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Posted at 11:00 AM ET, 07/12/2010

Forecast: Muggy, warm, and at times wet

By Jason Samenow

* Follow CWG on Facebook and Twitter | Weather Wall *

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


Back to work and the humidity is back, along with storm threat for evening commute.
Get the 'Digit' on Twitter


Today: Increasing clouds. P.M. storms likely. 86-90. | Tonight: Evening storms likely, then muggy. 70-75. | Tomorrow: Muggy, showers and storms likely in the p.m. 86-90. | A Look Ahead | Get Express Forecast by E-mail


So far this summer, we've had the heat, we've had the humidity, we just haven't had the rain. This week, we'll finally get some of that rain we've been missing along with the heat and humidity we've come to know so well. At least a chance of showers and thunderstorms is in the forecast every afternoon and evening. Maybe, just maybe, we can put away the sprinklers and our lawns will turn back to green.

Temperatures: Latest D.C. area temperature map powered by iMapWeather (base map by Google). Click and hold on map to pan. Double-click to zoom. Refresh page to update. See larger map on our Weather Wall.

Today (Monday): We start the day with sunshine, but clouds and humidity increase in the afternoon as winds (at 10 mph or so) blow in from the southwest and a disturbance approaches. Showers and thunderstorms are likely (60% chance) to develop in mid-afternoon in western suburbs, advancing through the entire metro region by the evening commute. The rain could be locally heavy. Before the rain arrives, highs should reach the mid-to-upper 80s. Confidence: Medium

Tonight: Showers and thunderstorms are likely in the evening (60% chance) but should subside after around 10 p.m. Rainfall totals should average 0.50-1" although some spots could see more or less. Overnight temperatures are mild, with lows 70-75 (suburbs-city). Confidence: Medium-High

How would you rate today's weather? Vote your call for today's Daily Digit (see Daily Digit box above). And keep reading for the forecast through the weekend...

Tomorrow (Tuesday): While the heat won't be anything like we had last week - the humidity is going to be much worse. Considerable cloud cover probably holds high temperature to 90 or lower, but dew points in the 70s feel gross. And with all the moisture in the air and another disturbance passing through the area, showers and thunderstorms are again likely (50-60% chance) in the afternoon and evening. Confidence: Medium-High

Tomorrow Night: Showers and thunderstorms are a decent possibility up until just before midnight, then it's partly cloudy and humid. Lows range from 73-78 (suburbs-city). Confidence: Medium-High


Wednesday's another very warm and obscenely humid day with a decent (40-50% chance) risk of showers and storms - especially in the afternoon and evening. Highs are around 90 with overnight lows in the 70s. Confidence: Medium

With weak high pressure over the region Thursday, the chance of showers and thunderstorms in the afternoon and evening drops down to around 20%. But the continuation of steamy flow from the south coupled with increased sunshine could make it one of the hotter days of the week with highs up around 95 (feeling closer to 100 with the humidity). Overnight, it's partly cloudy and warm, with lows 70-77 (suburbs-city). Confidence: Medium

Friday, Saturday, and Sunday -- at this point -- look pretty similar: hot and humid each day with highs 90-95 along with a 30% or so chance of afternoon and evening thunderstorms. The overnight periods will no doubt be muggy after any evening storms diminish, with lows in the 70s. Confidence: Medium

By Jason Samenow  | July 12, 2010; 11:00 AM ET
Categories:  Forecasts  
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It might be interesting at some point to explore the connection between record heat like last week and dryness. From what I can tell the all-time records (e.g. July 1936) were also during a dry spell. Part of the equation is that the heat dries things up. But also dry air heats more and the dry ground allows less evaporational cooling. Why, for example, is this week less hot?

Posted by: eric654 | July 12, 2010 6:14 AM | Report abuse

Dry weather and heat tend to correlate positively due to the high specific heat of water.

With the threat of rain EVERY DAY, this is hardly a "drought". MNR continues to hit my dance nights; tomorrow it's the Clarendon Ballroom swing dance! May also have to reschedule tomorrow's dental appointment into next week.

