Storm Prediction Center

MD 1767 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHWEST SOUTH DAKOTA AND ADJACENT PORTIONS OF NORTHWEST NEBRASKA
Mesoscale Discussion 1767 NWS Storm Prediction Center Norman OK 0213 PM CDT Mon Jul 27 2026 Areas affected...Southwest South Dakota and adjacent portions of northwest Nebraska Concerning...Severe potential...Watch possible Valid 271913Z - 272115Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorms developing across southwest South Dakota will likely pose a severe wind threat as they spread east across South Dakota and northwest Nebraska. Watch issuance may be required to address this potential. DISCUSSION...Recent visible/reflectivity imagery and lightning data shows early stages of deep convection within the Black Hills in southwest SD. This activity is largely being driven by weak upslope ascent, but should gradually propagate eastward as convection deepens and becomes increasingly influenced by mean westerly flow aloft. However, the KUDX VWP has recently sampled somewhat modest winds between 5-7 km (around 25 knots), resulting in slightly weaker deep-layer bulk shear than depicted by recent mesoanalyses. Regardless, the thermodynamic environment features sufficient buoyancy for sustained deep convection - especially with eastward extent into a plume of low 60s dewpoints. Additionally, strong heating has steepened low-level lapse rates to around 9 C/km downstream, which should foster cold pool development and further promote eastward propagation. Consequently, the expectation is for initially discrete convection to gradually grow upscale and propagate eastward through the evening hours. Severe winds will be the primary concern and could be as strong as 55-70 mph based on environmental conditions and output from recent high-res guidance, though the modest kinematic environment casts some uncertainty on overall storm organization/intensity. Trends will continue to be monitored and watch issuance may be required if/when upscale growth occurs. ..Moore/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...LBF...UNR...CYS... LAT...LON 42780079 42800315 42880361 43070386 43420405 44670399 44960340 44980263 44920148 44540085 44070053 43620019 43200023 43000036 42780079 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

MD 1768 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHEAST COLORADO INTO NORTHWEST KANSAS AND SOUTHWEST NEBRASKA
Mesoscale Discussion 1768 NWS Storm Prediction Center Norman OK 0241 PM CDT Mon Jul 27 2026 Areas affected...Northeast Colorado into northwest Kansas and southwest Nebraska Concerning...Severe potential...Watch possible Valid 271941Z - 272145Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorm development across parts of the central High Plains appears probable in the coming hours. Deep boundary-layer mixing coupled with ample buoyancy will likely yield a few strong/severe thunderstorms capable of severe wind gusts. Trends will be monitored for the need for watch issuance. DISCUSSION...Latest GOES imagery and regional radars show gradual deepening of cumulus and shallow convective showers/weak thunderstorms across far eastern CO into adjacent portions of northwest KS and southwest NE. This activity appears to largely be driven by very weak ascent along and north of a stalled baroclinic zone and ahead of a weak mid-level disturbance. Residual capping is slowly eroding across the region as temperatures breach 100 F. As temperatures continue to warm, thunderstorm coverage and intensity may increase, though confidence on overall storm coverage is limited given the weak forcing for ascent. Regardless, thunderstorms that can develop will likely mature within a thermodynamic environment featuring MLCAPE values upwards of 1500-2500 J/kg and deep boundary-layer mixing up to 2-3 km, which should favor robust updrafts and accelerating downdrafts. Consequently, strong to severe winds will be possible, and modest deep-layer wind shear may support some storm organization and the potential for loosely organized clusters. Limited confidence on thunderstorm coverage casts uncertainty on the need for watch issuance, but trends will continue to be monitored. ..Moore/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GID...LBF...GLD...BOU... LAT...LON 39210087 38890243 39090288 39440318 39940301 40540186 40730121 40810067 40450013 40079985 39789984 39609998 39370031 39210087 MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

