The National Weather Service has issued a Severe Thunderstorm Watch covering a broad stretch of the mid-Atlantic region, running through 8 p.m. this Wednesday, May 20th. The watch covers the following areas:
Southern Pennsylvania, all of Maryland, the Eastern Panhandle of West Virginia, Northern Virginia, the District of Columbia, and nearby coastal waters.
The watch zone runs approximately 55 miles north and south of a line stretching from 95 miles west-southwest of Martinsburg, West Virginia to 45 miles east of Harrisburg, Pennsylvania.
What Forecasters Are Warning About
This is not a routine watch. The National Weather Service is flagging the potential for scattered damaging wind gusts reaching up to 70 miles per hour, along with isolated large hail events with stones up to one inch in diameter possible.
Thunderstorms are expected to form and push eastward across the region, moving directly into a hot and unstable air mass sitting over the area right now. That combination of ingredients is what has forecasters concerned about the storms intensifying as they move through.
Watch vs Warning: What Is the Difference?
A watch does not mean severe weather is likely right now or that it is about to hit your neighborhood immediately. What it does mean is that the conditions are favorable for severe storms to develop, grow, and spread across the watch area.
Think of it as a heads-up rather than an alarm. It is the NWS telling residents to stay alert and be ready to act quickly if conditions change in their area.
A warning, by contrast, is issued when severe weather is either occurring or is immediately imminent. If a warning is issued for your specific location later today, that is the signal to take shelter right away.
What You Should Do Right Now
Anyone living or traveling through the watch zone should stay informed throughout the rest of the afternoon and into the evening. Keep a weather app, local radio, or TV alerts handy so you can respond quickly if a warning is issued for your specific area.
Stay aware of changing sky conditions, have a plan for where to shelter if a storm approaches, and avoid unnecessary outdoor activity if you see the weather turning threatening.
The watch remains in effect until 8 p.m. tonight.