Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0208 PM CDT Mon Jul 24 2023 Valid 251200Z - 261200Z ...Columbia Basin... Recent model guidance has trended drier and windier with surface conditions across eastern WA and OR in the wake of the cold front moving through on D1/Mon. Model soundings show afternoon RH values below 20-25% with winds gusts to 15-20 mph through the Cascade gaps and the western portions of the Columbia Basin. With the increased confidence in dry and breezy conditions over dry fuels, a few hours of elevated to near-critical fire-weather conditions now appear likely D2/Tues afternoon. Otherwise, the previous forecast remains valid with minimal changes for the latest forecast guidance. See the prior discussion for more information. ..Lyons.. 07/24/2023 .PREV DISCUSSION... /ISSUED 1247 AM CDT Mon Jul 24 2023/ ...Synopsis... Relatively strong mid-level flow will traverse the periphery of an upper ridge, poised to remain in place across the Interior West tomorrow/Tuesday. The stronger flow aloft may encourage dry downslope flow along the lee of the northern Sierra and parts of the higher terrain within the northern Rockies. Latest guidance consensus suggests that RH may drop below 20 percent in several locales as sustained westerly surface winds peak over 15 mph for at least a few hours, necessitating Elevated highlights. Meanwhile, monsoonal moisture will remain trapped near the stationary upper ridge, supporting at least scattered thunderstorm development with afternoon heating. Any lightning strikes that can occur within one of the more isolated dry fuel beds may promote localized wildfire-spread potential. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Sun Jul 23 22:01:02 UTC 2023.

MD 1686 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF MO INTO WEST-CENTRAL IL
Mesoscale Discussion 1686 NWS Storm Prediction Center Norman OK 0458 PM CDT Sun Jul 23 2023 Areas affected...Portions of MO into west-central IL Concerning...Severe potential...Watch unlikely Valid 232158Z - 240030Z Probability of Watch Issuance...5 percent SUMMARY...An isolated risk for severe hail and damaging winds may continue into the early evening. Watch issuance is not expected at this time. DISCUSSION...Scattered thunderstorms have developed late this afternoon along a weak surface trough across parts of northern/eastern MO as a weak mid-level disturbance cresting the upper ridge continues southeastward across the upper/mid MS Valley. The airmass downstream of this activity into central MO and west-central IL is moderately unstable, with MLCAPE generally 2000-2500 J/kg. But, deep-layer shear remains marginal, around 20-25 kt, given fairly modest mid/upper-level northwesterly flow. Still, occasional updraft organization has been noted with the strongest cores, with a recent 1 inch severe hail report. Isolated severe hail and damaging winds may remain a threat with this convection as it spreads slowly southward over the next couple of hours. Given the weak shear, watch issuance is not expected at this time. ..Gleason/Thompson.. 07/23/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...SGF...EAX... LAT...LON 39779333 39559212 39599083 39078997 38249005 37969152 38149303 38699365 39379363 39789333 39779333 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 23 2023 Valid 232000Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NORTHERN SC AND WESTERN NC... ...SUMMARY... Strong to severe storms will remain possible late this afternoon and evening, at least on an isolated basis, across the Southeast States as well as the northern/central Plains and Ozarks. A few strong wind gusts could also occur in Arizona. ...20Z Update... The Marginal Risk has been expanded westward to include more of southwest SD and western NE, based on latest short-term guidance, destabilization trends, and increasing cumulus near the Black Hills. The Marginal Risk has been trimmed in the wake of earlier convection across parts of FL and GA. Otherwise, no major changes have been made. See the previous discussion below for more details. ..Dean.. 07/23/2023 .PREV DISCUSSION... /ISSUED 1127 AM CDT Sun Jul 23 2023/ ...Carolinas... Mostly sunny skies are present today from much of GA across the Carolinas. Ample low-level moisture will yield afternoon MLCAPE values of 1500-2000 J/kg, along with rather strong mid/upper level winds. 