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Posted at 05:00 AM ET, 08/03/2011

Forecast: Cooling trend brings chances to break 90+ streak; showers & storms a threat today

forecast originally posted at 5 a.m., updated at 6:45 a.m. to increase rain chances

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

 
Our best shot at a sub-90-degree day in more than 2 weeks bumps the digit up 2 from Tues, but more humid
 
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EXPRESS FORECAST

Today: Mostly cloudy. 70% chance of showers/storms. Mid-80s to low 90s. | Tonight: 30% chance of evening storms. Upper 60s to mid-70s. | Tomorrow: Partly sunny. Isolated p.m. shower? Upper 80s to low 90s. | A Look Ahead | Get Express Forecast by E-mail

FORECAST IN DETAIL

Today would make 17 straight days at or above 90 at Reagan National - four short of the D.C. record for consecutive 90-degree days - but clouds and potential showers/storms mean that reaching 90 isn’t a sure bet today, though it’s well within the realm of possibility. The nice news, at least for those not interested in tying or setting yet another record this summer, is that every day through the weekend holds at least a chance of highs below 90. On the other hand, a high right at 90 or a little past is plausible each day as well.


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.

Today (Wednesday): Well look what we have here - mostly cloudy skies give us our best chance to fall short of 90 degrees in more than two weeks. It’s also a more humid day with showers and thunderstorms likely (70 percent chance). Rain is possible at any point in the day but with two favored time windows - early-to-mid morning, and then mid-afternoon into evening. If we get considerable sun (looking less likely), a few storms could be severe this afternoon with a small possibility of damaging winds. The Storm Prediction Center indicates a slight risk of severe weather. The amount of sun will also determine whether highs stall in the mid-to-upper 80s or reach the low 90s. Confidence: Medium

Thundercast:

Probability: 70%.
Coverage: Scattered to Widespread
Most Likely Timing: Before 10 a.m. and After 2 p.m.; slight severe risk mainly afternoon.

Tonight: Shower/storm chances decrease a bit to around 30% by or during the evening, followed by partial clearing overnight and lows in the upper 60s to low 70s in the suburbs to the mid-70s downtown. Confidence: Medium

Keep reading for the forecast through the weekend...

Tomorrow (Thursday): Some lingering low-level clouds - we’ll call the day partly sunny - give us a repeat chance to avoid 90 with highs probably somewhere in the upper 80s to low 90s. Humidity is still on the moderate to high end, despite a light breeze from the north, and there’s just enough moisture in the air that I’d still allow for the chance of an isolated afternoon shower or storm. Confidence: Medium

Tomorrow night: Partly cloudy and on the muggy side with lows in the upper 60s to mid-70s (suburbs to city). Confidence: Medium-High

A LOOK AHEAD

Light winds off the ocean keep the humidity around on Friday. We’re looking at a pretty similar day to Thursday with partly sunny skies and highs in the upper 80s to low 90s. Some showers and storms are possible out west toward the mountains, but odds seem slim (though not zero) that any make it into the metro area. Muggy air means mild Friday night lows in the 70s. Confidence: Medium

An approaching cold front brings back a chance of mainly afternoon/evening showers and storms on Saturday - about a 40% chance the way it looks now - as highs aim again for the upper 80s to low 90s under partly sunny skies and with amply humidity. Shower/storm chances likely continue Saturday night as the cold front comes through. Lows are muggy - in the 70s again. Confidence: Low-Medium

It’s uncertain whether the cold front fully clears the area for Sunday, so to be safe we need to keep a 30% chance of showers/storms in the forecast, at least for now, with partly to mostly sunny skies and highs in the upper 80s to mid-90s. Humidity may hang around too, though that’s highly dependent on the exact progress of the front. Confidence:Low-Medium

By  |  05:00 AM ET, 08/03/2011

Categories:  Forecasts

 
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