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Posted at 05:00 AM ET, 08/01/2011

Forecast: August picks up where July left off - more extreme heat

Detailed commentary: July heat was unprecendented | Graphic

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

 
New month, same old heat. Another day of nasty upper 90s.
 
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EXPRESS FORECAST

Today: Stifling heat. Slight chance of storms late. Mid-to-upper 90s. | Tonight: Partly cloudy, 72-79. | Tomorrow: Mostly sunny 93-97. | Get Express Forecast by E-mail

FORECAST IN DETAIL

Let’s begin with some good news: I do see a very gradual pattern shift towards modestly cooler temperatures in the week ahead. I also see several opportunities for showers and storms. The bad news is the week starts off stifling, and the cooling I’m talking about may only lower high temps to the upper 80s or low 90s from the upper 90s.

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): Unlike Sunday, when we had a dry heat, humidity re-joins the party today. Under a mix of clouds and sun, high temperatures reach the mid-to-upper 90s. Factoring in the humidity, it feels closer to 99-104. Late in the afternoon, a few thunderstorms may develop (20-30% chance) as a cold front nears. Confidence: Medium-High

Tonight: Thunderstorms are possible (20% chance) in the evening, but - like many days recently - most likely (30-40% chance) in the northern suburbs. Somewhat cooler air trickles in late at night with lows from the mid-to-upper 60s in the cooler suburbs to the low-to-mid 70s downtown. Confidence: Medium-High

Keep reading for the forecast through the weekend...

Tomorrow (Tuesday): Similar to Sunday, thanks to a wind from the north and northwest, the air is dry (dew points in the 50s). But abundant sun still cooks the region, with highs in the mid-90s. Confidence: Medium-High

Tomorrow night: Clouds and humidity increase as a warm front nears the region. A few storms (20-30% chance) could fire up, with lows in the 70s. Confidence: Medium-High

A LOOK AHEAD

Wednesday is tricky as a disturbance (riding along the northeast branch of the heat dome) and an attendant cold front push through the region. Showers and storms are a decent possibility (40-50% chance), most likely during the midday to early evening time frame. If we can muster enough sunshine before any rain, humid highs could reach the mid-90s. On the other hand, considerable cloud cover could hold highs in the upper 80s to near 90. The storm threat gradually diminishes Wednesday night, with lows in the 70s. Confidence: Medium

Thursday and Friday should both feature relatively low to moderate humidity levels, but more scorching sunshine. Highs both days head for the low-to-mid 90s. Overnights lows range from near 70 in the cooler suburbs to the upper 70s downtown. Confidence: Medium

Models track an area of low pressure through the region on Saturday, bringing increasing clouds and showers/storm chances especially late in the day and in the evening. Otherwise, it’s warm and humid, with highs in the upper 80s to near 90. Showers/storms gradually diminish Saturday night, with lows in the 70s. Sunday stands the better chance of being dry of the weekend days, with highs around 90. Confidence: Low-Medium

By  |  05:00 AM ET, 08/01/2011

Categories:  Forecasts

 
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