Day 1 Convective Outlook
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Issued: · Valid: –
Summary
Severe thunderstorms are possible this afternoon and evening across parts of the middle Missouri and Mississippi Valleys, with a risk of tornadoes and strong wind gusts. Isolated severe wind gusts may also occur across the central Plains, the Ohio Valley, the Mid-Atlantic, the Northeast, and the Southwest.
Product Text
000 ACUS01 KWNS 141956 SWODY1 SPC AC 141955 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Fri Aug 14 2026 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MIDWEST... ...SUMMARY... Severe thunderstorms remain possible this afternoon and evening across parts of the middle Missouri and middle Mississippi Valleys. Isolated severe wind gusts may also still occur in parts of the central Plains and from the Ohio Valley to the Mid-Atlantic, as well as parts of the Northeast and Southwest. ...20Z Update... The previous forecast (see below) remains on track, with only minor changes made to thunder and severe probabilities to reflect observations and the latest guidance consensus. ..Squitieri.. 08/14/2026 .PREV DISCUSSION... /ISSUED 1143 AM CDT Fri Aug 14 2026/ ...Mid Missouri and mid Mississippi Valleys... Thunderstorms have largely weakened through the early morning across the middle Missouri Valley, with more of a lingering persistence across Illinois/Indiana. Scattered showers remain rather common, however, regionally with semi-prevalent cloud cover. Multiple MCVs persist regionally at midday, including across central Iowa, and more prominently near the Nebraska/Iowa border. Regional WSR-88D data from Omaha/Des Moines/Davenport continue to sample enhanced westerlies (35-50 kt) between 4-8 km AGL in association with these MCVs. Primary severe risk across this region today will be linked to the amount of air mass recovery and associated destabilization that occurs along the southern periphery of the residual convection and ahead of the aforementioned slow-moving MCVs. Ample low-level moisture is in place, and differential heating between the residual cloud debris may yield an effective warm-front-like zone across southern Iowa or near the Iowa/Missouri border. The airmass along and south of this is forecast to destabilize and become moderately to strongly unstable by the late afternoon. This should result in renewed thunderstorm development by late afternoon into evening, with sufficient deep-layer shear to support organized updrafts and potentially some initial supercells. Modestly enhanced low-level winds/SRH could yield a tornado risk. Strong wind gusts will otherwise be possible with water-loaded downdrafts, as well as with any bowing segments through this evening. ...Ohio Valley/Central Appalachians/Mid-Atlantic... Outflows/differential heating across the lower Ohio Valley will influenced thunderstorm redevelopment this afternoon, while storms are starting to develop/increase across the Appalachians vicinity. Vertical shear will generally be weak, but strong updrafts and ample moisture will yield the potential for wet microbursts regionally. ...Central High Plains... A shortwave trough currently moving through the Lower Colorado River Valley is forecast to continue northeastward through the Four Corners. Ascent associated with this wave will combine with orographic lift in the foothills of the Rockies to support scattered convective initiation by early afternoon. Thunderstorms will then move northeastward into the moderately buoyant airmass over the central High Plains. Deep-layer shear will be modest but sufficient for a few organized updrafts capable of hail and damaging gusts. ...Northeast States... Influenced by strong northwesterly flow aloft, a few stronger to locally severe relatively low-topped storms may occur this afternoon across northern/upstate New York into southern New England, with strong/gusty winds as the primary hazard as convection progresses southeastward. ...Lower Colorado River ... With a moist air mass across the region, strong heating will support afternoon airmass destabilization, yielding moderate buoyancy this afternoon. Slightly stronger mid-level flow is anticipated over the southern Nevada vicinity, supporting the potential for isolated strong wind gusts. $$