Severe Storms

No watches are valid as of Sun Aug 21 17:58:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Sun Aug 21 2022 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The organized severe-thunderstorm threat is expected to be low on Monday. ...Mid Atlantic/Southern New England into the Carolinas... Convection is expected across a broad region of the eastern CONUS on Monday, within a moist and generally uncapped environment east of a weakening mid/upper-level trough. 20-30 kt midlevel southwesterly flow may sporadically support some modest storm organization, but weak midlevel lapse rates and potentially widespread cloudiness should limit buoyancy and updraft intensity. A threat for locally damaging wind gusts may eventually evolve in areas where stronger heating and steepening of low-level lapse rates can occur between rounds of convection. ...Northern Plains... While low-level moisture will remain relatively limited, diurnal heating will support weak to locally moderate destabilization across parts of the northern Great Plains Monday afternoon. Development and coverage of surface-based storms remain uncertain, and could be tied to convectively enhanced vorticity maxima emanating out of the northern Rockies. If surface-based storms develop, modest deep-layer shear within the weak northwesterly flow regime could support a couple stronger cells or clusters, though the severity of any such development remains uncertain and could be relatively limited. ...TX into LA/southern MS... Widespread convection is expected on Monday across much of TX into the ArkLaMiss region, as a low-amplitude mid/upper-level trough slowly traverses a very moist environment. The organized severe threat appears limited within this regime, due to weak midlevel lapse rates and deep-layer shear, with heavy rain expected to be the primary concern. However, isolated wet microbursts and/or outflow-driven clusters may produce localized gusty winds, especially from central TX into parts of the Rio Grande Valley, where somewhat stronger heating/destabilization may occur prior to storm arrival. ..Dean.. 08/21/2022 Read more

MD 1707 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF MID/UPPER OHIO VALLEY
Mesoscale Discussion 1707 NWS Storm Prediction Center Norman OK 1158 AM CDT Sun Aug 21 2022 Areas affected...Portions of mid/upper Ohio Valley Concerning...Severe potential...Watch unlikely Valid 211658Z - 211830Z Probability of Watch Issuance...20 percent SUMMARY...Storm coverage and intensity will increase gradually this afternoon. Isolated damaging winds and marginally severe hail (in the strongest storms) are the primary hazards. Convective trends will be monitored, but a watch is not currently anticipated this afternoon. DISCUSSION...Cloud breaks within the region have allowed a few thunderstorms to develop ahead of the cold front within a weakly capped environment. The front itself remains farther to the west near the IN/OH border. Continued heating within broken cloud cover will continue to promote greater boundary layer destabilization where around 1500 J/kg MLCAPE may continue to build northeastward into parts of eastern Ohio. Additional storms are likely to develop this afternoon given the upper-level support from the shortwave trough. Effective shear is modest 25-30 kts and will support multicell storms with perhaps isolated, marginal supercells storms. These storms will primarily pose a threat for damaging wind gusts, though the strongest storms could produce marginally severe hail given cold temperatures aloft. Some guidance shows other development occurring along the cold front later in the afternoon. The intensity of this activity is more uncertain as it will be impacted by convection that is occurring currently. The coverage of severe-caliber storms is the greatest source of uncertainty. Whether or not a watch is necessary will depend on convective trends regarding storm coverage and intensity this afternoon. At present, a watch is not anticipated. ..Wendt/Kerr.. 08/21/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK... LAT...LON 38548495 40278388 40818276 40848116 40498072 39588064 38308213 38098274 37908441 38118502 38548495 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Sun Aug 21 2022 Valid 211700Z - 221200Z There are no changes to the outlook. In addition to the fire-weather concerns described below, scattered diurnally driven thunderstorms are expected over the northern Rockies this afternoon into the evening where fuels are critically dry. While isolated ignitions will be possible away from the heavier precipitation, 0.75-1.0+ inch PW (sampled by regional 12z soundings/GOES-16 derived PW) and slow storm motions will favor a mixed wet-dry to wet storm mode -- precluding Dry Thunderstorm highlights. ..Weinman.. 