SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Fri Apr 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL INTO NORTHERN MISSOURI INTO FAR WESTERN ILLINOIS... ...SUMMARY... Severe thunderstorms are expected on Sunday from east Texas into the lower Missouri and middle Mississippi Valleys. The greatest damaging wind and tornado potential will be over central and northern Missouri into far western Illinois. ...Synopsis and Discussion... Models are in relatively good agreement depicting a negative-tilt shortwave trough and upper low moving northeastward from the TX Panhandle Sunday morning into IA by 00Z. The leading speed max will be compact but intense, resulting in rapid height falls across KS/MO/IA/IL. At the surface, low pressure will deepen from eastern OK into IA, with a cold front extending south from the low and sweeping eastward across MO, AR, and southeast IA during the day. As the low develops northward, a warm front will surge north across far eastern KS, MO and IL, with low 60s F dewpoints possible. Heating will occur as well, resulting in MUCAPE of 750-1000 J/kg. Although instability will not be particularly high, shear profiles will become quite strong, supporting supercells with tornado potential. Several models indicate cells along a line and/or QLCS type structures with activity moving rapidly across the area, in a region with over 300 m2/s2 ESRH. Storms may form before noon across far eastern KS and OK, with a maturing line of severe storms into western MO and northwest AR by 21Z. Damaging wind and isolated tornado risk will peak during the late afternoon or early evening, supported by the fast-moving shortwave trough. Depending on instability trends, sig/hatching could be added in later updates. ..Jewell.. 04/18/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Fri Apr 18 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL INTO NORTHERN MISSOURI INTO FAR WESTERN ILLINOIS... ...SUMMARY... Severe thunderstorms are expected on Sunday from east Texas into the lower Missouri and middle Mississippi Valleys. The greatest damaging wind and tornado potential will be over central and northern Missouri into far western Illinois. ...Synopsis and Discussion... Models are in relatively good agreement depicting a negative-tilt shortwave trough and upper low moving northeastward from the TX Panhandle Sunday morning into IA by 00Z. The leading speed max will be compact but intense, resulting in rapid height falls across KS/MO/IA/IL. At the surface, low pressure will deepen from eastern OK into IA, with a cold front extending south from the low and sweeping eastward across MO, AR, and southeast IA during the day. As the low develops northward, a warm front will surge north across far eastern KS, MO and IL, with low 60s F dewpoints possible. Heating will occur as well, resulting in MUCAPE of 750-1000 J/kg. Although instability will not be particularly high, shear profiles will become quite strong, supporting supercells with tornado potential. Several models indicate cells along a line and/or QLCS type structures with activity moving rapidly across the area, in a region with over 300 m2/s2 ESRH. Storms may form before noon across far eastern KS and OK, with a maturing line of severe storms into western MO and northwest AR by 21Z. Damaging wind and isolated tornado risk will peak during the late afternoon or early evening, supported by the fast-moving shortwave trough. Depending on instability trends, sig/hatching could be added in later updates. ..Jewell.. 04/18/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 PM CDT Fri Apr 18 2025 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF CENTRAL TEXAS NORTHEASTWARD INTO SOUTHERN MISSOURI... ...SUMMARY... Scattered strong to severe thunderstorms are possible mainly from Texas into southern Missouri on Saturday. Isolated strong storms may occur during the day across the Ohio Valley. ...Synopsis... An upper trough will fill slightly as it moves from AZ/NM into the southern Plains. Ahead of this feature a broad belt of strong southwest flow aloft will extend from the southern Plains into the Northeast, where a deepening upper low will develop into Quebec. Meanwhile, an upper ridge will remain situated over the Southeast. At the surface, a boundary will stretch from the northeastern states southwestward across the OH Valley and into northwest TX. The New England portion of this boundary will push east as a cold front during the day, with scattered convection in a weak instability but strong mean wind environment. The OH Valley portion of the front will be stationary, but a narrow band of instability will exist along it. Glancing warm advection with west/southwest winds and heating may yield a few thunderstorms, but sounding show relatively weak instability or overall severe potential. ...TX into southern MO and into the OH Valley... Early day storms are likely to exist from