12z CAM solutions show a more robust signal for higher thunderstorm coverage across parts of northern SC into central NC. Therefore have opted to add a SLGT risk for parts of SC/NC for this afternoon and evening. ...FL... A large but relatively disorganized MCS is moving across the northeast Gulf of Mexico into northern FL. Strong heating ahead of this system will lead to occasional intense storms along the leading edge of the combined outflow. Forecast soundings show rather limited deep-layer shear and lapse rates, suggesting that activity will not be very organized or long-lived. However, locally gusty/damaging winds could occur. ...Central/Northern Plains... A large area of moderate/strong instability and fast northwest flow aloft lies across much of the northern and central Plains today. Forecast soundings across the region from the eastern Dakotas into KS/MO show sufficient CAPE/shear for a conditional risk of supercells capable of large hail and damaging wind gusts. However, forcing is weak and confidence in where afternoon convective initiation will occur is low. Therefore will maintain a broad MRGL risk. The strongest signal in 12z models appears to extend from south-central NE across central/eastern KS into west-central MO. This and other corridors will be monitored through the afternoon for a potential upgrade. ...AZ... Easterly flow aloft today will again pose some risk of convection moving off the higher terrain of eastern/northern AZ into higher population areas. Damaging winds would be the main concern. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0205 PM CDT Sun Jul 23 2023 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHERN GREAT BASIN INTO SOUTHEASTERN OR AND WESTERN ID... ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE COLUMBIA BASIN IN EASTERN WA AND OR... ...Northern Great Basin... Widespread elevated and critical fire-weather conditions are expected D2/Monday ahead of the advancing trough. Updated fuels information across northwest NV lends higher confidence to critical conditions in lower elevations. The Critical area was expanded south and westward to better align with 25+ mph surface winds and low afternoon humidity. ...Columbia Basin and northern Rockies... As strong mid-level flow aligns with dry and warm surface conditions across portions of eastern WA and OR, westerly winds of 20-25 mph and higher gusts are expected over dry fuels. Several hours of widespread elevated and critical fire-weather conditions are expected to support the potential for rapid fire spread. A few showers and high-based thunderstorms are also possible later in the evening along and behind the cold front from far eastern WA into portions of western MT and the ID Panhandle. While not overly likely, any storms that do form may pose a risk for dry lightning strikes within modestly receptive fuels. please see the prior discussion for more information. ..Lyons.. 07/23/2023 .PREV DISCUSSION... /ISSUED 0123 AM CDT Sun Jul 23 2023/ ...Synopsis... A mid-level trough will remain in place across the Four Corners region as an upper trough traverses the Pacific Northwest tomorrow/Monday. Monsoonal moisture trapped beneath the mid-level ridge will encourage another day of scattered dry and wet thunderstorms across the Intermountain West. Given patchy, marginally receptive fuels, a couple of new fire starts are possible, resulting in localized wildfire-spread potential. The relatively greater potential for wildfire spread will exist across the Pacific Northwest as the passage of a mid-level trough will encourage critically dry and windy surface conditions. To the lee of the Cascades and northern Sierra, RH will dip below 15 percent by afternoon peak heating, with surface westerly winds sustaining over 20 mph in spots. The most likely region to see widespread 20+ mph wind speeds will be southeast Oregon into far northwest Nevada and far southwest Idaho, where Critical highlights have been introduced. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Sun Jul 23 2023 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST...MID/UPPER MS VALLEY...OH VALLEY...AND NORTHEAST... ...SUMMARY... Isolated severe thunderstorms are possible on Monday across parts of the Midwest, mid/upper Mississippi Valley, Ohio Valley, and Northeast. ...Synopsis... An upper ridge will remain anchored over the southern/central Rockies on Monday, as a mid/upper-level cyclone and attendant trough move into the Pacific Northwest, and a broad upper trough remains over much of the eastern CONUS. At the surface, a remnant boundary will be draped from somewhere near the Gulf Coast into the Mid Atlantic. A weak surface low may develop over the central Plains, while