08/21/2022 .PREV DISCUSSION... /ISSUED 0152 AM CDT Sun Aug 21 2022/ ...Synopsis... Upper ridging will be in place across the western U.S. as broad cyclonic flow aloft envelops the eastern two-thirds of the CONUS today. By evening, a pronounced mid-level trough will impinge on the Pacific Northwest and lift a monsoonal airmass across Oregon, fostering isolated high-based thunderstorm development. While some of the storms will be slow moving, enough potential exists for strikes to occur away from storm cores into dry fuel beds, warranting the continuation of isolated dry thunderstorm highlights. ...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 1128 AM CDT Sun Aug 21 2022 Valid 211700Z - 221200Z There are no changes to the outlook. In addition to the fire-weather concerns described below, scattered diurnally driven thunderstorms are expected over the northern Rockies this afternoon into the evening where fuels are critically dry. While isolated ignitions will be possible away from the heavier precipitation, 0.75-1.0+ inch PW (sampled by regional 12z soundings/GOES-16 derived PW) and slow storm motions will favor a mixed wet-dry to wet storm mode -- precluding Dry Thunderstorm highlights. ..Weinman.. 08/21/2022 .PREV DISCUSSION... /ISSUED 0152 AM CDT Sun Aug 21 2022/ ...Synopsis... Upper ridging will be in place across the western U.S. as broad cyclonic flow aloft envelops the eastern two-thirds of the CONUS today. By evening, a pronounced mid-level trough will impinge on the Pacific Northwest and lift a monsoonal airmass across Oregon, fostering isolated high-based thunderstorm development. While some of the storms will be slow moving, enough potential exists for strikes to occur away from storm cores into dry fuel beds, warranting the continuation of isolated dry thunderstorm highlights. ...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 1120 AM CDT Sun Aug 21 2022 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS PARTS OF THE OHIO VALLEY... ...SUMMARY... Isolated strong to briefly severe thunderstorms are expected this afternoon, mainly across parts of the Ohio and Tennessee River Valleys. ...Synopsis... Mid/upper ridging remains generally suppressed across the southern mid- and subtropical latitudes of the eastern Pacific into parts of the Southwest, and across the northern Mexican Plateau and Gulf Basin into the Atlantic. Much of the U.S. will remain under the influence of a weak branch of westerlies, well downstream of large, deep troughing centered over the mid-latitude Pacific, roughly between 140-170 W. This regime includes mean ridging across the Pacific coast into the Rockies, with an embedded short wave trough approaching the Pacific Northwest coast. Downstream, broad mean troughing prevails east of the Rockies, with the most substantive embedded short wave troughing forecast to continue slowly digging east-southeast of the mid/upper Mississippi Valley toward the Appalachians. Another weaker perturbation likely will very slowly progress across the southern Great Plains. Milder and, particularly, drier air has already infiltrated much of the northern Great Plains into Upper Midwest, and will gradually overspread much of the Ohio Valley, while a similar environment remains entrenched across much of New England. Seasonably high moisture content will continue to gradually become increasingly confined to parts of the Southwest, and Gulf into southern and mid Atlantic Coast states, by the end of the period. ...East of the Rockies... The lingering seasonably moist air, coupled with weak mid-level inhibition and large-scale forcing for ascent, is already contributing to considerable pre-frontal thunderstorm development across parts of the southern Great Plains into the Ohio Valley, lower Great Lakes region and Mid Atlantic. This will continue, with a further increase in storm coverage with boundary-layer heating through late afternoon. While the remnants of elevated mixed-layer air might enhance potential for localized downbursts across parts of north central and northeastern Texas by late afternoon, lower/mid tropospheric lapse rates across most areas are generally weak. Deep-layer mean flow and shear is also rather weak, but heavy precipitation loading and downward mixing of 20-30 kt southwesterly to westerly flow in the 850-500 mb layer, to the south and east of the digging short wave trough, might be enough to contribute to locally damaging downbursts in stronger storms, mainly across parts of the Ohio Valley. ...Southwest... Boundary-layer heating and mixing are forecast to remain somewhat modest for the time of year, with the stronger heating and deeper mixing mostly confined to the lower Colorado Valley. However, this may be sufficient, given the relatively moist conditions, to support sizable CAPE by late this afternoon. Aided by 10-20 kt northerly mid-level flow, if thunderstorms can cluster/consolidate sufficiently along the Rim late this afternoon, there appears to be potential for convection to gradually propagate off the higher terrain (and particularly toward the Colorado Valley) accompanied by a risk for strong surface gusts into this evening. ..Kerr/Wendt.. 08/21/2022 Read more

No watches are valid as of Sat Aug 20 17:54:01 UTC 2022.