MD 1769 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF CENTRAL IL
Mesoscale Discussion 1769 NWS Storm Prediction Center Norman OK 0258 PM CDT Mon Jul 27 2026 Areas affected...portions of central IL Concerning...Severe potential...Watch possible Valid 271958Z - 272130Z Probability of Watch Issuance...40 percent SUMMARY...Isolated strong wind gusts or hail could accompany stronger storms this afternoon. The need for a watch remains uncertain. DISCUSSION...Widely scattered thunderstorms are developing ahead of a surface trough across central IL within a very moist and unstable airmass. Strong northwesterly flow aloft is fostering 45+ kt effective shear magnitudes, which could support organized convection. However, large-scale ascent is nebulous across the area. Furthermore, looping visible satellite imagery shows a broadening cirrus shield over eastern IL associated with convection further east, and possible outflow/gravity waves spreading westward. It is uncertain if this may be helping initiate convection or will temper more robust development. While the overall thermodynamic/kinematic profiles across the area generally would support some severe risk, uncertainty is high. Trends will be monitored, and if intensity increases, WW 520 and 521 could be expanded westward, or a new watch issued if needed. ..Leitman/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...DVN... LAT...LON 41008800 40478795 40108837 40028887 40008938 40108989 40479040 40869041 41018977 41218875 41258823 41008800 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

MD 1770 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF EASTERN IN INTO WESTERN OH
Mesoscale Discussion 1770 NWS Storm Prediction Center Norman OK 0348 PM CDT Mon Jul 27 2026 Areas affected...portions of eastern IN into western OH Concerning...Severe potential...Watch possible Valid 272048Z - 272245Z Probability of Watch Issuance...60 percent SUMMARY...Severe potential could spread southeast into parts of western Ohio over the next couple of hours. Trends are being monitored and a downstream severe thunderstorm watch could be needed. DISCUSSION...A cluster of storms over central Indiana have shown some indications of intensification over the past 30 minutes both in radar imagery and based on recent local storm reports relaying gusts near 60 mph and localized wind damage. This activity will continue to spread east/southeast along a strong instability gradient within enhanced northwesterly flow aloft. While the environment overall is favorable for organized severe convection, uncertainty remains given persistent cloud cover across western OH and some indications of continued capping per SPC mesoanalysis. Nevertheless, temperatures in the 80s across far southwest OH and dewpoints in the low/mid 70s F could support at least sporadic strong gusts. Trends will be monitored for possible watch issuance over the next 1-2 hours. ..Leitman/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILN...IWX...IND... LAT...LON 41048484 40858440 40558385 40018361 39518355 39118381 39128459 39268518 39828585 40388634 40668615 40948587 41118556 41048484 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

WW 0520 Status Updates
STATUS REPORT ON WW 520 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NNE MSN TO 5 E MKE TO 15 NE BEH TO 30 NE FWA. ..LEITMAN..07/27/26 ATTN...WFO...LOT...IWX...GRR...MKX... STATUS REPORT FOR WS 520 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-043-075-091-097-197-272140- IL . ILLINOIS COUNTIES INCLUDED ARE COOK DUPAGE IROQUOIS KANKAKEE LAKE WILL INC003-007-017-033-039-049-069-073-085-087-089-091-099-103-111- 113-127-131-141-149-169-181-183-272140- IN . INDIANA COUNTIES INCLUDED ARE ALLEN BENTON CASS DE KALB ELKHART FULTON HUNTINGTON JASPER KOSCIUSKO LAGRANGE LAKE LA PORTE MARSHALL MIAMI NEWTON NOBLE PORTER PULASKI ST. JOSEPH STARKE WABASH WHITE WHITLEY Read more

