Storm Prediction Center

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Mon Apr 27 2026 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE ALLEGHENY PLATEAU TO THE MID ATLANTIC...AND ALSO FROM PARTS OF TEXAS TO THE CENTRAL GULF COAST REGION... ...SUMMARY... Strong to locally severe storms are possible across parts of the Allegheny Plateau into Mid Atlantic, as well as from west-central Texas to the central Gulf Coast, mainly Wednesday afternoon and evening. ...West-central TX into the Southeast/Central Gulf Coast... A substantial buoyancy reservoir is expected to persist from parts of central/south TX toward the lower MS Valley on Wednesday. Due to substantial early-week convection, considerable uncertainty remains regarding the potential for an ongoing isolated severe threat in the morning, and the location of the composite front/outflow and potential redevelopment during the afternoon and evening. With favorable instability and deep-layer shear, the environment will be conditionally favorable for organized convection, including potential for large hail and locally damaging wind. Large-scale ascent is likely to be displaced north of the primary surface boundary and strongest instability, so storm coverage remains uncertain, but isolated supercells and/or small clusters will be possible along/south of the front. An increase in severe probabilities may eventually be needed across parts of this region, depending on observational and guidance trends regarding boundary placement and anticipated storm coverage. ...Allegheny Plateau to the Mid Atlantic... A vigorous mid/upper-level shortwave trough is forecast to move from the Midwest toward the Mid Atlantic on Wednesday. An attendant surface low will move from the upper OH Valley toward the Delmarva region, with trailing front extending southwestward into parts of the Southeast, Carolinas, and Virginia by afternoon. The expectation for substantial early-day cloudiness and precipitation continues to result in uncertainty regarding potential for appreciable destabilization during the afternoon. If sufficient destabilization can occur, then favorable large-scale ascent and deep-layer shear related to the approaching shortwave trough could support organized storms, with a threat of damaging wind and possibly some hail. Due to the lingering uncertainties regarding destabilization, a broad Level 1/Marginal Risk is maintained with this outlook. An eventual increase in severe probabilities will be possible for parts of the region, depending on how the uncertainties are resolved. ..Dean.. 04/27/2026 Read more

WW 0161 Status Updates
STATUS FOR WATCH 0161 HAS NOT BEEN ISSUED YET Read more

WW 0160 Status Updates
STATUS REPORT ON WW 160 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..HART..04/27/26 ATTN...WFO...LSX...ILX...PAH...SGF... STATUS REPORT FOR WT 160 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-013-025-027-033-047-049-051-055-065-077-079-081-083-101- 117-119-121-133-135-145-157-159-163-189-191-193-272040- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CALHOUN CLAY CLINTON CRAWFORD EDWARDS EFFINGHAM FAYETTE FRANKLIN HAMILTON JACKSON JASPER JEFFERSON JERSEY LAWRENCE MACOUPIN MADISON MARION MONROE MONTGOMERY PERRY RANDOLPH RICHLAND ST. CLAIR WASHINGTON WAYNE WHITE MOC015-027-029-043-051-055-059-065-067-071-073-077-085-091-093- 099-105-113-123-125-131-135-139-141-149-151-153-157-161-167-169- 179-183-186-187-189-203-213-215-219-221-225-229-510-272040- MO . MISSOURI COUNTIES INCLUDED ARE BENTON CALLAWAY CAMDEN CHRISTIAN COLE CRAWFORD Read more

WW 0159 Status Updates
STATUS REPORT ON WW 159 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SW HUF TO 15 E HUF TO 25 NW IND TO 30 ENE IND. ..HART..04/27/26 ATTN...WFO...PAH...IND...LMK... STATUS REPORT FOR WS 159 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC185-272040- IL . ILLINOIS COUNTIES INCLUDED ARE WABASH INC013-021-025-027-037-051-055-063-081-083-093-097-101-105-109- 117-119-123-125-129-133-147-153-163-173-272040- IN . INDIANA COUNTIES INCLUDED ARE BROWN CLAY CRAWFORD DAVIESS DUBOIS GIBSON GREENE HENDRICKS JOHNSON KNOX LAWRENCE MARION MARTIN MONROE MORGAN ORANGE OWEN PERRY PIKE POSEY PUTNAM SPENCER SULLIVAN VANDERBURGH WARRICK Read more

