267 ACUS02 KWNS 150518 SWODY2 SPC AC 150516 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1216 AM CDT Wed Apr 15 2026 Valid 161200Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEW YORK AND SOUTHERN VERMONT... ...SUMMARY... Isolated strong to severe thunderstorms are possible on Thursday extending from southeast Missouri across the Ohio Valley and into parts of New York. ...Synopsis... An upper shortwave trough will spread east across the Midwest on Thursday, becoming oriented from the Lower Great Lakes to the central/southern Appalachians by Friday morning. At the surface, a front will sag south/southeast across the Great Lakes. Modest southwesterly low-level flow will maintain upper 50s to low 60s F dewpoints from the Mid-South into New York/southern New England. This should be sufficient for weak to moderate destabilization given modestly steep midlevel lapse rates. ... New York vicinity... Modest height falls are forecast across the region during the afternoon and evening within a low-level warm advection regime. Moderate to strong deep-layer mid/upper flow will overspread the moistening boundary layer, supporting effective shear magnitudes of 30+ kt. Heating into the mid/upper 70s will lead to steepening low-level lapse rates, while cool temperatures aloft (near -12 C at 500 mb) will support 1000-1500 J/kg MLCAPE. Isolated to scattered thunderstorms will develop during the afternoon. An accompanying risk of isolated large hail and damaging wind gusts is expected. ...Mid-South and Ohio Valley... Convection posing a risk for marginal hail may be going across parts of the MO Bootheel vicinity Thursday morning. Persistent warm advection should allow for airmass recovery by afternoon across this area and thunderstorms are forecast to redevelop during the afternoon with a continued risk for isolated hail and strong wind gusts. Additional isolated convection also develop into the Ohio Valley during the afternoon, though the thermodynamic environment may be more marginal due to possible morning showers and cloud cover lingering, limiting destabilization. However, if storms are able to develop, locally strong gusts and marginal hail will be possible. ..Leitman.. 04/15/2026 $$