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

Winter Storm Warning issued January 24 at 8:32PM EST until January 26 at 4:00AM EST by NWS Baltimore MD/Washington DC

Effective: Sat January 24, 2026, 8:32 PM
Expires: Sun January 25, 2026, 4:45 AM

...MAJOR WINTER STORM WILL IMPACT THE REGION THIS EVENING THROUGH SUNDAY EVENING... .A large area of precipitation will overrun Arctic air in place over the Mid-Atlantic. This will lead to widespread significant snow beginning this evening, with the potential for ice Sunday especially south of Highway 50 and near and east of Interstate 95. In addition to the high threat for significant snow and ice, very cold temperatures are expected tonight through the middle of next week with sub-zero wind chills likely at times. * WHAT...Heavy mixed precipitation expected. Total snow and sleet accumulations between 6 and 10 inches, with up to 12 inches possible, especially in the far northern and western suburbs of Washington and Baltimore. Ice accumulations between one and two tenths of an inch. * WHERE...Portions of DC, central, northeast, and northern Maryland, and northern Virginia. * WHEN...Until 4 AM EST Monday. * IMPACTS...Power outages and tree damage are likely due to the ice. Travel could be nearly impossible. The hazardous conditions could impact the Monday morning commute. * ADDITIONAL DETAILS...Snow will likely overspread the area tonight, becoming heavy at times with rates of one to two inches per hour possible at times. A mix with sleet or freezing rain is expected Sunday. Significant icing is possible especially south of Highway 50. Visibility of one-quarter mile or less is possible at times. A prolonged period of wind chills in the single digits and teens continues this evening and lasting through the middle of next week, with sub-zero wind chills possible at times.

If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. Persons should consider delaying all travel. Motorists should use extreme caution if travel is absolutely necessary.

This is only a test for monitoring of vital dissemination systems.

Effective: Sun January 25, 2026, 1:22 AM
Expires: Sun January 25, 2026, 1:32 AM

Monitoring message only. Please disregard.

Monitoring message only. Please disregard.

Winter Storm Warning issued January 24 at 8:32PM EST until January 26 at 4:00AM EST by NWS Baltimore MD/Washington DC

Effective: Sat January 24, 2026, 8:32 PM
Expires: Sun January 25, 2026, 4:45 AM

...MAJOR WINTER STORM WILL IMPACT THE REGION THIS EVENING THROUGH SUNDAY EVENING... .A large area of precipitation will overrun Arctic air in place over the Mid-Atlantic. This will lead to widespread significant snow beginning this evening, with the potential for ice Sunday especially south of Highway 50 and near and east of Interstate 95. In addition to the high threat for significant snow and ice, very cold temperatures are expected tonight through the middle of next week with sub-zero wind chills likely at times. * WHAT...Heavy mixed precipitation expected. Total snow and sleet accumulations between 10 and 14 inches, with up to 18 inches possible near the Mason-Dixon line. Ice accumulations up to a tenth of an inch, mainly across the northern Shenandoah Valley. * WHERE...Portions of north central and western Maryland, northern and northwest Virginia, and eastern and panhandle West Virginia. * WHEN...Until 4 AM EST Monday. * IMPACTS...Travel could be very difficult to impossible. * ADDITIONAL DETAILS...Snow will likely overspread the area tonight, becoming heavy at times with rates of one to two inches per hour possible at times. A mix with sleet or freezing rain is expected Sunday. Visibility of one-quarter mile or less is possible at times. A prolonged period of very cold wind chills continues this evening and lasting through the middle of next week.

If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. Persons should consider delaying all travel. Motorists should use extreme caution if travel is absolutely necessary.