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Fri Jul 15 2022 Valid 151700Z - 161200Z The forecast remains unchanged. See the previous discussion for greater details. ..Wendt.. 07/15/2022 .PREV DISCUSSION... /ISSUED 0157 AM CDT Fri Jul 15 2022/ ...Synopsis... Across the western US, the mid-level flow pattern will remain dominated by a prominent anticyclone centered over the Southwest and southern High Plains. To the west of the ridge, a Pacific trough will move shoreward, bolstering mid-level southwesterly flow across the Cascades and northern Rockies. Beneath the ridge, a strong monsoonal surge will support scattered to widespread thunderstorms across the Southwest. Meanwhile, very warm and dry conditions are expected across the southern and central High Plains with temperatures exceeding 100F. ...Northern Great Basin... Modest southwesterly flow along the periphery of the ridge will support dry downslope flow off the Sierra across portions of northern NV, southeastern OR and eastern ID. Surface RH below 15% and winds near 15 mph will support elevated fire weather concerns given area fuel ERC values above the 90th percentile. Winds should gradually weaken overnight as the shortwave and stronger flow aloft move quickly northeastward. To the south and east, monsoonal moisture will support scattered thunderstorms across portions of central and northeastern NV. Along the northwestern fringe of the monsoonal plume, model soundings show initially dry sub-cloud layers greater than 2km deep supporting dry strikes over receptive fuels. Storm coverage and PWATs are forecast to gradually increase through the day, supporting wetter storms. However, the potential for a few drier strikes initially within receptive fuels necessitates continuation of the IsoDryT area across north/northeastern NV. ...Southwest KS and the Panhandles... Beneath the center of a strong and sustained mid-level anticyclone, a very warm airmass should develop across portions of the southern and central High Plains this afternoon. Low-level southerly flow bolstered by a weak lee trough/decaying cold front may support gusty winds to 15-25 mph coincident with surface RH below 20%. Ongoing drought and excessive heat (temps greater than 100F) will favor curing of short-hour fuels and the possibility of Elevated fire weather conditions. ...Southern Cascades... A gradual increase in low-level westerly flow is forecast today as mid and upper-level winds strengthen with the passing trough. Hi-res guidance indicates at least localized potential for winds greater than 15 mph through terrain gaps and in the immediate lee of the southern Cascades. Dry and warm conditions with humidity below 30% may coincide with these gustier winds, supporting locally elevated fire weather conditions across portions of OR. However, uncertainty on the areal coverage of sustained elevated fire weather conditions remains high, precluding any Elevated delineations. ...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 1103 AM CDT Fri Jul 15 2022 Valid 151630Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL MONTANA INTO WESTERN NORTH DAKOTA... ...SUMMARY... Scattered strong to severe storms, including a risk of damaging winds and hail, will be possible across parts of the northern Rockies and High Plains today and tonight. ...MT/ND... Morning water vapor imagery shows a well-defined shortwave trough moving across eastern OR. This feature and its associated mid-level speed max will track across ID into MT this afternoon. Large-scale lift ahead of the trough is already resulting in scattered thunderstorms over the mountains of western MT, which will spread eastward into central/eastern MT this afternoon and evening. Hot surface temperatures in the 90s or low 100s are expected, yielding a deeply mixed boundary layer with 500-1000 J/kg of MLCAPE. This will support high-based convection capable of locally damaging wind gusts. This activity will likely spread into western ND after dark. Winds aloft weaken with southward extent, but at least isolated strong to severe wind gusts will be possible into parts of northern/eastern WY and western NE/SD this afternoon. ..Hart/Kerr.. 07/15/2022 Read more

No watches are valid as of Thu Jul 14 18:02:02 UTC 2022.

