7:40 p.m. update: With the exception of extreme southern Maryland, the storms have exited the region.  Enjoy the pleasant evening!

7:00 p.m. update: We are seeing some intense storms on the southern and southeastern periphery of our region (elsewhere it’s quiet and should remain so, aside from an isolated shower or two). The severe storm in Charles County has put down some quarter-size hail (at least), and it is racing into St. Mary’s County which could get some hail and possibly damaging wind gusts. The severe thunderstorm warning remains in effect through 7:30 p.m.

A new severe thunderstorm warning has been issued for extreme southeastern Fauquier County and western Stafford County until 7:45 p.m. It could also produce some hail.

All should be quiet once these storms cycle through.

6:42 p.m. update: These showers and the few isolated thunderstorms are very fast movers and have already mostly crossed I-95 into our eastern suburbs (and will cruise on by in the next 30-45 minutes). The National Weather Service just hoisted a severe thunderstorm warning for a lone intense cell in central Charles County moving into St. Mary’s County, in effect until 7:30 p.m. There’s not much to the west, so many of us may end up with a nicer than expected pre-sunset period. Still keep an eye out for any isolated showers that could pop up.

5:45 p.m. update: Showers and some embedded downpours have rapidly developed over the region. We’ve received some isolated reports of thunder, but there are no indications of severe weather.

5:15 p.m. update: So far relatively stable air is really inhibiting thunderstorm formation over the region. Radar shows some widely scattered showers, but nothing terribly disruptive. The most likely window for showers and storms remains 6-9 p.m., but they be weaker and more widely scattered than expected earlier today.


Radar & lightning: Latest D.C. area radar shows movement of precipitation and lightning strikes over past two hours. Refresh page to update. Click here or on image to enlarge. Or see radar bigger on our Weather Wall.

Detailed forecast through Thursday, from 4:45 p.m.

No sharknadoes tonight, but some showers and thunderstorms are likely, a few of which could be on the strong side. After 9 p.m., the weather settles. Thursday, on balance, is warm and tranquil, but a few storms could fire – mainly east and southeast of I-95.

Through Tonight: Showers and storms are a decent bet. Activity through 5 p.m. or so is mostly isolated (hit or miss). Between 5 and 9 p.m., a more solid cluster may develop and scoot through the region from west to east. Embedded within this cluster, a few storms may (25 percent chance) contain frequent lightning, very heavy rain, gusty winds and small hail. But the chance of truly severe storms is mostly confined to our south,  into central Virginia and southern Maryland. Partly cloudy after 9 or 10 p.m. and mild with lows in the upper 50s in our cooler suburbs to the low-to-mid 60s downtown. Light winds, except in showers/thunderstorms.

Tomorrow (Thursday): Drier air attempts to work into the region, but a sluggish, diffuse cold front over the region may try to conjure up some storms late in the afternoon and evening.  The best chance of storms  – at 30 percent –  is east and southeast of I-95.  Elsewhere, odds are closer to 20 percent and the day is more likely to be rain-free and enjoyably warm, with highs in the low 80s. Light winds from the west.

See Dan Stillman’s forecast through the holiday weekend. And if you haven’t already, join us on Facebook and follow us on Twitter . For related traffic news, check out Dr. Gridlock.

May 20, 2014. (Fred King via Flickr)

Pollen: Tree counts are HIGH at 201.28 grains per cubic meter. Grass counts are HIGH at 19.17 grains per cubic meter.  Weed and mold spore counts are LOW.

Note: The information about the Denver storm, previously in this post, has been moved here: Denver, Colorado area socked by extreme hailstorm, tornadoes