ZCZC SPCSWOMCD ALL ACUS11 KWNS 170333 SPC MCD 170333 NJZ000-PAZ000-DEZ000-MDZ000-WVZ000-VAZ000-170730- Mesoscale Discussion 0149 NWS Storm Prediction Center Norman OK 0933 PM CST Fri Feb 16 2024 Areas affected...Northeast West Virginia to western New Jersey Concerning...Heavy snow Valid 170333Z - 170730Z SUMMARY...A swath of moderate to heavy snowfall will continue to spread east across parts of the Mid-Atlantic over the next several hours. DISCUSSION...A swath of moderate snowfall continues to spread east from the upper OH River Valley region into the Mid-Atlantic based on recent regional reflectivity composites. Transient organized snow bands continue to be observed within this broader zone, resulting in visibility reductions from 1/2 to 1/4 mile and steady snowfall accumulations based on recent snow reports from the region. Favorable phasing of synoptic ascent ahead of the approaching shortwave trough and strong isentropic and frontogenetic lift within the 925-700 mb layer, which has been driving this activity so far, is expected to persist as the system pushes towards the East Coast over the next several hours. Latest forecast guidance depicts reasonably high probability in snowfall rates between 1-2 inch/hour across portions of the Mid-Atlantic region (and possibly as far east as the NJ coast) through 08 UTC. Based on observed trends, this depiction seems fairly reasonable. One caveat is a lingering warm/dry layer below 850 mb sampled by regional 00 UTC soundings and noted in surface observations across northern MD, southeast PA, and into western NJ, which may limit snowfall rates in the near term. However, a combination of evaporative cooling and persistent mesoscale ascent along the warm frontal zone should support adequate low-level saturation/cooling to allow for moderate to heavy snowfall in the coming hours. ..Moore.. 02/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...BGM...CTP...LWX...PBZ...RLX... LAT...LON 39027964 39317946 40797816 40987781 41047727 41097559 41007515 40867482 40557450 40117448 39847474 39707510 39607581 39587636 39537690 39397762 39217805 38927844 38757868 38677897 38687925 38787956 39027964 NNNN