WW 520 SEVERE TSTM IL IN MI LM 271645Z - 280000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 520 NWS Storm Prediction Center Norman OK 1245 PM EDT Mon Jul 27 2026 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Illinois Northern Indiana Western Lower Michigan Lake Michigan * Effective this Monday afternoon and evening from 1245 PM until 800 PM EDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph likely Scattered large hail and isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...Clusters of thunderstorms will track southeastward through the afternoon across the watch area. Damaging winds, large hail, and even a tornado or two are possible. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 70 miles north of Muskegon MI to 60 miles south southeast of Valparaiso IN. 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 519... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 31030. ...Hart Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Mon Jul 27 2026 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE LOWER GREAT LAKES AND MIDWEST STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS.... ...SUMMARY... Severe storms capable of strong to severe wind gusts and large hail are expected across the Great Lakes and Midwest through tonight. More sporadic occurrences of damaging wind are possible in the Mid-Atlantic, Tennessee Valley, central High Plains, and southeast Arizona. ...20z Update IL/IN... An evolving convective cluster across northern IL/IN and southern lower MI should continue to move south/southeast this afternoon. Low-level convergence is maximized along a weak CAPE/ThetaE gradient laying roughly near the IN/OH border. CAM guidance and observation trends suggest this may provide a focus for convection through this afternoon and evening gradually turning the cluster further southward. Moderate buoyancy and 40+ kt of deep-layer shear parallel to the boundary could support organized linear/bowing structures with severe/damaging gusts and perhaps some QLCS tornadoes possible across northern IN and possibly extending into western OH. However, leading stratiform and cloud cover could limit the eastern extent of the higher severe risk, and confidence in the convective evolution is very low. Additional development has been noted along the western flank of the complex over northern IL, with another cluster of storms exiting southern WI. It is possible that these new storms, and additional ascent tied to a westerly low-level jet will support a second cluster of severe storms eventually organizing and moving more south across IL/IN. Hot surface temperatures (90-95 F) and a very large reservoir of extreme buoyancy (MUCAPE 4000-5000 J/kg) extending into IL and western IN would support a risk for widespread severe/damaging gusts. Given the increased confidence in damaging winds this afternoon/evening, have shifted 30% wind probabilities farther south in IN. ...Central and northern High Plains... Scattered storms ongoing over the high plains should increase in coverage and intensity this afternoon. Steep mid-level lapse rates could promote severe wind gusts with stronger downdrafts, along with isolated hail. Minimal changes were made to the prior outlook, see MCD#1767 and MCD#1768 for more information. Additional scattered thunderstorms are ongoing over parts of the Mid Atlantic/Southeast and southern AZ. These storms should continue this afternoon with potential for sporadic damaging gusts owing to heavy water loading and moderate buoyancy. Limited vertical shear and only modest clustering suggest severe potential will remain isolated before diminishing overnight. ..Lyons.. 07/27/2026 .PREV DISCUSSION... /ISSUED 1149 AM CDT Mon Jul 27 2026/ ...Midwest/Ohio Valley... A large upper ridge remains present today over the central Plains/Rockies, with moderately strong northwest flow aloft from the Midwest into the OH Valley. A very moist and unstable low-level air mass resides from WI/IL into MI/IN/OH, where mostly clear skies will result in hot afternoon temperatures and MLCAPE values over 3000 J/kg. Multiple clusters of intense thunderstorms are ongoing over parts of WI tracking southeastward. These storms will move through this reservoir of high CAPE, leading to the potential for an active severe weather event today. However, details of how these clusters evolve are uncertain. Vertical shear across this region will support supercell structures, capable of damaging winds, hail, and isolated tornadoes this afternoon. However, the greater concern is if storms can congeal into a southeastward bowing system and that sweeps across Lower MI, eastern IL, IN, and western OH. Several morning CAM solutions indicate that risk, with storms spreading into KY overnight before weakening. Unfortunately, this synoptic pattern does not lend itself to a high-confidence convective forecast. ...High Plains... Widespread clouds are affecting parts of western NE this morning. However, strong heating will occur north and south of these clouds, leading to afternoon thunderstorms. The most active area will likely be over the Black Hills region where damaging winds and hail are possible. Farther south, widely scattered high-based thunderstorms will affect eastern CO/western KS with a risk of damaging wind gusts. