PM Update: Mostly calm in D.C through Wednesday; destructive storms likely in Midwest tonight, possible derecho


Radar & lightning: Latest regional 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.

After a round of showers this afternoon, the sun has re-emerged and radar shows little of concern locally. We can’t rule out a pop-up shower into the evening, but it’s mostly quiet, if a bit humid. Wednesday looks great overall, with slightly lower humidity than today and lots of sunshine. The storm risk holds off until late Wednesday night.

Through Tonight: Partly cloudy and humid this evening, with a 20 percent chance of a shower. After dark, the shower chances evaporate. Overnight lows range from near 60 in our cooler suburbs to the mid-to-upper 60s downtown. Light winds from the southwest.

Tomorrow (Wednesday): A good-looking day. Skies are mostly sunny with slightly lower humidity than today. Highs reach the mid-to-upper 80s with winds from the northwest around 10 mph.

See Matt Rogers’ 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.

A stray shower on May 27.  (WolfpackWx via Flickr)

A stray shower on May 27. (WolfpackWx via Flickr)

Pollen: Tree pollen is in the MODERATE range at 33.55 grains/cubic meter. Grass pollen is MODERATE (NAB range) at 15.34 grains/cubic meter, which is in the high range for local area grass counts. Weeds counts are LOW, and mold counts are HIGH.

High risk of severe weather/derecho in Iowa and Nebraska: The National Weather Service Storm Prediction Center has issued a rare “high risk” outlook for severe thunderstorms in parts of Iowa and Nebraska, including Omaha and Des Moines. It is expecting very large hail (exceeding 2-2.5 inches in diameter – baseball size), destructive straight line winds (80-90 mph gusts are possible) and the potential for strong tornadoes in this zone. A dangerous bow-shaped complex of thunderstorms (regional radar) in eastern Nebraska will propagate eastward into Iowa and may grow into a derecho as the evening wears on.

There is a 60 percent chance of damaging winds with 25 miles of a point in/close to the high risk area.

Probability of damaging winds with 25 miles of a point (National Weather Service Storm Prediction Center)

Probability of damaging winds with 25 miles of a point (National Weather Service Storm Prediction Center)

Tornado watches cover most of Nebraska and western Iowa and will likely expand eastward this evening. Active warnings: Severe Thunderstorm | Tornado

Also on Capital Weather Gang

Quick round of downpours to cycle through D.C. area this afternoon