eastern OK into MO and extending north of the OH River, in a zone of low-level theta-e advection. Marginal hail cannot be ruled out over southern parts of this regime where elevated instability will be stronger, but overall it appears widespread rain may reduce severe potential at that time. To the south, stronger instability will exist from OK into TX, with a destabilizing warm sector south of the quasi-stationary front. This front will extend roughly from eastern OK into southwest TX through the period, with substantial moisture flux northward into the lifting zone. As such, midday development is likely over much of west-central/northwest TX with expanding coverage across the remainder of northern TX, OK, and southern MO. Areas of elevated hail cannot be ruled out anywhere north of the front given strong deep-layer shear. Supercells with very large hail and perhaps a brief tornado prior to cold front surge are expected during the late afternoon over west-central TX south of the cold front, and perhaps as far north as the Red River as the low-level jet increases during the evening. Overnight, another round of storms will occur over western and central TX as the deeper cold front arrives coincident with the shortwave. Both damaging winds and embedded hail cores are expected with a linear storm mode. ..Jewell.. 04/18/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1137 AM CDT Fri Apr 18 2025 Valid 181700Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN/EASTERN NEW MEXICO INTO FAR WEST TEXAS... ...1630 Update... A faster southward progression of a backdoor cold front across the Texas Panhandle as far south as US-70 has temporarily mitigated fire weather concerns across the area. However, some northeastward retreat and daytime mixing should allow dry southwest flow to return to portions of northeastern New Mexico and the Texas Panhandle supporting at least a brief period of Elevated fire weather conditions to emerge within this zone. The Critical fire weather threat will continue for much of southeastern New Mexico. Eastern extent of Elevated highlights were trimmed along the Florida Atlantic Coast as higher dewpoints/relative humidity accompany southeasterly onshore flow. Farther inland however, Elevated fire weather conditions expected with east-southeast winds of 10-15 mph and relative humidity dropping into the 35-40 percent range this afternoon amid increasingly dry fuels. ..Williams/Lyons.. 04/18/2025 .PREV DISCUSSION... /ISSUED 1245 AM CDT Fri Apr 18 2025/ ...Synopsis... An upper trough initially in the Great Basin will move towards the Four Corners region today. A modest surface low in eastern New Mexico into West Texas will develop during the day. A cold front will continue to make southward progress into the southern Plains. ...New Mexico into West Texas... Elevated to critical fire weather conditions are again expected during the afternoon. Moderate mid-level flow across the Southwest and southern Plains and a modest surface low along the Texas/New Mexico border will drive 15-20 mph (up to 25 mph in the terrain) surface winds by the afternoon. RH will be slightly higher than Thursday on account of mid/upper-level clouds. Values of around 10% may occur, but will occur on a relatively local basis. 15-20% will be more common. The driest fuels will be in New Mexico and the Trans-Pecos. Farther east in the Texas Panhandle/South Plains, transitional/greening fuels will mitigate fire weather concerns even with similarly dry and windy conditions. ...Florida... Easterly winds of around 10 mph appear possible during the afternoon. RH of 25-35% can be expected along the western Peninsula. With dry fuels (current ERC data showing some locations above the 90th percentile), elevated fire weather is likely this afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1137 AM CDT Fri Apr 18 2025 Valid 181700Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN/EASTERN NEW MEXICO INTO FAR WEST TEXAS... ...1630 Update... A faster southward progression of a backdoor cold front across the Texas Panhandle as far south as US-70 has temporarily mitigated fire weather concerns across the area. However, some northeastward retreat and daytime mixing should allow dry southwest flow to return to portions of northeastern New Mexico and the Texas Panhandle supporting at least a brief period of Elevated fire weather conditions to emerge within this zone. The Critical fire weather threat will continue for much of southeastern New Mexico. Eastern extent of Elevated highlights were trimmed along the Florida Atlantic Coast as higher dewpoints/relative humidity accompany southeasterly onshore flow. Farther inland however, Elevated fire weather conditions expected with east-southeast winds of 10-15 mph and relative humidity dropping into the 35-40 percent range this afternoon amid increasingly dry fuels. ..Williams/Lyons.. 