D.C. area forecast: Summer sizzle with 90s and slight storm risks ahead of first unsettled weekend in a while

Today’s Daily Digit

A somewhat subjective rating of the day’s weather, on a scale of 1 to 10.

3
Our hot air mass hugs us just a bit harder today

Express Forecast

Today: Partly to mostly sunny, muggy, hot. Highs: 90-94.

Tonight: Mostly muggy and partly cloudy. Lows: 68-74.

Tomorrow: Hotter again. Mostly sunny. Highs: 93-98.

FORECAST IN DETAIL

Temperature Map

Temperatures: Latest D.C. area temperature map. See interactive map on our Weather Wall.

A cool upper level trough diving into the Western U.S. is see-sawing a hotter ridge of high pressure over the Eastern U.S. this week, triggering the hottest weather seen so far this year.  The heat builds today and tomorrow before we get enough cloudiness and storminess to halt the trend Thursday into Friday.  But the  humidity still hangs around as a front stalls over us, probably keeping it unsettled into the weekend. Unfortunately, our string of 11 straight nice weekends may end.

Today (Tuesday): The sticky air mass that invaded Monday intensifies a bit more today with highs in the low-to-mid 90s under partly to mostly sunny skies.  Light west winds range from 5 to 10 mph.  Since dew points should range from the upper 60s to around 70 vs. the middle 60s yesterday, the afternoon peak heat indices should feel like the upper 90s to low 100s unfortunately.  Be careful exerting too much out in the heat especially without fluids as the strong sun angle and hot temperatures can offer up heat stroke faster than normal.  There is a 20% chance of an isolated shower or storm during the afternoon and evening period.  Confidence: Medium-High

Tonight: Partly cloudy and muggy as the humidity stays moderate to high and temperatures only cool to the upper 60s in the outer suburbs to the low-to-mid 70s in the city.  Light winds from the southwest at around 5 mph. Confidence: Medium-High

For related traffic news, check out Dr. Gridlock. Keep reading for the forecast through the weekend…

Tomorrow (Wednesday): This may be our hottest day of the week as partly to mostly sunny skies and winds from the west at 5 to 10 mph strengthen the hot air mass to its potential peak levels.  We’re now thinking middle to upper 90s with heat indices in the afternoon reaching as high as the lower 100s.   We run a 20% risk of late afternoon or evening thunderstorms with the better chances north of the city.  Confidence: Medium-High

Tomorrow night: Just a few clouds around and very muggy again with lows only in the 70s along with light winds.  A thunderstorm complex could roll through the area after midnight, with northern areas more favored (30% chance).  Confidence: Medium-High

A LOOK AHEAD

Thursday could see a lingering thunderstorm complex around the area in the morning and then a 60% chance of re-firing of showers and storms during the day.  This combination of clouds and rain risks should keep high temperatures lower- perhaps in the upper 80s to low 90s range.   But if the storms/clouds are more dominant, we could hold lower in the 80s.  We don’t really get rid of that humidity just yet.  Thursday night may have a few evening storms, but then should be partly cloudy with lows a bit lower down into the upper 60s to low 70s. Confidence: Medium

Friday could see a bit more of the lingering cool front make better progress through the area so highs only manage to range in the 80s with partly cloudy skies and a 40% chance of showers and storms popping up again, especially in the afternoon in southern areas.  Humidity eases up just a touch though, so the day feels a bit better overall.  Partly cloudy Friday night after some scattered evening storm risks with lows in the 60s to low 70s again (warmest in the city as usual).  Confidence: Medium

Our beautiful weekend weather bonanza  may well end as a stalled front triggers periods of showers and storms.  Partly cloudy to overcast sky conditions mostly prevail with highs ranging through the 80s (intensity depending on timing details of clouds and precipitation).  While not as hot/humid as earlier in the week, there is still sufficient moderate humidity around to keep discomfort levels relatively high.  Saturday night sees storm risks too with lows in the upper 60s to low 70s.  Looks like about a 60% chance of showers and storms each period of the weekend with some potentially delivering very heavy downpours.  Confidence: Medium

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