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Jul 27 2026 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN GEORGIA AND ALABAMA INTO THE FLORIDA PANHANDLE AND NORTHERN FLORIDA... ...SUMMARY... Isolated severe storms capable of mainly damaging winds appear possible Wednesday over parts of southern Georgia and Alabama, and over much of northern Florida. A few severe storms are also possible over the central High Plains late in the day. ...Southeast... The upper trough over the eastern states will generally weaken as the low occludes over the Northeast. A surface low will redevelop over the Atlantic, with drier air spreading southeast across much of the eastern seaboard behind a cold front. Southern portions of the cold front will proceed southward across GA, AL, and into FL, and the corridor immediately ahead of this front will have severe wind potential. Strong heating will occur while a ribbon of 70s F dewpoints are maintained. Tall instability profiles per forecast soundings and MLCAPE over 3000 J/kg will favor high echo tops and possible water-loaded severe downbursts. Shear will be weak, but the general northwest flow regime on the far southern periphery of the upper trough will aid southeastward storm motion and locally severe wind gusts during the afternoon. ...Northern/Central High Plains... A lee trough will develop over eastern MT/WY into the western Dakotas as a minor disturbance rounds the upper ridge and enhances deep-layer shear late in the day. Mid 50s to near 60 F dewpoints will contribute to up to 2000 J/kg MLCAPE, and lapse rates will be relatively steep through a deep layer. Storms are likely to form along the length of the surface trough across eastern MT and WY, with activity spreading eastward into the western Dakotas during the evening. The deeply mixed boundary layer should support strong outflow, which may be locally damaging. Sporadic marginal hail cannot be ruled out as well. ..Jewell.. 07/27/2026 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0207 PM CDT Mon Jul 27 2026 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... On Day 2/Tuesday, occasionally breezy southwesterly winds of 10-15 mph amid RH values of 15-25% may generate locally elevated fire weather concerns across the Columbia Basin and portions of the northern Rockies where fuels remain dry. Please see the previous discussion for additional information. ..Elizalde-Garcia.. 07/27/2026 .PREV DISCUSSION... /ISSUED 1125 PM CDT Sun Jul 26 2026/ ...Synopsis... Another day of mid-level ridging will characterize the upper-air pattern for the western CONUS tomorrow (Tuesday). As in the past couple of days, upper flow pivoting around the ridge should continue to weaken in intensity, supporting a weaker surface wind field in turn. Widespread dry conditions are expected across western portions of the Great Basin toward the Pacific Northwest and northern Rockies. Nonetheless, the lack of a stronger surface wind field precludes fire weather highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1763 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN IOWA INTO FAR NORTHERN MISSOURI
Mesoscale Discussion 1763 NWS Storm Prediction Center Norman OK 1249 PM CDT Mon Jul 27 2026 Areas affected...Southern Iowa into far northern Missouri Concerning...Severe potential...Watch unlikely Valid 271749Z - 271945Z Probability of Watch Issuance...5 percent SUMMARY...An isolated hail threat may materialize through mid-afternoon across southern Iowa into far northern Missouri. In general, this activity is expected to remain sufficiently weak to negate the need for a watch. DISCUSSION...Convection has been gradually deepening per MRMS VIL and echo top imagery over the past hour across southwest to south-central IA. This activity appears to be largely driven by modest ascent along a weak frontal zone draped across the Plains, and is maturing within an environment featuring ample buoyancy (MUCAPE of around 3000 J/kg) and sufficient deep-layer wind shear for organized convection based on the KDMX VWP (which sampled a 0-6 km BWD of just under 25 knots). Given this environment, loosely organized convection appears possible and may pose a threat for sporadic large hail - most likely 1.25 inch or less. The primary modulating factor to overall storm longevity and intensity is increasing inhibition with southward extent and a lack of stronger synoptic forcing for ascent. Consequently, storms will most likely begin to weaken as they track south/southeast (this behavior has already been observed with a few leading cells) and will mainly pose an isolated/transient severe threat through the afternoon. ..Moore/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...DVN...DMX...EAX...OAX... LAT...LON 41929527 41749319 41639261 41419211 40829147 40539143 40309158 40259208 40319453 40469490 40749514 41659562 41859552 41929527 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