04/18/2025 .PREV DISCUSSION... /ISSUED 1245 AM CDT Fri Apr 18 2025/ ...Synopsis... An upper trough initially in the Great Basin will move towards the Four Corners region today. A modest surface low in eastern New Mexico into West Texas will develop during the day. A cold front will continue to make southward progress into the southern Plains. ...New Mexico into West Texas... Elevated to critical fire weather conditions are again expected during the afternoon. Moderate mid-level flow across the Southwest and southern Plains and a modest surface low along the Texas/New Mexico border will drive 15-20 mph (up to 25 mph in the terrain) surface winds by the afternoon. RH will be slightly higher than Thursday on account of mid/upper-level clouds. Values of around 10% may occur, but will occur on a relatively local basis. 15-20% will be more common. The driest fuels will be in New Mexico and the Trans-Pecos. Farther east in the Texas Panhandle/South Plains, transitional/greening fuels will mitigate fire weather concerns even with similarly dry and windy conditions. ...Florida... Easterly winds of around 10 mph appear possible during the afternoon. RH of 25-35% can be expected along the western Peninsula. With dry fuels (current ERC data showing some locations above the 90th percentile), elevated fire weather is likely this afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Fri Apr 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI VALLEY AND SOUTHWESTERN GREAT LAKES... ...SUMMARY... Scattered severe thunderstorms are possible from parts of the southern Plains northeastward through the mid Mississippi Valley and southwestern Great Lakes, mainly from late afternoon into early Saturday morning. Large to very large hail and severe wind gusts should be the main hazards, especially across the southern Plains where storms will be more concentrated. A few tornadoes also appear possible. ...Southern Plains to the Ozarks... Strong southwesterly mid to high-level flow will extend from the southern High Plains northeastward into the Great Lakes, downstream of a mid- to upper-level low over the Four Corners states. A cold front was analyzed from the Low Rolling Plains northeastward through central OK late this morning. This portion of the front will continue southeastward into the I-44 corridor but decelerate towards late afternoon. A dryline extends southward from the front over the TX Big Country. Despite widespread mid/high-level cloudiness, filtered heating of a moist/destabilizing airmass will likely result in a weakened cap by late afternoon. Initial supercell development should pose a threat for large to very large hail, potentially up to 2-3 inches in diameter. Model forecast hodographs and ample PW suggest a strong tendency towards upscale growth into an HP supercell and linear segment this evening from south-central OK northeastward towards the western part of the Ozark Plateau. Coincident with this expected convective mode evolution, an increase in the severe/damaging wind threat is anticipated. The threat for a few tornadoes remains apparent, especially across parts of OK along/south of the front, as favorable low-level shear will be present this evening where surface-based supercells and mesovortex potential may still exist. ...Lower MI to Mid Mississippi Valley... In wake of weakened thunderstorm activity across Lower MI, a warm sector will attempt to spread northward and destabilize across parts of the mid MS Valley and southern/central Great Lakes this afternoon. An upper trough will only slowly encroach on the Upper Midwest through late tonight. As a result, southwesterly flow aloft will be maintained and limited southeastward progression of a cold front is forecast. Model guidance continues to indicate surface-based thunderstorm development will be inhibited until peak heating, when frontal forcing and gradual erosion of the cap leads to isolated storms developing from MO northeastward towards the southwest Great Lakes. Uncertainty remains regarding timing, overall thunderstorm coverage, and the exact evolution of this activity. Nonetheless, strong shear through a deep layer and adequate buoyancy (due in part to steep mid-level lapse rates), will support organized thunderstorms. The stronger thunderstorms will probably pose a risk for severe hail and damaging winds. This severe threat may persist for much of the evening, and perhaps continuing into the early overnight hours. ..Smith/Thornton.. 