* Frost advisory Loudoun, Montgomery, Howard and Frederick counties tonight *
Another cool mid-April day is in the books. And despite intermittent chill in a breeze or in the shade, it still felt quite pleasant in the sun. Sunshine has become increasingly obscured with clouds as winds off the ocean push moisture into the area. Those clouds increase tonight and try to stick around most of tomorrow.
Through Tonight: Clouds increase overnight, probably toward mostly cloudy between midnight and morning as the marine layer builds inland. Lows range from about 33-39 most spots. A few locations may touch freezing far north or west, and frost is possible closer in even with temperatures in the mid-30s for lows.
Tomorrow (Friday): We likely have a fairly cloudy day ahead with ocean air in control. There’s some hint we may get winds to come more from the south by the second half of the day, which might start to break us into sun. But, the wedge of cool air often holds strong here, so don’t plan on a super fine one. Highs are mainly in the mid-to-upper 50s.
Pollen: Tree pollen is in the moderate range with 27.8 grain/cubin meter. Other pollens and mold spores are low. In the graph below, we get a sense that there’s still a lot more pollen to come. The 2014 line is a few days slow at this point, so today’s value is even lower than shown. Enjoy the break, the next few weeks should feature peak somewhere!