MD 1480 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE FL PENINSULA
Mesoscale Discussion 1480 NWS Storm Prediction Center Norman OK 1256 PM CDT Thu Jul 14 2022 Areas affected...Portions of the FL Peninsula Concerning...Severe potential...Watch unlikely Valid 141756Z - 142100Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe hail and damaging winds may occur with the strongest thunderstorms this afternoon. Watch issuance appears unlikely at this time. DISCUSSION...Convection has recently developed along both sea breezes on the west and east coasts of the FL Peninsula. MLCAPE of 2500-3000 J/kg will be common across this area with continued robust diurnal heating. Seasonably cool mid-level temperatures associated with a weak upper low over northern Cuba and the Bahamas are also contributing to this substantial buoyancy. Even though low-level winds will remain weak, some modest enhancement to the mid and upper-level flow field was noted in 12Z soundings from MFL/KEY due to the proximity of the upper low. Some anvil-level venting should occur with scattered to numerous thunderstorms that will develop over much of the FL Peninsula in the next few hours. This venting, along with the cool mid-level temperatures and moderate to strong instability, should aid in the production of isolated marginally severe hail with the more robust updrafts. Occasional strong to damaging downdraft winds may also occur as low-level lapse rates continue to steepen with daytime heating and as DCAPE increases to around 1000 J/kg. Still, current expectations are for the overall severe threat to remain isolated/marginal owing to the weak deep-layer shear. Accordingly, watch issuance appears unlikely at this time. ..Gleason/Thompson.. 07/14/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...MLB...TBW...JAX... LAT...LON 27798290 28548272 29148276 29398208 29138141 28378084 27628052 26968019 26128041 25438091 25398121 25818172 26538224 27798290 Read more

MD 1480 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF THE FL PENINSULA
Mesoscale Discussion 1480 NWS Storm Prediction Center Norman OK 1256 PM CDT Thu Jul 14 2022 Areas affected...Portions of the FL Peninsula Concerning...Severe potential...Watch unlikely Valid 141756Z - 142100Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe hail and damaging winds may occur with the strongest thunderstorms this afternoon. Watch issuance appears unlikely at this time. DISCUSSION...Convection has recently developed along both sea breezes on the west and east coasts of the FL Peninsula. MLCAPE of 2500-3000 J/kg will be common across this area with continued robust diurnal heating. Seasonably cool mid-level temperatures associated with a weak upper low over northern Cuba and the Bahamas are also contributing to this substantial buoyancy. Even though low-level winds will remain weak, some modest enhancement to the mid and upper-level flow field was noted in 12Z soundings from MFL/KEY due to the proximity of the upper low. Some anvil-level venting should occur with scattered to numerous thunderstorms that will develop over much of the FL Peninsula in the next few hours. This venting, along with the cool mid-level temperatures and moderate to strong instability, should aid in the production of isolated marginally severe hail with the more robust updrafts. Occasional strong to damaging downdraft winds may also occur as low-level lapse rates continue to steepen with daytime heating and as DCAPE increases to around 1000 J/kg. Still, current expectations are for the overall severe threat to remain isolated/marginal owing to the weak deep-layer shear. Accordingly, watch issuance appears unlikely at this time. ..Gleason/Thompson.. 07/14/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...MLB...TBW...JAX... LAT...LON 27798290 28548272 29148276 29398208 29138141 28378084 27628052 26968019 26128041 25438091 25398121 25818172 26538224 27798290 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Thu Jul 14 2022 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN ROCKIES/NORTHERN HIGH PLAINS...AND ACROSS PARTS OF THE UPPER MIDWEST VICINITY... ...SUMMARY... Isolated severe storms, including local risk for strong wind gusts and hail, will be possible across parts of the northern High Plains on Friday. Local severe risk may also occur across portions of the Upper Midwest during the day. ...Synopsis... A generally stagnant pattern aloft will persist Friday, with pronounced western and central U.S. ridging flanked by northeastern Pacific and eastern North America troughing. Weak short-wave features progressing through anticyclonic flow aloft will continue to support weak surface frontal progressions across the northern Rockies and northern Plains through the period. ...Northern Rockies/northern High Plains area... Another day of heating/modest destabilization is expected over the northern Intermountain region, ahead of another in a series of short-wave troughs progressing eastward within the belt of stronger, anticyclonic flow around the northern periphery of stout/persistent upper ridging. As in prior days, this will result in renewed, isolated convective development across the region. Given ample flow aloft to support locally organized, eastward-progressing storms, a few stronger convective elements will again become capable of producing gusty/damaging