04/18/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1133 AM CDT Fri Apr 18 2025 Valid 181630Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI VALLEY AND SOUTHWESTERN GREAT LAKES... ...SUMMARY... Scattered severe thunderstorms are possible from parts of the southern Plains northeastward through the mid Mississippi Valley and southwestern Great Lakes, mainly from late afternoon into early Saturday morning. Large to very large hail and severe wind gusts should be the main hazards, especially across the southern Plains where storms will be more concentrated. A few tornadoes also appear possible. ...Southern Plains to the Ozarks... Strong southwesterly mid to high-level flow will extend from the southern High Plains northeastward into the Great Lakes, downstream of a mid- to upper-level low over the Four Corners states. A cold front was analyzed from the Low Rolling Plains northeastward through central OK late this morning. This portion of the front will continue southeastward into the I-44 corridor but decelerate towards late afternoon. A dryline extends southward from the front over the TX Big Country. Despite widespread mid/high-level cloudiness, filtered heating of a moist/destabilizing airmass will likely result in a weakened cap by late afternoon. Initial supercell development should pose a threat for large to very large hail, potentially up to 2-3 inches in diameter. Model forecast hodographs and ample PW suggest a strong tendency towards upscale growth into an HP supercell and linear segment this evening from south-central OK northeastward towards the western part of the Ozark Plateau. Coincident with this expected convective mode evolution, an increase in the severe/damaging wind threat is anticipated. The threat for a few tornadoes remains apparent, especially across parts of OK along/south of the front, as favorable low-level shear will be present this evening where surface-based supercells and mesovortex potential may still exist. ...Lower MI to Mid Mississippi Valley... In wake of weakened thunderstorm activity across Lower MI, a warm sector will attempt to spread northward and destabilize across parts of the mid MS Valley and southern/central Great Lakes this afternoon. An upper trough will only slowly encroach on the Upper Midwest through late tonight. As a result, southwesterly flow aloft will be maintained and limited southeastward progression of a cold front is forecast. Model guidance continues to indicate surface-based thunderstorm development will be inhibited until peak heating, when frontal forcing and gradual erosion of the cap leads to isolated storms developing from MO northeastward towards the southwest Great Lakes. Uncertainty remains regarding timing, overall thunderstorm coverage, and the exact evolution of this activity. Nonetheless, strong shear through a deep layer and adequate buoyancy (due in part to steep mid-level lapse rates), will support organized thunderstorms. The stronger thunderstorms will probably pose a risk for severe hail and damaging winds. This severe threat may persist for much of the evening, and perhaps continuing into the early overnight hours. ..Smith/Thornton.. 04/18/2025 Read more

MD 0467 CONCERNING SEVERE THUNDERSTORM WATCH 142... FOR SOUTHERN WISCONSIN...LAKE MICHIGAN
Mesoscale Discussion 0467 NWS Storm Prediction Center Norman OK 0722 AM CDT Fri Apr 18 2025 Areas affected...Southern Wisconsin...Lake Michigan Concerning...Severe Thunderstorm Watch 142... Valid 181222Z - 181415Z The severe weather threat for Severe Thunderstorm Watch 142 continues. SUMMARY...A severe threat will likely continue over the next couple of hours from parts of southern Wisconsin eastward over Lake Michigan. Significant wind gusts and large hail will be possible with the strongest of cells. DISCUSSION...The latest high-resolution radar imagery from KMKX shows a cluster of strong to severe storms over southern Wisconsin, with a severe short line segment located about 40 statute miles to the west of Milwaukee, Wisconsin. The storms are located along an east-to-west gradient of instability, where the RAP is estimating MUCAPE around 1000 J/kg. RAP forecast soundings to the west of Milwaukee still have a temperature inversion from the surface to 850 mb, with strong effective shear above the inversion. This will continue to support elevated supercell development. In addition, forecast soundings have steep lapse rates in the 700 to 500 mb layer, which will aid a threat for large hail with supercells. Hailstones greater than 2 inches in diameter will be possible in the more intense cores. The stronger and faster moving line segments could also produce severe gusts, with 70+ mph gusts possible. The severe threat is expected to become more isolated later this morning. To the east of the current watch, watch issuance probably won't be needed. Trends will be monitored. ..Broyles/Gleason.. 04/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRR...LOT...MKX...ARX... LAT...LON 43328623 42978610 42648625 42508658 42488814 42558932 42619011 42769037 43059037 43369020 43578977 43598821 43528671 43328623 MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN Read more

WW 0142 Status Updates
