Severe Storms

WW 0691 Status Updates
STATUS REPORT ON WW 691 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SUPINIE..09/23/23 ATTN...WFO...DMX...ARX... STATUS REPORT FOR WS 691 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC001-009-013-015-017-023-025-027-029-033-037-049-063-067-069- 073-075-077-079-081-083-091-099-109-121-123-125-127-147-151-153- 157-161-169-171-181-187-189-195-197-232340- IA . IOWA COUNTIES INCLUDED ARE ADAIR AUDUBON BLACK HAWK BOONE BREMER BUTLER CALHOUN CARROLL CASS CERRO GORDO CHICKASAW DALLAS EMMET FLOYD FRANKLIN GREENE GRUNDY GUTHRIE HAMILTON HANCOCK HARDIN HUMBOLDT JASPER KOSSUTH MADISON MAHASKA MARION MARSHALL PALO ALTO POCAHONTAS POLK POWESHIEK SAC STORY TAMA WARREN WEBSTER WINNEBAGO WORTH WRIGHT 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 691 SEVERE TSTM IA 231835Z - 240300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 691 NWS Storm Prediction Center Norman OK 135 PM CDT Sat Sep 23 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Iowa * Effective this Saturday afternoon and evening from 135 PM until 1000 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Initially, a cluster of storms across north-central Iowa may produce large hail and/or locally damaging winds. Additional storms are expected to across the region later this afternoon into evening. The severe thunderstorm watch area is approximately along and 65 statute miles east and west of a line from 30 miles northwest of Mason City IA to 25 miles south of Des Moines IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 690... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Guyer Read more

WW 0690 Status Updates
STATUS REPORT ON WW 690 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SUPINIE..09/23/23 ATTN...WFO...EAX...SGF... STATUS REPORT FOR WS 690 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC091-103-107-121-209-232340- KS . KANSAS COUNTIES INCLUDED ARE JOHNSON LEAVENWORTH LINN MIAMI WYANDOTTE MOC013-015-025-033-037-041-047-053-061-083-089-095-101-107-115- 117-141-159-165-177-185-195-232340- MO . MISSOURI COUNTIES INCLUDED ARE BATES BENTON CALDWELL CARROLL CASS CHARITON CLAY COOPER DAVIESS HENRY HOWARD JACKSON JOHNSON LAFAYETTE LINN LIVINGSTON MORGAN PETTIS PLATTE RAY ST. CLAIR SALINE THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE Read more

WW 690 SEVERE TSTM KS MO 231800Z - 240200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 690 NWS Storm Prediction Center Norman OK 100 PM CDT Sat Sep 23 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Kansas Western and Central Missouri * Effective this Saturday afternoon and evening from 100 PM until 900 PM CDT. * Primary threats include... Scattered large hail likely with isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 65 mph possible A tornado or two possible SUMMARY...Scattered strong to severe thunderstorms may produce large hail and locally damaging winds this afternoon, with a secondary round of storms expected across the region later this afternoon into evening, which will likely include additional storm development to the west of the early afternoon storms. The severe thunderstorm watch area is approximately along and 55 statute miles east and west of a line from 10 miles northeast of Chillicothe MO to 55 miles south southeast of Olathe KS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 25025. ...Guyer Read more

