[This post has been updated.]

Most travelers in the D.C. area are likely to see rain at some point Friday — possibly heavy rain — and flooding is a concern, the Capital Weather Gang says. But the chances of storms diminish over the weekend, while the heat and humidity also decline.

A young girl at the Asian Festival. (Bing Cardenas Branigin)

See the Going Out Guide for many more weekend events.

The key travel issues to watch for are the the weather and the delays on four Metrorail lines for weekend maintenance projects.

Virginia Beltway

The rainy forecast led the Wilson Bridge project managers to cancel plans for extensive paving on the Capital Beltway this weeknd. On the one hand, this means no lengthy backups in the area of Telegraph Road this weekend. On the other, it means that drivers should prepare to encounter them next weekend, when they will be rescheduled.

Elsewhere in the Beltway corridor, the Virginia Department of Transportation plans to close one lane on the two-lane ramp from the outer loop to I-66 West from 6 a.m. to 2 p.m. Saturday for demolition of an old bridge abutment near the Dunn Loring Metrorail station.

Crews will resume the demolition on Monday from 5 a.m. to 3 p.m. and follow that schedule for up to ten days. Removal of the old bridge will create additional space for crews to extend the sound wall and make way for 12-foot lanes on I-66 West with a right shoulder in this area.

The work is part of the 495 Express Lanes project.

Metro weekend delays

The work will begin at 10 p.m. Friday and continue through the Metro train system’s midnight closing on Sunday.

Red Line: Free shuttle buses will replace trains between Grosvenor and Friendship Heights. The Medical Center and Bethesda stations will be closed.

Trains will operate between Shady Grove and Grosvenor and between Friendship Heights and Glenmont about every 10 minutes between 9:30 a.m. and 6 p.m. and at regular weekend intervals at other times, the transit authority says. If traveling through the work zone, add about a half hour to normal travel times.

Green Line: Trains will share a track between Fort Totten and Prince George’s Plaza. Add about 10 minutes to normal weekend travel times, Metro says.

Blue Line: Trains will share a track between Van Dorn Street and Franconia-Springfield, operating at or near normal weekend frequencies, the transit authority says.

Between 9 a.m. and 6:30 p.m. Saturday and Sunday, every other train will terminate at Van Dorn Street, rather than Franconia-Springfield. If you are riding through the work zone, figure on about 15 minutes of extra travel time.

Orange Line: Trains will share tracks between East Falls Church and West Falls Church and between Stadium-Armory and Cheverly. Throughout the weekend, trains are scheduled to leave the ends of the line every 24 minutes. Between 9 a.m. and 6:30 p.m. Saturday and Sunday, more trains will operate between Vienna and Stadium-Armory, so trains should reach platforms in that zone about every 12 minutes.

Yellow Line: As often happens, the work on the Green Line affects the extent of weekend service on the Yellow Line. All Yellow Line trains will end their northbound trips at Mount Vernon Square, rather than Fort Totten. To continue north, switch to the Green Line on the same platform.

Route 29 paving

Route 29 will be shifted and reduced to one lane in each direction between Merrilee Drive and Gallows Road on Friday night while crews pave the northbound lanes, the Virginia Department of Transportation says.

Maryland bridge inspections

The Maryland State Highway Administration conducts routine inspections of highway bridges on weekends, resulting in lane closings. From 4:30 a.m. to 11:30 a.m. Saturday, expect to find the right lane closed on southbound I-95 over the Little Patuxent River in Howard County. At those hours in that location, the traffic delays should be minimal.

Rockville Pike in Bethesda

The highway administration plans to close lanes along Rockville Pike between Jones Bridge Road and North Drive this weekend for median reconstruction.

The schedule calls for closing the left lane in each direction at 7 a.m. Saturday. Crews will also intermittently close the middle lane in each direction throughout the weekend to position construction equipment. All lanes will be open no later than 5 a.m. Monday.

Looking ahead

The Legg Mason tennis tournament is scheduled for July 28-Aug. 5 at the FitzGerald Tennis Center, 16th and Kennedy streets NW. That always means increased traffic congestion on upper 16th Street.

The Metrorail project listed above for the Red Line will again interrupt train service next weekend and on the weekend of Aug.10-12.

The paving work that is part of the Wilson Bridge project will again affect the Beltway/Telegraph Road interchange next weekend. Telegraph Road is scheduled to close in both directions on the bridge over the railroad tracks. For safety reasons, the work on the bridge also will interrupt train service on Metro’s Blue Line between Franconia-Springfield and King Street.

On this Sunday’s Commuter page in the Post’s Metro section, I’ll describe the range of temperatures that Metrorail riders encountered on trains this week.

Join me at noon EDT Monday for our weekly online discussion about all your local traffic and transit concerns.