THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 518 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 TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD PATAPSCO RIVER INCLUDING BALTIMORE HARBOR

SEVERE THUNDERSTORM WATCH 518 REMAINS VALID 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 TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD PATAPSCO RIVER INCLUDING BALTIMORE HARBOR

* WHAT. Up to one half foot of inundation above ground level expected in low lying areas due to tidal flooding. * WHERE. Shoreline in Anne Arundel County. * WHEN. From 8 PM this evening to midnight EDT tonight, especially around the time of high tide. * IMPACTS. At 2.6 feet, water may begin to pond in the parking lot at Annapolis City Dock, and surround the Alex Haley Memorial. * ADDITIONAL DETAILS. Tides one and a half to two feet above normal. The next high tide at Annapolis U.S. Naval Academy is at 9:33 PM.

* WHAT. Dangerously hot conditions with heat index values up to 112 expected. * WHERE. Portions of central, northern and southern Maryland, The District of Columbia and central and northern Virginia. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities.

* WHAT. Heat index values up to 109 expected. * WHERE. Portions of central, north central, northeast and northern Maryland 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 105. * WHERE. Portions of north central and western Maryland, northwest and western Virginia and eastern and panhandle West Virginia. * WHEN. Until 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur.

* WHAT. South winds 10 to 15 kt with gusts up to 25 kt. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, Patapsco River including Baltimore Harbor, and Patuxent River to Broomes Island MD. * WHEN. Until 2 AM EDT Thursday. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. South winds 10 to 20 kt with gusts up to 30 kt. * WHERE. Chesapeake Bay north of Drum Point MD, Tidal Potomac from Cobb Island MD to Smith Point VA, Chester River to Queenstown MD, Eastern Bay, and Choptank River to Cambridge MD and the Little Choptank River. * WHEN. Until 4 AM EDT Thursday. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. Oppressive heat with afternoon heat indices between 100 and 105 degrees. * WHERE. Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN. Until 8 PM EDT this evening. * IMPACTS. High temperatures and humidity may cause heat illnesses.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 518 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 WASHINGTON IN NORTHEAST MARYLAND CECIL IN NORTHERN MARYLAND BALTIMORE BALTIMORE CITY HARFORD IN SOUTHERN MARYLAND CHARLES IN WESTERN MARYLAND ALLEGANY IN VIRGINIA THIS WATCH INCLUDES 33 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 CITY OF WINCHESTER CLARKE FREDERICK 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 5 COUNTIES IN EASTERN WEST VIRGINIA HAMPSHIRE HARDY IN PANHANDLE WEST VIRGINIA BERKELEY JEFFERSON MORGAN THIS INCLUDES THE CITIES OF ABERDEEN, ALEXANDRIA, ANNAPOLIS, ARLINGTON, ARNOLD, ASPEN HILL, BALLENGER CREEK, BALTIMORE, BEL AIR, BERRYVILLE, BETHESDA, BOWIE, CAMP SPRINGS, CATONSVILLE, CHANTILLY, CHARLES TOWN, CHARLOTTESVILLE, CLINTON, COLLEGE PARK, COLUMBIA, CROZET, CULPEPER, CUMBERLAND, DAHLGREN, DUNDALK, EDGEWOOD, ELDERSBURG, ELKTON, ELLICOTT CITY, ESSEX, FAIRFAX, FALLS CHURCH, FALLSTON, FALMOUTH, FREDERICK, FREDERICKSBURG, FRONT ROYAL, FROSTBURG, GAITHERSBURG, GERMANTOWN, GLEN BURNIE, GORDONSVILLE, GREENBELT, GREENFIELD, HAGERSTOWN, HARRISONBURG, HARRISONBURG, HAVRE DE GRACE, HERNDON, JOPPATOWNE, LAUREL, LEESBURG, LURAY, MADISON, MANASSAS, MANASSAS PARK, MARTINSBURG, MCLEAN, MOOREFIELD, ODENTON, ORANGE, PARKVILLE, PAW PAW, PIKESVILLE, POTOMAC, RANDALLSTOWN, RESTON, ROCKVILLE, ROMNEY, 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, WINCHESTER, WINCHESTER, WOODBRIDGE, AND WOODSTOCK.

SEVERE THUNDERSTORM WATCH 518 REMAINS VALID UNTIL 10 PM EDT THIS EVENING FOR THE FOLLOWING AREAS THE DISTRICT OF COLUMBIA IN MARYLAND THIS WATCH INCLUDES 12 COUNTIES IN CENTRAL MARYLAND ANNE ARUNDEL HOWARD MONTGOMERY PRINCE GEORGES IN NORTH CENTRAL MARYLAND CARROLL FREDERICK WASHINGTON IN NORTHEAST MARYLAND CECIL IN NORTHERN MARYLAND BALTIMORE BALTIMORE CITY HARFORD IN SOUTHERN MARYLAND CHARLES IN VIRGINIA THIS WATCH INCLUDES 26 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 CITY OF WINCHESTER CLARKE FREDERICK MADISON RAPPAHANNOCK WARREN IN WEST VIRGINIA THIS WATCH INCLUDES 3 COUNTIES IN PANHANDLE WEST VIRGINIA BERKELEY JEFFERSON MORGAN THIS INCLUDES THE CITIES OF ABERDEEN, ALEXANDRIA, ANNAPOLIS, ARLINGTON, ARNOLD, ASPEN HILL, BALLENGER CREEK, BALTIMORE, BEL AIR, BERRYVILLE, BETHESDA, BOWIE, CAMP SPRINGS, CATONSVILLE, CHANTILLY, CHARLES TOWN, CHARLOTTESVILLE, CLINTON, COLLEGE PARK, COLUMBIA, CROZET, CULPEPER, DAHLGREN, DUNDALK, EDGEWOOD, ELDERSBURG, ELKTON, ELLICOTT CITY, ESSEX, FAIRFAX, FALLS CHURCH, FALLSTON, FALMOUTH, FREDERICK, FREDERICKSBURG, FRONT ROYAL, GAITHERSBURG, GERMANTOWN, GLEN BURNIE, GORDONSVILLE, GREENBELT, GREENFIELD, HAGERSTOWN, HAVRE DE GRACE, HERNDON, JOPPATOWNE, LAUREL, LEESBURG, MADISON, MANASSAS, MANASSAS PARK, MARTINSBURG, MCLEAN, ODENTON, ORANGE, PARKVILLE, PAW PAW, PIKESVILLE, POTOMAC, RANDALLSTOWN, RESTON, ROCKVILLE, SEVERN, SEVERNA PARK, SHEPHERDSTOWN, SILVER SPRING, SOUTH GATE, SPOTSYLVANIA COURTHOUSE, ST. CHARLES, STANARDSVILLE, STERLING, SUITLAND-SILVER HILL, TOWSON, WALDORF, WARRENTON, WASHINGTON, WASHINGTON, WESTMINSTER, WINCHESTER, WINCHESTER, AND WOODBRIDGE.