winds and marginally severe hail locally. During the evening, development of a southeasterly low-level jet over the northern High Plains may aid in continuation of ongoing storms, potentially spreading into the western Dakotas through evening, along with possible/local severe risk. ...Parts of the Upper Midwest vicinity... A rather pronounced mid-level trough cresting the ridge and shifting southeastward across the Upper Mississippi Valley region at the start of the period may be supporting ongoing/warm-advection-aided convection Friday morning. Minimal/local risk for gusty winds may then continue through the morning, spreading southeastward across southeastern Minnesota/northeastern Iowa and roughly the southern half of Wisconsin and adjacent northern Illinois. As the associated cold front shifts southeastward through the day, some southwestward development of convection may occur, perhaps into portions of west-central Illinois and northeastern Missouri through the afternoon and evening. Locally gusty/damaging winds and hail would be possible, before diminishing during the evening hours. ..Goss.. 07/14/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 2 NWS Storm Prediction Center Norman OK 1203 PM CDT Thu Jul 14 2022 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FOR PARTS OF THE DAKOTAS AND WESTERN MN... CORRECTED FOR OUTLOOK GRAPHICS (GEN TSTM LINE/SEVERE WIND PROBS) ...SUMMARY... The greatest conditional severe-weather concern is across parts of the Dakotas and western Minnesota, where large hail and damaging gusts are possible from late afternoon through tonight. ...Northern Plains this afternoon into tonight... A midlevel shortwave trough over southern SK/MB is cresting the midlevel ridge and will begin to move southeastward toward MN this evening into tonight. Some elevated convection is ongoing as of late morning over northeast ND, in a zone of weak warm advection near a northwest-southeast oriented warm front. The potential for diurnal, surface-based convection is in question along the front, given that surface temperatures will need to warm to 90F or above to remove convective inhibition across east/southeast ND, and clouds are upstream from this area now. If storms manage to form, the environment will conditionally favor supercells capable of producing large hail/damaging winds, and perhaps a tornado. However, the more probable scenario will be for slightly elevated storms/clusters to form along the immediate cool side of the front tonight, and spread southeastward toward western MN, with an attendant threat for large hail/damaging winds. ...Southern MT vicinity this afternoon through tonight... Daytime heating and local terrain circulations are expected to initiate at least widely scattered thunderstorms this afternoon across southern MT, in conjunction with subtle speed maxima within the monsoonal moisture plume around the northern periphery of the Four Corners high aloft. Westerly midlevel flow with relatively long/straight hodographs, deep mixing/inverted-v profiles, and modest buoyancy will support the potential for isolated severe outflow gusts and marginally severe hail with small clusters and high-based supercells from southern MT this afternoon into northeastern WY this evening. ...TX area this afternoon/evening... A cluster of storms is ongoing as of late morning across northeast/east central TX, in association with a diffuse midlevel trough and pocket of slightly cooler midlevel temperatures. Given the organized nature of the cold pool with these storms and weak northeasterly midlevel steering flow, the storms will likely persist through the afternoon while spreading southwestward. The 12z FWD sounding depicted a hybrid microburst environment, and strong surface heating in advance of the storms will result in steepening low-level lapse rates, moderate buoyancy (MLCAPE around 1500 J/kg), and DCAPE in the range of 1000-1500 J/kg. A few damaging/severe outflow gusts will be the main threat this afternoon through late evening. ...Southeast/FL this afternoon/evening... A weak midlevel trough persists from GA to the Carolinas, and a separate closed low is moving westward over the north coast of Cuba. Somewhat enhanced midlevel west-southwesterly flow will support the potential for semi-organized storms/clusters and isolated wind damage from southeast GA to the Carolina coasts this afternoon. Sea breeze convection is likely across the FL peninsula, with easterly flow aloft favoring storm motion and subsequent outflow mergers inland from the southeast FL coast to the west coast sea breeze. The strongest storms will be capable of producing isolated damaging downbursts, as well as marginally severe hail, given the strong buoyancy (MLCAPE near or above 3000 J/kg), DCAPE near 1000 J/kg, and slightly cooler midlevel temperatures compared to previous days. ...Eastern MA to southeastern ME this afternoon... Pockets of stronger surface heating, weak low-level convergence along a cold front and local sea breeze boundaries could support widely scattered thunderstorm development this afternoon. Though buoyancy will remain modest, somewhat enhanced midlevel flow and effective bulk shear in excess of 30 kt could support isolated strong/damaging gusts. ..Thompson.. 