MD 2187 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEAST NEBRASKA INTO SOUTHERN IOWA AND FAR NORTHWEST MISSOURI
Mesoscale Discussion 2187 NWS Storm Prediction Center Norman OK 0458 PM CDT Sat Sep 23 2023 Areas affected...Southeast Nebraska into southern Iowa and far northwest Missouri Concerning...Severe potential...Watch possible Valid 232158Z - 240000Z Probability of Watch Issuance...60 percent SUMMARY...Developing thunderstorms across southeast Nebraska will likely intensify over the coming hours, and will pose a risk for large hail and severe wind. Watch issuance may be needed to address this threat. DISCUSSION...Over the past 30-60 minutes, a cluster of cumulus has shown steady deepening on the intersection of the cold front and a subtle surface trough. A few deeper towers are noted in IR and low-level water-vapor imagery, which suggests convective initiation is probable within the next hour or so. 50-60 knot winds between 6-8 km AGL is supporting elongated hodographs with effective bulk shear values between 40-50 knots. This kinematic environment should support organized convection, including the potential for splitting supercells (though the propensity for splitting cells is somewhat uncertain given strong ascent along the front, which may foster somewhat quick upscale growth). The thermodynamic environment immediately downstream is becoming increasingly supportive for robust convection as surface temperatures warm into the upper 70s; however, cooler temperatures further east into southern IA/northern MO in the wake of prior convection cast some uncertainty onto the downstream intensity. Regardless, the severe threat is expected to increase in the coming hours across southeast NE into adjacent areas of IA and MO, and watch issuance is probable. ..Moore/Thompson.. 09/23/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DMX...EAX...OAX...TOP... LAT...LON 39999703 40469708 40859715 41009717 41989565 41979514 41689476 41019438 40309443 39939501 39779624 39759669 39999703 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0407 PM CDT Sat Sep 23 2023 Valid 251200Z - 011200Z A deepening trough across the western US will result in amplification of an eastward shifting ridge across the central/eastern US early next week. Cooler conditions, increasing relative humidity, and potential for widespread wetting rainfall is expected across much of the Pacific Northwest. Windy and dry conditions will be possible across the Great Basin and Northern Rockies, where little to no rainfall is expected. Beyond mid-week, breezy conditions may continue as persistent troughing brings waves of stronger mid-level flow across the west. ...Great Basin/Northern Rockies... An increase in south to southwest winds is expected for D3 - Monday across the Great Basin in response to increasing mid-level flow overspreading the region. Afternoon relative humidity reductions to 15-20 percent will overlap sustained winds 15-20 mph across northern Nevada, southeastward Oregon, and southwestern Idaho. Marginal fuels within this region will preclude the need to include Critical probabilities, though Elevated fire weather conditions are likely as further drying of fuels occurs with forecast strong winds. Lingering dry conditions will be possible on D4 - Tuesday, but winds will be much lighter mitigating the fire weather risk. For the extended period, models suggest continued troughing across the west will bring cool and wet conditions across the Pacific Northwest into Great Basin and the Northern Rockies. Further drying will be likely across the southwest, with potential for breezy conditions. Overall, confidence is low in where any dry/breezy conditions will overlap receptive fuels along with potential for wetting rainfall. ..Thornton.. 09/23/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Sat Sep 23 2023 Valid 232000Z - 241200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN KANSAS...NORTHEASTERN OKLAHOMA...WESTERN MISSOURI...EXTREME NORTHWESTERN ARKANSAS... ...SUMMARY... Large to very large hail, wind damage and a few tornadoes remain possible today across parts of the Upper Midwest, Lower Missouri Valley to the southern Plains. A tornado or two may also occur in parts of the coastal Mid-Atlantic. ...20Z Update... The main change made to this outlook was to trim southern portions of severe probabilities across the Mid Atlantic in tandem with the passage of Ophelia. Some uncertainty remains pertaining to the details of convective evolution across portions of the Upper Midwest, hence no changes have been made to the outlook. Though storms have reduced instability some across the MS Valley, enough heating is underway which could modify the airmass enough to support a few additional strong to severe storms. Otherwise, the rest of the forecast remains on track, with additional supercells likely to develop across southeastern KS into eastern OK and western MO with a threat for severe gusts and very large hail. A few tornadoes also remain possible, especially over far eastern SD into southern MN, where backed low-level flow supports enlarged hodographs. ..Squitieri.. 09/23/2023 .PREV DISCUSSION... /ISSUED 1139 AM CDT Sat Sep 23 2023/ ...Upper Midwest/Lower Missouri Valley/Southern Plains... A cluster of storms with history of periodic large hail/severe-caliber wind gusts this morning across eastern Nebraska persists into western Iowa at midday, while generally trending downscale and a bit weaker. These storms seem likely to outpace the primary reservoir of buoyancy with greater early-day inhibition with eastward extent, but some short-term severe risk may nonetheless continue. This convection casts some uncertainty regarding the northward extent of more appreciable surface-based destabilization later today, but strong/potentially severe thunderstorm redevelopment is still expected later this afternoon near the surface wind shift/occluded front. This would primarily be the case beginning around mid/late afternoon, coincident with the approach of the upper vort/speed max over South Dakota/northern Nebraska/northwest Iowa vicinity. At least a modest corridor of severe-conducive instability may materialize especially across northwest Missouri/west-central Iowa and southwest/south-central Minnesota. Supercell-favorable hodographs will reside across much of the region, with the potential for large hail, damaging winds, and possibly tornadoes, particularly if more cloud breaks/destabilization occurs in proximity to the surface low/triple point. Farther south, another corridor of persistent convection since mid-morning has been across far eastern Kansas into northwest/western Missouri. These storms have occasionally produced severe hail, and this may continue for a time this afternoon even as warm advection/850 mb convergence weakens. The primary scenario is otherwise expected to near-frontal deep convective development late this afternoon into evening, with a moderate to strongly unstable environment, particularly to the southwest of the eastern Kansas/northwest Missouri early day storms. Steep lapse rates/ample buoyancy and enlarged hodographs will support initial supercell potential, capable of very large/damaging hail, severe wind gusts and possibly some tornado risk, with storms tending to grow upscale during the evening. CAPE will lessen somewhat with southwestward extent into north-central/northwest Texas where greater boundary-layer mixing and lesser dewpoints will be found, but with greater DCAPE and downdraft-acceleration potential in support of local wind threat. ...Mid-Atlantic States/Tidewater... Currently centered over northeast North Carolina, Tropical Storm Ophelia is expected to continue to weaken as it generally moves north-northeastward through tonight. Reference the National Hurricane Center for latest details. Even while the system will gradually weaken, some tornado risk will focus along coastal areas of southeast Virginia toward the Delmarva today, and possibly eventually as far north as New Jersey. Any such potential is expected to generally relate to convection that can deepen/sustain and pivot toward the coast, especially if it interacts with the warm front where low-level/deep-layer shear will be maximized with surface-rooted buoyancy. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Sat Sep 23 2023 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... No changes are needed to the current D2 Fire Weather Outlook. See previous discussion below. ..Thornton.. 09/23/2023 .PREV DISCUSSION... /ISSUED 0155 AM CDT Sat Sep 23 2023/ ...Synopsis... Fire weather concerns will remain limited for Sunday. The upper wave currently over WY is forecast to deamplify as it shifts east/northeast into the Great Lakes region. In its wake, upper ridging will become established over the central CONUS, resulting in a muted surface pressure regime with generally weak winds. Two exceptions will be the northern Plains and across the western Great Basin. Over the Dakotas, 15-20 mph gradient winds in the vicinity of the weakening surface low are likely, but cool, post-frontal temperatures will limit RH reductions. Across the western Great Basin, a deepening surface low over the northeast Pacific, juxtaposed with a building surface high over the central Rockies, will strengthen low to mid-level flow. 15-25 mph downslope winds are possible in the lee of the Sierra Nevada, and may overlap with areas of 20-25% RH; however, latest fuel analyses indicate fuels are currently not receptive across this region. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0689 Status Updates
STATUS REPORT ON WW 689 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2176 ..MOORE..09/22/23 ATTN...WFO...CYS...LBF...UNR... STATUS REPORT FOR WS 689 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC007-013-033-045-069-105-123-157-161-165-222340- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER BOX BUTTE CHEYENNE DAWES GARDEN KIMBALL MORRILL SCOTTS BLUFF SHERIDAN SIOUX SDC033-047-102-222340- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE CUSTER FALL RIVER OGLALA LAKOTA WYC005-009-011-015-027-045-222340- WY . WYOMING COUNTIES INCLUDED ARE Read more

