Oxon Hill, MD

Severe Thunderstorm Watch 455 remains in effect until 900 PM EDT

MD 
.    Maryland counties included are

Anne Arundel         Baltimore           Calvert             
Caroline             Carroll             Cecil               
Charles              Dorchester          Frederick           
Harford              Howard              Kent                
Montgomery           Prince Georges      Queen Anne's        
St. Marys            Somerset            Talbot              
Washington           Wicomico            Worcester           




Maryland independent cities included are

Baltimore City       

... Flash Flood Watch in effect through late tonight... 

The National Weather Service in Sterling Virginia has issued a

* Flash Flood Watch for portions of Maryland, the District of 
  Columbia, and Virginia, including the following areas, in 
  Maryland, Anne Arundel, Calvert, Carroll, central and 
  southeast Howard, central and southeast Montgomery, Charles, 
  Frederick MD, northern Baltimore, northwest Harford, northwest 
  Howard, northwest Montgomery, Prince Georges, southeast 
  Harford, southern Baltimore, and St. Marys. The District of 
  Columbia. In Virginia, Arlington/Falls Church/Alexandria, 
  Culpeper, eastern Loudoun, Fairfax, King George, Madison, 
  northern Fauquier, Orange, Prince William/Manassas/Manassas 
  Park, Rappahannock, southern Fauquier, Spotsylvania, Stafford, 
  and western Loudoun. 

* Through late tonight

* thunderstorms with heavy rainfall are expected across the region
  this afternoon and evening. The potential for training
  thunderstorms exists, which could result in several inches of
  rain in one to two hours. Soils are already very moist, meaning
  most of this rain would rapidly run off.

* Runoff from excessive rainfall may cause rapid rises of water 
  in low-lying and poor drainage areas as well as streams and 
  creeks, resulting in flash flooding. Urban areas will be most 
  susceptible. 

Precautionary/preparedness actions... 

A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.

You should monitor later forecasts and be prepared to take action
should flash flood warnings be issued.



Rcm

... Heat advisory remains in effect until 8 PM EDT this evening... 

* heat index values... around 105 degrees due to temperatures in 
  the lower 90s and dewpoints in the mid to upper 70s.

* Impacts... the heat and humidity may cause heat stress during 
  outdoor exertion or extended exposure.

Precautionary/preparedness actions... 

A heat advisory means that a period of high temperatures is
expected. The combination of high temperatures and high humidity
will create a situation in which heat illnesses are possible.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

To reduce risk during outdoor work, the occupational safety and
health administration recommends scheduling frequent rest breaks
in shaded or air conditioned environments. Anyone overcome by
heat should be moved to a cool and shaded location. Heat stroke
is an emergency - call 911.