ZCZC SPCSWOMCD ALL ACUS11 KWNS 162220 SPC MCD 162220 NYZ000-CTZ000-NJZ000-PAZ000-DEZ000-MDZ000-DCZ000-VAZ000-WVZ000-170015- Mesoscale Discussion 1659 NWS Storm Prediction Center Norman OK 0520 PM CDT Tue Jul 16 2024 Areas affected...Portions of the Mid-Atlantic into southern New England Concerning...Severe Thunderstorm Watch 548... Valid 162220Z - 170015Z The severe weather threat for Severe Thunderstorm Watch 548 continues. SUMMARY...A corridor of severe/damaging wind potential is becoming apparent across far eastern Pennsylvania, northern New Jersey, and into adjacent portions of southern New York and southwest Connecticut. Further south into Maryland and Virginia, thunderstorm development appears probable in the coming hours with an attendant wind risk. DISCUSSION...GOES IR imagery and lightning trends over the past hour have shown a steady intensification trend of convection across far eastern PA into northern NJ with a few wind damage reports already noted. Given favorable buoyancy and steep (8 C/km) low-level lapse rates immediately downstream, this wind damage threat should persist as storms move towards the coast and/or southwest CT. Further to the southwest into MD and VA, convection has largely struggled to remain sustained over the past hour - likely due to generally weak forcing for ascent driven mainly by diurnal heating and some lift along a diffuse lee trough axis. However, early signs of convective development has been recently along an outflow boundary associated with upstream convection across WV. Deeper convection may materialize east of the Appalachians as the boundary moves into a more buoyant air mass. Very warm surface conditions (temperatures in the upper 90s, low 100s) are resulting in deep boundary-layer mixing up to 2 km, which, when combined with PWAT values around 1.75 inch, should be supportive of wet downbursts with an attendant severe/damaging wind risk. Convective coverage remains uncertain, but recent WoFS guidance continues to show at least scattered thunderstorm development, suggesting the wind risk continues across southern portions of WW 548. ..Moore.. 07/16/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...ALY...PHI...CTP...LWX... LAT...LON 39867407 39627477 39437574 38947644 38487699 38337734 38377772 38447797 38697822 38927823 39147803 39537766 39807736 40027698 40177662 40277629 40547556 40627512 40917478 41197465 41507433 41617396 41627364 41567344 41387319 41157316 40967338 40737358 40637371 40297394 39997397 39867407 NNNN