* WHAT. Heat index values up to 102 expected. * WHERE. Portions of northern Delaware, central, northern, and southern New Jersey, and southeast Pennsylvania. * WHEN. From 10 AM to 10 PM EDT Tuesday. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS. This is the start of a prolonged period of excessive heat with high temperatures in the mid to upper 90s through the week. The early season heat combined with the prolonged nature of the heat may cause heat related impacts that exceed anticipate heat illnesses or on heat sensitive infrastructure normally associated with a Heat Advisory.

* WHAT. For the first Small Craft Advisory, south winds 10 to 15 kt with gusts up to 20 kt. For the second Small Craft Advisory, south winds 10 to 20 kt with gusts up to 25 kt expected. * 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. For the first Small Craft Advisory, until 2 AM EDT Monday. For the second Small Craft Advisory, from 2 PM Monday to 2 AM EDT Tuesday. * IMPACTS. Conditions will be hazardous to small craft.

* WHAT. Max temperatures between 90 and 95 degrees with heat index values around 100 expected. * WHERE. Central Pennsylvania. * WHEN. From noon to 8 PM EDT Tuesday. * 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 forecast heat wave during the month of June has not been experienced in decades.

* WHAT. For the Heat Advisory, heat index values up to 98 expected. For the Excessive Heat Watch, dangerously hot conditions with heat index values of 100 to 105 possible. * WHERE. Portions of northern Delaware, central, northern, and southern New Jersey, and southeast Pennsylvania. * WHEN. For the Heat Advisory, from 10 AM Tuesday to 6 AM EDT Wednesday. For the Excessive Heat Watch, from Wednesday morning through Saturday evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS. A prolonged period of excessive heat with high temperatures in the 90s is expected through this week. The heat is forecast to worsen as the week goes on, with it peaking late in the week and into the weekend. These early season heat events combined with the prolonged nature of it may cause an increase in heat related impacts such heat illnesses or on heat sensitive infrastructure.