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Posted at 05:00 AM ET, 09/05/2011

Forecast: Frequent rains for September’s first full week; risk of flooding

Sunshine elusive; flash flood watch tonight-Tues. night

Flash flood watch 8 p.m. tonight thru 8 p.m. Tuesday
Where are Katia and Lee? Hurricane Tracking Center

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

 
Subpar end of summer. Sticky with shower and storm chances increasing throughout day.
 
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EXPRESS FORECAST

Today: Increasing shower and t’storm chances. Low 80s. | Tonight: Showers and storms likely. 60-65. | Tuesday: Showers and storms likely. Mid-70s. | Get Express Forecast by E-mail

FORECAST IN DETAIL

Our long, hot summer gets washed away this week, starting with likely downpours today. A stalled front draped over the area captures a stream of rich moisture surging northward, including the remnants of tropical storm Lee. Several inches of rain may drench the region over the next few days, with the highest amounts towards the mountains. With persistent cloud cover, temperatures run cooler than average - generally in the 70s.

Today (Monday): Although we may have some intervals of partial sunshine, clouds tend to dominate. Shower and thunderstorms are possible any time today, but odds increase from 30% in the morning to 60% by late afternoon. With a humid, unstable airmass overhead, a few storms could be on the strong side. Winds from the south (10-15 mph) should lift high temperatures to 79-83, possibly higher if there are any extended breaks in the cloud cover (or lower if little-no sun). Confidence: Medium

Tonight: Shower and thunderstorm chances continue rising, to near 80% after dark. Some of this activity may be slow moving with heavy rain. Rainfall amounts will be highly variable, but 1-2 inches is a good general forecast, with isolated higher amounts. Not good news for the Terps-Hurricanes game at Byrd Stadium. After 1 or 2 am, storms may decrease some (odds drop to 40-50%) as the responsible cold front actually slips to our south, with lows 60-65. Confidence: Medium-High

Keep reading for the forecast through the midweek...

Tomorrow (Tuesday): Showers and storms are once again likely (70% chance), especially during the afternoon. With the remnants of tropical storm Lee arriving in the area, heavy rainfall is possible and flood watches may be required. Winds will be from the north, so it’s cooler, with highs in the low-to-mid 70s. Confidence: Medium

Tomorrow night: Showers and thunderstorms - some with heavy rain - are likely, especially before midnight. Does not look good for Strasburg’s return. Later at night, it’s mostly cloudy with a 40% chance of showers, and lows near 60. Confidence: Medium

A LOOK AHEAD

It takes most of Wednesday for the remnant moisture from Lee to move out of the region and, even afterwards, rain chances continue intermittently into Friday as a stalled frontal boundary remains in our vicinity. Wednesday brings the best chance of rain (60-70%) but opportunities present themselves Thursday (50-60% chance) and Friday (40-50% chance), especially in the afternoon/evening (timing subject to change), as several waves ride along the front. Highs each days are in the low-to-mid 70s with lows around 60. Confidence: Low-Medium

High pressure building in from the north may finally kick the front out of here, giving us a break from rain chances over the weekend. Sunshine even? We’ll see. Highs are likely to be in the 70s, with lows in the 50s. Confidence:Low

By  |  05:00 AM ET, 09/05/2011

Categories:  Forecasts

 
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