WW 0159 Status Updates
STATUS REPORT ON WW 159 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SW HUF TO 15 E HUF TO 25 NW IND TO 30 ENE IND. ..HART..04/27/26 ATTN...WFO...PAH...IND...LMK... STATUS REPORT FOR WS 159 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC185-272040- IL . ILLINOIS COUNTIES INCLUDED ARE WABASH INC013-021-025-027-037-051-055-063-081-083-093-097-101-105-109- 117-119-123-125-129-133-147-153-163-173-272040- IN . INDIANA COUNTIES INCLUDED ARE BROWN CLAY CRAWFORD DAVIESS DUBOIS GIBSON GREENE HENDRICKS JOHNSON KNOX LAWRENCE MARION MARTIN MONROE MORGAN ORANGE OWEN PERRY PIKE POSEY PUTNAM SPENCER SULLIVAN VANDERBURGH WARRICK Read more

WW 159 SEVERE TSTM IL IN KY 271610Z - 272300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 159 NWS Storm Prediction Center Norman OK 1110 AM CDT Mon Apr 27 2026 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Illinois Southern and Central Indiana Northern Kentucky * Effective this Monday morning and evening from 1110 AM until 600 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...Elevated storms will spread generally eastward and potentially pose a hail risk while damaging wind risk may increase into western/southern Indiana as well as an upstream linear cluster of storms moves into the region. The severe thunderstorm watch area is approximately along and 35 statute miles east and west of a line from 15 miles east of Lafayette IN to 20 miles west southwest of Owensboro KY. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 158... 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 27025. ...Guyer Read more

WW 0158 Status Updates
STATUS REPORT ON WW 158 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 E SLO TO 25 SSE MTO TO 20 SW HUF. ..HART..04/27/26 ATTN...WFO...LSX...ILX...DVN... STATUS REPORT FOR WS 158 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC025-033-049-079-101-159-272040- IL . ILLINOIS COUNTIES INCLUDED ARE CLAY CRAWFORD EFFINGHAM JASPER LAWRENCE RICHLAND 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 0158 Status Updates
STATUS REPORT ON WW 158 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 E SLO TO 25 SSE MTO TO 20 SW HUF. ..HART..04/27/26 ATTN...WFO...LSX...ILX...DVN... STATUS REPORT FOR WS 158 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC025-033-049-079-101-159-272040- IL . ILLINOIS COUNTIES INCLUDED ARE CLAY CRAWFORD EFFINGHAM JASPER LAWRENCE RICHLAND 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 158 SEVERE TSTM IL 271330Z - 272100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 158 NWS Storm Prediction Center Norman OK 830 AM CDT Mon Apr 27 2026 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and Southern Illinois * Effective this Monday morning and afternoon from 830 AM until 400 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 70 mph likely A tornado or two possible SUMMARY...A bowing linear cluster will continue to steadily move eastward with additional development to its southeast. Large hail and damaging winds are the primary concerns, especially as the air mass continues to warm/destabilize across southern and central Illinois through late morning and afternoon. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 20 miles north northwest of Quincy IL to 40 miles east southeast of Mattoon IL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). 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 156...WW 157... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25030. ...Guyer Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 AM CDT MON APR 27 2026 ...Severe thunderstorms expected over parts of the mid Mississippi Valley and Mid-South today and tonight... * LOCATIONS... Southern and Central Illinois Central and Eastern Missouri Western Kentucky Western Indiana Northern and Central Arkansas Western Tennessee * HAZARDS... Several tornadoes, a couple intense Widespread damaging winds Scattered large hail, some baseball size * SUMMARY... Numerous severe thunderstorms are expected from the mid Mississippi/lower Ohio Valleys into the Mid-South through this evening, with a threat for multiple strong to intense tornadoes (EF-3+), widespread severe/damaging wind gusts, and scattered large to very large hail. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 AM CDT MON APR 27 2026 ...Severe thunderstorms expected over parts of the mid Mississippi Valley and Mid-South today and tonight... * LOCATIONS... Southern and Central Illinois Central and Eastern Missouri Western Kentucky Western Indiana Northern and Central Arkansas Western Tennessee * HAZARDS... Several tornadoes, a couple intense Widespread damaging winds Scattered large hail, some baseball size * SUMMARY... Numerous severe thunderstorms are expected from the mid Mississippi/lower Ohio Valleys into the Mid-South through this evening, with a threat for multiple strong to intense tornadoes (EF-3+), widespread severe/damaging wind gusts, and scattered large to very large hail. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. Read more

