Day 1 Convective Outlook
Issued: · Valid: –
Summary
Scattered strong to locally severe thunderstorms capable of producing damaging winds and occasional tornadoes are expected this afternoon and evening across the lower Great Lakes, upper Ohio Valley, and the Atlantic Piedmont. A marginal risk of severe thunderstorms also exists for parts of the Southwest and Northern Plains through tonight, with potential for isolated hail and strong wind gusts.
Product Text
000 ACUS01 KWNS 021951 SWODY1 SPC AC 021949 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Sun Aug 02 2026 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE EAST AS WELL AS PARTS OF THE SOUTHWEST AND NORTHERN PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorm development is expected this afternoon and evening across parts of the lower Great Lakes and upper Ohio Valley into the middle and southern Atlantic Piedmont. Damaging winds are the primary hazard, although a tornado could occur. ...20Z Update... Only minor changes were made with this update. The MRGL Risk was expanded slightly eastward in portions of eastern SC, where an ongoing cluster of thunderstorms will continue to pose a risk of damaging wind gusts, given a very warm/moist downstream air mass. Farther north, the MRGL Risk was expanded into parts of northern NJ and northeast PA. Clouds breaks have supported modest destabilization of a moist air mass, and high-resolution guidance depicts thunderstorms moving into the area tonight -- focused along a northward-moving warm front. Despite modest instability, enhanced low-level flow/shear overspreading the region in tandem with the warm front could support a couple loosely organized cells/clusters with an accompanying risk of damaging wind gusts and perhaps a brief tornado. Elsewhere, the forecast remains on track and no changes were needed. ..Weinman.. 08/02/2026 .PREV DISCUSSION... /ISSUED 1116 AM CDT Sun Aug 02 2026/ ...Eastern States... Current satellite imagery shows a positively titled shortwave trough extending from Lower MI southwestward into the Mid-South, while recent surface analysis places a corridor of low pressure associated with this shortwave from the Middle OH Valley into the Lower Great Lakes. Several surface lows are embedded within this broader area of low pressure, including a primary low over north-central OH/western Lake Erie. A cold front extends southward from this low to the TN/NC border vicinity before arcing back more southwestward through central AL and southern MS. This system (i.e. both the shortwave trough and associated cold front) is forecast to gradually push eastward while weakening. Airmass preceding this system is very moist, evidenced by upper 60s/low 70s dewpoints and PW values at or above 2 inches on the regional 12Z soundings. Widespread cloud cover is in place, but ample moisture has already resulted in airmass destabilization, although the overall buoyancy will remain muted by poor lapse rates. General expectation is for thunderstorm coverage to increase substantially over the next few hours, fostered by a combination of low-level confluence and modest large-scale ascent. Low to mid-level flow throughout the eastern periphery of the shortwave trough is generally expected to be modest, ranging from around 40 kt across the Allegheny Plateau/upper Ohio Valley/lower Great Lakes vicinity to 20 kt across GA and SC. Consequently, a few more organized storms are possible across portions of the Allegheny Plateau, upper Ohio Valley, and lower Great Lakes, while a largely disorganized multicellular mode is anticipated elsewhere. Water-loaded downbursts are the primary risk, although low-level shear/SRH in the presence of a moist boundary layer suggests a brief tornado is possible where greater storm organization is expected. ...North Dakota/northwest Minnesota... Expansive upper ridging exists from southern CA/western AZ through the Plains and into Manitoba and Ontario. A strong shortwave trough is forecast to progress through Canadian Prairie Provinces within the northern periphery of this ridging. A cold front associated with this wave is expected to push eastward across the Dakotas, interacting with a moistening airmass across the region. A conditional risk for severe thunderstorms exists this afternoon, but most of the guidance keeps the airmass capped and free of deep convection. Better potential for thunderstorm development is expected overnight and into tomorrow morning as large-scale ascent attendant to the approaching shortwave combines with warm-air advection to foster elevated thunderstorm development. Isolated instances of hail and a strong gust or two are possible with these storms. ...Southeast Arizona/far southwest New Mexico... Widely scattered thunderstorms should develop over the mountains/higher terrain of the central/southern Arizona/New Mexico border vicinity this afternoon. Moderate easterly/northeasterly mid-level flow should favor southwestward motion into the lower terrain of southeast Arizona. Modest buoyancy should allow for storm persistence across southeast AZ, including the potential for isolated strong to severe gusts. $$