SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 AM CDT Sat Apr 26 2025 Valid 261300Z - 271200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTH-CENTRAL OK AND FAR NORTH-CENTRAL TX INTO EASTERN OK... ...SUMMARY... Strong to potentially severe storms are possible later today across parts of the southern High Plains into the ArkLaTex region. Highest coverage is expected from south-central Oklahoma and far north-central Texas into eastern Oklahoma. Isolated severe storms are also across parts of the Mid Atlantic and Carolinas. ...NM into the Southern Plains and ArkLaTex... Early morning satellite and radar imagery shows a convectively enhanced vorticity maximum moving into western OK, with strong (to occasionally severe) thunderstorms ongoing along its eastern and southern periphery. The MCV is expected to continue east-southeastward, likely progressing along a stationary boundary that extends west to east along the Red River vicinity. Moderate downstream airmass destabilization is anticipated over the next several hours downstream of the MCV across eastern OK and far northeast TX. In general, bulk shear across the region will be modest. However, there could be some localized enhancement of the shear across the eastern periphery of the MCV where slightly stronger low-level southerly flow is anticipated. These environmental conditions will help support a continued risk for severe thunderstorms into eastern OK and adjacent northeast TX. Overall severe coverage is expected to be high enough to warrant increased wind probabilities from south-central OK/far north-central TX into eastern OK. The increased shear could also result in a greater tornado threat and tornado probabilities were increased across eastern OK. Farther west, thunderstorm development will likely continue along the outflow boundary moving southward across the Texas South Plains. Southward progression of this boundary will likely slow throughout the day as southerly low-level flow strengthens in response to a tightening lee trough and a nocturnal low-level jet that develops ahead of another shortwave trough. Isolated severe storms are possible along this outflow as well as the stalled front/lee trough expected to extend from eastern NM into southeast CO. Storm development across these areas is less certain, with limited coverage currently anticipated. A few widely spaced supercells are possible with at least a localized threat of large hail, strong/severe gusts, and possibly even a tornado. ...Northeast/Mid Atlantic/Carolinas... Recent satellite imagery shows a well-defined shortwave trough moving through southern Ontario and the adjacent Upper Great Lakes region. Surface analysis places the low associated with this shortwave over Lake Ontario, with a cold front extending from this low back southwestward through the central Appalachians, TN Valley, and Mid-South. Expectation is for the shortwave trough to continue eastward in the Northeast throughout the day, with the attendant surface low progressing more northeastward through New England. The associated cold front will also progress eastward, moving through the northern Mid-Atlantic by this evening and the remainder of the Mid-Atlantic States by tonight. A relatively moist airmass is already in place ahead of this front, and thunderstorm development appears likely along the front as it moves eastward throughout the period. Highest coverage is anticipated from the Hudson Valley/NYC vicinity southward across the Delmarva to the Chesapeake Bay. Gradually strengthening midlevel flow and deep-layer shear could support a few stronger cells/clusters during the afternoon and evening. Diurnal heating will be tempered by cloud cover, limiting the overall buoyancy and updraft magnitude. Even so, some locally damaging wind and small to near-severe hail could accompany the strongest storms. Best overlap between the buoyancy and shear is expected from NJ into the Delmarva vicinity from 18Z to 21Z. ..Mosier/Broyles.. 04/26/2025