MD 1764 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF FAR EASTERN IL INTO IN
Mesoscale Discussion 1764 NWS Storm Prediction Center Norman OK 0108 PM CDT Mon Jul 27 2026 Areas affected...portions of far eastern IL into IN Concerning...Severe potential...Watch likely Valid 271808Z - 271945Z Probability of Watch Issuance...95 percent SUMMARY...An intense bow echo is developing across northeast IL south of Chicago. Potential is increasing for a swath of severe/damaging gusts to develop southeast across parts of far eastern IL into northern/central IN through early evening. A new watch is likely downstream from WW 520. DISCUSSION...A supercell over northeast IL is transitioning toward an intense bow. This is occurring within a corridor of strong/extreme instability (3000-4000 J/kg MLCAPE) and 45+ kt effective shear magnitudes. The downstream airmass into central IN will support maintenance of this developing bow as convection develops southeast at around 40-45 kt. KLOT radar indicates 80 kt winds just a few hundred feet above ground level. Given the favorable thermodynamic and kinematic environment downstream, a swath of damaging winds to 80 mph will be possible across western portions of WW 519 over the next hour. Convection is expected to continue into central IN this afternoon into early evening. In addition to intense/damaging wind gusts, isolated large hail and a tornado or two also are possible. A downstream watch will likely be needed soon. ..Leitman/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILN...IWX...IND...LOT...ILX... LAT...LON 41848732 41548667 41078593 40338542 39828524 39458532 39148563 38918604 38768645 38738688 38828748 39208783 39888796 40658810 41218798 41518797 41738785 41848732 MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

