FORECAST IN DETAIL
Today is poised to be the week’s toastiest day with widespread mid-90s and heat indices into the low 100s. Tomorrow still runs hot, but we increase the risk of mostly afternoon and evening thunderstorms; this lessens the intensity and duration of the heat. Conditions cool into Thursday and Friday with some reduction in humidity, but we could see it creep back up again later this weekend.
With apologies to Mark Twain, if you don’t like the present weather in D.C., just wait a few days. Volatility has been the hallmark of the summer so far as we see bouts of heat and humidity frequently offset by periodic cooler conditions (often around the weekend!). The hotter stretches have tended to outperform the cooler ones just marginally, keeping us running slightly warmer-than-normal, but at least we’re not stuck in the soup of the steamy summers of years past.
Today (Tuesday): The heat is on as we cook temperatures up to the middle to even upper 90s under mostly sunny skies. Humidity edges higher with dew points in the middle to upper 60s (moderate to high range). Winds from the south and southwest at 10 to 15 mph with gusts to 20 at times may take an edge off the heat if you’re in the shade (not so much in the sun).
There’s a 30-40 percent chance of afternoon and evening thunderstorms , with the highest chances in our west and northwest areas. A few storms could be strong to severe. Confidence: Medium-High
Tonight: Scattered showers and storms this evening and even overnight (40 percent chance) as a disturbance jogs through the region. Rainfall amounts are highly variable from none to a quick 0.5 inch or even more in the heaviest downpours. In the thick, muggy air, lows only drop to the upper 60s to middle 70s around the area. Winds from the west and southwest at 5 to 10 mph. Confidence: Medium
For related traffic news, check out Dr. Gridlock. Keep reading for the forecast through the weekend…
Tomorrow (Wednesday): Partly to mostly cloudy with scattered afternoon/evening thunderstorms. Highs should be able to reach near 90 or into the low 90s, but clouds and storms should limit the duration at the hottest levels. West to southwest winds at 5 to 10 mph, although higher gusts are possible in thunderstorms. In fact, some isolated storms could be severe. Confidence: Medium
Tomorrow night: Becoming partly cloudy after scattered evening storms with temperatures cooling late at night down into the 60s. Breezes from the northwest at 5-10 mph help to lower humidity finally. Confidence: Medium
A LOOK AHEAD
Thursday and Friday should be fairly nice days overall with partly to mostly sunny skies and highs ranging through the mid to upper 80s. The humidity falls some with lower dew points (although not as low as last weekend’s beautiful levels!). Thursday night offers a few clouds with pleasant conditions as lows drop through the 60s, but may hold more in the upper 60s right in the city. Confidence: Medium
The weekend offers a split picture. I want to keep our fine weekend weather streak going strong, but the weather pattern wants to bring the next round of heat/humidity into the area by Sunday, unfortunately. Saturday looks to be the winner still with mid-to-upper 80s and mostly sunny skies. Humidity is low to the edge-of-moderate. Saturday night looks partly cloudy, a bit more humid, and lows in the upper 60s to low 70s. Sunday aims for partly to mostly sunny skies with moderate humidity as the temperature readings reach back into the lower 90s once more. There could be an isolated storm either weekend afternoon/evening, but I’m not seeing a strong rain signal at the moment. Confidence: Medium