The National Weather Forecast for today - Snow will extend from New England through Virginia, across the Appalachians, over the eastern half of the Great Lakes region, and through eastern Kentucky, Tennessee and the southern Appalachians. Rain will fall from southern Texas across the Gulf Coast states and into Georgia and the Carolins. Rainshowers, with snow over the higher mountains, will dampen the Pacific Northwest, northern California and move across Idaho and northern Utah. Snow showers will dot the central Rockies. Elsewhere skies will be partly cloudy and sunny. Very cold temperatures will move into the lower Mississippi Valley, the southern Appalachians and also continue over the south and central Plains. It will not be as cold over the northern Plains, but continue quite cold over the mid Mississippi and Ohio Valleys. The Pacific Northwest and northern will be cool. The remainder of the nation will have seasonable temperatures.

Washington: Today - Snow by afternoon, possibly neavy at times, tapering off tonight, high in the mid 30s, low in the 20s. Winds will be light and variable. The chance of precipitation is 80 per cent . Sunday - Cloudy and cold, high in the mid 30s.

Maryland: Today - Snow, possibly mixed with rain in the south, may be heavy at times, expected to taper off tonight, high in the 30s, low in the 20s. Sunday - Cloudy and cold high in the mid 30s, low in the 20s.

Virginia: Today - Snow, possibly mixed with or changing to rain the south , may be heavy at times, high in the 30s, low in the 20s. Sunday - Cloudy and cold, high will range from the 30s to near 40.

Lower Potomac and Chesapeake Bay - Snow developing by afternoon and tapering off tonight. Winds will be from the northeast at 10 to 20 knots becoming gusty tonight. Waves in ice free waters will average near 2 feet. Visibility will be less than 1 mile in snow.

Extended Area Outlook for Monday through Wednesday - Fair Monday with a chance of snow Tuesday night, clearing Wednesday. Highs will be in the mid 20s to mid 30s, lows in the teens to mid 20s. Normal Washington temperatures for the period are a high of 47 and a low of 29.

West Virginia: Today - Snow, tapering off to flurries by nightfall highs will range from the upper 20s to mid 30s, low in the 20s. Sunday - Snow flurries, high near 30.

Almanac Data today - Sun rises 6:56 a.m., sets 5:49 p.m.; moon rises 2:06 p.m., sets 3:45 a.m.; Tides: high 4:33 a.m. and 4:59 p.m., low 11:20 a.m. and 11:53 p.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from the tides above. Annapolis (1 1/2), Bloody Point Lighthouse (4 1/2), Deale, Md. (4 1/2), Colonial Beach (6), Norfolk, (1 1/2), Virginia Beach (1) , Solomons Island (6 1/2), Point Lookout (7).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 3 p.m., period was 28 for the pollutant, particulate matter. Index values between 25 and 49 indicate fair air quality. When the index exceeds 100 the air is considered very unhealthy and individuals with lung, heart and eye ailments are urged to restrict their activity. The forecast for today indicates that the air quality will improve.

The National Weather Service forecasts the Potomac River stage at Little Falls should remain near 3.5 feet today.