another weak surface low/trough will move eastward across the OH Valley vicinity. ...Northeast... A shortwave mid/upper-level trough is forecast to move from the lower Great Lakes toward northern New England on Monday. Modest low-level moisture and diurnal heating will support MLCAPE of 750-1500 by late morning into the afternoon, and scattered thunderstorm development is expected from central PA into parts of NY/VT, immediately in advance of the shortwave. Southwesterly midlevel flow associated with the upper trough will support effective shear generally in the 25-35 kt range, sufficient for a few modestly organized cells/clusters capable of locally damaging wind and possibly some hail. ...OH Valley and vicinity... Most guidance suggests a weak surface low/trough will move slowly eastward across parts of the OH Valley on Monday. This may aid in diurnal thunderstorm development within an environment characterized by moderate to strong buoyancy (MLCAPE 1500-3000 J/kg). Storm coverage and location remain rather uncertain, but effective shear of 20-30 kt within a weak northwesterly flow regime could support a few stronger multicells and clusters capable of producing hail and locally damaging wind. ...Mid/upper MS Valley and Midwest... A low-predictability northwest-flow regime will remain in place from parts of the northern/central Plains into the Midwest and mid/upper MS Valley on Monday. The details of storm development, coverage, and timing remain uncertain, but the environment will be conditionally favorable for supercells and organized clusters wherever notable diurnal destabilization can occur. Morning convection may be ongoing Monday morning across parts of eastern NE/KS into western IA/MS, in association with a southwesterly low-level jet. A localized severe hail/wind threat cannot be ruled out with the stronger morning storms. Outflow and potential MCV development related to morning convection may support redevelopment farther south toward the Ozarks Monday afternoon/evening, with some continued potential for isolated severe hail/wind with the strongest storms. Diurnal development will also be possible farther north into parts of MN/WI, within a weak but persistent low-level warm advection regime. If storms can mature in this area, isolated southeast-moving supercells will be possible. Nocturnal convection may develop late Monday night as the low-level jet increases, potentially posing an isolated severe risk into parts of IA/MO. ...Northern UT into the northern Rockies... High-based convection is expected Monday afternoon/evening in association with a shortwave trough moving around the periphery of the upper ridge. Localized severe gusts will be possible from northern UT into parts of the northern Rockies, though with limited instability, storm intensity and organization remains uncertain at this time. Severe-wind probabilities may eventually be needed if confidence increases in more organized storm development. ..Dean.. 07/23/2023 Read more

WW 0539 Status Updates
STATUS REPORT ON WW 539 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NW GPT TO 30 W MOB TO 20 ENE MOB TO 25 NW PNS TO 15 NNE PNS TO 20 ENE PNS TO 15 WSW PFN TO 25 SSW TLH TO 30 SSE TLH TO 20 W CTY. ..BENTLEY..07/22/23 ATTN...WFO...MOB...TAE...JAX...LIX... STATUS REPORT FOR WS 539 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC003-097-222340- AL . ALABAMA COUNTIES INCLUDED ARE BALDWIN MOBILE FLC033-037-045-067-113-123-222340- FL . FLORIDA COUNTIES INCLUDED ARE ESCAMBIA FRANKLIN GULF LAFAYETTE SANTA ROSA TAYLOR MSC039-047-059-222340- MS . MISSISSIPPI COUNTIES INCLUDED ARE GEORGE HARRISON JACKSON Read more

MD 1681 CONCERNING SEVERE THUNDERSTORM WATCH 540... FOR PORTIONS OF EXTREME EASTERN TEXAS...CENTRAL AND SOUTHERN LOUISIANA INTO SOUTHERN MISSISSIPPI
Mesoscale Discussion 1681 NWS Storm Prediction Center Norman OK 0456 PM CDT Sat Jul 22 2023 Areas affected...portions of extreme eastern Texas...central and southern Louisiana into southern Mississippi Concerning...Severe Thunderstorm Watch 540... Valid 222156Z - 222330Z The severe weather threat for Severe Thunderstorm Watch 540 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 540. Damaging gusts remain the primary threat, though an instance or two of large hail cannot be ruled out. DISCUSSION...Multicellular clusters have organized roughly into two west-east oriented bands of storms over the past couple of hours, with a history of a couple of strong, damaging gusts. MRMS mosaic radar imagery suggest that the cores of the stronger