Winds at National Airport
Wind speeds reported in the hourly observation are 2 minute averages in the 10 minutes preceding the observation time (usually H+55). Peak gusts are reported only when gusts reach or exceed 25 knots. Gusts are reported only if recorded in the 10 minutes preceding the observation time.

Wind speed and direction over the previous 8 hours at National Airport

  Another wind speed and direction website

Wind Contours

Tides

Accuweather's Real-time Radar View
(check on T-storms in the area before going down to the marina for an evening sail)

NBC StormCenter4 
Select a 4 Winds Neighborhood Storm Station in Alexandria. Arlington, or the District

River Temperature and Level

Local Forecast (Accuweather)

Local Forecast (Wunderground)

Marine Forecast (Potomac)

Marine Forecast (Chesapeake)

SSA's Weather Links Page

Wind on the Bay  (Thomas Point Light)

NOAA National Weather Service Graphic Forecasts