The issuance of Mesoscale Discussion #708 by NWS/Storm Prediction Center at 1641 UTC established the main area of focus for thunderstorm downburst wind generation as the plateau and Allegheny Mountain region of western Pennsylvania and northern West Virginia. The latest multi-sensor analysis in Figure 1 captures the rapid development of a squall line along an eastward-advancing cold front in western Pennsylvania. This convective system consists of vigorous multicellular storm clusters that appear prominently in both MRMS reflectivity and GOES-19 cloud convection imagery. A significant diagnostic feature is the high lightning probability within the storm cores. This enhanced electrical activity underscores the robust updraft strength and high liquid- and ice-phase water content, creating a highly favorable environment for severe downburst generation as these convective cells mature.
Figure 1. GOES-19 day cloud convection, LightningCast lightning probability, and MRMS radar reflectivity at 2000 UTC 13 May 2026.
Atmospheric profiling from Pittsburgh (PIT) area ACARS and RAP model soundings (1700–1800 UTC) in Figure 2 show strong consensus for severe wind potential. Both platforms exhibit classic "hourglass" profiles, characterized by dry air in the low-to-mid levels flanking a moist convective layer. Wet-Bulb Zero (WBZ): Positioned near the 750-mb level, enhanced melting-induced cooling and downdraft acceleration. WGP: MWPI-derived Wind Gust Potential ranging from 38 to 44 knots. This thermodynamic environment directly supports the concurrent GOES-19 Microburst Risk (MBR) imagery, which indicates moderate downburst potential over southwestern PA. Shortly after 2000 UTC, thunderstorm downburst wind damage was observed in the Morgantown-Fairmont, WV area near the southern terminus of the squall line.
-StormRangerWX
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