WW 0689 Status Updates
STATUS REPORT ON WW 689 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2176 ..MOORE..09/22/23 ATTN...WFO...CYS...LBF...UNR... STATUS REPORT FOR WS 689 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC007-013-033-045-069-105-123-157-161-165-222340- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER BOX BUTTE CHEYENNE DAWES GARDEN KIMBALL MORRILL SCOTTS BLUFF SHERIDAN SIOUX SDC033-047-102-222340- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE CUSTER FALL RIVER OGLALA LAKOTA WYC005-009-011-015-027-045-222340- WY . WYOMING COUNTIES INCLUDED ARE Read more

WW 689 SEVERE TSTM NE SD WY 221935Z - 230300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 689 NWS Storm Prediction Center Norman OK 135 PM MDT Fri Sep 22 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Nebraska Southwest South Dakota Eastern Wyoming * Effective this Friday afternoon and evening from 135 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Isolated severe thunderstorms including some supercells are expected to develop through mid/late afternoon and spread east-northeastward across the region through early evening. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 35 miles east northeast of Gillette WY to 55 miles south southeast of Scottsbluff NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 24025. ...Guyer Read more

WW 689 SEVERE TSTM NE SD WY 221935Z - 230300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 689 NWS Storm Prediction Center Norman OK 135 PM MDT Fri Sep 22 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Nebraska Southwest South Dakota Eastern Wyoming * Effective this Friday afternoon and evening from 135 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Isolated severe thunderstorms including some supercells are expected to develop through mid/late afternoon and spread east-northeastward across the region through early evening. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 35 miles east northeast of Gillette WY to 55 miles south southeast of Scottsbluff NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 24025. ...Guyer Read more

