High pressure will make for a beautiful end to the work week with temperatures in the mid 80s and dew points back in the low 50s. We all know unfortunately that it can't last. It is still August after all. So what will the weekend bring? It appears a widespread area of low pressure will push into the region and heavy rain appears to be a good possibility. HPC's rainfall potential map above from Saturday morning through Monday morning shows upwards of 2 inches of rainfall possible for much of the Mid Atlantic including the D.C. and Baltimore Metro Areas.
So let's get into the nitty-gritty of the weekend forecast. Here is my take on the system.
Set Up: High pressure will gradually move off the east coast on Friday, setting up a return flow across the Mid Atlantic which will help pump a little more moisture into the region. Saturday will feature that same high continuing to pump in moisture, and a new area of low pressure (whose current energy is over the Pacific Northwest) begin to move in from the west. This low will help spawn showers and thunderstorms Saturday afternoon, but the main convergence appears to come through Saturday night into Sunday to really get the rain going across the area.
Timing: If you want to be outdoors this weekend, Saturday morning will be your best bet if you want to stay dry. There is a chance for storms Saturday afternoon and night, and increasing chances for more heavy precipitation Sunday morning through Sunday afternoon. The BEST CHANCE for rainfall will be Sunday morning between Midnight and Noon.
Severe Threat: The biggest threat of severe weather may be Saturday afternoon with some pre-frontal thunderstorms with damaging winds and large hail. Those would be isolated in nature. Sunday morning may feature a chance for damaging winds if a line develops, as well as the chance for very heavy rainfall with precipitable water values around 2 inches.
Drought Improvements? A moderate drought has settled into the region as seen below. If we really do recieve this rain, it will help the region a lot and keep it from heading into a more severe drought. As this drought monitor is from last Thursday, we have seen beneficial rains since then so hopefully we are already cracking into the deficit.
- Credit: Brad Rippey, U.S. Dept. of Agriculture