MD 1703 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEASTERN IOWA INTO WEST CENTRAL/CENTRAL ILLINOIS
Mesoscale Discussion 1703 NWS Storm Prediction Center Norman OK 1251 PM CDT Sat Aug 20 2022 Areas affected...southeastern Iowa into west central/central Illinois Concerning...Severe potential...Watch possible Valid 201751Z - 202015Z Probability of Watch Issuance...40 percent SUMMARY...Widely scattered strong storms appear likely to develop through late afternoon and may pose a risk for primarily marginally severe hail and locally damaging surface gusts. It is not certain that a severe weather watch will be needed, but trends will continue to be monitored. DISCUSSION...Moderately large mixed-layer CAPE (in excess of 1000 J/kg) appears to be developing to the south-southeast of a broad, weak surface cyclone centered over east central Iowa. This is occurring beneath a residual pocket of colder mid-level air, in the wake of one short wave impulse pivoting northeastward into southwestern portions of the Great Lakes region and ahead of a trailing impulse digging across Iowa. Southwesterly to west-southwesterly flow in the 850-500 mb layer across the destabilizing environment is on the order of 20-30+ kt, and may still be marginally sufficient to support occasional supercell structures. Scattered thunderstorm development is already underway, and a gradual further increase and intensification of storms seems probable through the remainder of the afternoon, in response to additional daytime heating and large-scale forcing for ascent. Ambient vertical vorticity near and within a corridor south-southeast of the surface low might contribute to some risk for a brief, weak tornado in stronger cells. However, low-level hodographs are generally small, and the more prominent potential convective hazards appear to be marginally severe hail and locally strong surface gusts. ..Kerr/Bunting.. 08/20/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...LSX...DVN... LAT...LON 39859109 40989151 41899108 41728963 40288765 39478820 39188905 39199065 39859109 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Sat Aug 20 2022 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER AND MIDDLE OHIO VALLEY... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday across parts of the mid and upper Ohio Valley. ...Synopsis... A closed upper low will continue to move eastward and become more of an open wave Saturday into Sunday. This trough is expected to undergo some weakening through the day on Sunday. A weak surface low may develop in central/eastern Ohio by late afternoon/evening. A cold front will continue to push eastward through the Ohio and parts of the Tennessee Valleys. ...Ohio Valley... Cloud cover is expected to be prevalent across the region. Despite these clouds, cold temperatures aloft and perhaps some areas of muted surface heating will support in the neighborhood of 1000-1500 J/kg MLCAPE. Locally higher buoyancy is possible into Kentucky/Tennessee where cloud cover will probably be less widespread. By afternoon widely scattered to scattered storms are expected to develop along and ahead of the cold front. Effective shear of 20-25 kts farther north to near 30 kts south (nearly perpendicular to the front) will support marginally organized multicell and isolated supercell storms. Strong/damaging wind gusts will be the primary hazard. Given the weak surface low, surface winds may be backed in parts of eastern/southern Ohio. There, a conditional threat for a brief tornado will exist. ...Arizona... Numerous storms are again expected on Sunday. Some guidance does suggest that a cluster of storms will develop along the Mogollon Rim and move off the terrain to the south/southwest. However, given the high PWAT values and potential for cloud cover, low-level lapse rates may not become overly steep. If greater heating can occur by tomorrow afternoon, low-end wind probabilities may become warranted. ..Wendt.. 08/20/2022 Read more

MD 1702 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN IN INTO WESTERN OH
