* WHAT. West winds 15 to 25 kt with gusts up to 35 kt and waves 2 to 4 ft possible. * WHERE. Tidal Potomac River from Key Bridge to Smith Point VA, and Chesapeake Bay and adjoining estuaries north of Smith Point VA. * WHEN. From Sunday evening through Monday afternoon. * IMPACTS. Strong winds can cause hazardous waves which could capsize or damage vessels.

* WHAT. Visibility around one quarter mile or less in areas of dense fog. * WHERE. Carroll, Northern Baltimore, Cecil, Southern Baltimore, Anne Arundel, Northwest Howard, Central and Southeast Howard, Northwest Harford and Southeast Harford Counties. * WHEN. Until 10 AM EST this morning. * IMPACTS. Hazardous driving conditions due to low visibility.

Areas of dense fog with visibilities reduced below one nautical mile persist over northern portions of the Chesapeake Bay. The fog will gradually improve this morning after sunrise. Mariners navigating these waters should exercise caution and follow USCG Rule of Conduct of vessels in restricted visibility.

* WHAT. For the Small Craft Advisory, south winds 10 to 20 kt with gusts up to 25 kt expected. For the Gale Watch, northwest winds 15 to 25 kt with gusts up to 35 kt possible. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, Chesapeake Bay north of North Beach MD, Patapsco River including Baltimore Harbor, Chester River to Queenstown MD, Eastern Bay, and Patuxent River to Broomes Island MD. * WHEN. For the Small Craft Advisory, from 6 AM to 6 PM EST Sunday. For the Gale Watch, from Sunday evening through Monday afternoon. * IMPACTS. Strong winds can cause hazardous waves which could capsize or damage vessels.

* WHAT. For the Small Craft Advisory, south winds 10 to 20 kt with gusts up to 25 kt expected. For the Gale Watch, northwest winds 15 to 25 kt with gusts up to 35 kt possible. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, Chesapeake Bay north of North Beach MD, Patapsco River including Baltimore Harbor, Chester River to Queenstown MD, Eastern Bay, and Patuxent River to Broomes Island MD. * WHEN. For the Small Craft Advisory, from 6 AM to 6 PM EST Sunday. For the Gale Watch, from Sunday evening through Monday afternoon. * IMPACTS. Strong winds can cause hazardous waves which could capsize or damage vessels.

* WHAT. Flooding caused by excessive rainfall continues to be possible. * WHERE. The District of Columbia. The following areas for Maryland, Anne Arundel, Cecil, Central and Southeast Howard, Central and Southeast Montgomery, Charles, Northern Baltimore, Northwest Harford, Prince Georges, Southeast Harford and Southern Baltimore, and northern Virginia, including the following areas, Arlington/Falls Church/Alexandria, Central and Southeast Prince William/Manassas/Manassas Park, Fairfax, Southern Fauquier and Stafford. * WHEN. From Sunday afternoon through late Sunday night. * IMPACTS. Excessive runoff may result in creeks and streams to flow out of their banks. Flooding may also occur in poor drainage and urban areas. Storm drains and ditches may become clogged with debris. * ADDITIONAL DETAILS. - Two to three inches of rain are mostly likely Sunday through late Sunday night with the heaviest rain falling during the afternoon and evening. This amount of rain could cause flooding of small streams, creeks and urban areas. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information

Moisture being transported north from the Chesapeake and Delaware Bays and into the cool air across the region has led to an expanding area of locally dense fog and low stratus clouds. Where the low cloud layer intersects the higher terrain is where the most widespread and dense fog will be found. In addition, a thin film of black ice could form on untreated surfaces across the region along and to the north and west of the Interstate 81 and 83 corridors where temperatures dipped into the upper 20s to low 30s prior to the cloud cover and fog expanding into those areas. Exercise caution if you plan to travel this morning. Allow extra time for travel, slow down and ensure that you have plenty of braking distance between you and the vehicle ahead. The fog will gradually dissipate between 930 AM and 10 AM.