* WHAT. Heat index values up to 105 expected. * WHERE. Caroline, Kent MD, Queen Annes, and Talbot Counties. * WHEN. From 10 AM this morning to 7 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 103 expected. * WHERE. Portions of northern Delaware, central and southern New Jersey, and southeast Pennsylvania. * WHEN. From 11 AM this morning to 7 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 491 IN EFFECT UNTIL 11 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. Heat index values up to 105. * WHERE. Caroline, Kent MD, Queen Annes, and Talbot Counties. * WHEN. Until 7 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 97. * WHERE. Portions of northern Delaware, central and southern New Jersey, and southeast Pennsylvania. * WHEN. Until 7 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

The areas affected include. Chesapeake Bay from Pooles Island to Sandy Point MD. Chester River to Queenstown MD. Patapsco River including Baltimore Harbor. At 313 PM EDT, Doppler radar indicated a strong thunderstorm, capable of producing winds to around 30 knots. This thunderstorm was located over North Point State Park, moving east at 15 knots.

* WHAT. North winds 10 to 20 kt with gusts up to 30 kt expected. * WHERE. Tidal Potomac River from Key Bridge to Cobb Island MD, Chesapeake Bay north of Sandy Point MD, Patapsco River including Baltimore Harbor, and Chester River to Queenstown MD. * WHEN. From 10 PM this evening to 2 PM EDT Monday. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. North winds 10 to 20 kt with gusts up to 30 kt expected. * WHERE. Chesapeake Bay from Sandy Point MD to Smith Point VA, Tidal Potomac from Cobb Island MD to Smith Point VA, Eastern Bay, Choptank River to Cambridge MD and the Little Choptank River, Patuxent River to Broomes Island MD, and Tangier Sound and the inland waters surrounding Bloodsworth Island. * WHEN. From midnight tonight to 6 PM EDT Monday. * IMPACTS. Conditions will be hazardous to small craft.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 489 IN EFFECT UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING AREAS IN PENNSYLVANIA THIS WATCH INCLUDES 22 COUNTIES IN CENTRAL PENNSYLVANIA ADAMS CENTRE CLINTON COLUMBIA CUMBERLAND DAUPHIN FRANKLIN FULTON HUNTINGDON JUNIATA LANCASTER LEBANON LYCOMING MIFFLIN MONTOUR NORTHUMBERLAND PERRY SCHUYLKILL SNYDER SULLIVAN UNION YORK THIS INCLUDES THE CITIES OF BERWICK, BLOOMSBURG, CARLISLE, CHAMBERSBURG, DANVILLE, GETTYSBURG, HARRISBURG, HERSHEY, HUNTINGDON, LANCASTER, LAPORTE, LEBANON, LEWISBURG, LEWISTOWN, LOCK HAVEN, MCCONNELLSBURG, MIFFLINTOWN, MOUNT UNION, NEWPORT, POTTSVILLE, RENOVO, SELINSGROVE, SHAMOKIN, STATE COLLEGE, SUNBURY, WAYNESBORO, WILLIAMSPORT, AND YORK.

SEVERE THUNDERSTORM WATCH 489 REMAINS VALID UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING AREAS IN PENNSYLVANIA THIS WATCH INCLUDES 18 COUNTIES IN CENTRAL PENNSYLVANIA ADAMS COLUMBIA CUMBERLAND DAUPHIN FRANKLIN FULTON HUNTINGDON JUNIATA LANCASTER LEBANON MIFFLIN MONTOUR NORTHUMBERLAND PERRY SCHUYLKILL SNYDER UNION YORK THIS INCLUDES THE CITIES OF BERWICK, BLOOMSBURG, CARLISLE, CHAMBERSBURG, DANVILLE, GETTYSBURG, HARRISBURG, HERSHEY, HUNTINGDON, LANCASTER, LEBANON, LEWISBURG, LEWISTOWN, MCCONNELLSBURG, MIFFLINTOWN, MOUNT UNION, NEWPORT, POTTSVILLE, SELINSGROVE, SHAMOKIN, SUNBURY, WAYNESBORO, AND YORK.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 491 IN EFFECT UNTIL 11 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 21 COUNTIES IN CENTRAL VIRGINIA ALBEMARLE CITY OF CHARLOTTESVILLE CITY OF FREDERICKSBURG GREENE KING GEORGE 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 MADISON RAPPAHANNOCK THIS INCLUDES THE CITIES OF ABERDEEN, ALEXANDRIA, ANNAPOLIS, ARLINGTON, ARNOLD, ASPEN HILL, BALLENGER CREEK, BALTIMORE, BEL AIR, BETHESDA, BOWIE, CALIFORNIA, CAMP SPRINGS, CATONSVILLE, CHANTILLY, 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, GAITHERSBURG, GERMANTOWN, GLEN BURNIE, GORDONSVILLE, GREENBELT, HAVRE DE GRACE, HERNDON, HUNTINGTOWN, JOPPATOWNE, LAUREL, LEESBURG, LEXINGTON PARK, LUSBY, MADISON, MANASSAS, MANASSAS PARK, MCLEAN, NORTH BEACH, ODENTON, ORANGE, PARKVILLE, PIKESVILLE, POTOMAC, PRINCE FREDERICK, RANDALLSTOWN, RESTON, ROCKVILLE, SEVERN, SEVERNA PARK, SILVER SPRING, SOUTH GATE, SPOTSYLVANIA COURTHOUSE, ST. CHARLES, STANARDSVILLE, STERLING, SUITLAND-SILVER HILL, TOWSON, WALDORF, WARRENTON, WASHINGTON, WASHINGTON, WESTMINSTER, AND WOODBRIDGE.

THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH 491 IN EFFECT UNTIL 11 PM EDT THIS EVENING FOR THE FOLLOWING AREAS IN DELAWARE THIS WATCH INCLUDES 2 COUNTIES IN CENTRAL DELAWARE KENT 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 3 COUNTIES IN SOUTHERN NEW JERSEY ATLANTIC CAPE MAY CUMBERLAND THIS INCLUDES THE CITIES OF ATLANTIC CITY, CENTREVILLE, CHESTERTOWN, DENTON, DOVER, EASTON, GEORGETOWN, HAMMONTON, MILLVILLE, AND OCEAN CITY.

SEVERE THUNDERSTORM WATCH 489 REMAINS VALID UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING AREAS IN PENNSYLVANIA THIS WATCH INCLUDES 10 COUNTIES IN CENTRAL PENNSYLVANIA ADAMS CUMBERLAND DAUPHIN FRANKLIN FULTON LANCASTER LEBANON PERRY SCHUYLKILL YORK THIS INCLUDES THE CITIES OF CARLISLE, CHAMBERSBURG, GETTYSBURG, HARRISBURG, HERSHEY, LANCASTER, LEBANON, MCCONNELLSBURG, NEWPORT, POTTSVILLE, WAYNESBORO, AND YORK.