Washington DC (LWX) — the National Weather Service forecast in plain English · Plaincast

What has changed

Heavier showers over the DC Metro have now pushed east. Additional showers continue through early afternoon, though mostly from DC northward. A few thunderstorms possible in Central VA late this afternoon.

Messages

1) Storm chances linger through at least Saturday, with a possibly drier finish to the weekend.

2) Seasonably warm ahead of a mid-week cold front.

Discussion

KEY MESSAGE 1. Storm chances linger through at least Saturday, with a possibly drier finish to the weekend.

Most of the heavy shower activity of the DC metro earlier this morning has pushed east and out of the area. Additional light to moderate showers are noted over northern MD, pushing east to the Baltimore area. A few light showers possible elsewhere, though it looks to be mostly dry into the afternoon.

Additional showers and a few thunderstorms develop this afternoon to evening over the Potomac Highlands into the central Virginia Piedmont region. Overall conditions today will yield more clouds than sun. This is accompanied by high temperatures in the mid 70s to low 80s, locally a bit cooler across the mountains.

The cold front initially north of the Mason-Dixon Line is forecast to settle toward the Virginia-North Carolina border by tonight. Despite the frontal passage, its more diffuse nature will only bring a limited drop in temperatures and humidity levels. Saturday morning will start off in the 60s which comes with further shower and thunderstorm chances throughout the day. The focus is driven by an elongated trough currently crossing the Arklatex states. As this array of embedded shortwaves lift across the Tennessee Valley toward the southern Mid-Atlantic, storm chances increase in earnest. The 00Z high-resolution model suite shows an uptick in rainfall amounts, some of which are on the higher end (1 to 2 inches in 24 hours). With precipitable water values in the 1.75 to 2.00 inch range and deep warm cloud layers, some fairly efficient storms are possible in this environment. As such, the Weather Prediction Center supports a Slight risk for excessive rainfall on Saturday, especially across the I-95 urban corridor. Will continue to monitor the situation as new mesoscale guidance arrives.

Coming off temperatures similar to today, expect a slight warm up into Sunday with highs returning to the mid 80s. Some residual shower activity is possible to start the day. However, the local area will be in the wake of the passing shortwave trough. Expect some increase in humidity as the boundary to the south returns northward as a warm front. Unlike previous days, a fair amount of sunshine is possible, particularly for the second half of the day. Sunday night's low temperatures will fall into the 60s to low 70s.

KEY MESSAGE 2. Seasonably warm ahead of a mid-week cold front.