The drier pattern that had settled into the Palmetto State the last two weeks of September is not likely to last much longer.
Heavy rain is likely, especially over the Upstate and western Midlands, starting Monday afternoon and periodically lasting through the remainder of the week. The heavy rain could lead to scattered areas of flash flooding, particularly in hillier terrain.
A change in the weather pattern is the primary cause for the heavy rain potential. A deep trough of low pressure is expected to stall over the lower Mississippi River Valley for much of this week. At the same time, the strong subtropical ridge that had been dominating the state will shift into the Atlantic waters. The winds between these two systems will be out of the south, which will transport moisture into the state as the week progresses. This moisture will lead to an increase in showers and a few thunderstorms over much of the state. Despite the increase in moisture, average rainfall over the Midlands, Pee Dee, and Lowcountry will be around an inch this week, but there will be neighborhoods that see locally more in scattered downpours.
The Upstate is in line to see the most rain. 2 to 5 inches are forecast. A few spots could receive in excess of 6 inches, especially near the Escarpment. A slow decrease in rain coverage is forecast over the Upstate by Friday or Saturday. However, rain chances are likely to stay elevated until Sunday over the remainder of the state.
The tropics have quieted down now that Hurricane Sam has bypassed Bermuda and is recurving into the open Atlantic Ocean. Victor weakened to a tropical depression over the open ocean. The Hurricane Center is monitoring an area of disturbed weather near the Bahamas. It has a low chance of development later this week or next weekend, but strong wind shear is likely to prevent it from becoming a powerful system.
