* WHAT. Flash flooding caused by excessive rainfall continues to be possible. * WHERE. Portions of DC, including the following , District of Columbia, Maryland, including the following areas, Anne Arundel, Central and Southeast Howard, Central and Southeast Montgomery, Northwest Howard, Northwest Montgomery, Prince Georges and Southern Baltimore, and northern Virginia, including the following areas, Arlington/Falls Church/Alexandria, Central and Southeast Prince William/Manassas/Manassas Park, Eastern Loudoun, Fairfax and Northwest Prince William. * WHEN. Until 10 PM EDT this evening. * 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. Low-water crossings may be flooded. * ADDITIONAL DETAILS. - Multiple rounds of heavy showers and thunderstorms will move across the area today into this evening. Rainfall amounts of 1 to 2 inches are likely, with isolated amounts of 3 to 4 inches possible. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information

SMWLWX The National Weather Service in Sterling Virginia has issued a * Special Marine Warning for. Tidal Potomac from Cobb Island MD to Smith Point VA. Tidal Potomac from Indian Head to Cobb Island MD. * Until 900 PM EDT. * At 726 PM EDT, a severe thunderstorm capable of producing waterspouts was located 7 nm south of Fairview Beach, moving east at 25 knots. HAZARD. Wind gusts 34 knots or greater and waterspouts. SOURCE. Radar indicated. IMPACT. Boaters in small craft could be thrown overboard by suddenly higher winds and waves capsizing their vessel. Waterspouts can easily overturn boats and create locally hazardous seas. * Locations impacted include. Breton Bay, Saint Clements Bay, Westmoreland State Park, Maryland Point, Nanjemoy Creek, Port Tobacco River, Cobb Island, Swan Point, Coltons Point, Mathias Point, U.S. 301 Nice Memorial Bridge, Wicomico River, White Point Beach, Popes Creek, Fairview Beach, and Dahlgren.

SMWLWX The National Weather Service in Sterling Virginia has issued a * Special Marine Warning for. Chesapeake Bay from Pooles Island to Sandy Point MD. Chesapeake Bay north of Pooles Island MD. * Until 800 PM EDT. * At 657 PM EDT, severe thunderstorms capable of producing waterspouts were located along a line extending from 6 nm north of Middle River to Pooles Island to 6 nm east of Tolchester Beach, moving northeast at 40 knots. HAZARD. Wind gusts 34 knots or greater and waterspouts. SOURCE. Radar indicated. IMPACT. Boaters in small craft could be thrown overboard by suddenly higher winds and waves capsizing their vessel. Waterspouts can easily overturn boats and create locally hazardous seas. * Locations impacted include. Turkey Point, Gunpowder River, Northeast River, Tolchester Beach, Worton Point, Pooles Island, Spesutie Island, Aberdeen Proving Ground, Havre De Grace, and Middle River.

* WHAT. South winds 10 to 15 kt expected with gusts up to 20 kt expected. * WHERE. Chesapeake Bay north of Sandy Point MD, Patapsco River including Baltimore Harbor, and Chester River to Queenstown MD. * WHEN. Until noon EDT Thursday. * IMPACTS. Conditions will be hazardous to small craft.

TORLWX The National Weather Service in Sterling Virginia has issued a * Tornado Warning for. West central Montgomery County in central Maryland. * Until 745 PM EDT. * At 714 PM EDT, a confirmed tornado was located over Poolesville, moving east at 20 mph. A tornado is on the ground. TAKE COVER NOW! HAZARD. Damaging tornado. SOURCE. Weather spotters confirmed tornado. IMPACT. You are in a life-threatening situation. Flying debris may be deadly to those caught without shelter. Mobile homes will be destroyed. Considerable damage to homes, businesses, and vehicles is likely and complete destruction is possible. * The tornado will be near. Germantown, Gaithersburg, Montgomery Village, North Potomac, and Boyds around 720 PM EDT. Other locations impacted by this tornadic thunderstorm include Dawsonville and Darnestown.

At 722 PM EDT, a confirmed tornado was located near Boyds, or near Poolesville, moving east at 20 mph. This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW! HAZARD. Damaging tornado. SOURCE. Weather spotters confirmed tornado. IMPACT. You are in a life-threatening situation. Flying debris may be deadly to those caught without shelter. Mobile homes will be destroyed. Considerable damage to homes, businesses, and vehicles is likely and complete destruction is possible. The tornado will be near. Germantown, Gaithersburg, Montgomery Village, North Potomac, and Boyds around 725 PM EDT. Other locations impacted by this tornadic thunderstorm include Dawsonville and Darnestown.

At 732 PM EDT, a confirmed tornado was located over Gaithersburg, moving east at 25 mph. This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW! HAZARD. Damaging tornado. SOURCE. Radar confirmed tornado. IMPACT. You are in a life-threatening situation. Flying debris may be deadly to those caught without shelter. Mobile homes will be destroyed. Considerable damage to homes, businesses, and vehicles is likely and complete destruction is possible. The tornado will be near. Germantown, Gaithersburg, and Montgomery Village around 740 PM EDT. Other locations impacted by this tornadic thunderstorm include Darnestown.

TORLWX The National Weather Service in Sterling Virginia has issued a * Tornado Warning for. North central Carroll County in north central Maryland. * Until 800 PM EDT. * At 732 PM EDT, a severe thunderstorm capable of producing a tornado was located near Westminster, moving northeast at 15 mph. HAZARD. Tornado. SOURCE. Radar indicated rotation. IMPACT. For those in the direct path of a tornado touchdown, flying debris will be dangerous to those caught without shelter. Damage to roofs, siding, and windows may occur. Mobile homes may be damaged or destroyed. Tree damage is likely. * This dangerous storm will be near. Westminster around 735 PM EDT. Other locations impacted by this tornadic thunderstorm include Uniontown.

TORLWX The National Weather Service in Sterling Virginia has issued a * Tornado Warning for. Central Montgomery County in central Maryland. * Until 815 PM EDT. * At 728 PM EDT, a confirmed tornado was located over Germantown, moving east at 25 mph. This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW! HAZARD. Damaging tornado. SOURCE. Radar confirmed tornado. IMPACT. You are in a life-threatening situation. Flying debris may be deadly to those caught without shelter. Mobile homes will be destroyed. Considerable damage to homes, businesses, and vehicles is likely and complete destruction is possible. * The tornado will be near. Germantown, Rockville, Gaithersburg, Olney, Aspen Hill, Montgomery Village, and Redland around 735 PM EDT. Other locations impacted by this tornadic thunderstorm include Spencerville, Laytonsville, Brookeville, Washington Grove, Sandy Spring, Ednor, Ashton, Brinklow, Derwood, and Burtonsville.