MD 0568 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR CENTRAL MISSOURI INTO WEST-CENTRAL AND SOUTHWEST ILLINOIS
Mesoscale Discussion 0568 NWS Storm Prediction Center Norman OK 1156 AM CDT Mon Apr 27 2026 Areas affected...central Missouri into west-central and southwest Illinois Concerning...Severe potential...Watch likely Valid 271656Z - 271900Z Probability of Watch Issuance...80 percent SUMMARY...A surface-based, severe-storm threat is expected to increase this afternoon. All hazards are possible, including the potential for strong tornadoes. A Tornado Watch will likely be required. DISCUSSION...Deep-moist convection remains active along the immediate cold side of an outflow boundary stretching from the St. Louis metropolitan area into central MO near Warsaw. To the south of that boundary, cloud breaks have allowed boundary-layer temperatures to warm into the upper 70s, which when coupled with dewpoints in the mid to upper 60s and steep mid-level lapse rates is resulting in MLCAPE of 1500-2500 J/kg with decreasing cap strength. Latest model guidance suggests that the influx of the moderately unstable air mass into the ongoing storms will support a gradual uptick in intensity by early afternoon, confined largely along the current position of the outflow boundary. The deleterious effects of the active cold pools casts uncertainty of the preferred storm mode immediately along the boundary, in an otherwise increasingly favorable environment for tornadic supercells as afternoon progresses. However, even in a mixed-mode case, the overall environmental evolution will support all severe-weather hazards, including the potential for strong tornadoes. ..Mead/Guyer.. 04/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...SGF...EAX... LAT...LON 38679274 39019152 39328990 38778948 38168963 37969245 37929327 38519334 38679274 MOST PROBABLE PEAK TORNADO INTENSITY...120-145 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

MD 0569 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN
Mesoscale Discussion 0569 NWS Storm Prediction Center Norman OK 1252 PM CDT Mon Apr 27 2026 Areas affected...southeast Minnesota...northeast Iowa...and southwest Wisconsin Concerning...Severe potential...Watch unlikely Valid 271752Z - 272015Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe storms are possible this afternoon with the primary hazard being hail up to 1.0-1.5" in diameter. DISCUSSION...Early-afternoon water-vapor imagery indicates a vigorous vorticity maximum over northern IA into southern MN, lifting to northeast. At the surface, 17z analysis placed a low over south-central MN with a cold front trailing to the south-southwest, and a trough/wind shift extending southeast into eastern IA. Convection is in the process of deepening as of 17z along the cold front in north-central IA amidst a marginally unstable air mass with estimated MLCAPE of 250-500 J/kg, per objective analysis. Breaks in the clouds ahead of the cold front will allow for further destabilization this afternoon, especially given the height falls/mid-level cooling overspreading the region from the west/southwest. As such a few strong to potentially severe storms are expected to develop along and ahead of the surface low and cold front this afternoon with the primary hazard being hail up to 1.0-1.5" in diameter. Veered low-level winds (evident in RAP forecast soundings) are expected to limit a more robust tornado threat, at least along the cold front. A potentially more favorable low-level wind profile likely exists along/east of the surface wind shift preceding the cold front. The most likely location for a brief spin up is along and to the southeast of the surface low track where local maximum in surface vorticity will coincide with 0-3-km CAPE of 100-125 J/kg. ..Mead/Guyer.. 04/27/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MKX...DVN...ARX...MPX...DMX... LAT...LON 43249360 44199277 44519158 44128998 42799001 42249125 42079218 42519343 43249360 MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

