PM Update: Clouds finally break as heat heads in

Temperatures threaten to near or top 90 Wed & Thur

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Those pesky clouds! We're finally seeing some real breaks in the overcast deck this afternoon. It should be only the beginning of some "much needed sunshine" following our recent period of gloomy days. Temperatures have responded and are rising toward highs near 80 across the area. We'll see a few more clouds roll by tonight, along with patchy fog, but then the heat is on. Our May without 90s (so far) is looking like it won't want to finish that way.

Webcam: Latest view of D.C. from the Netherlands Carillon at Arlington National Cemetery. Courtesy National Park Service. Refresh page to update. See this image bigger on our Weather Wall.

Through Tonight: Clouds continue to break through evening, some continue to float by overnight. Temperatures near the mid-70s at sunset fall to lows around 60 in the suburbs to the mid-60s downtown. As winds go light overnight, a few areas of fog may form prior to sunrise.

Tomorrow (Wednesday): Think of tomorrow as practice for Thursday and the upcoming summer. Besides some patchy morning fog, Wednesday is looking mostly sunny, pretty humid and quite warm (or hot, especially factoring in heat indices). Highs should reach into and past the mid-80s most spots with many locations threatening to hit or top 90 late in the day. An afternoon or evening storm may pop up, but it should be isolated if it does.

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Heat source: Canada often sends us a change in local weather, but usually it's colder air or some precipitation. This time we're looking at heat moving in (or building in) from the north. An upper-level ridge of high pressure is causing abnormally toasty temperatures in southeast Canada as well as much of the northeast United States today. Toronto is headed for highs in the 80s this afternoon, and may reach 90 tomorrow while interior New England sees similar or higher temperatures.