MD 2176 CONCERNING SEVERE THUNDERSTORM WATCH 689... FOR SOUTHEAST WYOMING INTO THE NEBRASKA PANHANDLE
Mesoscale Discussion 2176 NWS Storm Prediction Center Norman OK 0526 PM CDT Fri Sep 22 2023 Areas affected...Southeast Wyoming into the Nebraska Panhandle Concerning...Severe Thunderstorm Watch 689... Valid 222226Z - 230030Z The severe weather threat for Severe Thunderstorm Watch 689 continues. SUMMARY...The severe risk continues across WW 689, with the greatest near-term severe risk downstream of a supercell across the northwestern Nebraska Panhandle and perhaps across far the far southwestern Nebraska Panhandle. Large to very large hail will be the primary threat. DISCUSSION...Over the past hour, a pair of supercells have matured across the NE Panhandle with multiple reports of 1-2.5 inch hail. Elongated hodographs across the region remain very favorable for supercell maintenance with effective bulk shear values upwards of 50 knots. However, the recent demise of the supercell over the southern NE Panhandle, coupled with several failed attempts at additional convective initiation over southeast WY, hints that thermodynamics are a modulating factor in this environment. The expectation over the next 1-2 hours is for the greatest severe risk to reside downstream of the supercell over the northwestern NE Panhandle where ascent along a subtle surface confluence axis will likely compensate for diminishing downstream buoyancy. Given the favorable wind profiles and steep mid-level lapse rates, large to very large hail should be the primary concern. Elsewhere across WW 689, signs of upstream ascent in regional reflectivity trends, persistent agitated cumulus clusters, and several recent attempts at convective initiation all suggest that additional storm development is possible. Recent GOES imagery shows the deepest cumulus/ the most robust CI attempts are occurring across far southeast WY and the far southwestern NE Panhandle where low-level convergence is regionally maximized. Hence, the severe threat may be locally higher downstream of this cumulus cluster over the next 1-2 hours if a supercell can become established. However, the probability of surface-based CI occurring may begin to wane beyond the next couple of hours with the onset of nocturnal cooling shortly after sunset. ..Moore.. 09/22/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...UNR...BOU...CYS... LAT...LON 40790253 40840345 41530460 42710525 43290581 43580570 43660540 43110386 42400273 41800228 41440210 41010213 40840228 40790253 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0402 PM CDT Fri Sep 22 2023 Valid 241200Z - 301200Z Shortwave ridging over the western US will quickly breakdown ahead of a Pacific trough moving onshore late this weekend into early next week. As the upper ridge breaks down and strong flow aloft moves overhead, localized dry and breezy conditions are possible across parts of the Northwest, Great Basin, and Rockies. By mid week next week, rain chances are forecast to increase limiting fire-weather concerns over much of the Northwest. Some fire concerns may linger over the Great Basin and Rockies, but confidence is low. ...Northern Great Basin and Rockies... Early next week, enhanced mid-level flow associated with the Pacific trough will begin to overspread much of the western CONUS including the Great Basin and northern Rockies. While temperatures and humidity are not expected to be overly warm/dry, the increase in southwesterly flow aloft may support localized pockets of dry and breezy conditions (winds 15-20 mph and RH below 25%) as early as D3/Sunday, continuing trough midweek. Fuels across much of the region have not been overly favorable for fire spread in recent weeks from precipitation and cooler temperatures. Further uncertainty exists regarding the chance for additional precipitation with the trough as it continues to move eastward through the week. However, the introduction of gusty winds may allow for some drying of fine fuels enough to support a low chance for fire-weather conditions through the forecast period. Ensemble and deterministic guidance suggest the most likely corridors for low-end fire-weather conditions will exist across portions of northern CA/NV into southern ID, and across parts of the Rockies in northern CO/southern WY, and western MT. However, with the uncertainties regarding fuel availability and precipitation chances, confidence in sustained critical fire-weather conditions is low. Towards the end of the extended forecast period, model guidance diverges on the overall amplification of the upper-level flow pattern and the subsequent risk for critical fire-weather conditions. Some indications for a return to strong ridging may favor a slow increase in fire-weather concerns late in the month. Conversely, a cut-off low or persistent troughing, as indicated by some ensemble guidance, may also allow for cooler and wetter conditions across the western US into October. ..Lyons.. 