Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
041 ACUS02 KWNS 141731 SWODY2 SPC AC 141729 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Tue Jul 14 2026 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN MID-ATLANTIC REGION... ...SUMMARY... Isolated strong to severe storms are possible across parts of the northern Mid-Atlantic on Wednesday. ...Parts of the Lower Great Lakes and Northeast/New England... To the south of a persistent deep-layer cyclone east of Hudson Bay, another in a series of mid/upper shortwave troughs is forecast to move across parts of New England on Wednesday. A cold front (whose position will be influenced by D1/Tuesday convection) will move southward across the northern Mid-Atlantic vicinity. Strong heating is expected near/south of the cold front, with temperatures rising through the 90s F, and approaching 100 F in some areas. Amid this strong heating, moisture will be sufficient for moderate destabilization, while rather strong mid/upper-level northwesterly flow will provide sufficient deep-layer shear for organized convection. While a zone of conditionally favorable environment is expected near the front, uncertainty remains regarding the coverage (if any) of diurnal storm development. ARW-based CAMs remain the most aggressive in developing isolated storms near the front during the afternoon, with most other guidance remaining muted at best. While confidence remains rather low, a Marginal Risk has been added for parts of the northern Mid-Atlantic, where the relative greatest signal for isolated storm development overlaps the most favorable environment. Locally damaging wind may be the most likely threat, given the hot conditions and steep low-level lapse rates, though hail cannot be ruled out, with supercell-favorable shear and sufficient instability expected to be in place. Across parts of Maine and vicinity, relatively low-topped convective showers (perhaps capable of sporadic lightning flashes) may develop during the afternoon, as the mid/upper-level shortwave trough moves across the region. Gusty winds could accompany this convection, due to the presence of steep low-level lapse rates and modestly enhanced low-level westerly flow. At this time, convection is expected to remain too weak and low-topped for an organized severe threat. Farther west into parts of the Great Lakes, some guidance suggests potential for very isolated storm development, along the portion of the front that extends west-northwest from the northern Mid-Atlantic region. Large-scale ascent currently appears weak to negligible across this area, but the environment will otherwise be favorable for a localized damaging-wind threat, with steep low-level lapse rates, moderate buoyancy, and relatively favorable deep-layer shear. Severe probabilities may eventually be needed, if confidence increases in storm development across parts of lower MI/northern OH or points farther northwest. ...Parts of the Northwest/northern Rockies... Scattered storms are again expected across parts of western/central MT and northern WY, in the presence of monsoonal moisture. Increased cloudiness and somewhat weaker diurnal heating (compared to D1/Tuesday) may tend to limit a more organized severe threat in the presence of modest deep-layer flow/shear, though locally strong storms will be possible during the afternoon and evening. A few strong storms may also develop across parts of central/northern OR, where modestly stronger mid/upper-level flow will overlap the northern extent of appreciable destabilization. ..Dean.. 07/14/2026 $$