storms are quite deep, with 30 dBZ echoes extending to 60 kft in spots, with 50 dBZ echoes reaching over 35 kft. Though deep-layer shear remains modest, 21Z mesoanalysis depicts over 4000 J/kg MLCAPE residing ahead of these deep cores (driven mainly by rich low-level moisture beneath 6-7 C/km mid-level lapse rates per latest RAP forecast soundings). Furthermore, the RAP forecast soundings show PWATS well over 2 inches given the rich moisture. As such, water-loading within these deep storm cores may promote additional damaging gusts (some potentially exceeding severe limits), and even an instance or two of large hail cannot be completely ruled out. The severe threat should persist through the remainder of the diurnal heating cycle, or when storms overturn all of the boundary layer over land, which ever comes first. ..Squitieri.. 07/22/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MOB...JAN...LIX...LCH...SHV... LAT...LON 31699438 31959182 31989098 31518986 30778923 30308926 29468969 29219049 29329176 29559259 29879362 31699438 Read more

WW 0541 Status Updates
STATUS REPORT ON WW 541 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..07/22/23 ATTN...WFO...TOP...GLD...DDC...ICT...GID...LBF... STATUS REPORT FOR WS 541 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC027-029-039-041-051-053-061-065-089-105-123-127-137-141-143- 147-153-157-161-163-167-169-179-183-195-201-222240- KS . KANSAS COUNTIES INCLUDED ARE CLAY CLOUD DECATUR DICKINSON ELLIS ELLSWORTH GEARY GRAHAM JEWELL LINCOLN MITCHELL MORRIS NORTON OSBORNE OTTAWA PHILLIPS RAWLINS REPUBLIC RILEY ROOKS RUSSELL SALINE SHERIDAN SMITH TREGO WASHINGTON NEC001-019-029-035-041-047-057-059-061-063-065-073-079-081-083- 085-087-099-101-111-129-135-137-145-169-181-222240- NE . NEBRASKA COUNTIES INCLUDED ARE ADAMS BUFFALO CHASE CLAY CUSTER DAWSON DUNDY FILLMORE FRANKLIN Read more

WW 541 SEVERE TSTM KS NE 222030Z - 230400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 541 NWS Storm Prediction Center Norman OK 330 PM CDT Sat Jul 22 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Kansas Southern Nebraska * Effective this Saturday afternoon and evening from 330 PM until 1100 PM CDT. * Primary threats include... Scattered large hail likely with isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Widely scattered supercell storms are forming over southern Nebraska. These storms will track southward through the afternoon and early evening, posing a risk of very large hail and damaging winds. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 30 miles north northwest of Imperial NE to 50 miles east southeast of Concordia KS. 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 539...WW 540... 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 500. Mean storm motion vector 33025. ...Hart Read more

WW 539 SEVERE TSTM AL FL GA MS CW 221645Z - 230000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 539 NWS Storm Prediction Center Norman OK 1145 AM CDT Sat Jul 22 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Alabama Northern Florida including the Panhandle Southern Georgia Southern Mississippi Coastal Waters * Effective this Saturday morning and evening from 1145 AM until 700 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms are developing along a boundary sagging southward across the Gulf Coast region. A few of these storms will pose a risk of damaging downburst winds through the afternoon. The severe thunderstorm watch area is approximately along and 45 statute miles north and south of a line from 5 miles northwest of Gulfport MS to 25 miles northeast of Jacksonville FL. 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 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29025. ...Hart Read more

WW 0540 Status Updates
STATUS REPORT ON WW 540 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..07/22/23 ATTN...WFO...LCH...LIX...JAN... STATUS REPORT FOR WS 540 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS LAC001-003-005-007-009-011-019-033-037-039-045-047-053-055-063- 077-079-091-093-095-097-099-103-105-115-117-121-125-222240- LA . LOUISIANA PARISHES INCLUDED ARE ACADIA ALLEN ASCENSION ASSUMPTION AVOYELLES BEAUREGARD CALCASIEU EAST BATON ROUGE EAST FELICIANA EVANGELINE IBERIA IBERVILLE JEFFERSON DAVIS LAFAYETTE LIVINGSTON POINTE COUPEE RAPIDES ST. HELENA ST. JAMES ST. JOHN THE BAPTISTST. LANDRY ST. MARTIN ST. TAMMANY TANGIPAHOA VERNON WASHINGTON WEST BATON ROUGE WEST FELICIANA MSC005-035-045-073-091-109-113-147-157-222240- MS . MISSISSIPPI COUNTIES INCLUDED ARE AMITE FORREST HANCOCK LAMAR MARION PEARL RIVER PIKE WALTHALL WILKINSON Read more