Mesoscale Discussion 1702 NWS Storm Prediction Center Norman OK 1225 PM CDT Sat Aug 20 2022 Areas affected...Eastern IN into western OH Concerning...Severe potential...Watch possible Valid 201725Z - 201930Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorms capable of damaging wind gusts and possibly some hail will increase this afternoon. Watch issuance is possible. DISCUSSION...A storm cluster over northeast IN has shown some intensification early this afternoon, and this trend may continue as storms move into a destabilizing environment across western OH, where diurnal heating of a moist environment is supporting MLCAPE of 1500-2000 J/kg. Modest southwesterly midlevel flow along the eastern flank of the deep-layer cyclone across eastern IA is supporting 20-30 kt of effective shear, which will support the potential for semi-organized multicell clusters through the afternoon. Locally damaging wind gusts will likely be the primary threat, especially as low-level lapse rates steepen downstream this afternoon. Weak midlevel lapse rates and only modest deep-layer shear should temper the hail threat to some extent, though with seasonably cool temperatures aloft, some isolated hail will also be possible. Watch issuance is possible this afternoon in response to these threats, depending on observational trends with the developing storm cluster and downstream destabilization. ..Dean/Bunting.. 08/20/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...IWX...IND... LAT...LON 40418517 41308487 41668381 41488282 40908269 39828340 39458401 39778486 39978503 40418517 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1134 AM CDT Sat Aug 20 2022 Valid 201700Z - 211200Z ...NO CRITICAL AREAS... The forecast remains on track, and no changes were made with this update. For details, see the previous discussion below. ..Weinman.. 08/20/2022 .PREV DISCUSSION... /ISSUED 1218 AM CDT Sat Aug 20 2022/ ...Synopsis... A mid-upper-level trough will move east slowly across the Great Lakes and Ohio Valley and the western ridge will continue to build north into southwest Canada. Much of the contiguous United States will be seasonably cool, moist, or both. Additionally, absent any strong mid-upper-level height gradients or surface-pressure gradients, large-scale winds will remain generally light. Thunderstorms are likely atop dry fuels in Idaho and Montana, but overall high coverage and sufficiently moist precipitable water values should support wetting rains. Thus, large-scale fire weather concerns should be minimal on Saturday. ...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 1132 AM CDT Sat Aug 20 2022 Valid 201630Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF CENTRAL ILLINOIS AND FROM SOUTHEAST INDIANA ACROSS WESTERN OHIO... ...SUMMARY... Scattered severe storms with damaging winds and large hail will be possible this afternoon and evening across central Illinois and from eastern Indiana into western Ohio. ..Midwest/Ohio Valley/Ozarks... A weak surface low over central IA will move slowly southeast through tonight as an associated cold front also moves east, extending from west-central IL into central MO and southern KS by 00z. Despite ongoing precipitation/cloud cover over portions of IL/IN, pockets of more substantial destabilization are expected by afternoon, especially from southern/eastern IN into southwest OH where slightly higher boundary layer moisture exists and stronger heating is expected. With minimal CINH by early/mid afternoon, more concentrated thunderstorm development or re-intensification is expected near the cold front/upper low across eastern IA/central IL, with a second area over eastern IN/western OH. Elsewhere, more isolated strong/severe storms will be possible within the Marginal Risk area near and in advance of the front with severe winds the primary hazard. Southwesterly mid-level flow will contribute to effective shear ranging from 30-35 kts this afternoon which will support multicells and a few transient supercell structures. Damaging winds will be the primary severe hazard, with instances of large hail also possible primarily over eastern IA/central IL where cooler mid-level temperatures will exist. Some potential for low-level rotation may exist with supercell structures east of the surface low this afternoon, and have retained the low tornado probabilities in this area. ...South Texas... A low over the western Gulf of Mexico is expected to move northwestward toward Deep South Texas. Refer to the latest National Hurricane Center advisory for additional forecast details regarding Potential Tropical Cyclone Four. While a modest strengthening of southeasterly low-level winds may occur, present indications are that the low/mid-level wind field will likely remain sufficiently weak to preclude a tornado risk. ..Bunting/Dean.. 08/20/2022 Read more

No watches are valid as of Fri Aug 19 18:03:01 UTC 2022.

