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Posted at 12:15 PM ET, 08/18/2010

Forecast: Heavy rain briefly interrupts summer

By Dan Stillman

Warmth returns tomorrow, but no intense heat on horizon

* Flood Warnings expire; heavy rain totals | Flood Watch thru tonight *
* Storm impacts: | Share storm photos *
* Weather and war throughout history | How many 90s? Play to win *
* Outside now? Radar, lightning, temps & more: Weather Wall *

updated at 12:15 p.m.; originally posted at 5 a.m.

Today's Daily Digit
A somewhat subjective rating of the
day's weather, on a scale of 0 to 10.


In some ways, the cool & dreary rain is a nice change from 90+. Though I'd much prefer a taste of 80 & sun.
Get the 'Digit' on Twitter


Today: Overcast with rainy a.m., occasional p.m. showers. Mid-to-upper 70s | Tonight: Chance of more rain. Mid-to-upper 60s. | Tomorrow: Becoming partly sunny. 20-30% chance of showers/storm. Mid-to-upper 80s. | A Look Ahead | Get Express Forecast by E-mail


Summer is interrupted for the second time this week. After an overcast and showery Sunday with highs only near 80, it's an even rainier and cooler day today. It's all part of a shift in weather pattern that has us facing no intense heat in the foreseeable future, but rather a return to warm and moderately humid conditions starting tomorrow. Shower and storm chances threaten a comeback this weekend, though only in the low-to-moderate range for now.

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.

Today (Wednesday): Rain that was moderate to heavy at times for much of the morning -- resulting in some flooding and water rescues -- becomes lighter and more intermittent during the afternoon as the steadiest and heaviest stuff pulls away to the east/northeast. Mid-to-upper 70s is about the best we can do for highs with overcast skies all day long. Confidence: Medium-High

Rain totals have mostly fallen in the 0.75"-3" range with some locally heavier and lighter amounts. The jackpot has been southern to central Montgomery County (with a report of more more than 3.5" in Rockville), northern Fairfax County and northwest D.C. See radar-estimated storm totals here.

P.M. Commute & Tonight: If it holds together (50% chance), another batch of steadier, heavier rain could arrive by or during the commute home and last into a good part of the evening, potentially causing more flooding problems. Even if that batch doesn't hold together well, there's a good chance of at least occasional lighter shows, which may (40% chance) linger at times overnight as well. Some drizzle, mist and/or fog are also possible. Lows mainly settle in the mid-to-upper 60s with continued cloudy skies. Confidence: Low-Medium

Keep reading for the forecast through the weekend...

Tomorrow (Thursday): While higher pressure tries to dry us out, we still run a risk (20-30% chance) of a couple showers and an afternoon thunderstorm. Clouds could be slow to clear during the morning, with a decent chance of at least partial sunshine in the afternoon. With enough sun, highs should get to the mid-to-upper 80s. Humidity's in the moderate to high range. Confidence: Medium

Tomorrow Night: It's a quiet and partly to mostly clear night with lows in the mid-60s (coolest suburbs) to near 70 (downtown). Confidence: Medium-High


High pressure holds court on Friday. The result is a partly to mostly sunny and warmer day as highs likely climb to near 90 or into the low 90s. Humidity remains noticeable but not too bad. Got plans Friday night? ... nothing to worry about as far as the weather is concerned. Confidence: Medium-High

Our warm, but not unusually so, pattern persists this weekend. Shower/storm chances are slight on Saturday with partly to mostly sunny skies, and about 20-30% on Sunday as a cold front getting closer from the west increases the clouds. Highs max out in the mid-80s to near 90 with morning lows in the mid-60s to near 70. Humidity stays in that middle range -- could be better, could be worse. Confidence: Medium

By Dan Stillman  | August 18, 2010; 12:15 PM ET
Categories:  Forecasts  
Save & Share:  Send E-mail   Facebook   Twitter   Digg   Yahoo Buzz   StumbleUpon   Technorati   Google Buzz   Previous: Rain totals mounting, heaviest moving northeast
Next: PM Update: More rain possible into the night


Everyone make it okay on their commute? See any roads covered with water? (hope you didn't drive through them!)