MD 1765 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF THE MID-ATLANTIC
Mesoscale Discussion 1765 NWS Storm Prediction Center Norman OK 0111 PM CDT Mon Jul 27 2026 Areas affected...Parts of the Mid-Atlantic Concerning...Severe potential...Watch unlikely Valid 271811Z - 272015Z Probability of Watch Issuance...5 percent SUMMARY...The potential for damaging downburst winds should increase through late afternoon as thunderstorm coverage increases across portions of the Mid-Atlantic. DISCUSSION...Convection has been percolating across the greater Mid-Atlantic region from late morning through early afternoon. While much of this activity has been fairly shallow and transient so far, a few stronger cores have briefly pulsed to near severe limits before decaying. Weak deep-layer wind shear will continue to modulate overall storm intensity and longevity; however, steady diurnal heating through broken cloud cover has allowed temperatures to warm into the 80s and low 90s within a somewhat moist air mass. This heating/mixing has allowed low-level lapse rates to increase to around 8 to 8.5 C/km, which is favorable for strong downbursts capable of producing damaging winds (most likely 40-60 mph). GOES imagery shows several deepening towers and cumulus clusters, hinting that thunderstorm coverage will continue to increase - especially along a subtle surface trough/weak front draped across the region. The potential for damaging gusts should increase in tandem with thunderstorm coverage, but the overall threat should remain sufficiently localized and transient to preclude watch issuance. ..Moore/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...CTP...LWX... LAT...LON 38207507 37887551 37947593 38207613 38617667 39087684 39667684 40417673 40977659 41447642 41837595 41947547 41907481 41767428 41547395 41257373 40717366 39987386 39387441 38857489 38207507 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

MD 1766 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN GEORGIA INTO SOUTHEASTERN SOUTH CAROLINA
Mesoscale Discussion 1766 NWS Storm Prediction Center Norman OK 0151 PM CDT Mon Jul 27 2026 Areas affected...Eastern Georgia into southeastern South Carolina Concerning...Severe potential...Watch unlikely Valid 271851Z - 272045Z Probability of Watch Issuance...5 percent SUMMARY...Thunderstorms developing across eastern Georgia and into adjacent portions of southeastern South Carolina may pose a damaging wind risk this afternoon. Watch issuance is not expected. DISCUSSION...Growing cumulus and the early stages of thunderstorm development are noted across portions of southeast GA into adjacent areas of SC. This activity comes as diurnal heating erodes inhibition head of a weak mid-level perturbation (the remnants of an early-morning MCS) that is approaching the region. Thunderstorm intensification and coverage should slowly increase as weak ascent ahead of the perturbation overspreads the region and daytime heating continues to bolster buoyancy (MLCAPE values are expected to reach around 3000-3500 J/kg). Very weak deep-layer wind shear will limit storm longevity and intensity, but steepening low-level lapse rates near 8.5 C/km will favor accelerating downdrafts and strong downburst with swaths of damaging winds (most likely peaking between 40-60 mph). Given the poor kinematic environment and the isolated nature of the threat, watch issuance is not expected. ..Moore/Hart.. 07/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...CAE...GSP...JAX...FFC...TAE... LAT...LON 31688100 31418127 31228265 31238318 31438365 31828371 32068357 32738332 33368311 33538296 33768275 33838262 33988231 34058200 34028162 33858128 33548089 33158064 32868058 32358066 31688100 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

