* WHAT. During the period of the Excessive Heat Watches, dangerously hot conditions with heat index values around 105 are possible. * WHERE. In Maryland, Washington County. In Virginia, Shenandoah, Frederick VA, Page, Warren and Clarke Counties. In West Virginia, Morgan, Berkeley and Jefferson Counties. * WHEN. For the first Excessive Heat Watch, from Monday morning through Monday evening. For the second Excessive Heat Watch, from Tuesday morning through Tuesday evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. * ADDITIONAL DETAILS. Very warm and humid conditions will persist into the overnight hours. Ensure to stay hydrated and find ways to stay cool.

* WHAT. During the period of the Excessive Heat Watches, dangerously hot conditions with heat index values up to 110 are possible. * WHERE. Portions of central, north central, northeast, northern and southern Maryland, The District of Columbia and central, northern and northwest Virginia. * WHEN. For the first Excessive Heat Watch, from Monday morning through Monday evening. For the second Excessive Heat Watch, from Tuesday morning through Tuesday evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. * ADDITIONAL DETAILS. Very warm and humid conditions will persist into the overnight hours. Ensure to stay hydrated and find ways to stay cool.

SMWLWX The National Weather Service in Sterling Virginia has issued a * Special Marine Warning for. Chesapeake Bay from Pooles Island to Sandy Point MD. Chester River to Queenstown MD. Patapsco River including Baltimore Harbor. * Until 245 PM EDT. * At 114 PM EDT, a strong thunderstorm was located over North Point State Park, moving east at 10 knots. HAZARD. Wind gusts 34 knots or greater. SOURCE. Radar indicated. IMPACT. Boaters in small craft could be thrown overboard by suddenly higher winds and waves capsizing their vessel. * Locations impacted include. Pinehurst, North Point State Park, Fort Smallwood Park, Hart Miller Island, Gibson Island, Bodkin Point, Tolchester Beach, Pooles Island, and Sevenfoot Knoll.

For the following areas. Chesapeake Bay from Pooles Island to Sandy Point MD. Chester River to Queenstown MD. Patapsco River including Baltimore Harbor. At 137 PM EDT, a strong thunderstorm was located near Sevenfoot Knoll, moving east at 10 knots. HAZARD. Wind gusts 34 knots or greater. SOURCE. Radar indicated. IMPACT. Boaters in small craft could be thrown overboard by suddenly higher winds and waves capsizing their vessel. Locations impacted include. Pinehurst, North Point State Park, Fort Smallwood Park, Hart Miller Island, Gibson Island, Bodkin Point, Tolchester Beach, Pooles Island, and Sevenfoot Knoll.

The areas affected include. Chesapeake Bay from Pooles Island to Sandy Point MD. Chesapeake Bay from Sandy Point to North Beach MD. Chester River to Queenstown MD. Eastern Bay. Patapsco River including Baltimore Harbor. At 103 PM EDT, Doppler radar indicated developing thunderstorms along a line extending from North Point State Park to near Annapolis to 9 nm east of National Harbor, moving east at 10 knots.

High air temperatures in the upper 90s coupled with higher humidity along the waters of the Tidal Potomac and Chesapeake Bay are resulting in localized heat indices of around 100 to 105 degrees. The potential for showers and thunderstorms exists this afternoon, which would cool the air temperatures. Monitor the latest forecasts and warnings for updates on this situation. Be prepared to drink plenty of fluids, stay in an air- conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances. This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.

* WHAT. For the Excessive Heat Warning, dangerously hot conditions with heat index values around 110 expected. For the Excessive Heat Watch, dangerously hot conditions with heat index values up to 110 possible. * WHERE. Portions of central, northeast, northern and southern Maryland, The District of Columbia and central and northern Virginia. * WHEN. For the Excessive Heat Warning, from 11 AM to 8 PM EDT Monday. For the Excessive Heat Watch, from Tuesday morning through Tuesday evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. * ADDITIONAL DETAILS. Very warm and humid conditions will persist into the overnight hours. Ensure to stay hydrated and find ways to stay cool.

* WHAT. For the Heat Advisory, heat index values around 105 to 109 expected. For the Excessive Heat Watch, dangerously hot conditions with heat index values up to 110 possible. * WHERE. Portions of central and north central Maryland and central, northern and northwest Virginia. * WHEN. For the Heat Advisory, from 11 AM to 8 PM EDT Monday. For the Excessive Heat Watch, from Tuesday morning through Tuesday evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. * ADDITIONAL DETAILS. Very warm and humid conditions will persist into the overnight hours. Ensure to stay hydrated and find ways to stay cool.

* WHAT. For the Excessive Heat Warning, dangerously hot conditions with heat index values around 105 expected. For the Excessive Heat Watch, dangerously hot conditions with heat index values up to 105 possible. * WHERE. In Maryland, Washington County. In Virginia, Shenandoah, Frederick VA, Page, Warren and Clarke Counties. In West Virginia, Morgan, Berkeley and Jefferson Counties. * WHEN. For the Excessive Heat Warning, from 11 AM to 8 PM EDT Monday. For the Excessive Heat Watch, from Tuesday morning through Tuesday evening. * IMPACTS. Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. * ADDITIONAL DETAILS. Very warm and humid conditions will persist into the overnight hours. Ensure to stay hydrated and find ways to stay cool.

* WHAT. For the Heat Advisory, heat index values to 104 expected. For the Excessive Heat Watch, dangerously hot conditions with heat index values up to 110 possible. * WHERE. Adams, Cumberland, Dauphin, Franklin, Lancaster, Lebanon, Perry, and York Counties. * WHEN. For the Heat Advisory, from noon today to noon EDT Monday. For the Excessive Heat Watch, from Monday afternoon through Tuesday evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events.