07/14/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Thu Jul 14 2022 Valid 141700Z - 151200Z Minor changes were made to the fire weather highlights to reflect the latest guidance consensus. Otherwise, the previous forecast (see below) remains on track. ..Squitieri.. 07/14/2022 .PREV DISCUSSION... /ISSUED 0109 AM CDT Thu Jul 14 2022/ ...Synopsis... The dominant upper ridge over the Four Corners region will remain in place for the next several days and will limit overall boundary-layer and surface wind speeds. However, this feature will also promote hot conditions across the Southern Plains into the Southwest and diurnal thunderstorm chances across the Great Basin and Four Corners region. This synoptic regime will limit the potential for widespread fire weather concerns, but will support regional threats across parts of Nevada and western Kansas. ...Nevada... Despite a generally weak synoptic regime, deep diurnal boundary-layer mixing, coupled with downslope flow off the Sierra Nevada, will likely result in sustained winds around 15 mph across northwest to north-central NV this afternoon. Poor overnight RH recovery is noted across this region, and afternoon RH values should once again fall into the teens for much of the risk area. While critical wind speeds are not expected given weak flow aloft, fuels remain receptive across the region and will support areas of elevated fire weather conditions. Such conditions may overlap with parts of northeast NV that received lightning strikes Wednesday afternoon, posing a threat for holdover fires, though confidence in the northeastern extent of dry/windy conditions is somewhat low. ...West Kansas... A low-amplitude mid-level wave cresting the upper ridge is supporting modest lee pressure falls along the northern High Plains. This trough is expected to consolidate into a weak low over the central Plains, and will support another day of a dry return-flow pattern across western KS. The low wind-speed bias that is common in most guidance under this type of pattern is noted in yesterday's surface observations with observed gusts coming in stronger than anticipated by most deterministic and ensemble solutions. For today, a slightly stronger regional pressure gradient should yield winds closer to 15-20 mph with gusts up to 30 mph (after accounting for the noted low bias). Afternoon minimum RH values in the low 20s appear likely over a region with ERC values near or above the 80th percentile (outside of where thunderstorms tracked Wednesday evening). This should support areas of elevated conditions this afternoon. ...Dry Thunderstorms... Regional 00 UTC soundings continue to sample steep mid-level lapse rates and ample monsoonal moisture across the Four Corners region and diminishing moisture quality with western extent into Nevada. This matches well with latest satellite-based total precipitable water estimates, which show PWAT values between 0.75 to 0.9 inches across eastern NV. This thermodynamic regime supported a mix of wet and dry thunderstorms yesterday (Wednesday) across NV and western UT. Rainfall amounts increased with eastward extent into central UT (per MRMS QPE estimates). A similar regime is expected for today with isolated dry/wet thunderstorms across central to eastern NV where PWAT values near or below 0.75 inches are expected, and fuels remain receptive after receiving only localized pockets of wetting rainfall on Wednesday. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1479 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF CENTRAL TX
Mesoscale Discussion 1479 NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 14 2022 Areas affected...Portions of central TX Concerning...Severe potential...Watch unlikely Valid 141620Z - 141845Z Probability of Watch Issuance...20 percent SUMMARY...A loosely organized complex of thunderstorms may pose an isolated threat for strong to damaging winds through the afternoon. Watch issuance appears unlikely at this time. DISCUSSION...A cluster of convection developed overnight across northeast TX on the eastern periphery of an upper ridge centered over the Southwest. This cluster has persisted through the morning while moving slowly southwestward. Although low/mid-level flow across much of TX is expected to remain modest, around 15-25 kt of northeasterly mid-level winds should encourage the ongoing thunderstorms to continue progressing southwestward across parts of central TX through the early afternoon. A rather moist airmass is in place ahead of this activity, with surface dewpoints generally in the upper 60s to low 70s. Strong diurnal heating will likely continue over the next several hours based on recent visible satellite trends, and instability should further increase in tandem with steepening low-level lapse rates. Even with deep-layer shear remaining modest, the moderate to strong instability forecast to develop, including substantial DCAPE with inverted-v forecast soundings, should support an isolated risk for strong to damaging winds. Still, current expectations are for this damaging wind threat to remain fairly isolated, and watch issuance appears unlikely at this time. ..Gleason/Thompson.. 07/14/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...HGX...FWD...EWX...SJT... LAT...LON 31079524 30099569 29959660 30039761 30559855 31389908 32149912 32879871 33099799 33079691 32549686 31669638 31079524 Read more

No watches are valid as of Wed Jul 13 17:59:02 UTC 2022.