WW 540 SEVERE TSTM LA MS TX CW 221915Z - 230200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 540 NWS Storm Prediction Center Norman OK 215 PM CDT Sat Jul 22 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Louisiana Southern Mississippi East Texas Coastal Waters * Effective this Saturday afternoon and evening from 215 PM until 900 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms continue to develop along a boundary sagging into southern Louisiana/Mississippi. The strong cells along this line will pose a risk of locally damaging wind gusts. The severe thunderstorm watch area is approximately along and 45 statute miles north and south of a line from 45 miles west southwest of Fort Polk LA to 40 miles east northeast of Slidell LA. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 539... 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 29025. ...Hart Read more

MD 1680 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN NEW MEXICO AND THE WESTERN TEXAS PANHANDLE INTO SOUTHWEST TEXAS
Mesoscale Discussion 1680 NWS Storm Prediction Center Norman OK 0354 PM CDT Sat Jul 22 2023 Areas affected...Eastern New Mexico and the western Texas Panhandle into Southwest Texas Concerning...Severe potential...Watch unlikely Valid 222054Z - 222300Z Probability of Watch Issuance...20 percent SUMMARY...Scattered storms capable of large hail and strong winds possible late afternoon/early evening. DISCUSSION...Scattered thunderstorm development is expected across eastern New Mexico through the afternoon and early evening, with some uncertainty as to how far into Texas storms will track. Cumulus has increased across northeastern New Mexico with attempts at cell development over the last hour. Additionally, areas of convection ongoing across the high terrain may move into the lower elevations through the afternoon as well. MLCAPE is observed around 1000-2000 J/kg. Shear is largely confined to far northeastern New Mexico into the Texas Panhandle. Given uncertainty in coverage and if storms will track into the best shear/instability overlap, a watch is unlikely at this time. Isolated instances of large hail and gusty winds will be possible. ..Thornton/Hart.. 07/22/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LUB...AMA...MAF...PUB...ABQ... LAT...LON 35200526 35830477 36380435 36850379 37050334 37030272 36700255 36340240 35930238 35510236 35190240 34730240 34110247 33860261 33690278 33570299 33410347 33310398 33680481 34290533 35200526 Read more

MD 1679 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR WESTERN WISCONSIN AND MINNESOTA
Mesoscale Discussion 1679 NWS Storm Prediction Center Norman OK 0336 PM CDT Sat Jul 22 2023 Areas affected...western Wisconsin and Minnesota Concerning...Severe potential...Watch unlikely Valid 222036Z - 222230Z Probability of Watch Issuance...20 percent SUMMARY...Scattered storms capable of large hail may continue through the afternoon. DISCUSSION...Ongoing thunderstorm activity across Minnesota and Wisconsin have produced scattered reports of 0.50"-1.25" hail, along with one report of 2.5 inch hail near Marcell, MN. Convection is further aided by a mid-level impulse digging southward across Minnesota at this time. RAP sounding analysis indicates largely straight hodographs with steep low-level lapse rates and unstable conditions through the profile. MLCAPE around 1500 J/kg overlaps deep layer shear around 30-35 kts. Discrete convection has been able to produce larger hail within this environment. Forcing for ascent remains somewhat weak, though moisture convergence is evident from surface objective analysis and surface observations. Uncertainty if discrete storm mode will continue and duration/coverage of the large hail threat. Instances of sub-severe hail and hail up to 1-1.5 will be possible. Trends will continue to be monitored but a watch is unlikely to be issued at this time. ..Thornton/Hart.. 07/22/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX...FGF...FSD... LAT...LON 44379096 44239102 43899172 43809258 43729337 43719403 43779495 43829552 43829606 44099621 44419633 45019605 46239555 46859556 47359558 48109504 48059356 47749298 47109277 46479275 46169227 46009175 45689092 45299056 44379096 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jul 22 2023 Valid 222000Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS AND SOUTHEAST... ...SUMMARY... Strong to severe thunderstorms capable of large hail and damaging winds remain possible