No Mesoscale Discussions are in effect as of Fri Aug 19 18:03:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1202 PM CDT Fri Aug 19 2022 Valid 201200Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OZARKS INTO THE MID MISSISSIPPI VALLEY...MIDWEST/OHIO VALLEY...AND GREAT LAKES...... ...SUMMARY... Isolated strong to severe thunderstorms may occur Saturday across parts of the Ozarks into the mid Mississippi Valley, Midwest/Ohio Valley, and Great Lakes. Occasional damaging winds and marginally severe hail should be the main threats. ...Ozarks...Mid-MS and OH Valleys...Great Lakes... An upper low/trough will migrate east across the Midwest/Great Lakes vicinity on Saturday. Deep-layer west/southwesterly flow associated with this system will remain moderate, with around 25-40 kt midlevel flow forecast. At the surface, a weak low over eastern IA Saturday morning will drift east/southeast across northern IL. Meanwhile, a cold front will develop east/southeast across IL/MO/KS/OK. A seasonally moist boundary-layer will exist ahead of the surface low/cold front with dewpoints in the mid 60s likely. Midlevel lapse rates are forecast to remain modest (around 6.5 C/km), but pockets of stronger heating of the moist boundary-layer will contribute to MLCAPE values around 1000-2000 J/kg. Effective shear magnitudes to around 35 kt will result in at least transient supercells and briefly organized clusters. Some consideration was given to an upgrade to a Slight risk across parts of MO/IL. However, uncertainty due to possible morning convection and cloud cover, along with decreasing large-scale ascent with southward extent will preclude an upgrade at this time. Isolated strong to severe gusts and hail will be the main concern with this activity as bands and clusters of storms shift east through the evening. ..Leitman.. 08/19/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Fri Aug 19 2022 Valid 191700Z - 201200Z The forecast remains on track, and no changes were made with this update. See the previous discussion below for details. ..Weinman.. 08/19/2022 .PREV DISCUSSION... /ISSUED 0141 AM CDT Fri Aug 19 2022/ ...Synopsis... An upper-level shortwave trough evident on water vapor imagery this morning near the California-Oregon-Nevada border is forecast to shift slowly eastward and weaken throughout the day. Concurrently, an axis of monsoonal moisture (PW values around 1") extending northward from Arizona will also shift eastward into western Utah and southern Idaho. Consequently, clouds and precipitation are likely early in the day along this axis. On the northeastern periphery of this moisture axis across portions of central Idaho and southwestern Montana, sufficient heating and destabilization will likely lead to scattered thunderstorm development in the afternoon over the higher terrain. Despite borderline environmental characteristics for dry thunderstorms (i.e., PW values around 0.75" and surface RH values around 30%), numerous CG lightning flashes are expected over dry fuels with limited rainfall accumulation expected outside of thunderstorm cores. Thus, an isolated dry thunderstorm area has been delineated to highlight this fire-weather concern. ...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 1122 AM CDT Fri Aug 19 2022 Valid 191630Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SOUTHEAST IA...NORTHERN MO...AND FAR NORTHWEST IL... ...SUMMARY... The most favorable area for isolated to perhaps scattered severe hail and wind is across parts of southern/eastern Iowa, northern Missouri, and far northwest Illinois from late afternoon through mid-evening. ...IA/MO/IL vicinity... To the south and southeast of a vertically stacked low over southwest MN, pockets of greater boundary-layer heating are evident across parts of IA into MO and IL. Amid cool mid-level temperatures around -12 C at 500 mb, moderate buoyancy with MLCAPE of 1000-2000 J/kg should become common by late afternoon. A scattering of thunderstorms is expected during this time frame into the evening, focused along the primary surface cold front and confluence bands ahead of it. While stronger deep-layer shear will be found in the southwest quadrant of the broader cyclone, a swath of moderate mid-level