Severe Weather is possible Sunday across much of Virginia and the Lower Mid-Atlantic. The Storm Prediction Center has placed all of Virginia under a SLIGHT RISK for severe weather. Damaging straight-line winds and hail are the main risks, with an isolated tornado possible.
CAPE (Convective Available Potential Energy) will reach 1000 to 2000 J/kg, (Joules per kilogram) which is plenty of thunderstorm fuel for these storms to develop ahead of a cold front Sunday afternoon. We’ll have to watch for a few individual discrete supercells that may try to form ahead of a developing line of straight-line damaging winds. These storms have the potential of producing a few tornadoes.
By early afternoon Sunday, thunderstorms will cross Far Southwest Virginia and gradually move east of Interstate 77. By mid-afternoon, severe storms are expected across the Shenandoah Valley. Damaging wind gusts in excess of 60 MPH, along with large hail are expected in a line of thunderstorms.
By late afternoon Sunday, discrete thunderstorms may form ahead of the main line of thunderstorms. These storms need to be watched for tornadic development and large hail. We expect the main line of severe storms to roll across Interstate 85 and 95 after 5:00 p.m. Sunday. Some of these storms could produce straight line damaging winds in excess of 70 MPH.
By Sunday evening, a line of severe storms, producing damaging straight-line winds (and an isolated tornado,) will be possible across the Hampton Roads and Chesapeake Bay Region, east into the Delmarva. The severe threat will start to diminish and turn into a very heavy rain threat, with localized flooding possible.
It is VERY IMPORTANT to know where your “safe place” is BEFORE severe weather hits your area. By the time the storm is right on top of you, it may be too late. Straight-line winds can and feel like a tornado, however, there’s obviously a difference. Straight-line winds are a significant push of air in one direction usually associated with thunderstorms. Please take all modes seriously and seek shelter when a severe warning is issued. Top floors DO NOT protect you! If you do not have a basement, move in an interior room with no windows. A bathroom is generally a good place to be, using a helmet over your head or bed mattress to protect your body from falling debris.