into this evening across parts of the central Plains. Storms capable of isolated damaging gusts may persist into this evening across parts of the Southeast, and develop by early evening over parts of Arizona. ...20Z Update... The Slight Risk has been trimmed slightly across parts of AL/GA, in the immediate wake of storms sagging southward toward the Gulf Coast. The Marginal Risk has been expanded across parts of northern MN, southwest MN into southeast SD, and north-central NE, where developing cumulus and storm initiation has been recently observed within a somewhat favorable (but weakly forced) environment, with hail and localized damaging gusts the primary threats. A small part of the Marginal Risk has been trimmed across far northeast MN/northwest WI, where substantial redevelopment appears likely in the wake of earlier convection. Otherwise, no major changes have been made. Storms capable of locally damaging winds will remain possible through the afternoon across parts of the Southeast, and may develop by early this evening across parts of Arizona. Storms capable of hail and localized severe gusts may increase in coverage late this afternoon and evening across parts of the central Plains, with a more isolated threat into the upper Midwest. See the previous discussion below for more information. See MCD 1677 for more information regarding the threat across parts of the central Plains. ..Dean.. 07/22/2023 .PREV DISCUSSION... /ISSUED 1118 AM CDT Sat Jul 22 2023/ ...KS Vicinity... Morning visible satellite imagery shows clear skies over most of KS, where strong heating will combine with dewpoints in the mid 60s to yield afternoon MLCAPE around 1500 J/kg. Large scale forcing is subtle in this region, with weak mid-level height rises and diffuse surface boundaries expected to influence storm potential. Nevertheless, most 12z CAM solutions continue to show potential for widely scattered thunderstorms by late afternoon. Deep northwest flow aloft will provide sufficient vertical shear for rotating updrafts capable of large hail and damaging wind gusts. ...Gulf Coast Region... A weak surface boundary extends from southern MS eastward into southern GA today. The air mass along and south of the boundary is very moist and unstable. Scattered thunderstorms are expected to affect this region through the afternoon. The southern fringe of stronger mid-level westerlies lies along the boundary, and will likely result in at least isolated instances of damaging wind gusts. Please refer to MCD #1675 for further details. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Sat Jul 22 2023 Valid 231200Z - 241200Z ...Southern California... Updated Hi-res model guidance has trended stronger with the aforementioned shortwave rotating around the west side of the upper-level ridge. Area model soundings show dry low-levels, with deep inverted V structures, and sufficient CAPE for thunderstorms across portions of the southern California mountains and deserts. The stronger shortwave, and presence of increasing monsoon moisture lend higher confidence in dry thunderstorm coverage being slightly higher than previously forecast. Storms are most likely across portions of the High deserts and eastern most Transverse Ranges. More localized storms are possible farther west across the Ventura and Peninsular Ranges, but uncertainty increases toward the coast. With the greater confidence in isolated storm coverage, dry fuels and lightning, an IsoDryT area has been added for portions of southern CA. ...Northern Great Basin into southern/western ID... In addition to gusty winds and lower humidity, isolated thunderstorms are possible across portions of northeastern NV, into far eastern OR and southern ID D2/Sun evening into early D3/Mon. With a deep and dry mixed layer present on area forecast soundings, little wetting rain potential is expected with any storms able to develop. The highest confidence in storm coverage is across portions of eastern ID where less receptive fuels are present. However, very isolated dry storms are possible, with some potential for lightning ignitions within receptive fuels, across portions of far southeast OR and southwestern ID. ..Lyons.. 