WW 0159 Status Updates
STATUS REPORT ON WW 159 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..HART..04/27/26 ATTN...WFO...PAH...IND...LMK... STATUS REPORT FOR WS 159 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC185-271840- IL . ILLINOIS COUNTIES INCLUDED ARE WABASH INC011-013-021-023-027-037-045-051-055-057-063-081-083-093-097- 101-105-107-109-117-119-121-125-129-133-147-153-157-163-165-167- 171-173-271840- IN . INDIANA COUNTIES INCLUDED ARE BOONE BROWN CLAY CLINTON DAVIESS DUBOIS FOUNTAIN GIBSON GREENE HAMILTON HENDRICKS JOHNSON KNOX LAWRENCE MARION MARTIN MONROE MONTGOMERY MORGAN ORANGE OWEN PARKE PIKE POSEY PUTNAM SPENCER SULLIVAN TIPPECANOE VANDERBURGH VERMILLION VIGO WARREN WARRICK Read more

WW 0160 Status Updates
STATUS FOR WATCH 0160 HAS NOT BEEN ISSUED YET Read more

WW 0158 Status Updates
STATUS REPORT ON WW 158 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNW ALN TO 35 SSW DEC TO 20 NE MTO TO 25 SSW DNV TO 25 NNW DNV. ..HART..04/27/26 ATTN...WFO...LSX...ILX...DVN... STATUS REPORT FOR WS 158 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-023-025-027-029-033-035-045-049-051-079-101-117-121-135- 159-173-183-189-271840- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CLARK CLAY CLINTON COLES CRAWFORD CUMBERLAND EDGAR EFFINGHAM FAYETTE JASPER LAWRENCE MACOUPIN MARION MONTGOMERY RICHLAND SHELBY VERMILION WASHINGTON 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

