* WHAT. Heat index values between 95 and 100 degrees in valley locations. * WHERE. Central Pennsylvania. * WHEN. From noon to 8 PM EDT Tuesday. * IMPACTS. The combination of heat and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. The heat wave is expected to continue through next weekend with the hottest temperatures of the summer so far.

* WHAT. Heat index values around 100 expected. * WHERE. In Maryland, Washington and Central and Eastern Allegany Counties. In West Virginia, Eastern Mineral, Berkeley, Jefferson, and Morgan Counties. * WHEN. From noon to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 100 expected. * WHERE. Central Pennsylvania. * WHEN. From noon Tuesday to 8 PM EDT Thursday. * IMPACTS. Hot temperatures and high humidity may cause heat-related illnesses. * ADDITIONAL DETAILS. The heat wave is expected to continue into the weekend with the hottest temperatures of the summer so far. The longevity of the heat wave has not been experienced in decades during the month of June.

* WHAT. South winds 10 to 15 kt with gusts up to 25 kt. * WHERE. Chesapeake Bay north of Pooles Island MD, Patapsco River including Baltimore Harbor, Chester River to Queenstown MD and Patuxent River to Broomes Island MD. * WHEN. Until midnight EDT tonight. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. South winds 10 to 20 kt with gusts up to 25 kt. * WHERE. Chesapeake Bay from Pooles Island 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, and Tangier Sound and the inland waters surrounding Bloodsworth Island. * WHEN. Until 2 AM EDT Tuesday. * IMPACTS. Conditions will be hazardous to small craft.