STATUS REPORT ON WW 142 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 E JVL TO 35 N MKE. ..KERR..04/18/25 ATTN...WFO...MKX... STATUS REPORT FOR WS 142 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS WIC059-079-089-101-127-133-181440- WI . WISCONSIN COUNTIES INCLUDED ARE KENOSHA MILWAUKEE OZAUKEE RACINE WALWORTH WAUKESHA LMZ644-645-646-671-673-675-181440- CW . ADJACENT COASTAL WATERS INCLUDED ARE PORT WASHINGTON TO NORTH POINT LIGHT WI NORTH POINT LIGHT TO WIND POINT WI WIND POINT WI TO WINTHROP HARBOR IL LAKE MICHIGAN FROM PORT WASHINGTON TO NORTH POINT LIGHT WI 5NM OFFSHORE TO MID LAKE LAKE MICHIGAN FROM NORTH POINT LIGHT TO WIND POINT WI 5NM Read more

WW 142 SEVERE TSTM WI LM 181055Z - 181600Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 142 NWS Storm Prediction Center Norman OK 555 AM CDT Fri Apr 18 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Wisconsin Lake Michigan * Effective this Friday morning from 555 AM until 1100 AM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Multiple supercells and bowing structures will spread quickly eastward this morning across southern Wisconsin. Scattered large hail around 1-2 inches in diameter and 60-70 mph wind gusts may occur with this activity. The severe thunderstorm watch area is approximately along and 30 statute miles north and south of a line from 40 miles west of Madison WI to 30 miles east northeast of Racine WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27050. ...Gleason Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CDT Fri Apr 18 2025 Valid 181300Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Scattered severe thunderstorms are possible from parts of the southern Plains northeastward toward the upper Great Lakes, mainly from late afternoon into early Saturday morning. Large to very large hail and severe wind gusts should be the main hazards, especially across the southern Plains where storms will be more concentrated. A few tornadoes also appear possible. ...Upper Great Lakes to Mid Mississippi Valley... Ongoing, mostly elevated thunderstorms aided by persistent low-level warm/moist advection and steep mid-level lapse rates should continue to pose a large hail and damaging wind threat as they spread quickly eastward across southern WI this morning. This activity should eventually weaken later this morning as it continues moving across Lower MI into a less unstable environment. Behind this initial activity, the surface warm sector will attempt to spread northward across parts of the Upper Midwest and Great Lakes today, as longwave troughing gradually develops eastward over the northern/central Plains and Southwest. Given the positive tilt/orientation of this upper troughing and enhanced southwesterly flow aloft expected to persist through the period, a strong cold front should make only slow southeastward progress. A cap will likely inhibit surface-based convective development until peak afternoon heating and frontal forcing can help lift parcels to their LFC. Given nebulous forcing aloft, there is still a fair amount of uncertainty regarding overall convective coverage this afternoon/evening. Even so, any thunderstorms that can develop along or ahead of the front could pose a threat for severe hail and damaging winds, with strong deep-layer shear aiding updraft organization. This severe threat may persist for much of the evening, and perhaps continuing into the early overnight hours. ...Southern Plains to the Ozarks... The southern portion of the cold front is forecast to decelerate and eventually stall over parts of OK later today. A dryline will extend southward from a weak frontal low across northwest to west-central TX by late afternoon. Even with widespread mid/high-level cloudiness present, robust daytime heating of the moist warm sector is anticipated across the southern Plains today. The low-level cap should eventually be breached by late afternoon/early evening (around 22-00Z), particularly along/near the cold front, and perhaps the front/dryline intersection as well. Strong southwesterly flow aloft and related deep-layer shear will likely support organized severe convection. Initial supercell development should pose a threat for large to very large hail, potentially up to 2-3 inches in diameter. With time, upscale growth into multiple clusters/short line segments is expected through the evening into early Saturday morning, as a south-southwesterly low-level jet gradually strengthens. An increase in the severe/damaging wind threat is anticipated as this mode transition occurs. The threat for a few tornadoes remains apparent, especially across parts of OK along/south of the front, as favorable low-level shear will be present this evening where supercells may still exist. Even with a higher concentration of thunderstorms expected across the southern Plains, the messy convective mode this evening and tendency for convection to be undercut by the cold front currently limit confidence in delineating a corridor of greater severe hail/wind potential. ..Gleason/Broyles.. 04/18/2025 Read more