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 PM CDT Mon Apr 27 2026 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR NORTH-CENTRAL/NORTHEAST TEXAS...SOUTHEAST OKLAHOMA...CENTRAL/SOUTHERN ARKANSAS...NORTHERN LOUISIANA...NORTHERN MISSISSIPPI... ...SUMMARY... Scattered strong to severe thunderstorm development is probable across parts of the southeastern Great Plains through the lower Mississippi and Tennessee Valleys Tuesday afternoon and evening. Large to very large hail, swaths of damaging wind, and a few tornadoes are possible. ...Southeastern Great Plains into the Tennessee Valley... Within broad southwesterly flow aloft, a mid/upper-level shortwave trough is forecast to move from the south-central Rockies toward the mid MS Valley on Tuesday. Other low-amplitude vorticity maxima may move from TX toward the TN Valley and Southeast, to the south of the primary shortwave trough. These features will impinge upon a reservoir of strong instability extending from the southern Plains into the lower MS Valley, resulting in a potentially active severe weather episode Tuesday afternoon into Tuesday night. Elevated convection will likely be ongoing across parts of the region Tuesday morning, which could pose a threat for large hail and locally gusty winds, especially within the more favorable lapse rate/buoyancy environment across the southern Plains into the ArkLaTex. Strong diurnal destabilization will be possible by Tuesday afternoon, to the east of a dryline across TX, and along and to the warm side of an outflow-influenced front extending from southeast OK toward the mid MS Valley. Evolution of storm development remains uncertain, but initiation will be possible along the dryline/front and any other outflow boundaries in place by afternoon. Strong buoyancy (MLCAPE of 3000-4000 J/kg across TX, and 2000 J/kg as far east as the ArkLaMiss) and favorable deep-layer shear will support supercell development, with an attendant threat of very large hail initially. Modestly enhanced low-level flow from east TX into the ArkLaMiss will also support some tornado potential, with some conditional risk of a strong tornado with any sustained supercell. An increase in storm coverage should lead to development of storm clusters and potentially an MCS that would spread eastward into the evening, with one or more swaths of damaging wind possible. Storms should eventually weaken late in the period as they encounter weaker instability with eastward extent, but the severe threat could persist through much of the night with any organized storm structures. ..Dean.. 04/27/2026 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 PM CDT Mon Apr 27 2026 Valid 281200Z - 291200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR NORTH-CENTRAL/NORTHEAST TEXAS...SOUTHEAST OKLAHOMA...CENTRAL/SOUTHERN ARKANSAS...NORTHERN LOUISIANA...NORTHERN MISSISSIPPI... ...SUMMARY... Scattered strong to severe thunderstorm development is probable across parts of the southeastern Great Plains through the lower Mississippi and Tennessee Valleys Tuesday afternoon and evening. Large to very large hail, swaths of damaging wind, and a few tornadoes are possible. ...Southeastern Great Plains into the Tennessee Valley... Within broad southwesterly flow aloft, a mid/upper-level shortwave trough is forecast to move from the south-central Rockies toward the mid MS Valley on Tuesday. Other low-amplitude vorticity maxima may move from TX toward the TN Valley and Southeast, to the south of the primary shortwave trough. These features will impinge upon a reservoir of strong instability extending from the southern Plains into the lower MS Valley, resulting in a potentially active severe weather episode Tuesday afternoon into Tuesday night. Elevated convection will likely be ongoing across parts of the region Tuesday morning, which could pose a threat for large hail and locally gusty winds, especially within the more favorable lapse rate/buoyancy environment across the southern Plains into the ArkLaTex. Strong diurnal destabilization will be possible by Tuesday afternoon, to the east of a dryline across TX, and along and to the warm side of an outflow-influenced front extending from southeast OK toward the mid MS Valley. Evolution of storm development remains uncertain, but initiation will be possible along the dryline/front and any other outflow boundaries in place by afternoon. Strong buoyancy (MLCAPE of 3000-4000 J/kg across TX, and 2000 J/kg as far east as the ArkLaMiss) and favorable deep-layer shear will support supercell development, with an attendant threat of very large hail initially. Modestly enhanced low-level flow from east TX into the ArkLaMiss will also support some tornado potential, with some conditional risk of a strong tornado with any sustained supercell. An increase in storm coverage should lead to development of storm clusters and potentially an MCS that would spread eastward into the evening, with one or more swaths of damaging wind possible. Storms should eventually weaken late in the period as they encounter weaker instability with eastward extent, but the severe threat could persist through much of the night with any organized storm structures. ..Dean.. 04/27/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1150 AM CDT Mon Apr 27 2026 Valid 271630Z - 281200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS EAST/SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...WESTERN KENTUCKY...AND NORTHWEST TENNESSEE... ...SUMMARY... Numerous severe thunderstorms are expected from the mid Mississippi/lower Ohio Valleys into the Mid-South through this evening, with a threat for multiple strong to intense tornadoes (EF3+), widespread severe/damaging wind gusts, and scattered large to very large hail. ...Mid Mississippi Valley/Midwest into the Mid-South/Lower Mississippi Valley... Forecast scenario largely unchanged in that a very