Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
SPC AC 021626 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Wed Apr 02 2025 Valid 021630Z - 031200Z ...THERE IS A HIGH RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO EARLY TONIGHT FROM EASTERN ARKANSAS INTO THE LOWER OHIO VALLEY... ...SUMMARY... A tornado outbreak is expected this afternoon into early tonight from parts of the lower Mississippi Valley into the Mid-South and lower Ohio Valley. Numerous tornadoes, along with multiple EF3+ tornadoes, appear likely. In addition, tornadoes, significant severe wind gusts, and large hail to very large hail will be possible across a broad area from north Texas northeastward to the southern Great Lakes. ...OH/MS Valleys through tonight... In response to an ejecting midlevel trough and associated 110 kt 500 mb jet streak, a surface cyclone will develop northeastward from IA to Lake Superior. Severe storms are ongoing in a broken band from west central IL across MO into northwest AR/eastern OK, which demarcates the effective frontal zone and focus for additional storm development through the afternoon. The warm sector in advance of these storms is characterized by boundary-layer dewpoints in the low-mid 60s across IL/MO and near 70 F from the Ark-La-Tex into the Ark-La-Miss. Low-level moisture will continue to spread northward through the day on 50-70 kt flow 1-2 km above ground level, and surface heating in cloud breaks will boost MLCAPE into the 2000-3000 J/kg range with only weak convective inhibition through the afternoon. The northern extent of the surface warm sector (northeast IL across northern IN/northwest OH/southern Lower MI) will be modulated by ongoing convection. The primary jet streak/cyclone will be displaced northwest of the unstable warm sector, though flow will remain strong in the warm sector with long hodographs and substantial low-level shear/hodograph curvature. Convective mode is expected to be somewhat messy with embedded supercells within an increasingly extensive band of storms through the afternoon/evening. Convective inhibition will be sufficiently weak to support some potential for a few supercells ahead of the band in the open warm sector. The tornado threat will be maximized for the more discrete storms within or ahead of the main band, where a few intense (EF3+) tornadoes will be possible. Otherwise, evolution into an extensive squall line is expected with an accompanying threat for damaging winds (60-80 mph) and occasional large hail (1.5-2.5 inches in diameter - especially with persistent supercells). Overnight, the northern portion of the squall line will eventually move east of the more unstable warm sector and weaken from OH into western PA. The southern portion of the convective band is expected to pivot gradually to a more WSW-ENE orientation favoring training convection along and atop the conglomerate cold pool. ...North TX/southeast OK this evening through Thursday morning... In the wake of the ejecting IA-Lake Superior jet streak, midlevel flow will tend to amplify/back with time over TX, downstream of the amplifying large-scale trough over the Southwest. This will contribute to weak cyclogenesis across northwest TX along the residual baroclinic zone, and a strengthening warm advection regime along/north of the boundary tonight. The open warm sector will likely remain capped (per the warm elevated mixed layer observed this morning over TX), but the environment will favor elevated supercells to the cool side of the boundary. Very large hail in excess of 2 inches in diameter and isolated severe gusts will be the main threats with these elevated storms overnight. ..Thompson/Jirak.. 04/02/2025 CLICK TO GETWUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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