Tornado Watch in effect for Midlands, Lowcountry through Tuesday evening
Tuesday afternoon update: A Tornado Watch is in effect for much of the Midlands and Lowcountry until 9 PM. A line of strong and severe thunderstorms moving across Georgia early Tuesday afternoon will push east-northeast through the afternoon and evening. The development of additional thunderstorms ahead of the convective line is possible, some of which may be supercells capable of producing tornadoes and damaging wind gusts. It should be noted that the atmosphere does support the possibility for strong and long-track tornadoes.
All severe risks could impact the Palmetto State this week as a multi-day severe weather outbreak unfolds across the Southeast.
Surface analysis late Monday morning depicts an area of low pressure centered over the Great Lakes, with an attendant cold front stretching from the Mid-Mississippi River Valley to the Southern Plains. To the south of that feature, low pressure is seen over Central Texas. Severe weather is likely from Central Texas east to Mississippi Monday, but that threat is expected to shift east by Tuesday as storms congeal into a line. This severe potential doesn't just exist in the Palmetto State on Tuesday, as another round of severe thunderstorms could develop on Wednesday.
Tuesday's storm potential comes in later in the day for much of the state. High-resolution weather models suggest the arrival of thunderstorms in the Upstate by the early afternoon. A lifting warm front will help destabilize the atmosphere through Tuesday evening, especially for the Midlands and Lowcountry. This keeps the risk for strong storms higher, with the Storm Prediction Center's outlook showing an "enhanced" risk, which is a 3 on a 1-to-5 scale. Damaging winds are the primary risk for Tuesday's storms, however, an isolated tornado and large hail cannot be ruled out. The severe weather risk Wednesday shifts further west, with an "enhanced" risk being introduced to the Upstate. Model guidance suggests a complex of thunderstorms will approach the Upstate bringing the risk of damaging winds and a few embedded tornadoes Wednesday evening. Aside from the severe risk Tuesday and Wednesday, the potential for flooding is also present across the Palmetto State as atmospheric moisture approaches 2-inches. Weather models indicate the training of thunderstorms, which would optimize rainfall potential in any given location.
Since there is a multi-day risk for strong and severe thunderstorms, it is important to understand basic severe weather terminology. A watch indicates that the atmospheric ingredients are in place to lead to severe thunderstorms or tornadoes. Watches are typically issued for large geographical areas, sometimes covering an area equivalent to several states. On top of the wide geographical expanse, they are typically longer lasting than warnings. A warning is only issued if severe weather is occurring in a specific location, typically covering a few counties or less at any given time. Warnings are usually shorter duration events, with most warnings lasting less than one hour. It is important to note that a tornado warning does not always mean a tornado is on the ground, but it does mean that rotation is present in the atmosphere and a tornado is possible. Whether for tornadoes or severe thunderstorms, the issuance of a warning means people in the path of the warned storm should seek shelter immediately.