MD 1468 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF SOUTHERN GEORGIA INTO EASTERN NORTH CAROLINA
Mesoscale Discussion 1468 NWS Storm Prediction Center Norman OK 1257 PM CDT Wed Jul 13 2022 Areas affected...portions of southern Georgia into eastern North Carolina Concerning...Severe potential...Watch possible Valid 131757Z - 131900Z Probability of Watch Issuance...40 percent SUMMARY...Damaging gusts and isolated large hail may accompany the stronger storms this afternoon, especially in SC into southern NC. A WW issuance is possible. DISCUSSION...The combination of weak mid-level troughing, lee surface troughing, and ample heating of a moist low-level airmass has supported increased storm coverage/intensity across the Southeast Atlantic Coastline within the past hour or so. The rich low-level moisture and modest low-level lapse rates are contributing to 2000+ J/kg MLCAPE per 17Z mesoanalysis. In addition, RAP forecast soundings show unidirectional (southwesterly) tropospheric flow, but some speed shear in the surface-500 mb layer, contributing to 25-35 kts of effective bulk shear. As such, marginal organization of stronger multicell clusters/transient supercells may support a couple of damaging gusts and perhaps an instance or two of hail this afternoon. A locally more organized severe threat may also materialize across eastern SC into far southern NC given the modest shear profiles. A WW issuance is possible if storms continue to intensify across SC. ..Squitieri/Thompson.. 07/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM...CHS...CAE...JAX...FFC... TAE... LAT...LON 30798342 33408108 36167802 36577717 36387627 35927589 35157646 33637878 32328014 31308111 30938146 30668249 30798342 Read more

MD 1467 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF CENTRAL MISSISSIPPI INTO EXTREME WESTERN ALABAMA
Mesoscale Discussion 1467 NWS Storm Prediction Center Norman OK 1236 PM CDT Wed Jul 13 2022 Areas affected...portions of central Mississippi into extreme western Alabama Concerning...Severe potential...Watch possible Valid 131736Z - 131900Z Probability of Watch Issuance...40 percent SUMMARY...Some severe gust potential exists if storms should congeal ahead of a pre-existing outflow boundary. A WW issuance is possible if upscale-growing storms become apparent. DISCUSSION...Mainly elevated storms are in progress across northern MS immediately north of an outflow boundary resulting from earlier convection. This outflow boundary is in the process of stalling along a northwest to southeast oriented line from just west of STF to west of SEM. As the southward-moving convection in northern MS crosses the boundary, the storms will ingest 2000+ J/kg MLCAPE driven by surface temperatures/dewpoints above 90F/75F. Given robust surface-850 mb mixing and 7+ C/km low-level lapse rates, severe gusts may develop from the stronger storms, and a semi-organized wind threat may materialize should storms grow upscale into a convective cluster. Also, the 12Z JAN observed sounding shows mid-level lapse rates exceeding 7.5 C/km. As such, an instance or two of marginally severe hail may also occur. Both observations and model guidance suggest weak tropospheric wind fields and associated shear, so upscale growth/storm organization will be entirely dependent on cold pool mergers. As such, convective trends will be monitored through the afternoon for upscale growth for the consideration of a Severe Thunderstorm Watch issuance. ..Squitieri/Thompson.. 07/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BMX...MOB...MEG...JAN... LAT...LON 33909075 33468934 33278858 32898758 32638726 32378725 32038756 31868840 31688914 31718997 32009060 32269080 33089099 33909075 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Wed Jul 13 2022 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTH-CENTRAL U.S....AND PARTS OF THE SOUTHEAST... ...SUMMARY... A marginal wind-damage and hail threat will be possible across parts of the northern Plains and mid Missouri Valley on Thursday. A marginal wind-damage threat may also develop in parts of the Carolinas into Georgia. ...Synopsis... A large upper ridge will remain anchored over the western and central U.S., flanked by eastern Pacific and eastern U.S. troughing. A resulting/largely weak surface pattern is expected across most of the U.S., though a weak front lingering across the Southeast will help focus thunderstorms through the period. ...Northern Rockies/northern High Plains to the Upper Midwest... While a capped boundary layer across a large portion of the north-central U.S. will hinder convective development through much of the day, heating/destabilization -- particularly over the higher terrain of the northern Rockies -- will likely yield isolated storm development. Given a belt of enhanced, anticyclonic westerly/west-southwesterly flow aloft around the northern periphery of the upper ridge, storms will spread into lower elevations with time. Given the dry/deep mixed layer, locally gusty/damaging winds may occur near a few of the strongest storms. Meanwhile, convective initiation into the northern Plains/Upper Midwest is difficult to quantify areally/temporally, given the nebulous surface pattern. Development will likely be loosely