An upper level low is tracking northward from the Gulf of America just off the west coast of Florida and is headed to a position just offshore of South Carolina. Heavy rain threats will be increasing Wednesday afternoon as bands of showers and thunderstorms sweep through the Lowcountry and into the Midlands. Rain rates of around 1-2” per hour were recorded in the Beaufort area Wednesday morning.
The Weather Prediction Center has most of the Lowcountry from around the Beaufort area north to Georgetown highlighted in a “Slight” risk for flash flooding through Wednesday evening. That is a level 2 out of 4 for flash flood risk. Severe thunderstorms are not expected, but the onshore flow will feed showers today making scattered showers efficient rain producers. Showers are likely to more intermittent across the Midlands, and flooding will be less of a concern. Still, a few isolated locations could see some flash flooding from Wednesday’s storms across the Capitol region. Flash Flooding risks for Wednesday are in the “Marginal” category in this area.
Showers will not be quite as numerous or as heavy Thursday. Again, the Lowcountry will be favored for rain Thursday, and it could be heavy at times. Flash flooding risks in the Lowcountry will be in the “Marginal” category Thursday. The upper low that is moving over the Palmetto state late this week has spawned a surface low pressure area that will track close to the coastline and head northward into the weekend, decreasing heavy rain threats.
Total rainfall will be highly variable, but areas east of I-95 can expect substantial rainfall before the weekend begins. Much of this area is expected to receive over 2” of rainfall, with up to 3” in some spots. The heaviest rain this week is going to be occurring where it is most needed. The Myrtle Beach area and a large chunk of the Pee Dee is in moderate to severe drought.
This weekend, a frontal system will approach the region from the west, pushing out the coastal low into the Atlantic. After a dry start to the weekend, showers and thunderstorms are expected to develop by Saturday evening. This system will stall and linger into next week. During that time, we can expect a few daily thunderstorms, mainly in the afternoon and early evening hours.