07/22/2023 .PREV DISCUSSION... /ISSUED 0104 AM CDT Sat Jul 22 2023/ ...Synopsis... The upper-level ridge will start to shift east on Sunday which will allow some stronger mid-level flow to overspread the Northwest and the northern Great Basin. Downslope flow in the lee of the Sierra and deep mixing across northern Nevada/southern Oregon will allow winds to increase to 15 to 20 mph during the afternoon amid single-digit relative humidity. Some enhancement of the flow is possible across southern Nevada on Sunday as a weak mid-level shortwave trough moves northward around the western edge of the anticyclone. This shortwave trough is currently across central New Mexico and may undergo some convective enhancement during the D1/Saturday period. Due to the influence of Day 1 convection on the strength of this trough, will not add an Elevated area at this time. Some elevated conditions are possible in the Snake River Plain on Sunday as stronger mid-level flow overspreads the region and low pressure develops in the northern Great Basin. However, fuels in the area remain only marginally dry. Therefore, an Elevated delineation is not warranted at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Jul 22 2023 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF ARIZONA...AND ALSO ACROSS PARTS OF GEORGIA AND THE CAROLINAS... ...SUMMARY... Thunderstorms with isolated damaging wind will be possible across parts of Georgia and the Carolinas on Sunday. Thunderstorms with isolated severe thunderstorm gusts are also possible mainly Sunday evening over portions of Arizona. ...Synopsis... An upper ridge centered over the Four Corners region is forecast to build into a larger portion of the central/southern Plains on Sunday, as an upper trough over the eastern CONUS gradually weakens and shifts eastward. At the surface, a weakening cold front will likely be draped somewhere from south-central TX northeastward into southern parts of LA/MS/AL, central/southern GA, and the eastern Carolinas. A weak surface low may develop over the northern High Plains and move southeastward along a surface trough. ...Parts of Georgia and the Carolinas... Moderate buoyancy is expected to develop along/ahead of the cold front across parts of the Southeast. The most favorable overlap of instability, stronger flow aloft, and storm coverage is expected from parts of Georgia into the Carolinas, immediately in advance of the main upper trough. Scattered to numerous thunderstorms may develop during the afternoon, with deep-layer shear sufficient for a few modestly organized cells/clusters capable of localized damaging gusts and small to perhaps marginally severe hail. Isolated strong storms may also develop farther west near the southern Appalachians, within a drier but modestly unstable regime. Coverage of the severe threat appears too low for probabilities at this time, but some threat for isolated damaging gusts could evolve in this area as well. ...Arizona... Very strong heating and increasing PW will support isolated to scattered thunderstorm development during the late afternoon near the Mogollon Rim, and potentially into the lower deserts across AZ. Isolated microbursts will be possible with the initial development. 15-20 kt of easterly midlevel flow along the southern periphery of the ridge may support a few outflow-driven, westward-moving clusters capable of at least localized severe gusts into Sunday evening. Some threat could reach as far as the lower CO River Valley before weakening. ...Central/northern Plains into the Midwest... A broad portion of the central/northern Plains and Midwest will reside in a regime characterized by northwesterly mid/upper-level flow, modest low-level moisture, relatively steep low/midlevel lapse rates, and generally weak large-scale ascent. Very isolated storm development will be possible within this regime, with sufficient instability and deep-layer to support a conditional supercell risk. Severe probabilities may eventually be needed for some part of this area, if confidence increases in the location and coverage of potential development. ..Dean.. 07/22/2023 Read more

WW 0535 Status Updates
STATUS REPORT ON WW 535 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BUNTING..07/21/23 ATTN...WFO...MEG... STATUS REPORT FOR WS 535 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC031-035-037-077-093-107-111-123-211940- AR . ARKANSAS COUNTIES INCLUDED ARE CRAIGHEAD CRITTENDEN CROSS LEE MISSISSIPPI PHILLIPS POINSETT ST. FRANCIS MSC003-009-013-017-027-033-057-071-081-093-095-107-115-117-119- 135-137-139-141-143-145-161-211940- MS . MISSISSIPPI COUNTIES INCLUDED ARE ALCORN BENTON CALHOUN CHICKASAW COAHOMA DESOTO ITAWAMBA LAFAYETTE LEE MARSHALL MONROE PANOLA PONTOTOC PRENTISS QUITMAN TALLAHATCHIE TATE TIPPAH TISHOMINGO TUNICA UNION YALOBUSHA Read more

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