Station Name: DIFFICULT RUN NEAR GREAT FALLS, VA
Data Source: Water Data - usgc.gov

Elevation Above Sea Level: 184 feet

Nearest Address:
9200 Old Dominion Dr
McLean, VA 22102
Fairfax County

GPS Coordinates: 38.97594346, -77.24581439

Nearby Water Temperatures

Flood Watch issued July 6 at 2:23PM EDT until July 7 at 12:00AM EDT by NWS Baltimore MD/Washington DC

Effective: Mon July 6, 2026, 2:23 PM
Expires: Tue July 7, 2026, 12:00 AM

...The combination of a slow moving frontal zone with a tropical air mass in place will increase the risk of flash flooding through this evening... * WHAT...Flash flooding caused by excessive rainfall continues to be possible. * WHERE...Washington DC, and portions of Maryland, including the following areas, Anne Arundel, Calvert, Carroll, Cecil, Central and Southeast Howard, Central and Southeast Montgomery, Charles, Frederick, Northern Baltimore, Northwest Harford, Northwest Howard, Northwest Montgomery, Prince Georges, Southeast Harford, Southern Baltimore, St. Marys and Washington, Virginia, including the following areas, Albemarle, Arlington/Falls Church/Alexandria, Central and Southeast Prince William/Manassas/Manassas Park, Clarke, Culpeper, Eastern Loudoun, Fairfax, Frederick, Greene, King George, Madison, Northern Fauquier, Northern Virginia Blue Ridge, Northwest Prince William, Orange, Page, Rappahannock, Shenandoah, Southern Fauquier, Spotsylvania, Stafford, Warren and Western Loudoun, and panhandle West Virginia, including the following areas, Berkeley, Jefferson and Morgan. * WHEN...Until midnight EDT tonight. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. * ADDITIONAL DETAILS... - Multiple rounds of heavy rainfall are possible through this evening, some of which may occur over areas which recently experienced flooding rains. Slow storm motions and repeat thunderstorm activity will occur within a tropical air mass. Hourly rainfall rates could push into the 2 to 3 inch range in the strongest storms, with an inch in 20 minutes possible. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information.

You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.

Marine Weather Statement issued July 6 at 3:30PM EDT by NWS Baltimore MD/Washington DC

Effective: Mon July 6, 2026, 3:30 PM
Expires: Mon July 6, 2026, 6:00 PM

A few southeasterly wind gusts to around 20 knots are possible this afternoon. Inexperienced mariners, especially those operating smaller vessels, should exercise extra caution if navigating the waters during this time.