* Flood Warning for entire area through late tonight *
Rainfall totals through 12 a.m.: Reagan National 4.00 inches (daily record) | Dulles: 5.00 inches (monthly record) | BWI Marshall: 4.64 inches (daily record) | Rainfall totals from NWS
12:00 a.m. – Worst of torrent lifts north of Beltway, but rain not totally over and flood risk to linger
Rain has eased considerably inside the Beltway, if not stopped, but heavy rain continues in parts of our northern and western suburbs.
Over the next couple of hours, this rain will lift north and decrease, but some additional heavy rainfall is possible in northern Prince William, western Fairfax, Loudoun, northern Montgomery and Frederick counties – which have seen some of the worst flooding in the last hour or so, including several high water rescue situations.
Here are numerous reports of flash flooding we’ve received via the National Weather Service since 8 p.m., which include high water rescues in five counties:
- “Motorist in truck stranded” in Clifton, Va.
- “Water rescue” in Annandale in Fairfax County on Woodburn Rd.
- “A few dozen” roads blocked by high water in Charles County
- “Water begins entering homes” in Huntington near Cameron Run in Fairfax County
- “Water rescue” on Montgomery County’s Bradley Boulevard in Potomac
- “Flood” at Rock Creek Parkway in the District. Southbound lanes closed.
- Two water rescues in Arcola, west of South Riding in Loudoun County: one along Rt. 50 by Fleetwood Rd and a second at Evergreen Mills Road and Belmont Ridge Road.
- “Two vehicles trapped in swift water” in Prince William County near Bull Run
- “Vehicle stranded in high water” near Gaithersburg (Montgomery County), on Game Preserve Road
- “Water rescue” in Frederick County, near Walkersville.
- “Water rescue” in Chevy Chase, Md. (Montgomery County) on Beach Drive near Kensington Parkway
- “Water rescue” in North Potomac, Md. (Montgomery County) on Quince Orchard Road
- “Water rescue” in Clarksburg, Md. (Montgomery County) on Md. 355 at Little Seneca Creek.
- “Water rescue” in Chevy Chase, Md. (Montgomery County) at Beach Drive and East-West Highway.
Even in areas where the rain has tapered, a number of streams are still rising and may overflow their banks. Overnight, avoid driving on routes near streams and creeks and do not, under any circumstance, try to drive across a flooded road.
Overall today, a widespread 3 to 6 inches of rain has fallen across the region, with isolated amounts of 6 to 8 inches – making this a historic July rainfall. Unfortunately, it has saturated the ground and we are expecting additional opportunities for heavy rainfall over the next week which will likely mean more flooding issues.
We will have a detailed recap of this event posted Sunday or early Monday.
For the forecast for Sunday, when we could see some more showers and storms, scroll down. This is the last update in this post. Our next post will publish at 6 a.m. Sunday.
11:00 p.m. – Flooding and high water rescue numbers mount, but end in sight
The steadiest and heaviest rain has exited regions south of the Beltway although scattered areas of heavy downpours persist. North of the Beltway, very heavy rain continues. We do expect the worst of the rain to continue shifting north over the next two to three hours, but hazardous conditions remain with many areas of high water. We advise staying in, if possible, and remind you not to attempt crossing a flooded roadway.
10:15 p.m. – Flooding reports increasing as historic July rain event continues to unfold
In the last hour, we’re seeing reports of cars stranded in high water and floodwaters entering homes as rainfall totals exceed half a foot in some areas.
Washington’s rainfall total is nearing 4 inches, a record for the date, and an exceptional amount of rain for any time of year:
9:30 p.m. – Flash flood warnings expanded as rainfall amounts reach 3 to 6 inches
Flash flood warnings, previously in effect south and southwest of the Beltway, have been extended east and north, covering areas around Alexandria and the Interstate 270 corridor from Bethesda through Germantown.
Reagan National Airport’s record-setting rainfall amount is up to 3.31 inches while Dulles’ total, a record for July, is up to 4.05 inches.
We’ve received many reports of 5-inch totals.
Unsurprisingly, many streams are overflowing their banks and poor drainage areas are flooding. Please use caution and stay in if you can this evening.
