Analysis of Radar Signatures and Environmental Characteristics of Destructive Hail and Wind Producing Storms in the Mid-Atlantic

With the introduction of the “Destructive” and “Considerable” tags for Severe Thunderstorm Warnings across the National Weather Service (NWS) in 2021, it is critical for NWS meteorologists to be able to delineate between base severe thunderstorms (greater than or equal to 58 mph winds and/or 1.0-inch hail), considerable severe thunderstorms (greater than or equal to 70 mph winds and/or 1.75-inch hail), and destructive severe thunderstorms (greater than or equal to 80 mph winds and/or 2.75-inch hail). Given the substantial impact that destructive severe thunderstorms can have on life and property, warnings with the “Destructive” tag now activate the Wireless Emergency Alert (WEA) system, much like Tornado Warnings. Given this additional responsibility of triggering the WEA system for such events, it is critical for forecasters to be able to identify both the environmental conditions and the radar signatures that are conducive to the development of these storms. This capability allows NWS forecasters to provide optimal warning services, aligning with the agency goal of protecting life and property.

This study examined radar signatures and environmental variables associated with observed destructive severe weather events in NWS Baltimore/Washington’s county warning area over a 15-year period from 2009 to 2023. WSR-88D Doppler radar data from both the KLWX and KDOX radars were examined to determine critical reflectivity, velocity, and dual-pol patterns that preceded these destructive events. Additionally, RAP/RUC analyses were examined to assess levels of instability, vertical wind shear, and various other parameters preceding these events. The outcomes of this study are intended to help forecasters promptly identify environments favorable for destructive storms, ultimately leading to improved warnings to the public. The results aim to empower radar operators with the confidence to identify radar signatures associated with these events.