The Washington Post begins a redesigned and more informative weather feature today on this page. The expanded weather news includes daily recreational forecasts for the seashore and mountains, a new 6- to 10-day long-range forecast in addition to the 3- to 5-day forecast, and a new regional forecast map to accompany an enlarged and improved national forecast map.

Also new are daily weather statistics from suburban Virginia and Maryland, recorded at Dulles and Baltimore-Washington international airports. Official Washington weather data is recorded at National Airport.

The data from Dulles and BWI will better reflect the weather experienced by residents in the suburbs, where temperatures are regularly as much as 10 degrees cooler year-round than in the "heat island" of downtown Washington. The District's downtown core, National Airport and much of Alexandria are almost always warmer than outlying areas, largely because of the high concentration of buildings and roads that absorb and retain heat. In winter, the Potomac River, which is warmer than the winter air, also moderates temperatures.

The new weather feature also will provide clearer tide information for the Potomac River and Chesapeake Bay and list daily almanac data not previously reported, including barometric pressures, normal high and low temperatures for each day and the "apparent temperature."

The apparent temperature, also called the heat or comfort index in summer and the wind-chill factor in winter, is a composite of temperature, humidity and wind. It reflects what the weather feels like to people outdoors. A 96-degree temperature may actually seem hotter if the humidity is high. Several days last month had apparent temperatures above 105 degrees.

Other weather news changes include a two-day weather forecast for U.S. and foreign cities, which should be of greater use to travelers. The previous foreign cities list did not provide forecasts but gave only temperatures and weather conditions from the previous day.

Weather forecasts and data in the new section are being provided by Accu-Weather, one of the nation's largest private forecasting services. Weather stories in The Post will now frequently reflect forecasts of both Accu-Weather and the National Weather Service, giving readers two weather predictions for major regional storms or unusual weather systems. Because of budget constraints, the National Weather Service has cut back on some of its specialized forecasting services and recently announced it is considering eliminating all regional forecasts.

During last winter's snows, forecasts varied widely among the National Weather Service, Accu-Weather and other private forecasting companies that provide weather information for the Washington region.

Accu-Weather also provides forecasts for about 50 newspapers nationally and in the Washington region for Amtrak, Metro, the Metropolitan Washington Council of Governments, several federal agencies and numerous city and county governments and local school systems.