Update, 4:45 p.m.: Severe thunderstorm warning until 5:30 p.m. for northern Fairfax and central Montgomery county. Storm capable of producing quarter-size hail near American Legion Bridge. Storm is moving NW up I-270 corridor.
Some sun today helped us reach milder highs than recently, with afternoon temps up near 70 many spots. Of course, abundant cold air aloft associated with our meandering upper low has responded to that sun by helping create showers and storms this afternoon. This activity, some with heavy rain and hail, should wind down as we start to lose the sun’s heat heading through sunset.
Through Tonight: Locally numerous (but not every location will get a lot) showers and thunderstorms will persist into the evening. Brief rainfall rates in excess of 1″ per hour are possible with the heaviest activity and this may lead to some flash flooding. Hail has also been reported in many spots thanks to the cold air aloft. Gusty winds are also a threat. As we get to and past sunset, rain should begin to decrease, but scattered activity may persist until about midnight before becoming isolated as the night goes. Lows range from near 50 to the mid-50s.
Tomorrow (Thursday): The upper-level low continues to weaken and shift off to the northeast of the area. We’re not totally done with it, as such clouds should remain numerous, though we can probably expect partly cloudy overall. We’ll also run into a slight chance of showers during the heating of the day, but compared to the last two days it should be easier to deal with. Highs head for the mid-70s or so.
Pollen update: The most recent pollen counts were washed out by rain.
Tornado drought: Jason wrote about the tornado drought over the last year the other day in relation to past discussions regarding tornadoes and climate change. Yesterday, Patrick Marsh of the Storm Prediction Center posted some more stats. In his analysis of F/EF1+ tornadoes over the decades, he found that the current slump is about 10x less likely than the surplus of 2011-2012.