tied to a short-wave disturbance moving through the anticyclonic belt of flow, especially as a low-level jet strengthens nocturnally. While limited storm coverage expected at this time should temper overall severe potential, ample west-northwesterly/northwesterly flow aloft suggests that a few clusters of southeastward-moving storms will evolve, which would likely be accompanied by some risk for locally damaging wind gusts and hail. Such risk will likely continue well into the evening, given low-level warm advection associated with the aforementioned south-southwesterly low-level jet. ...The Southeast... Diurnal heating/destabilization is expected across the Southeast in the vicinity of a weak/remnant cold front expected to extend from southeastern Virginia across the Carolinas, and westward across the central Gulf Coast states. Given the degree of destabilization, weak ascent near this boundary will result in development of scattered to numerous thunderstorms across the region. While fairly modest shear will limit storm organization, some clustering/upscale growth is expected, which could result in local instances of gusty winds, and perhaps marginal hail, with east-northeastward-moving storms. Risk should diminish through the evening, in tandem with gradual diurnal stabilization. ..Goss.. 07/13/2022 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Wed Jul 13 2022 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTH-CENTRAL U.S....AND PARTS OF THE SOUTHEAST... ...SUMMARY... A marginal wind-damage and hail threat will be possible across parts of the northern Plains and mid Missouri Valley on Thursday. A marginal wind-damage threat may also develop in parts of the Carolinas into Georgia. ...Synopsis... A large upper ridge will remain anchored over the western and central U.S., flanked by eastern Pacific and eastern U.S. troughing. A resulting/largely weak surface pattern is expected across most of the U.S., though a weak front lingering across the Southeast will help focus thunderstorms through the period. ...Northern Rockies/northern High Plains to the Upper Midwest... While a capped boundary layer across a large portion of the north-central U.S. will hinder convective development through much of the day, heating/destabilization -- particularly over the higher terrain of the northern Rockies -- will likely yield isolated storm development. Given a belt of enhanced, anticyclonic westerly/west-southwesterly flow aloft around the northern periphery of the upper ridge, storms will spread into lower elevations with time. Given the dry/deep mixed layer, locally gusty/damaging winds may occur near a few of the strongest storms. Meanwhile, convective initiation into the northern Plains/Upper Midwest is difficult to quantify areally/temporally, given the nebulous surface pattern. Development will likely be loosely tied to a short-wave disturbance moving through the anticyclonic belt of flow, especially as a low-level jet strengthens nocturnally. While limited storm coverage expected at this time should temper overall severe potential, ample west-northwesterly/northwesterly flow aloft suggests that a few clusters of southeastward-moving storms will evolve, which would likely be accompanied by some risk for locally damaging wind gusts and hail. Such risk will likely continue well into the evening, given low-level warm advection associated with the aforementioned south-southwesterly low-level jet. ...The Southeast... Diurnal heating/destabilization is expected across the Southeast in the vicinity of a weak/remnant cold front expected to extend from southeastern Virginia across the Carolinas, and westward across the central Gulf Coast states. Given the degree of destabilization, weak ascent near this boundary will result in development of scattered to numerous thunderstorms across the region. While fairly modest shear will limit storm organization, some clustering/upscale growth is expected, which could result in local instances of gusty winds, and perhaps marginal hail, with east-northeastward-moving storms. Risk should diminish through the evening, in tandem with gradual diurnal stabilization. ..Goss.. 07/13/2022 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Wed Jul 13 2022 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTH-CENTRAL U.S....AND PARTS OF THE SOUTHEAST... ...SUMMARY... A marginal wind-damage and hail threat will be possible across parts of the northern Plains and mid Missouri Valley on Thursday. A marginal wind-damage threat may also develop in parts of the Carolinas into Georgia. ...Synopsis... A large upper ridge will remain anchored over the western and central U.S., flanked by eastern Pacific and eastern U.S. troughing. A resulting/largely weak surface pattern is expected across most of the U.S., though a weak front lingering across the Southeast will help focus thunderstorms through the period. ...Northern Rockies/northern High Plains to the Upper Midwest... While a capped boundary layer across a large portion of the north-central U.S. will hinder convective development through much of the day, heating/destabilization -- particularly over the higher terrain of the northern Rockies -- will likely yield isolated storm development. Given