Southerly winds are gusting to around 20 knots in the open waters of the northern Chesapeake Bay. Winds are expected to diminish in a few hours. Inexperienced mariners, especially those operating smaller vessels, should exercise caution if navigating the waters during this time.

* WHAT. During the Excessive Heat Warnings, dangerously hot conditions with heat index values around 105 to 108 expected. * 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 Warning, until 8 PM EDT this evening. For the second Excessive Heat Warning, from 11 AM to 8 PM EDT Tuesday. * 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, adding heat stress to those without air conditioning. Ensure to stay hydrated and find ways to stay cool.

* WHAT. During the Excessive Heat Warnings, dangerously hot conditions with heat index values around 110 expected. * WHERE. Portions of central, northeast, northern and southern Maryland, The District of Columbia and central and northern Virginia. * WHEN. For the first Excessive Heat Warning, until 8 PM EDT this evening. For the second Excessive Heat Warning, from 11 AM to 8 PM EDT Tuesday. * 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, adding heat stress to those without air conditioning. Ensure to stay hydrated and find ways to stay cool.

* WHAT. During the Heat Advisories, hot conditions with heat index values around 105 expected. * WHERE. Portions of central and north central Maryland and central, northern and northwest Virginia. * WHEN. For the first Heat Advisory, until 8 PM EDT this evening. For the second Heat Advisory, from 11 AM to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses to occur. * ADDITIONAL DETAILS. Very warm and humid conditions will persist into the overnight hours, adding heat stress to those without air conditioning. Ensure to stay hydrated and find ways to stay cool.

The Maryland Department of the Environment has issued a Code ORANGE Air Quality Alert Monday for the Maryland suburban DC region. A Code Orange Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases and the elderly. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors. For more information on ground-level ozone and fine particles visit the web site mde.maryland.gov/programs/air/AirQualityMonitoring/Pages/index.aspx.

The Maryland Department of the Environment has issued a Code ORANGE Air Quality Alert Monday for the Baltimore City Metro and Annapolis region. A Code Orange Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases and the elderly. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors. For more information on ground-level ozone and fine particles visit the web site mde.maryland.gov/programs/air/AirQualityMonitoring/Pages/index.aspx.