WASHINGTON — Hopefully everybody enjoyed the weekend because rain is a’coming and it’s here to stay – at least through the first part of Thursday.
The D.C. metro area will get in on the action that comes from the Midwest (although nowhere near the severity) for this week as a strong closed area of low pressure sits and slowly spins to the east. At the same time, a warm front is to our south by the Virginia and North Carolina border. This warm front will slowly push north by Wednesday morning and its attending cold front will move out of the plains and sweep through our area during Wednesday evening, clearing the region by Thursday.
Rain will pick up in intensity through the day on Tuesday. Temperatures will barely make it out of the 50s with a breezy easterly wind.
By Wednesday we can expect warming temperatures with a nice southerly breeze, shooting our daytime highs to near 70. With that push of warm air ejecting from the Gulf of Mexico, and multiple disturbances floating through the region we can expect some thunderstorms on Tuesday night through the day on Wednesday and some could be on the strong/severe side.
Expect a few lingering showers on Thursday morning before we finally break this pattern and get some clearing by Thursday afternoon.
Here’s a breakdown of each day:
Tuesday: Breezy with temperatures not above the 50s. Chance of rain all day, falling light to moderate at times, picking up in intensity in the evening hours.
Tuesday night: Rain continues to increase in intensity. We could have some thunderstorms in the mix as well. Temperatures drop just a smidge from our daytime highs on Tuesday, most likely bottoming out in the mid 50s.
Wednesday: Warming quickly with a southeasterly breeze at 10-20 mph or more, temperatures will reach near 70. Rain chances will continue through the day as well as the threat of thunderstorms. We could have strong to severe thunderstorms in the listening area on Wednesday.
Wednesday overnight: Rain showers moving out and off the coast from the west to the east. Temperatures fall to around 60 degrees with winds decreasing.
Thursday: A few lingering showers are possible early in the morning but will clear by the afternoon (if not before). Temperatures will top out in the mid 70s.
Obviously, due to the low progression of this system, we are bound to have to watch the flooding potential.
There is a good chance of flash flooding across the region. Please be mindful of this when you are driving around the next few days and avoid any water covered roadways. The above graphic is the flash flood guidance for our area. In other words how much rain needs to fall in a 6-hour period to achieve flooding status (as of April 28, 2014). This shows around an inch in the D.C. area and anywhere from 2-3 inches west and 3.5 inches to the south.
Compare that graphic with this graphic and you can see why flooding may be a concern for the region over the next few days:
Our in-house model shows that the Blue Ridge Mountains will be the sweet spot of accumulated rainfall through at least Wednesday afternoon — however, average amounts through from Monday night through Thursday morning will be anywhere from 3 to 5 inches of accumulated rainfall with higher amounts likely. And this is why the National Weather Service issued a Flash Flood Watch for Tuesday night into late Wednesday.
Not only has a Flash Flood Watch been issued but a flood watch has been issued for Opequon Creek near Martinsburg in Berkeley and Jefferson Counties, Seneca Creek at Dawsonville affecting Montgomery County and Monocacy River in Frederick County, Maryland for Wednesday evening through Thursday evening.
So there we have it. We will continue to update you with any thoughts on chances of severe weather by the time we head into Wednesday. I really think that will be our best chance to get some severe activity with the relatively moist air mass in place, conditions could be conducive to see some damaging winds and possibly a small tornado risk.
Until then, just keep happy thoughts until Friday because that will be our first fully dry day this work week.