a belt of enhanced, anticyclonic westerly/west-southwesterly flow aloft around the northern periphery of the upper ridge, storms will spread into lower elevations with time. Given the dry/deep mixed layer, locally gusty/damaging winds may occur near a few of the strongest storms. Meanwhile, convective initiation into the northern Plains/Upper Midwest is difficult to quantify areally/temporally, given the nebulous surface pattern. Development will likely be loosely tied to a short-wave disturbance moving through the anticyclonic belt of flow, especially as a low-level jet strengthens nocturnally. While limited storm coverage expected at this time should temper overall severe potential, ample west-northwesterly/northwesterly flow aloft suggests that a few clusters of southeastward-moving storms will evolve, which would likely be accompanied by some risk for locally damaging wind gusts and hail. Such risk will likely continue well into the evening, given low-level warm advection associated with the aforementioned south-southwesterly low-level jet. ...The Southeast... Diurnal heating/destabilization is expected across the Southeast in the vicinity of a weak/remnant cold front expected to extend from southeastern Virginia across the Carolinas, and westward across the central Gulf Coast states. Given the degree of destabilization, weak ascent near this boundary will result in development of scattered to numerous thunderstorms across the region. While fairly modest shear will limit storm organization, some clustering/upscale growth is expected, which could result in local instances of gusty winds, and perhaps marginal hail, with east-northeastward-moving storms. Risk should diminish through the evening, in tandem with gradual diurnal stabilization. ..Goss.. 07/13/2022 Read more

MD 1466 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF FAR SOUTHERN LOWER MI...NORTHEASTERN IN...AND NORTHERN OH
Mesoscale Discussion 1466 NWS Storm Prediction Center Norman OK 1226 PM CDT Wed Jul 13 2022 Areas affected...Portions of far southern Lower MI...northeastern IN...and northern OH Concerning...Severe potential...Watch unlikely Valid 131726Z - 132030Z Probability of Watch Issuance...5 percent SUMMARY...Isolated strong/gusty winds and marginally severe hail may occur as thunderstorms move east-southeastward this afternoon. Watch issuance is not expected. DISCUSSION...A few thunderstorms have developed this afternoon across far southern Lower MI along/near a weak surface front. This convection is occurring beneath a mid/upper-level trough. Relatively cool mid-level temperatures and daytime heating of a modestly moist low-level airmass have contributed to the development of weak instability from parts of southern Lower MI into northern IN/OH. Generally weak west-northwesterly winds at low levels gradually strengthen with height through mid levels. Around 30-35 kt of deep-layer shear should support modest updraft organization, with mainly multicells possible. Isolated instances of strong/gusty winds and marginally severe hail may occur with the more robust convection as it moves east-southeastward this afternoon. The weak instability is expected to limit the overall coverage and intensity of severe thunderstorms, and watch issuance is not expected at this time. ..Gleason/Thompson.. 07/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...CLE...ILN...DTX...IWX...GRR...IND... LAT...LON 40828634 41368601 41978520 42158474 42118358 41238069 40618078 40118223 40268539 40828634 Read more

MD 1466 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF FAR SOUTHERN LOWER MI...NORTHEASTERN IN...AND NORTHERN OH
Mesoscale Discussion 1466 NWS Storm Prediction Center Norman OK 1226 PM CDT Wed Jul 13 2022 Areas affected...Portions of far southern Lower MI...northeastern IN...and northern OH Concerning...Severe potential...Watch unlikely Valid 131726Z - 132030Z Probability of Watch Issuance...5 percent SUMMARY...Isolated strong/gusty winds and marginally severe hail may occur as thunderstorms move east-southeastward this afternoon. Watch issuance is not expected. DISCUSSION...A few thunderstorms have developed this afternoon across far southern Lower MI along/near a weak surface front. This convection is occurring beneath a mid/upper-level trough. Relatively cool mid-level temperatures and daytime heating of a modestly moist low-level airmass have contributed to the development of weak instability from parts of southern Lower MI into northern IN/OH. Generally weak west-northwesterly winds at low levels gradually strengthen with height through mid levels. Around 30-35 kt of deep-layer shear should support modest updraft organization, with mainly multicells possible. Isolated instances of strong/gusty winds and marginally severe hail may occur with the more robust convection as it moves east-southeastward this afternoon. The weak instability is expected to limit the overall coverage and intensity of severe thunderstorms, and watch issuance is not expected at this time. ..Gleason/Thompson.. 07/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...CLE...ILN...DTX...IWX...GRR...IND... LAT...LON 40828634 41368601 41978520 42158474 42118358 41238069 40618078 40118223 40268539 40828634 Read more