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Posted at 05:00 AM ET, 05/17/2011

Forecast: Periodic downpours today

Showers & storms all week, but heaviest today

Flash flood watch through late tonight - for possibility of rainfall rates of 1-2” per hour; Coastal flood advisory for tidal Potomac and Chesapeake Bay

(originally posted at 5 a.m., updated at 8:30 a.m.)

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

 
Widespread frequent showers and storms frustrate if you have to be outside for any length of time.
 
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EXPRESS FORECAST

Today: Showers and storms, some heavy. 70-75.| Tonight: Additional showers/storms. 58-62.| Tomorrow: Mostly cloudy, more showers and storms. 70-75. | Get Express Forecast by E-mail

FORECAST IN DETAIL

What a fine mess we have here. A super slow-moving gyre of low pressure is just gradually grinding its way in our direction. It’s at its most powerful today, generating heavy showers and thunderstorms at times, keeping plenty of clouds in the sky, and holding our temperatures down in the low to maybe mid-70s. This pattern type persists through the week, although the odds of showers each day gradually diminish as it loses some steam.


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 (Tuesday): Wet is the word of the day as low pressure to our south feeds in a plentiful supply of clouds, showers, storms, and humid (but not hot) air across our area. Timing out the heaviest bands of precipitation is difficult, but an initial estimate could be late morning into early afternoon. A half to an inch of rain is possible today with locally heavier amounts. Highs should be in the low-to-mid 70s, but that should occur only intermittently in between showers and storms. Expect light winds from the east. Confidence: Medium-High

Tonight: Mostly cloudy with more showers and storms. The heaviest activity is expected in the evening hours. We could see another half inch or even higher in locally heavy evening downpours. Lows in the upper 50s to low 60s along with light winds. Confidence: Medium-High

Keep reading for the forecast through the weekend...

Tomorrow (Wednesday): Not as much of a soaker as today, but still widespread coverage of showers and storms expected (70% likelihood), especially by the afternoon. High temperatures are again in the low-to-mid 70s under mostly cloudy skies and accompanied by light winds. Confidence: Medium

Tomorrow night: The “broken record” forecast continues with showers and storms (60% chance- especially in evening), cloudy skies, light winds, and lows in the upper 50s to low 60s. Confidence: Medium

A LOOK AHEAD

Thursday aims for partly to mostly cloudy skies with another round of especially afternoon showers and storms (40% chance). Highs are in the middle 70s with the warmest weather when the sun makes some occasional appearances between the clouds (could spike higher). Thursday night is partly cloudy with a 30% chance of especially evening showers/storms and lows in the upper 50s to low 60s again. Confidence: Medium

Friday and Saturday show incremental improvement with partly cloudy skies, a reduced chance of afternoon and evening thunderstorms (around 30% both days), and slightly warmer temperatures. We could see mid-to-upper 70s on Friday with upper 70s to near 80 on Saturday. Lows continue in the upper 50s to low 60s. Confidence: Medium

As Jason noted yesterday, Sunday still has a shot at being an overall better day with partly to maybe- just maybe- mostly sunny skies with low (but not quite zero) chances. Highs aim for the low to maybe mid-80s. After this week of frequent rains, we’ll welcome this chance to dry out the mushrooms! Confidence: Low-Medium

By  |  05:00 AM ET, 05/17/2011

Categories:  Forecasts

 
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