MD 0466 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST IOWA...SOUTHERN WISCONSIN
Mesoscale Discussion 0466 NWS Storm Prediction Center Norman OK 0505 AM CDT Fri Apr 18 2025 Areas affected...Northeast Iowa...Southern Wisconsin Concerning...Severe potential...Watch unlikely Valid 181005Z - 181230Z Probability of Watch Issuance...20 percent SUMMARY...An isolated threat for large hail and severe gusts will likely continue across parts of northeast Iowa over the next few hours. The threat is also expected to affect parts of southern Wisconsin. Weather watch issuance is unlikely. DISCUSSION...The latest high-resolution radar imagery from Des Moines shows a cluster of thunderstorms across northeast Iowa and far southwest Wisconsin. Some of these storms have produced severe reports over the last couple of hours. The cluster will continue to move eastward into southern Wisconsin this morning. RAP forecast soundings from northeast Iowa into southern Wisconsin have a temperature inversion up to about 850 mb. Across northeast Iowa, MUCAPE is estimated by the RAP in the 1000 to 2000 J/kg range. Instability further to the east is considerably less, but an increase in instability could still occur as warm advection continues through the morning. In addition, RAP analysis across northeast Iowa has effective shear generally in the 40 to 50 knot range. This environment should support elevated supercells capable of producing isolated large hail. In spite of the low-level temperature inversion, a strong to severe gust will also be possible. The severe threat should develop eastward across southern Wisconsin but may become more isolated as the storms outrun the instability further to the west. ..Broyles/Gleason.. 04/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...MKX...DVN...ARX...DMX... LAT...LON 42458882 42479059 42539253 42669327 43109340 43499266 43488999 43368824 42768793 42508828 42458882 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0234 AM CDT Fri Apr 18 2025 Valid 211200Z - 261200Z ...DISCUSSION... An upper shortwave trough will weaken as it spreads east/northeast from the Mid/Upper MS Valley to the Lower Great Lakes on Day 4/Mon. The associated surface low will likewise shift northeast from eastern IA/IL into Ontario, while a trailing cold front moves across much of the Midwest. Modest boundary-layer moisture will aid in weak destabilization and some low-end severe thunderstorm risk could develop across parts of the Ohio Valley/Lower Great Lakes vicinity. The southern extent of this front will stall across the Mid-South and Sabine Valley. Richer low-level moisture ahead of the surface boundary across parts of the South could support some thunderstorm risk as well, but nebulous forcing and weak vertical shear will limit severe potential. On Days 5-8/Tue-Fri, a low-amplitude, weak flow pattern is forecast. Southerly low-level flow across the Gulf and southern Plains will allow for northward moisture transport across OK/TX and vicinity. Diurnal thunderstorm activity could be possible each day given modest west/southwest flow atop a moist warm sector. However, a rather nondescript surface pattern amid weak large-scale forcing will likely preclude widespread severe potential, though localized areas of severe storms could still occur given favorable moisture/instability, particularly along any dryline features. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0234 AM CDT Fri Apr 18 2025 Valid 211200Z - 261200Z ...DISCUSSION... An upper shortwave trough will weaken as it spreads east/northeast from the Mid/Upper MS Valley to the Lower Great Lakes on Day 4/Mon. The associated surface low will likewise shift northeast from eastern IA/IL into Ontario, while a trailing cold front moves across much of the Midwest. Modest boundary-layer moisture will aid in weak destabilization and some low-end severe thunderstorm risk could develop across parts of the Ohio Valley/Lower Great Lakes vicinity. The southern extent of this front will stall across the Mid-South and Sabine Valley. Richer low-level moisture ahead of the surface boundary across parts of the South could support some thunderstorm risk as well, but nebulous forcing and weak vertical shear will limit severe potential. On Days 5-8/Tue-Fri, a low-amplitude, weak flow pattern is forecast. Southerly low-level flow across the Gulf and southern Plains will allow for northward moisture transport across OK/TX and vicinity. Diurnal thunderstorm activity could be possible each day given modest west/southwest flow atop a moist warm sector. However, a rather nondescript surface pattern amid weak large-scale forcing will likely preclude widespread severe potential, though localized areas of severe storms could still occur given favorable moisture/instability, particularly along any dryline features. Read more

MD 0465 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHERN IOWA
