SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jun 19 2025 Valid 191630Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EARLY EVENING ACROSS THE MID-ATLANTIC REGION... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS THE NORTHERN PLAINS... ...SUMMARY... Severe thunderstorms are expected across much of the Mid-Atlantic region this afternoon and evening, and to a lesser extent into the Carolinas and over portions of New England. Severe/damaging wind gusts are the primary concern. An isolated large hail and damaging wind threat should also develop across parts of the northern Plains/Upper Midwest, primarily during the evening/overnight hours. ...Eastern US... A broad and low-amplitude shortwave trough is moving across the Great Lakes region and Ohio Valley today. Ahead of the trough, visible satellite imagery shows mostly clear skies from eastern NY and much of New England southward across the Mid-Atlantic region and Carolinas. Warm/moist conditions will develop by mid-afternoon, yielding MLCAPE values of 2000-3000 J/kg across this broad area. Scattered thunderstorms are expected to develop, with the highest concentrations moving off the higher terrain of PA/VA/NC and tracking eastward across the ENH risk area. Forecast soundings along this corridor show 35-50 knot westerly flow aloft, which will aid in thunderstorm organization and longevity. Low-level winds are relatively weak/veered, and mid-level lapse rates are marginal for intense updrafts. This suggests that damaging wind gusts are the primary concern today. ...ND/MN/WI This Evening/Tonight... A large upper ridge has become established across the Rockies and High Plains, with the primary westerlies now extending from MT into the Dakotas and Great Lakes. Several weak perturbations will top the ridge today and tonight, and a strengthening low-level jet will encourage the development of clusters of thunderstorms. One cluster is expected this evening over parts of MN/WI, with a risk of large hail. There is increasing concern for a cluster of storms developing across southern ND, which may persist through the night into southern MN. While this scenario is only shown in a handful of 12z models, have shifted the SLGT farther south for this conditional risk. ..Hart/Wendt.. 06/19/2025