Update, 6:40 p.m.: Severe thunderstorm warning in effect for Arlington, Alexandria, Falls Church and the District through 7:15 p.m. Storm moving through may produce small hail and gusty winds.

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.

Our cool Memorial Day weather regime is history thanks to the warm front which boosted temperatures into the low 80s this afternoon. After a few widely scattered thunderstorms this evening, we settle into a very warm, muggy weather regime to last through the weekend.

Through Tonight:  Hit or miss thunderstorms (30 percent chance) will rapidly zip through the region this evening, with most activity before 9 p.m.  A few storms could produce brief downpours and strong winds gusts.  Then, it’s tranquil and mild.  Under a soft breeze from the south, lows range from the low 60s in the cooler suburbs to near 70 downtown.

Tomorrow (Wednesday): Mostly sunny and hot…perhaps the hottest day of the summer so far.  Highs climb into the low 90s, with winds from the southwest at 5-15 mph.  Humidity levels are moderate-to-high, not quite in the oppressive range.

See Kathryn Prociv’s forecast through the weekend. And if you haven’t already, join us on Facebook and follow us on Twitter . For related traffic news, check out Dr. Gridlock.

Pollen: Tree counts are MODERATE, grasses HIGH, weeds LOW, and mold LOW-MODERATE.