It does look like rain will taper around midnight, but bands of heavy rainfall are likely for the next few hours and another inch or two could fall.
Here’s a remarkable radar loop showing the rain event in its entirety to this point:
8:20 p.m. – Record July rainfall at Dulles, record daily rainfall at National
Dulles Airport has posted its wettest July day on record (records there date back to 1963), with nearly 4 inches through 8 p.m.
Reagan National Airport’s rainfall total was up to at least 2.85 inches through 8:30 p.m., besting the daily record (for July 21) of 2.56 inches from 1911 (set at 24th and M. St in the District).
7:45 p.m. – Flash flood warning south and southwest of Beltway
The rainfall totals are really piling just south and southwest of the District, into the 3 to 4-inch range. The ground is saturated and with more heavy rain for the next several hours, flash flood warnings have been issued. Another 1 to 3 inches of rain cannot be ruled out.
Radar does show the back edge of the rainfall advancing north, but there are still several more hours of downpours to go before it tapers. Throughout the region, most areas have seen at least two inches now. Through 7 p.m., Reagan National Airport had picked up 2.26 inches, closing in on the daily record of 2.56 inches from 1911.
5:50 p.m. – Flood warnings in effect for much of region
Moderate to heavy rain all afternoon has put down 1 to 3 inches of rain and another 1 to 2 inches are possible before it tapers around midnight. Rising creeks and streams may overflow their banks, resulting in flooded roads. In addition, look out for water buildup in areas with poor drainage.
Remember, if you encounter a flooded road, turn around; do not risk drowning. Judging water depth after dark will be especially difficult.
Widespread rainfall totals are expected to reach 2 to 4 inches with locally higher amounts. See rainfall amounts through 5 p.m. at the bottom of this post.
From 5:02 p.m.
Saturday never really had a chance to be anything but a washout. A center of low pressure situated over eastern North Carolina has kept our region steadfastly entrenched in moderate to heavy rainfall since the morning hours. Add that to the cool conditions and a gusty north wind, and you have the perfect recipe for a “stay inside” kind of Saturday. Steady precipitation will abate late tonight, but a prolonged stretch of gloomy and wet weather has just begun.
Get our daily forecasts on your Amazon Alexa device. Click here to find out how.
Through tonight: Periods of moderate rain continue through the evening hours. Short-term guidance suggests that as the center of low pressure moves up the Chesapeake Bay over the next several hours, the heaviest axis of rainfall will begin to focus east of the District, from Anne Arundel County in Maryland to the Eastern Shore. An extra 2 to 4-plus inches of rain in these locations is a strong bet.
In the District and surrounding suburbs, moderate precipitation will probably continue for several more hours, not completely shutting off until after midnight. In these locations, I am expecting another 1 to 2-plus inches of rain to fall before it’s all said and done.
It should be overcast and cool overnight, with low temperatures settling in the mid-60s. Some scattered showers may develop late, but most of us will be rain-free after about 2 a.m. Gusty winds (15 to 20 mph) will continue for the majority of the overnight period, gradually switching from the north/northeast to the west. Areas of fog are likely to develop around daybreak.
View the weather at The Washington Post.
Tomorrow (Sunday): The low pressure that supplied all of Saturday’s rain will be well beyond our area by Sunday morning, having taken a wide left hook and tracked inland toward central Pennsylvania. Nevertheless, we will still spend the majority of Sunday under overcast skies, with increasing chances of showers and thunderstorms by the afternoon. Temperatures and humidity will rise, with high temperatures in the low 80s and dew points rising into the low 70s. Showers and some thunderstorms are likely, especially by Sunday afternoon and evening. Shower chances continue overnight Sunday as we stay overcast, warm and muggy, with low temperatures in the low 70s.
Rain totals so far: Lots of big rainfall totals so far today, numbers that will surely increase over the next several hours.
And if you prefer, here is a more formal but less pretty list of Saturday rainfall totals from the National Weather Service. With final daily totals expected to end up in the 2 to 4-plus-inch range, Saturday will easily be the most widespread one-day rainfall the region has seen in a month.
Want our 5 a.m. forecast delivered to your email inbox? Subscribe here.