Posted by: Bombo47jea | July 12, 2010 8:02 AM | Report abuse

eric654, are you connecting the rain we had recently to the reduced range in low-to-high temperatures? I do like what you are saying & think I follow :-) The 0.5"-2.0" range of rain in the region may indeed be one reason high temperatures are a bit cooler. But really the jet stream is more responsible. We don't have a macro-meteorological jet stream pattern that normally would give us a strong high pressure system like we were seeing during our record heat. The subsiding air from this strong high pressure system was even preventing CLOUDS from forming!

Posted by: Camden-CapitalWeatherGang | July 12, 2010 8:24 AM | Report abuse

So is there any chance that tonight's Screen on the Green won't be rained out?

Posted by: Melewen | July 12, 2010 8:41 AM | Report abuse

Camden, what you say makes sense. The moisture would tend to compress the range of temperatures, for example the low and high in Reno was 60 and 93. But that doesn't always work since Phoenix has been dry but 91 and 107 yesterday (a crisp 88 this AM). I forgot that the strong high last week is very different from the weak/broad trough aloft today.

My thought was more narrow which was that the very extreme high temperatures were preceded by a drought. That seemed to be the case last week and 1936 (according the wikipedia july 1936 article). I was wondering if that has to be the case, whether an extreme high requires dryness.

Posted by: eric654 | July 12, 2010 8:49 AM | Report abuse


Think it looks pretty bad for Screen on the Green. Maybe a 1 in 3 chance it's dry. Check our PM Update around 3:30 pm for the latest info and radar.

Posted by: CapitalWeatherGang | July 12, 2010 9:46 AM | Report abuse

re the DAILY threat of afternoon t-storms: BOOOO! bring back the "drought." some of us have afternoon/evening outdoor plans.... BOOOO!

i'd like to place my order for all this rain to be moved to night in camelot!


Posted by: walter-in-fallschurch | July 12, 2010 10:02 AM | Report abuse

The influence of the continental upper level ridge seems to be at least temporarily less than it has been for a while. I guess the Atlantic ridge is better for rain chances around here so we should enjoy it!

Posted by: Ian-CapitalWeatherGang | July 12, 2010 10:16 AM | Report abuse

So we're back to the typical Washington D.C. summer forecast of "Hazy, hot and humid with a chance of afternoon or evening thunderstorms". People who have lived here all their lives like me expect this forecast daily June - August.

Posted by: rwalker66 | July 12, 2010 10:18 AM | Report abuse

The 12z NAM wants to give us back a good chunk of our missing rain of late in the next 2.5 days.

Posted by: Ian-CapitalWeatherGang | July 12, 2010 10:33 AM | Report abuse

Postponed my dental appointment until I'm back from my vacation in August.

Now the only thing I need to worry about Tuesday is the evening swing dance.

Today's rain threat seems to have SOARED from 20% to 70%.

Posted by: Bombo47jea | July 12, 2010 1:02 PM | Report abuse

The 12z NAM is a sight for sore eyes and brown grass! Bring it on.

Posted by: formerwxman1 | July 12, 2010 1:04 PM | Report abuse

YEAH!!! RAIN!!!! YEAH!!!!!

Not only do I fully agree with formerwxman1, but the 135+ evergreen and deciduous trees that I've planted since moving across town to Michigan Park also agree with you.

Bring it on!!! End the drought we're suffering from!!!

Posted by: TominMichiganParkDC | July 12, 2010 2:03 PM | Report abuse

The radar looks great! Yeah, bring on the rain!

Posted by: natsncats | July 12, 2010 2:16 PM | Report abuse

eric654, I would say yes :)

Screen on the Green tonight, I personally would like to go? But I am worried about precipitation...

Yes though the rain potential tonight and over the next 2.5days as Ian mentions.. very good news. I too am excited!

Posted by: Camden-CapitalWeatherGang | July 12, 2010 2:46 PM | Report abuse

Pouring buckets in Suitland. There's a line of people lining up at the windows just staring. It's very amusing.

Posted by: Brian-CapitalWeatherGang | July 12, 2010 3:03 PM | Report abuse

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