


Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
985 ACUS48 KWNS 060830 SWOD48 SPC AC 060829 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0329 AM CDT Sun Jul 06 2025 Valid 091200Z - 141200Z ...DISCUSSION... An upper ridge will remain in place across the Southwest while zonal mid-level flow continues to support embedded impulses traversing the northern CONUS this week into next weekend. The first notable mid-level impulse, which will bring severe potential to the central U.S. in the Days 2-3 time-frame, will approach the East Coast while slowing its forward advance. The impulse should reach the East Coast by Day 4 (Wednesday), providing adequate lift for at least scattered thunderstorms through the remainder of the week. Given preceding rich low-level moisture, ample buoyancy will be available to support at least isolated strong storms with potentially damaging gusts. A more pronounced mid-level trough will approach the Northern Plains in the Days 4-5 (Wednesday-Thursday) period, resulting in strong surface troughing and the northward advection of rich low-level moisture. Medium range guidance consensus shows that strong instability will precede the upper/surface troughs, favoring the development of severe storms. The first chance for severe storms will be over the western Dakotas on Wednesday as the upper trough approaches from the Northern Rockies. Upper support in this region does not currently appear robust, so severe storms may occur on a more isolated basis (hence no severe probabilities introduced at this time). However, there is medium range guidance agreement in the upper trough ejecting into the northern Plains on Day 5 (Thursday), with some guidance suggesting that instability could become extreme. Though it is difficult to confidently pinpoint storm mode this far in advance, guidance hints at the development of a persistent, elongated convective system, which may be capable of supporting all severe hazards, especially severe winds. Severe probabilities have been added to address this scenario. As the pronounced mid-level trough progresses eastward, more organized severe storms are possible over the MS Valley and perhaps points east Day 6 onward. However, the intensity, coverage, and location of severe potential will be highly dependent on the evolution of convection from previous days, which is hard to know this far in advance. Therefore, severe probabilities have been withheld this outlook. ..Squitieri.. 07/06/2025