* WHAT. Heat index values up to around 105 to 107 expected, with heat index values generally between 100 and 104 degrees west of the Blue Ridge Mountains. * WHERE. Portions of central, north central, northeast, northern, southern and western Maryland, The District of Columbia, central, northern and northwest Virginia and eastern and panhandle West Virginia. * WHEN. From 11 AM to 8 PM EDT Saturday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur. * ADDITIONAL DETAILS. Oppressive heat and humidity will overspread the area Saturday and last into Sunday. Little relief from the heat is expected Saturday night with low temperatures in mid 70s to near 80 for most, which will compound heat stress on those without air conditioning.

* WHAT. Heat index values up to around 105 to 107 expected, with heat index values generally between 100 and 104 degrees west of the Blue Ridge Mountains. * WHERE. Portions of central, north central, northeast, northern, southern and western Maryland, The District of Columbia, central, northern and northwest Virginia and eastern and panhandle West Virginia. * WHEN. From 11 AM to 8 PM EDT Saturday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur. * ADDITIONAL DETAILS. Oppressive heat and humidity will overspread the area Saturday and last into Sunday. Little relief from the heat is expected Saturday night with low temperatures in mid 70s to near 80 for most, which will compound heat stress on those without air conditioning.