westerlies should extend east towards the IA/MO/IL border area yielding effective bulk shear of 25-35 kts. This area should be most favored for a few lower-end supercells and small multicell clusters mainly producing isolated severe hail and damaging wind until convection wanes later this evening. ...KS... In the wake of ongoing elevated convection, a corridor of destabilization is expected near and behind the surface cold front drifting south from southern NE/northwest KS. Buoyancy will remain limited and mid-level lapse rates were relatively modest in upstream 12Z soundings from North Platte and Rapid City. Nevertheless, the presence of 30-40 kt mid-level west-northwesterlies to the southwest of the vertically stacked low in southern MN will support a threat for a few cells producing isolated severe hail and wind during the late afternoon to early evening. ...Eastern GA/coastal Carolinas... Generally stratiform rain with isolated deeper convection has been slowly drifting east over southern NC and far eastern SC. This has convectively reinforced a weak baroclinic zone across the region with a 1017-mb mesolow over eastern SC. This minor cyclone should drift north towards central NC through tonight. A rather localized corridor of enhanced low-level SRH near the track of this low conditionally supports a threat for a brief tornado. Otherwise, locally damaging winds will be possible with scattered multicell clusters that emanate out of GA later this afternoon. ...Central/western AZ... A few strong storms with locally gusty winds may materialize during the late afternoon and early evening across the region within a very moist air mass. Potential for organized severe storms appears limited owing to weak deep-layer shear/mid-level lapse rates. ..Grams/Wendt.. 08/19/2022 Read more

No watches are valid as of Thu Aug 18 18:01:01 UTC 2022.

No Mesoscale Discussions are in effect as of Thu Aug 18 18:01:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1157 AM CDT Thu Aug 18 2022 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL PLAINS INTO THE UPPER MIDWEST...AND ACROSS PARTS OF GEORGIA AND SOUTH CAROLINA... ...SUMMARY... Isolated severe thunderstorms appear possible Friday across parts of the central Plains into the Upper Midwest. Occasional hail and damaging winds should be the main threats. Sporadic strong gusts also may accompany thunderstorms across parts of Georgia and South Carolina Friday afternoon. ...KS/MO/IA... A mid/upper level low/trough will develop east/southeast across the Upper Midwest on Friday. 25-40 kt mid/upper level northwesterly flow will overspread portions of the northern/central Plains into the lower MO Valley and Upper Midwest. At the surface, weak low pressure will meander east/southeast across the southern MN/IA vicinity. A cold front will extend southwest from the low and slowly shift east across the central Plains to the lower MO Valley. Modest boundary-layer moisture will be in place ahead of the front as afternoon temperatures climb into the 80s. Midlevel lapse rates around 7 C/km above the modest boundary-layer moisture will contribute to moderate instability (1000-2000 J/kg MLCAPE). Effective shear magnitudes around 25-35 kt will support some organized multicell clusters and transient supercells. Isolated strong to severe gusts and marginally severe hail will be possible with the strongest cells during the afternoon and evening. ...GA/SC... Deep-layer flow will remain modest across the region, on the southern periphery of the eastern U.S. upper trough. However, some weak speed shear and 25-35 kt midlevel flow will result in marginal effective shear magnitudes around 25 kt. This may support some transient/briefly organized multicell clusters in the vicinity of a weak surface low and stationary front draped across central GA into SC. Midlevel lapse rates will remain poor, but surface dewpoints in the 70s will contribute to MLCAPE as high as 1500 J/kg. Low-level flow will remain weak, generally less than 10-15 kt through 1 km. However, steepening low-level lapse rates and PW values near 2 inches will support water-loaded downdrafts capable of sporadic strong gusts and wind damage through the afternoon. ..Leitman.. 08/18/2022 Read more