Mesoscale Discussion 0465 NWS Storm Prediction Center Norman OK 1242 AM CDT Fri Apr 18 2025 Areas affected...Northern Iowa Concerning...Severe potential...Watch unlikely Valid 180542Z - 180815Z Probability of Watch Issuance...20 percent SUMMARY...A threat for marginally severe hail is expected over the next few hours across northern Iowa. Weather watch issuance appears unlikely. DISCUSSION...The latest water vapor imagery shows west to southwest flow over the Upper Midwest, with some anticyclonic curvature. In spite of some ridging, the RAP suggests a minor shortwave trough is moving through Iowa. At the surface, a front extends northeastward across central Iowa. Scattered thunderstorms are ongoing to the northwest of the front in the vicinity of Sioux City, Iowa. RAP forecast soundings to the north of front over much of northern Iowa have an inversion up to near 800 mb. MUCAPE is up to 1500 J/kg with effective shear in the 50 to 60 knots range. 700-500 mb lapse rates are near 8 C/km. As warm advection continues overnight, this environment should support elevated supercell development. Supercells may be able to produce isolated large hail, but any threat is expected to remain isolated. ..Broyles/Gleason.. 04/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...DMX...FSD...OAX... LAT...LON 42289246 42249433 42179531 42229595 42539635 42729641 42889639 43239600 43429526 43449260 43179150 42459149 42289246 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CDT Fri Apr 18 2025 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO SOUTHWEST ILLINOIS... ...SUMMARY... Severe thunderstorms are possible on Sunday from east Texas into the Middle Mississippi Valley. ...East Texas to the Middle Mississippi Valley... An upper trough over the central/southern Plains Sunday morning will lift northeast across the Mid-MO/Upper MS Valley through early Monday. At the surface, low pressure will migrate northeast from OK to WI as a cold front sweeps east across portions of the Ozarks/Mid-MS Valley and the ArkLaTex vicinity. Ahead of the surface low and cold front, a warm front will lift northward across the Mid-MS and Lower OH Valley through Sunday evening. Moderate deep-layer southwesterly flow atop a modestly moist warm sector ahead of the surface cold front should support some risk for severe thunderstorms from the ArkLaTex into the Mid-MS Valley. All severe hazards appear possible with potential for a mixed mode of supercells and linear segments. However, quite a bit of uncertainty remains regarding exact forecast details as several periods of heavy rain and thunderstorms are expected across the region leading into Sunday. This could impact which areas see greater destabilization coincident with increasing southwesterly flow and stronger ascent. Furthermore, the ECMWF suite of forecast guidance is a slower and further south outlier compared to GFS/NAM guidance. As a result, the outlook area for Day 3/Sunday may continue to shift in the coming days as details become better resolved. ..Leitman.. 04/18/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CDT Fri Apr 18 2025 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TEXAS INTO SOUTHWEST ILLINOIS... ...SUMMARY... Severe thunderstorms are possible on Sunday from east Texas into the Middle Mississippi Valley. ...East Texas to the Middle Mississippi Valley... An upper trough over the central/southern Plains Sunday morning will lift northeast across the Mid-MO/Upper MS Valley through early Monday. At the surface, low pressure will migrate northeast from OK to WI as a cold front sweeps east across portions of the Ozarks/Mid-MS Valley and the ArkLaTex vicinity. Ahead of the surface low and cold front, a warm front will lift northward across the Mid-MS and Lower OH Valley through Sunday evening. Moderate deep-layer southwesterly flow atop a modestly moist warm sector ahead of the surface cold front should support some risk for severe thunderstorms from the ArkLaTex into the Mid-MS Valley. All severe hazards appear possible with potential for a mixed mode of supercells and linear segments. However, quite a bit of uncertainty remains regarding exact forecast details as several periods of heavy rain and thunderstorms are expected across the region leading into Sunday. This could impact which areas see greater destabilization coincident with increasing southwesterly flow and stronger ascent. Furthermore, the ECMWF suite of forecast guidance is a slower and further south outlier compared to GFS/NAM guidance. As a result, the outlook area for Day 3/Sunday may continue to shift in the coming days as details become better resolved. ..Leitman.. 