Posted by: Camden-CapitalWeatherGang | August 18, 2010 8:32 AM | Report abuse

Thanks for accurate forecast. Spared heavy watering chores last night.
Lots of inches deep standing water on 29 in western Fairfax county, which can cover up some wicked potholes. Poor visibility, lots of people not turning on their lights. The usual terrible rainy day commute stuff.

Posted by: FIREDRAGON47 | August 18, 2010 8:54 AM | Report abuse

FIREDRAGON47, ugh. Sounds about right though, I guess. At least...this spared you watering!

Posted by: Camden-CapitalWeatherGang | August 18, 2010 10:55 AM | Report abuse

Do I have this right? There is a 50 chance there could be rain tonight. If it does rain, there is a chance it could be heavy. And even if it's not heavy, there is a 40 percent that we could have showers that linger overnight? Taken together, it may rain more but it may not?

Posted by: realclear | August 18, 2010 12:54 PM | Report abuse

Can you please comment on the potential for an East Coast hurricane next week? Apparently there was a GFS run yesterday that had one going into Long Island...

Posted by: newsregister | August 18, 2010 1:03 PM | Report abuse

I don't see this next batch being a big deal, there was a lot more support for this morning's event. Re: storm next week, the new run shifted it toward the Canadian maritimes.

Posted by: Ian-CapitalWeatherGang | August 18, 2010 1:07 PM | Report abuse



Posted by: Dan-CapitalWeatherGang | August 18, 2010 1:14 PM | Report abuse

Hi Weather Gang:

I recently heard a scientist on TV say, during a long interview, and in the context of global warming/climate change, that the Washington DC area's weather is changing. I found it interesting that he specifically mentioned our area, and singled it out as an example of a place that has a changing weather pattern due to global warming/climate change. I know this is provokes intense political debate -- esp. in this town -- but I assume that there is some fact and fiction in there somewhere. So, can you help us sort out the facts? Considering last winter, and the record number of days of heat we've had this summer, with any other facts that you would know better than I, do you think our weather is changing from the norms we've been seen for the last 20-30 years? I look forward to your answer, mostly just to know if I should dread winters and summers here! :)

Posted by: csaah | August 18, 2010 1:21 PM | Report abuse

Excellent question. I,too, am very interested in a future look at this by CWG. Has the climate we have lived through in the past few seasons been mostly just an eons-old cyclical pattern for this region? Or is it perhaps a rare, random confluence of El Nino/NAO/etc? And is it over now? (Ha!)

Posted by: Kyriakos777 | August 18, 2010 1:42 PM | Report abuse

if last winter is in anyway related to global warming, i'm all for it!

Posted by: walter-in-fallschurch | August 18, 2010 2:29 PM | Report abuse

It sure looks like the moisture has made it over the mountains in the form of rain.

Posted by: rocotten | August 18, 2010 2:32 PM | Report abuse

2.75" in NE DC (Capitol hill area) thus far.

All CWG has to do is call for heavy rains inside the beltway and you know it'll go north or south :)

Posted by: jojo2008 | August 18, 2010 2:37 PM | Report abuse

About 70% of the past winter's snow fell during an 11-day period from Jan 31-Feb 10 and there were some clearly defined abnormalities (Greenland block, El Nino) in play.

So far we haven't had a tropical weather system move through here, nor, thankfully, tornadoes. Records snowfalls, yes, and a summer that probably (hopefully?) won't equal 1980 in intensity. And some bad thunderstorms, definitely.

There were 3.5 million living in the DC area in 1980; today's figure is about 5.5 million, so 2 million more people are impacted by the weather hereabouts than in 1980, or the memorable 1979 snows. Meanwhile, the local infrastructure generally hasn't kept up with population growth.

And of course we now have the internet, which helps amplify weather issues. My point? While it's fun to kvetch about and get excited by the weather, I don't see this year's abnormalities mean D.C.'s weather has gone completely berserk. We're still not in Kansas, Toto.

Posted by: JerryFloyd1 | August 18, 2010 3:16 PM | Report abuse


Actually, the jackpot was indeed inside (and along and just to the north and west of) the northern branch of the Beltway. Radar-estimated totals tell the story.

Posted by: Dan-CapitalWeatherGang | August 18, 2010 4:13 PM | Report abuse

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