D.C. area forecast: Warm/humid through Thursday with storm risks; much cooler holiday weekend

Today’s Daily Digit

A somewhat subjective rating of the days weather, on a scale of 1 to 10.

6
More sun than yesterday and pleasantly warm, but humidity literally sticks around.

Express Forecast

Today: Partly to mostly sunny. Slight late day storm risk. Highs 83-87.

Tonight: Partly cloudy. Lows 64-70.

Tomorrow: Partly sunny, 30% storm risk. Highs 86-89.

FORECAST IN DETAIL


Radar & lightning:Latest D.C. area radar shows movement of precipitation and lightning strikes over past two hours. Refresh page to update. Click here or on image to enlarge. Or see radar bigger on our Weather Wall.

‘Oh the humidity’ will be the most resonant refrain over the next few days as we get more of a summertime feel of mainly 80-degree weather between today and Thursday.  A big cold front evicts the squishy air mass from our area by late Thursday so that the holiday weekend feels considerably cooler with highs in the 70s and lows in the cool 40s to 50s. Some showers may sneak into the weekend’s second half though.

Today (Tuesday):  A big cold front is taking the slow, scenic route through the Midwest, allowing our humid air mass to strengthen over the next few days. More sun (partly sunny) and a somewhat stagnant air mass today lead to higher temperatures today ranging mostly through the middle 80s.  Winds are from the southwest at 5 to 10 mph.  A 20 percent chance of an afternoon or evening shower/storm continues.  Confidence: Medium-High

Tonight: Partly cloudy with more light breezes at 5-10 mph from the southwest keep temperatures warm around the area.  They only drop into the 60s in most areas, but some spots in the city including our favorite heat island, National Airport, could settle down only to 70 degrees. Confidence: Medium-High

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

Tomorrow (Wednesday): Partly sunny skies continue for what should be our hottest day of the week.  Temperatures elevate to the mid-to-upper 80s, but some areas could touch 90F and nearly all of us should feel heat indices into the low-to-mid 90s due to moderate humidity.  A 30 percent chance of showers and storms exists mainly in the afternoon and evening.  The winds are from the south and southwest at mainly 5-10 mph once more. Confidence: Medium-High

Tomorrow night: Partly cloudy and muggy with a lingering 30 percent risk of showers and storms mainly through the evening hours.  Lows hold in the mid-to-upper 60s with a few near-70 degree readings in the city.  Light winds from the southwest at 5-10 mph. Confidence: Medium-High

A LOOK AHEAD

Thursday is the big air mass transition day of the week as a powerful cold front carves its way through our humid air mass.  Highs are restrained by increasing cloud cover, so we favor low-to-mid 80s here with a 70 percent likelihood of showers and storms by midday and through the afternoon.  Some of them could be heavy with gusty winds and downpours to challenge driving.  It’s still humid though until Thursday night when the cooler air mass rushes in under partly cloudy skies.  We still have scattered showers and storms (40% risk) Thursday night as lows drop lower by dawn to the middle 50s suburbs and low 60s in the city.  Confidence: Medium

Friday is day one of a new air mass with a cool, breezy flow from the northwest, partly sunny skies (may be some lingering AM clouds), and highs only in the low-to-mid 70s.  It will feel a lot better as the dew points collapse into the dry 40s.  Friday night finds a few clouds, cooler weather, and lows dropping down into the low-to-mid 50s in the city, but mid-to-upper 40s in the outer suburbs. Confidence: Medium

The holiday weekend is forecast to be cooler-than-normal.  Saturday is still expected to be the best day with mostly sunny skies and highs in the low 70s along with dry humidity.  Sunday and Monday could see a disturbance approach the area with more clouds and a few showers late Sunday into Monday (30% risk right now).  Highs are again mainly in the low 70s (we should be in the upper 70s per climatology).  Saturday night is the cooler one with suburban lows in the 40s and city lows in the 50s.  Sunday night should see lows range through the 50s due to cloud cover. Confidence: Low-Medium

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