active severe-weather/tornado day is expected regionally, especially into late afternoon and this evening. Initially, a relatively long-lived linear cluster of convection persists at late morning across east-central/south-central Illinois, with additional initially elevated storms on its eastern/southern periphery, moving from eastern Illinois into Indiana, with severe hail and damaging winds persisting as early day hazards. Over time, air mass will continue to moisten and rapidly destabilize along/south of the MCS-associated outflow from central Missouri into south-central Illinois. A mid/upper-level trough will eject northeastward from the northern/central Plains into the Midwest and middle Mississippi Valley through the period. Low-level mass response will encourage the primary surface low to consolidate across Minnesota/Wisconsin by this evening, with a warm front effectively delineated by the morning convection. Strengthening west-southwesterly flow aloft associated with a 50-70 kt mid-level jet will overspread much of the warm sector by peak heating, and a 35-45 kt south-southwesterly low-level jet will both provide ample low-level and deep-layer shear to support supercells. Initially discrete surface-based development appears likely to occur into mid-afternoon across the mid Mississippi Valley/Mid-South ahead of the surface cold front, and perhaps along weak low-level confluence zones in the open warm sector including generally near the confluence of the Mississippi/Ohio Rivers southward into the Mid-South. These supercells will exist in a very favorable environment for tornadoes through the afternoon and evening, and multiple strong to intense tornadoes (EF2/3+) appear likely, especially from parts of Missouri into Illinois along/near the effective front. This strong tornado potential will also likely extend farther south within the warm sector into the Mid-South. By early evening, convection will probably tend to consolidate into clusters of supercells and then more linear segments with some increase in damaging wind potential aside from large hail and a continued multi-mode tornado risk tonight. ...ArkLaTex into Texas... While storm coverage may trend lesser with southwest extent, the potential for at least isolated intense storms will exist across the region. Supercells capable of producing large to very large hail and occasional damaging winds are expected. Increasing low-level warm/moist advection tonight could foster additional robust thunderstorms along the retreating dryline and eventually the southward-moving cold front. ..Guyer/Weinman.. 04/27/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1150 AM CDT Mon Apr 27 2026 Valid 271630Z - 281200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS EAST/SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...WESTERN KENTUCKY...AND NORTHWEST TENNESSEE... ...SUMMARY... Numerous severe thunderstorms are expected from the mid Mississippi/lower Ohio Valleys into the Mid-South through this evening, with a threat for multiple strong to intense tornadoes (EF3+), widespread severe/damaging wind gusts, and scattered large to very large hail. ...Mid Mississippi Valley/Midwest into the Mid-South/Lower Mississippi Valley... Forecast scenario largely unchanged in that a very active severe-weather/tornado day is expected regionally, especially into late afternoon and this evening. Initially, a relatively long-lived linear cluster of convection persists at late morning across east-central/south-central Illinois, with additional initially elevated storms on its eastern/southern periphery, moving from eastern Illinois into Indiana, with severe hail and damaging winds persisting as early day hazards. Over time, air mass will continue to moisten and rapidly destabilize along/south of the MCS-associated outflow from central Missouri into south-central Illinois. A mid/upper-level trough will eject northeastward from the northern/central Plains into the Midwest and middle Mississippi Valley through the period. Low-level mass response will encourage the primary surface low to consolidate across Minnesota/Wisconsin by this evening, with a warm front effectively delineated by the morning convection. Strengthening west-southwesterly flow aloft associated with a 50-70 kt mid-level jet will overspread much of the warm sector by peak heating, and a 35-45 kt south-southwesterly low-level jet will both provide ample low-level and deep-layer shear to support supercells. Initially discrete surface-based development appears likely to occur into mid-afternoon across the mid Mississippi Valley/Mid-South ahead of the surface cold front, and perhaps along weak low-level confluence zones in the open warm sector including generally near the confluence of the Mississippi/Ohio Rivers southward into the Mid-South. These supercells will exist in a very favorable environment for tornadoes through the afternoon and evening, and multiple strong to intense tornadoes (EF2/3+) appear likely, especially from parts of Missouri into Illinois along/near the effective front. This strong tornado potential will also likely extend farther south within the warm sector into the Mid-South. By early evening, convection will probably tend to consolidate into clusters of supercells and then more linear segments with some increase in damaging wind potential aside from large hail and a continued multi-mode tornado risk tonight. ...ArkLaTex into Texas... While storm coverage may trend lesser with southwest extent, the potential for at least isolated intense storms will exist across the region. Supercells capable of producing large to very large hail and occasional damaging winds are expected. Increasing low-level warm/moist advection tonight could foster additional robust thunderstorms along the retreating dryline and eventually the southward-moving cold front. ..Guyer/Weinman.. 04/27/2026 Read more