04/18/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Fri Apr 18 2025 Valid 191200Z - 201200Z ...Synopsis... An upper-level trough will eject into the southern Plains on Saturday, though it will lose some amplitude during the period. A cold front will continue southward into more of the southern High Plains and eventually the Permian Basin. A surface low near the Trans-Pecos/Big Bend will deepen during the day before weakening during the evening as the trough lifts northeastward. ...Trans-Pecos/Big Bend... Though cooler/moist air to the east and north will limit the areal extent, elevated fire weather will occur within the Trans-Pecos and Big Bend Saturday afternoon. Moderate to strong mid-level winds will remain in the region during the afternoon and the surface low will also be deepest during the favorable diurnal heating maximum. Cloud cover should be minimal in this area given the presence of dry air aloft. Surface winds of 15-20 mph are likely along with RH of 5-20%. Areas of southeast New Mexico into the South Plains could see briefly elevated conditions, but uncertainty in duration is too great for highlights. ...Florida... Continued dry easterly flow will once again promote elevated fire weather along the western Peninsula during the afternoon. Models indicate winds could be slightly stronger than on Friday (10-15 mph). RH will fall to similar levels, however (25-35% anticipated by the afternoon. Very dry fuels will support fire spread. ..Wendt.. 04/18/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Fri Apr 18 2025 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN/EASTERN NEW MEXICO INTO FAR WEST TEXAS... ...Synopsis... An upper trough initially in the Great Basin will move towards the Four Corners region today. A modest surface low in eastern New Mexico into West Texas will develop during the day. A cold front will continue to make southward progress into the southern Plains. ...New Mexico into West Texas... Elevated to critical fire weather conditions are again expected during the afternoon. Moderate mid-level flow across the Southwest and southern Plains and a modest surface low along the Texas/New Mexico border will drive 15-20 mph (up to 25 mph in the terrain) surface winds by the afternoon. RH will be slightly higher than Thursday on account of mid/upper-level clouds. Values of around 10% may occur, but will occur on a relatively local basis. 15-20% will be more common. The driest fuels will be in New Mexico and the Trans-Pecos. Farther east in the Texas Panhandle/South Plains, transitional/greening fuels will mitigate fire weather concerns even with similarly dry and windy conditions. ...Florida... Easterly winds of around 10 mph appear possible during the afternoon. RH of 25-35% can be expected along the western Peninsula. With dry fuels (current ERC data showing some locations above the 90th percentile), elevated fire weather is likely this afternoon. ..Wendt.. 04/18/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1240 AM CDT Fri Apr 18 2025 Valid 191200Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST-CENTRAL TEXAS INTO SOUTHERN MISSOURI... ...SUMMARY... Scattered strong to severe thunderstorms are possible from central Texas into the Ohio Valley on Saturday. ...Synopsis... A northern stream upper shortwave trough will shift east across Ontario/Quebec and the Great Lakes to the Northeast on Saturday. Meanwhile, a cold front will shift southeast across the Ohio Valley through afternoon. Further south, a southern stream upper trough over the Southwest will become negatively tilted as it spreads eastward over the southern Plains by Sunday morning. The southwest extent of the Ohio Valley cold front will stall over TX/OK and into the Ozarks for much of the day as warm advection maintains a moist warm sector ahead of the boundary prior to stronger height falls overspreading the region near/after 00z. ...OK/TX into the Ohio Valley - Saturday morning/afternoon... Fast southwesterly deep-layer flow parallel to the surface boundary will result in a substantial area of ongoing rain and thunderstorms Saturday morning from eastern OK into the Ozarks and northeast along the surface front through the Ohio Valley. While instability will remain limited, strong deep layer flow and cool temperatures aloft could support sporadic strong gusts and marginally severe hail diurnally. ...TX/OK into the Ozarks - Saturday late afternoon/evening... Convection is likely to redevelop late Saturday afternoon along the cold front in persistent low-level warm advection and as a low-level jet increases toward evening. Supercell wind profiles are evident in forecast soundings, with cool temperatures aloft supporting a corridor of moderate MLCAPE (1000-2000 J/kg) from west-central TX and north TX into southeast OK/western AR. Initial supercells could pose a risk for large hail and a tornado or two. Convection may become undercut by the southeast-advancing cold front with time into the evening hours, with some upscale growth into training clusters of line segments. While inhibition will increase into the nighttime hours, some risk for isolated damaging gusts could accompany any linear development as well. ..Leitman.. 04/18/2025 Read more