* WHAT. Southwest winds 10 to 15 kt with gusts up to 20 kt expected. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, and Chesapeake Bay and adjoining estuaries north of Drum Point MD. * WHEN. From 1 PM this afternoon to 11 PM EDT this evening. * IMPACTS. Conditions will be hazardous to small craft.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 553 IN EFFECT UNTIL 10 PM EDT THIS EVENING FOR THE FOLLOWING AREAS THIS WATCH INCLUDES THE FOLLOWING ADJACENT COASTAL WATERS CHESAPEAKE BAY NORTH OF POOLES ISLAND MD CHESAPEAKE BAY FROM POOLES ISLAND TO SANDY POINT MD CHESAPEAKE BAY FROM SANDY POINT TO NORTH BEACH MD CHESAPEAKE BAY FROM NORTH BEACH TO DRUM POINT MD CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA PATAPSCO RIVER INCLUDING BALTIMORE HARBOR CHESTER RIVER TO QUEENSTOWN MD EASTERN BAY CHOPTANK RIVER TO CAMBRIDGE MD AND THE LITTLE CHOPTANK RIVER PATUXENT RIVER TO BROOMES ISLAND MD TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH ISLAND

* WHAT. Southwest winds 10 to 15 kt with gusts up to 20 kt expected. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, and Chesapeake Bay and adjoining estuaries north of Drum Point MD. * WHEN. Until 11 PM EDT this evening. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. Heat index values up to 106. * WHERE. Portions of central, north central, northeast, northern and southern Maryland, The District of Columbia and central, northern and northwest Virginia. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur.

* WHAT. Heat index values up to 102. * WHERE. In Maryland, Washington County. In Virginia, Rockingham, Shenandoah, Frederick VA, Page, Warren and Clarke Counties. In West Virginia, Morgan, Berkeley and Jefferson Counties. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur.

* 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, Prince Georges and Southern Baltimore, and northern Virginia, including the following areas, Arlington/Falls Church/Alexandria, Central and Southeast Prince William/Manassas/Manassas Park and Fairfax. * WHEN. From 2 PM EDT this afternoon through 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. * ADDITIONAL DETAILS. - Thunderstorms this afternoon and evening could have intense rain rates exceeding 2 inches per hour. If locally repetitive or prolonged thunderstorms develop, flash flooding could occur in flood prone urban and suburban areas. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information

* WHAT. Heat index values between 100 and 104. * WHERE. Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN. Until 8 PM EDT this evening. * IMPACTS. High temperatures and high humidity may cause heat illnesses.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 553 IN EFFECT UNTIL 10 PM EDT THIS EVENING FOR THE FOLLOWING AREAS IN DELAWARE THIS WATCH INCLUDES 3 COUNTIES IN CENTRAL DELAWARE KENT IN NORTHERN DELAWARE NEW CASTLE IN SOUTHERN DELAWARE SUSSEX IN MARYLAND THIS WATCH INCLUDES 4 COUNTIES IN NORTHEAST MARYLAND CAROLINE KENT QUEEN ANNE'S TALBOT IN NEW JERSEY THIS WATCH INCLUDES 4 COUNTIES IN SOUTHERN NEW JERSEY ATLANTIC CAPE MAY CUMBERLAND SALEM THIS INCLUDES THE CITIES OF ATLANTIC CITY, CENTREVILLE, CHESTERTOWN, DENTON, DOVER, EASTON, GEORGETOWN, HAMMONTON, MILLVILLE, OCEAN CITY, PENNSVILLE, AND WILMINGTON.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 553 IN EFFECT UNTIL 10 PM EDT THIS EVENING FOR THE FOLLOWING AREAS THE DISTRICT OF COLUMBIA IN MARYLAND THIS WATCH INCLUDES 13 COUNTIES IN CENTRAL MARYLAND ANNE ARUNDEL HOWARD MONTGOMERY PRINCE GEORGES IN NORTH CENTRAL MARYLAND CARROLL FREDERICK IN NORTHEAST MARYLAND CECIL IN NORTHERN MARYLAND BALTIMORE BALTIMORE CITY HARFORD IN SOUTHERN MARYLAND CALVERT CHARLES ST. MARYS IN VIRGINIA THIS WATCH INCLUDES 31 COUNTIES IN CENTRAL VIRGINIA ALBEMARLE CITY OF CHARLOTTESVILLE CITY OF FREDERICKSBURG GREENE KING GEORGE NELSON ORANGE SPOTSYLVANIA IN NORTHERN VIRGINIA ARLINGTON CITY OF ALEXANDRIA CITY OF FAIRFAX CITY OF FALLS CHURCH CITY OF MANASSAS CITY OF MANASSAS PARK CULPEPER FAIRFAX FAUQUIER LOUDOUN PRINCE WILLIAM STAFFORD IN NORTHWEST VIRGINIA CLARKE MADISON PAGE RAPPAHANNOCK SHENANDOAH WARREN IN WESTERN VIRGINIA AUGUSTA CITY OF HARRISONBURG CITY OF STAUNTON CITY OF WAYNESBORO ROCKINGHAM IN WEST VIRGINIA THIS WATCH INCLUDES 1 COUNTY IN PANHANDLE WEST VIRGINIA JEFFERSON THIS INCLUDES THE CITIES OF ABERDEEN, ALEXANDRIA, ANNAPOLIS, ARLINGTON, ARNOLD, ASPEN HILL, BALLENGER CREEK, BALTIMORE, BEL AIR, BERRYVILLE, BETHESDA, BOWIE, CALIFORNIA, CAMP SPRINGS, CATONSVILLE, CHANTILLY, CHARLES TOWN, CHARLOTTESVILLE, CHESAPEAKE BEACH, CLINTON, COLLEGE PARK, COLUMBIA, CROZET, CULPEPER, DAHLGREN, DUNDALK, DUNKIRK, EDGEWOOD, ELDERSBURG, ELKTON, ELLICOTT CITY, ESSEX, FAIRFAX, FALLS CHURCH, FALLSTON, FALMOUTH, FREDERICK, FREDERICKSBURG, FRONT ROYAL, GAITHERSBURG, GERMANTOWN, GLEN BURNIE, GORDONSVILLE, GREENBELT, GREENFIELD, HARRISONBURG, HARRISONBURG, HAVRE DE GRACE, HERNDON, HUNTINGTOWN, JOPPATOWNE, LAUREL, LEESBURG, LEXINGTON PARK, LURAY, LUSBY, MADISON, MANASSAS, MANASSAS PARK, MCLEAN, NORTH BEACH, ODENTON, ORANGE, PARKVILLE, PIKESVILLE, POTOMAC, PRINCE FREDERICK, RANDALLSTOWN, RESTON, ROCKVILLE, SEVERN, SEVERNA PARK, SHENANDOAH, SHEPHERDSTOWN, SILVER SPRING, SOUTH GATE, SPOTSYLVANIA COURTHOUSE, ST. CHARLES, STANARDSVILLE, STANLEY, STAUNTON, STAUNTON, STERLING, STRASBURG, SUITLAND-SILVER HILL, TOWSON, WALDORF, WARRENTON, WASHINGTON, WASHINGTON, WAYNESBORO, WAYNESBORO, WESTMINSTER, WOODBRIDGE, AND WOODSTOCK.