09/22/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Sep 22 2023 Valid 222000Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTH-CENTRAL HIGH PLAINS...AND THE COASTAL MID-ATLANTIC... ...SUMMARY... Severe thunderstorms are possible across parts of the north-central High Plains this afternoon and this evening. A few tornadoes are also possible over the coastal southern Mid-Atlantic/Tidewater region overnight into tomorrow morning. ...20Z Update... ...North-Central High Plains... As mentioned in recently issued MCD #2174, the severe-thunderstorm threat is expected to increase with time across the region this afternoon. Wind profiles will become increasingly favorable for organized storms, and a couple of supercells may evolve with time. Steep midlevel lapse rates and cool temperatures aloft will support large hail of 1.5 to 2 inches in diameter, conditional on supercell development. A tornado or two will also be possible if multiple sustained supercells can develop and mature. Severe Thunderstorm Watch #689 was recently issued to cover the potential risk across the region. ...Coastal southern Mid-Atlantic/Tidewater... No significant changes have been made by NHC to the forecast track of Tropical Storm Ophelia, with the system still expected to be onshore over the central NC coast by 12Z tomorrow. Stable conditions are in place across this region now, but an increasingly moist and buoyant boundary layer is expected to advect into the region overnight. This could support a few stronger convective cores, which, given the strong low-level wind fields, could then produce brief tornadoes. ..Mosier.. 09/22/2023 .PREV DISCUSSION... /ISSUED 1134 AM CDT Fri Sep 22 2023/ ...North-central High Plains... Scattered thunderstorms are still ongoing at midday across western portions of Nebraska/South Dakota, generally in association with a lead shortwave trough downstream of a more prominent upper trough over the northern Intermountain region. In this wake of this activity, the primary corridor of diurnal destabilization will be focused in a northwest/southeast-oriented corridor across eastern Wyoming into the Nebraska Panhandle and extreme southwest South Dakota. Aided by low-level upslope flow/differential heating and the approach of the upstream trough/speed max, the aforementioned corridor is where at least isolated severe storms are expected to develop into mid/late afternoon, and subsequently move through this relatively narrow corridor of modest instability (MLCAPE 750-1250 J/kg). Long hodographs with 40+ kt effective shear will support supercells capable of large hail (locally significant 2+ inch), and possibly some tornado risk given the relatively moist environment. These storms should spread east-northeastward across much of the north-central Plains tonight, with the potential for large hail and locally damaging winds continuing possibly into the overnight. ...Coastal southern Mid-Atlantic/Tidewater... The potential for supercells and a few tornadoes is expected to increase late tonight as Potential Tropical Cyclone 16 approaches the coast. Reference the National Hurricane Center for the latest track/intensity forecast details. While inland areas are currently stable with respect to surface-based convection, higher theta-e air will accompany a warm front shifting toward the coast late tonight, all while low/mid-level winds strengthen on the northern periphery of the Potential Tropical Cyclone. Supercell-favorable ingredients are expected to be maximized across coastal eastern North Carolina into far southeast Virginia. This is where MLCAPE in the 500-1500 J/kg range is possible, despite midlevel lapse rates only slightly greater than moist adiabatic. Enlarging and well-curved hodographs are expected, with effective SRH of 300-500 m2/s2. A few tornadoes are possible mainly during the overnight into early Saturday. ...Iowa... An MCV continues to drift east-northeastward across western Iowa at midday. While plentiful cloud cover and some showers/thunderstorms precede the MCV, modest destabilization should gradually occur mainly across eastern Iowa this afternoon. Some stronger to locally severe storms could develop accordingly, aided by influences of the MCV. ...Eastern Oklahoma/ArkLaTex... While a few stronger storms could occur today, severe potential is expected to remain very limited across the region as warm advection abates and mid-level lapse rates remain modest. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Fri Sep 22 2023 Valid 231200Z - 241200Z ...NO CRITICAL AREAS... ...20z Update... No changes will be made to the current outlook. Overall fire-weather concerns are expected to remain below Elevated criteria and localized across the lee of the Rockies and northern Great Basin. See the previous discussions for more information. ..Lyons.. 09/22/2023 .PREV DISCUSSION... /ISSUED 0130 AM CDT Fri Sep 22 2023/ ...Synopsis... Fire weather concerns should remain fairly localized for Saturday along the High Plains. A surface low and an attendant surface trough are forecast to deepen as they migrate east across the Plains on Saturday. This will establish a zonal flow regime across much of the Rockies and High Plains by late morning. Downslope warming/drying along the CO Front Range and in the lee of the Sangre de Cristo and Sandia/Manzano Mountains, augmented by diurnal heating, should promote areas of 15-25% RH as winds increase to 15-20 mph (with locally drier/windier in terrain-favored locations). Somewhat meager mid to upper-level winds should confine the strongest surface winds close to terrain features - with the exception of southeast WY into adjacent portions of NE/northeast CO where surface gradient winds will be stronger. This, combined with somewhat marginal fuel status outside of far northeast NM and southern CO, will limit the coverage of elevated conditions and the overall fire weather threat. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0688 Status Updates
STATUS REPORT ON WW 688 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..LYONS..09/21/23 ATTN...WFO...GID... STATUS REPORT FOR WT 688 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC089-123-141-183-220040- KS . KANSAS COUNTIES INCLUDED ARE JEWELL MITCHELL OSBORNE SMITH NEC001-019-035-061-079-099-129-181-220040- NE . NEBRASKA COUNTIES INCLUDED ARE ADAMS BUFFALO CLAY FRANKLIN HALL KEARNEY NUCKOLLS WEBSTER 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

