Strong storms to cap a hot day. Damaging wind, heavy rain, hail possible.

Afternoon temperatures heading deep into the 90s, rising humidity and an approaching cold front are setting the table for a significant thunderstorm threat in the D.C. region late Wednesday afternoon and evening. Although severe weather is unwelcome, any rainfall associated with it is much needed.

The Storm Prediction Center has placed the area under a Level 2 of 5 severe weather risk. Storms could produce heavy rain, dangerous lightning, wind gusts near or over 60 mph and large hail up to 1 inch in diameter. There could be more than one round of storms, with several inches of rain and localized flooding possible in those places that see multiple storms.

Storms could move in from west to east as soon as mid- to late afternoon. Any storms during this period have the best chance of turning severe, but it’s uncertain how many storms will develop. There’s higher confidence in more numerous storms Wednesday evening, but it’s less certain whether there will still be enough energy in the atmosphere for them to be strong to severe.

Timing: Midafternoon into Wednesday night, with multiple rounds possible:
- 3 to 8 p.m.: Isolated to scattered strong to severe storms.
- 8 p.m. to 3 a.m.: Scattered storms likely, some possibly strong to severe.
- After 3 a.m.: Chance of lingering weaker showers and storms.
Duration: 30 to 60 minutes, except longer where multiple storms pass.
Most likely impacts: Frequent lightning, isolated damaging wind gusts, heavy rain, hail.
Possible impacts: Isolated flooding; numerous damaging wind gusts; large hail; a brief, weak tornado.
Keep an eye out for: Storms that could dump 1 to 2 inches of rain in just an hour or two; bow-shaped storms on radar that generate localized wind gusts near or over 70 mph.

The scenario Wednesday includes an approaching cold front in the lower atmosphere and a disturbance in the upper-level flow, both running into an unstable atmosphere across the Mid-Atlantic.

Weather models suggest the potential for two or more distinct rounds of showers and storms.

The first batch is a less certain. It could develop in the high terrain to the west or along a subtle wind shift in the lee of the Appalachians, perhaps around 3 to 5 p.m., with storms potentially passing near the Beltway and Interstate 95 around 5 to 7 p.m.

Additional storminess is likely later Wednesday evening ahead of the front. It could last several hours, with the heaviest rain and most boisterous thunderstorms moving through around 9 p.m. to midnight, and lingering rains continuing into the overnight hours.

How much the atmosphere destabilizes, and thus becomes conducive to severe storms, depends in part on the amount of cloud cover through the afternoon. But there’s a good chance that a moderate amount of “storm fuel” will develop, given the intense heat and abundant moisture in the atmosphere. Strengthening winds aloft could foster organization of storm cells into longer-lived clusters, especially in the evening.

The chief hazards include pockets of damaging winds caused by downbursts, which are thunderstorm winds that blow downward and then fan out when reaching the ground. Intense lightning will also accompany any potent storms.

Repeated passage of storms over several hours could lead to some instances of flooding, particularly during the evening. About 2 to 3 inches could fall in a few locations. It’s also not out of the question that nearby spots end up closer to dry.

June rainfall is running about 3 to 4 inches below average, or less than 25 percent of what’s typical in D.C. and to the south, during what is usually one of the wettest months of the year. Drought reentered the area last week and is probably expanding, given the hot and dry conditions of late.