SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Mon Oct 20 2025 Valid 201630Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The severe thunderstorm risk is low today. ...Synopsis and Discussion... Current satellite imagery shows a pair of shortwave troughs traversing the CONUS: a sharp, well-defined wave moving across the Northeast and a lower-amplitude, more broad wave progressing through the northern High Plains/northern Plains. The majority of the CONUS is characterized by dry and stable conditions as high pressure follows in the wake of a strong cold front associated with the Northeast shortwave trough. The only exception is across New England and far southern FL, which remain ahead of the cold front. The cold front is expected to continue eastward/northeastward through New England today, while becoming increasingly occluded as the associated surface low tracks more northerly. A band of showers is ongoing across New England now, but scant buoyancy across the region has kept storms shallow thus far. A few instances of lightning are still possible within this band as well as a few stronger, convective augmented gusts. However, the overall severe probability should remain too low to introduce an outlook area. A few isolated thunderstorms are possible ahead of the front in south FL as well, but weak shear should preclude any severe threat. Two other areas could see isolated thunderstorms this afternoon/evening and overnight, both associated with the western shortwave trough moving across the northern Plains into the Upper Midwest. A few isolated thunderstorms are possible this afternoon/evening across southeast MT and adjacent northeast WY and western SD amid strong forcing for ascent and cooling mid-level temperatures. Aa instance or two of small hail is possible as well. Farther southeast, a few thunderstorms are possible overnight into early tomorrow morning from the Arklatex into northwest MS as the cold front associated with this shortwave moves through. These storms should be post-frontal with very limited severe potential. ..Mosier/Jirak.. 10/20/2025
