PM Update: The rain train continues into Friday; a square cloud???

* Flash flood watch through this evening | Flooded roads *


Radar & lightning: Latest regional 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.

Bouts of showers and thundershowers are likely this evening and again Friday. We’ve had some isolated cases of flooding in our western suburbs this afternoon and more cannot be ruled out over the next day. We have to wait until late Friday night to start drying out.

Through Tonight: We’ll see a break in the rain this evening for a brief window, but additional showers and thundershowers may stream in from the south after 7 or 8 p.m. The activity may be scattered – so there’s about a 50/50 chance of rain through the pre-dawn hours, when the rain chances then fall to around 30 percent. It’s muggy overnight, with lows 66-70 (suburbs-city). Light winds from the southeast at 5-10 mph.

Tomorrow (Friday): Mostly cloudy, warm and humid, with increasing showers and thundershower chances as the day wears on – from around 30 percent in the morning to 70 percent in the afternoon. Heavy rain is possible and we may see flooding arise in a few areas. Highs are in the low 80s, with winds from the southwest around 10 mph.

See David Streit’s forecast through early next week. And if you haven’t already, join us on Facebook and follow us on Twitter . For related traffic news, check out Dr. Gridlock.

Downpours at 14th and T St., NW, D.C. June 11 (EllenO via Flickr)

Downpours at 14th and T St., NW, D.C. June 11 (EllenO via Flickr)

Pollen: Tree counts are LOW-MODERATE, grass counts are LOW, weed counts are LOW, and mold spores are HIGH, given the recent wetness.

Square cloud from International Space Station: From the International Space Station, U.S. astronaut Reid Wilson tweeted this view of an apparent “square cloud” adjacent to Kamchatka’s volcano field:

But it’s not really a square cloud – it just took on that appearance from Wilson’s perspective. Tom Yulsman of Discover’s ImaGeo blog captured another view of the same cloud mass from NASA’s Aqua satellite which is more contoured.  Yulsman notes the abrupt delineation between clouds and no clouds is real, however – owing to the differential heating between ocean and land.

Also on Capital Weather Gang

Rare spooky-sweet event: Full 'Honey Moon' coincides with Friday the 13th