WW 688 TORNADO KS NE 212150Z - 220300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 688 NWS Storm Prediction Center Norman OK 450 PM CDT Thu Sep 21 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of North central Kansas South central Nebraska * Effective this Thursday afternoon and evening from 450 PM until 1000 PM CDT. * Primary threats include... A couple tornadoes possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Supercells will persist into this evening along a stationary front across southern Nebraska, with the potential to produce a couple of tornadoes and isolated very large hail of 2 to 2.5 inches in diameter. Some clustering of storms is expected later this evening into early tonight, with some increase in the threat for damaging winds as storms spread east-southeastward along the Nebraska/Kansas border. The tornado watch area is approximately along and 35 statute miles east and west of a line from 25 miles north of Kearney NE to 90 miles south of Hastings NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && OTHER WATCH INFORMATION...CONTINUE...WW 687... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26010. ...Thompson Read more

WW 0687 Status Updates
STATUS REPORT ON WW 687 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..LYONS..09/21/23 ATTN...WFO...GLD...GID...LBF... STATUS REPORT FOR WT 687 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC039-063-065-109-137-147-153-163-179-193-220040- KS . KANSAS COUNTIES INCLUDED ARE DECATUR GOVE GRAHAM LOGAN NORTON PHILLIPS RAWLINS ROOKS SHERIDAN THOMAS NEC005-029-041-047-049-063-065-069-073-075-083-085-087-091-101- 111-113-117-135-137-145-171-220040- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR CHASE CUSTER DAWSON DEUEL FRONTIER FURNAS GARDEN GOSPER GRANT HARLAN HAYES HITCHCOCK HOOKER KEITH LINCOLN LOGAN MCPHERSON PERKINS PHELPS RED WILLOW THOMAS Read more

WW 687 TORNADO KS NE 211950Z - 220300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 687 NWS Storm Prediction Center Norman OK 250 PM CDT Thu Sep 21 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northwest Kansas Southwest Nebraska * Effective this Thursday afternoon and evening from 250 PM until 1000 PM CDT. * Primary threats include... A few tornadoes possible Scattered large hail likely with isolated very large hail events to 3 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms are expected to rapidly develop this afternoon along a dryline and warm front lying across the area. Supercells capable of very large hail and a few tornadoes are expected. The tornado watch area is approximately along and 60 statute miles east and west of a line from 35 miles south southwest of Hill City KS to 60 miles north northwest of North Platte NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28025. ...Hart Read more