SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Wed Jun 18 2025 Valid 181630Z - 191200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING FROM SOUTHEAST MISSOURI EASTWARD ACROSS MUCH OF ILLINOIS/INDIANA...WESTERN OHIO...AND NORTHERN KENTUCKY... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE MID-ATLANTIC REGION... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening from parts of southeast Missouri northeastward to the southern Great Lakes. Scattered to numerous damaging winds, isolated large hail, and tornadoes all appear possible. Severe thunderstorms with damaging winds may also develop across parts of the Mid-Atlantic. ...Midwest... A well-defined shortwave trough is currently over western MO, tracking rapidly eastward. At the surface, a low is centered over northeast MO, with a very moist/unstable air mass in place across much of IL/IN. As large-scale forcing for ascent and strengthening wind fields overspread the unstable warm sector, supercell thunderstorms are expected to rapidly develop. All severe hazards, including a few tornadoes, appear possible through the afternoon as storms track rapidly northeastward across IL into central/northern IN. Refer to MCD #1345 for further details. Congealing outflow may eventually lead to a greater damaging wind threat as storms spread into lower MI and northern OH. To the southeast of this early thunderstorm scenario, another zone of convective initiation is expected from southeast MO into parts of KY/southern IN. These storms are more likely to grow upscale by early evening, with a risk of damaging winds spreading into southern OH and central KY. Have expanded the ENH slightly eastward to better cover this area. ...Mid Atlantic... Visible satellite imagery shows mostly clear skies and strong heating occurring over northern/central VA, where a hot/humid airmass is present. Thunderstorms are expected to develop off the terrain this afternoon and spread eastward into the DelMarVa region. Sufficient flow aloft and steep low-level lapse rates will promote a risk of strong storms capable wind damage. Isolated strong storms may also affect south-central VA and northern NC later this afternoon as well. Refer to MCD #1344 for further details. ..Hart/Wendt.. 06/18/2025