WW 0521 Status Updates
STATUS FOR WATCH 0521 HAS NOT BEEN ISSUED YET Read more

WW 0521 Status Updates
STATUS FOR WATCH 0521 HAS NOT BEEN ISSUED YET Read more

WW 521 SEVERE TSTM IL IN 271840Z - 280100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 521 NWS Storm Prediction Center Norman OK 240 PM EDT Mon Jul 27 2026 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of East Central Illinois Central Indiana * Effective this Monday afternoon and evening from 240 PM until 900 PM EDT. * Primary threats include... Widespread damaging winds and isolated significant gusts to 80 mph likely Isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...An intensifying cluster of thunderstorms over northwest Indiana will track southward this afternoon through a very moist and unstable air mass. Severe wind gusts are expected along the leading edge of the storms, along with some risk of large hail and a tornado or two. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 15 miles north northeast of Lafayette IN to 35 miles south of Bloomington IN. 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 519...WW 520... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 31035. ...Hart Read more

WW 0520 Status Updates
STATUS REPORT ON WW 520 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SSW MTW TO 45 SE MBL TO 15 WSW MBS. ..LEITMAN..07/27/26 ATTN...WFO...LOT...IWX...GRR...MKX... STATUS REPORT FOR WS 520 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC031-043-075-091-097-197-271940- IL . ILLINOIS COUNTIES INCLUDED ARE COOK DUPAGE IROQUOIS KANKAKEE LAKE WILL INC003-007-017-033-039-049-069-073-085-087-089-091-099-103-111- 113-127-131-141-149-151-169-181-183-271940- IN . INDIANA COUNTIES INCLUDED ARE ALLEN BENTON CASS DE KALB ELKHART FULTON HUNTINGTON JASPER KOSCIUSKO LAGRANGE LAKE LA PORTE MARSHALL MIAMI NEWTON NOBLE PORTER PULASKI ST. JOSEPH STARKE STEUBEN WABASH WHITE WHITLEY Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 PM CDT Mon Jul 27 2026 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN MID ATLANTIC INTO THE CAROLINAS AND PARTS OF THE APPALACHIANS... ...SUMMARY... Severe thunderstorms capable of damaging winds and isolated hail are possible from the southern Mid-Atlantic into the Carolinas and parts of the Appalachians Tuesday into Tuesday evening. A tornado threat may develop from southeast Virginia into eastern North Carolina. Isolated severe wind gusts and large hail may occur in the central High Plains. ...Southern Mid Atlantic / Appalachians / Carolinas... An upper trough will gradually deepen and move southeastward across the Mid Atlantic, with the left-front quadrant of the upper jet moving across VA and NC. At the surface, low pressure will deepen ahead of a cold front, with wind shift roughly from eastern PA into central VA and NC during the afternoon. A moist and unstable air mass will develop across the region, and shear profiles will become increasingly favorable for supercells. The most favorable combination of shear and instability looks to be from parts of eastern VA into east-central/northeast NC. Here, 850 mb winds will increase out of the southwest to around 30 kt, with effective SRH possibly into the 200-300 m2/s2 range. A tornado or two is possible, with perhaps a transition to bows producing damaging winds. This area will be watched closely into the Day 1 period. Farther north and also within the surface trough, shear will be weaker aloft. However, favorable low-level shear may yield a brief tornado as well into eastern PA/NJ. Otherwise, additional storms are likely across the Appalachians as surface heating occurs beneath the relatively cool temperatures aloft. Low-level winds will be more veered in these areas, but long hodographs and substantial instability will still favor hail and locally damaging winds. ...Central High Plains... Strong heating will occur under the upper ridge, with a weak lee trough developing. Surface winds will back to easterly late in the day and evening, which will increase upslope-flow and yield a moderately unstable environment by afternoon with MLCAPE of 1500-2500 J/kg. This will support scattered thunderstorm development along the high terrain within a kinematic environment featuring 30-35 kt westerly deep-layer shear. Transient supercell structures appear possible, which suggest some marginally severe hail potential despite the warm mid-level temperatures. Generally mixed-modes should persist into the evening into eastern CO and far western NE with locally strong gusts. ..Jewell.. 07/27/2026 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 PM CDT Mon Jul 27 2026 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTHERN MID ATLANTIC INTO THE CAROLINAS AND PARTS OF THE APPALACHIANS... ...SUMMARY... Severe thunderstorms capable of damaging winds and isolated hail are possible from the southern Mid-Atlantic into the Carolinas and parts of the Appalachians Tuesday into Tuesday evening. A tornado threat may develop from southeast Virginia into eastern North Carolina. Isolated severe wind gusts and large hail may occur in the central High Plains. ...Southern Mid Atlantic / Appalachians / Carolinas... An upper trough will gradually deepen and move southeastward across the Mid Atlantic, with the left-front quadrant of the upper jet moving across VA and NC. At the surface, low pressure will deepen ahead of a cold front, with wind shift roughly from eastern PA into central VA and NC during the afternoon. A moist and unstable air mass will develop across the region, and shear profiles will become increasingly favorable for supercells. The most favorable combination of shear and instability looks to be from parts of eastern VA into east-central/northeast NC. Here, 850 mb winds will increase out of the southwest to around 30 kt, with effective SRH possibly into the 200-300 m2/s2 range. A tornado or two is possible, with perhaps a transition to bows producing damaging winds. This area will be watched closely into the Day 1 period. Farther north and also within the surface trough, shear will be weaker aloft. However, favorable low-level shear may yield a brief tornado as well into eastern PA/NJ. Otherwise, additional storms are likely across the Appalachians as surface heating occurs beneath the relatively cool temperatures aloft. Low-level winds will be more veered in these areas, but long hodographs and substantial instability will still favor hail and locally damaging winds. ...Central High Plains... Strong heating will occur under the upper ridge, with a weak lee trough developing. Surface winds will back to easterly late in the day and evening, which will increase upslope-flow and yield a moderately unstable environment by afternoon with MLCAPE of 1500-2500 J/kg. This will support scattered thunderstorm development along the high terrain within a kinematic environment featuring 30-35 kt westerly deep-layer shear. Transient supercell structures appear possible, which suggest some marginally severe hail potential despite the warm mid-level temperatures. Generally mixed-modes should persist into the evening into eastern CO and far western NE with locally strong gusts. ..Jewell.. 07/27/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1149 AM CDT Mon Jul 27 2026 Valid 271630Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MIDWEST... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE CENTRAL HIGH PLAINS... CORRECTED FOR THUNDERSTORM LINES ...SUMMARY... Severe storms capable of strong to severe wind gusts and large hail are expected across the Great Lakes and Midwest through tonight. More sporadic occurrences of damaging wind are possible in the Mid-Atlantic, Tennessee Valley, central High Plains, and southeast Arizona. ...Midwest/Ohio Valley... A large upper ridge remains present today over the central Plains/Rockies, with moderately strong northwest flow aloft from the Midwest into the OH Valley. A very moist and unstable low-level air mass resides from WI/IL into MI/IN/OH, where mostly clear skies will result in hot afternoon temperatures and MLCAPE values over 3000 J/kg. Multiple clusters of intense thunderstorms are ongoing over parts of WI tracking southeastward. These storms will move through this reservoir of high CAPE, leading to the potential for an active severe weather event today. However, details of how these clusters evolve are uncertain. Vertical shear across this region will support supercell structures, capable of damaging winds, hail, and isolated tornadoes this afternoon. However, the greater concern is if storms can congeal into a southeastward bowing system and that sweeps across Lower MI, eastern IL, IN, and western OH. Several morning CAM solutions indicate that risk, with storms spreading into KY overnight before weakening. Unfortunately, this synoptic pattern does not lend itself to a high-confidence convective forecast. ...High Plains... Widespread clouds are affecting parts of western NE this morning. However, strong heating will occur north and south of these clouds, leading to afternoon thunderstorms. The most active area will likely be over the Black Hills region where damaging winds and hail are possible. Farther south, widely scattered high-based thunderstorms will affect eastern CO/western KS with a risk of damaging wind gusts. ..Hart/Moore.. 07/27/2026 Read more