Washington data at 7 p.m. (EST) yesterday: Highest temperature since 7 a.m. yesterday, 41 degrees at 2:30 p.m. Lowest temperature since midnight, 33 degrees at 7:51 a.m. Deficiency of temperature since Feb. 1, 109 degrees. Deficiency of temperature since Jan. 1, 199 degrees. Record high temperature for today, 76 degrees in 1976. Record low temperatures for today, 3 degrees in 1903. Relative humidity: Maximum, 89 per cent at 8 a.m; Minimum, 76 per cent at 4 p.m. 24-hour precipitation since Feb. 1, .99 inch. Excess of precipitation since Jan. 1, 3:50 inches. Highest observed wind from the south-southwest at 2:46 p.m. Local Temp., Humidity(TABLE) ime(COLUMN)T.(COLUMN)H. 12 midnight(COLUMN)35(COLUMN)82 1 a.m.(COLUMN)34(COLUMN)85 2 a.m.(COLUMN)34(COLUMN)85 3 a.m.(COLUMN)34(COLUMN)85 4 a.m.(COLUMN)34(COLUMN)85 5 a.m. (COLUMN)85 6 a.m.(COLUMN)34(COLUMN)85 7 a.m.(COLUMN)34(COLUMN)85 8 a.m.(COLUMN)34(COLUMN)89 9 a.m.(COLUMN)34(COLUMN)89 10 a.m.(COLUMN)34(COLUMN)85 11 a.m.(COLUMN)35(COLUMN)85 12 noon(COLUMN)36(COLUMN)82 1 p.m.(COLUMN)38(COLUMN)79 2 p.m.(COLUMN)39(COLUMN)79 3 p.m.(COLUMN)39(COLUMN)79 4 p.m.(COLUMN)40(COLUMN)76 5 p.m.(COLUMN)39(COLUMN)76 6 p.m.(COLUMN)38(COLUMN)79 7 p.m.(COLUMN)38(COLUMN)76(END TABLE) Temperatures ending 7 p.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)30(COLUMN)25 Albuquerque(COLUMN)33(COLUMN)14 Amarillo(COLUMN)27(COLUMN)13 Anchorage(COLUMN)32(COLUMN)26 Asheville(COLUMN)51(COLUMN)29 Atlanta(COLUMN)61(COLUMN)39 Atlanta City(COLUMN)36(COLUMN)22 Austin(COLUMN)55(COLUMN)42 Baltimore(COLUMN)33(COLUMN)24 Billings(COLUMN)13(COLUMN)05 Birmingham(COLUMN)58(COLUMN)30 Bismarck(COLUMN)13(COLUMN)05 Boise(COLUMN)38(COLUMN)21 Boston(COLUMN)44(COLUMN)29 Brownsville(COLUMN)60(COLUMN)52 Buffalo(COLUMN)29(COLUMN)24 Burlington, Vt.(COLUMN)26(COLUMN)37 Casper(COLUMN)18(COLUMN)-03 Charleston,S.C.(COLUMN)48(COLUMN)43 Charleston, W.V.(COLUMN)35(COLUMN)31 Charlotte(COLUMN)43(COLUMN)28 Cheyenne(COLUMN)18(COLUMN)-05 Chicago(COLUMN)15(COLUMN)-01 Cincinnati(COLUMN)30(COLUMN)21 Cleveland(COLUMN)31(COLUMN)13 Columbia, S.C.(COLUMN)43(COLUMN)40 Columbus(COLUMN)29(COLUMN)19 Dal.-Ft. Worth(COLUMN)40(COLUMN)32 Dayton(COLUMN)31(COLUMN)18 Denver(COLUMN)24(COLUMN)07 Des Moines(COLUMN)14(COLUMN)-04 Detroit(COLUMN)03 Duluth(COLUMN)15(COLUMN)00 El Paso(COLUMN)55(COLUMN)27 Fairbanks(COLUMN)11(COLUMN)-08 Fargo(COLUMN)09(COLUMN)-03 Flagstaff(COLUMN)35(COLUMN)04 Great Falls(COLUMN)22(COLUMN)12 Helena(COLUMN)27(COLUMN)02 Honolulu(COLUMN)86(COLUMN)71 Houston(COLUMN)60(COLUMN)44 Indianapolis(COLUMN)27(COLUMN)05 Jackson(COLUMN)75(COLUMN)32 Jacksonville(COLUMN)27(COLUMN)50 Juneau(COLUMN)37(COLUMN)32 Kansas City(COLUMN)21(COLUMN)-04 Las Vegas(COLUMN)54(COLUMN)35 Little Rock(COLUMN)79(COLUMN)30 Los Angles(COLUMN)70(COLUMN)47 Louisville(COLUMN)35(COLUMN)26 Memphis(COLUMN)48(COLUMN)30 Miami Beach(COLUMN)74(COLUMN)67 Midland(COLUMN)58(COLUMN)28 Milwaukee(COLUMN)15(COLUMN)03 Mpls.-St. Paul(COLUMN)17(COLUMN)-05 Nashvilles(COLUMN)43(COLUMN)28 New Orleans(COLUMN)59(COLUMN)38 New York(COLUMN)36(COLUMN)32 Norfolk(COLUMN)38(COLUMN)33 North Platte(COLUMN)10(COLUMN)-19 Oklahoma City(COLUMN)29(COLUMN)20 Omaha(COLUMN)13(COLUMN)-10 Orlando(COLUMN)65(COLUMN)57 Philadelphia(COLUMN)34(COLUMN)25 Phoenix(COLUMN)59(COLUMN)39 Pittsburgh(COLUMN)34(COLUMN)29 Portland, Me.(COLUMN)33(COLUMN)24 Portland, Or.(COLUMN)46(COLUMN)39 Providence(COLUMN)35(COLUMN)21 Relaigh(COLUMN)38(COLUMN)34 Rapid City(COLUMN)12(COLUMN)-09 Reno(COLUMN)40(COLUMN)26 Richmond(COLUMN)41(COLUMN)28 St. Louis(COLUMN)26(COLUMN)08 St. Prbg.-Tampa(COLUMN)65(COLUMN)57 Salt Lake City(COLUMN)35(COLUMN)19 San Antonio(COLUMN)54(COLUMN)48 San Diego(COLUMN)66(COLUMN)52 San Francisco(COLUMN)54(COLUMN)50 San Juan(COLUMN)85(COLUMN)69 St. Ste. Marie(COLUMN)22(COLUMN)09 Seattle(COLUMN)47(COLUMN)40 Shreveport(COLUMN)45(COLUMN)34 Sioux Falls(COLUMN)09(COLUMN)-12 Tulsa(COLUMN)30(COLUMN)20 Washington(COLUMN)41(COLUMN)34 Wichita(COLUMN)23(COLUMN)05(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)T. Aberdeen snow(COLUMN)1 p.m.(COLUMN)30 Amsterdam(COLUMN)haze(COLUMN)1 p.m.(COLUMN)28 Ankara(COLUMN)pt. cldy(COLUMN)3 p.m.(COLUMN)43 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)57 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)63 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)23 Birmingham(COLUMN)smoke(COLUMN)1 p.m.(COLUMN)34 Brussels(COLUMN)clear(COLUMN)1 p.m.(COLUMN)30 Casablanca(COLUMN)clear(COLUMN)noon(COLUMN)77 Copenhagen(COLUMN)snow(COLUMN)1 p.m.(COLUMN)30 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)37 Geneva(COLUMN)rain(COLUMN)1 p.m.(COLUMN)48 Hong Kong(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)54 Lisbon(COLUMN)rain(COLUMN)noon(COLUMN)59 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)37 Madrid(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)61 Malta(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Madrid(COLUMN)Pt. cldy(COLUMN)1 .(COLUMN)79 Moscow(COLUMN)pt. cldy(COLUMN)3 p.m.(COLUMN)7 New Delhi(COLUMN)pt. cldy(COLUMN)5 p.m.(COLUMN)57 Nice(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)50 Oslo(COLUMN)clear(COLUMN)1 p.m.(COLUMN)19 Paris(COLUMN)rain(COLUMN)1 p.m.(COLUMN)30 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)25 Rome(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)61 Saigon(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)82 Sofia(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)37 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)21 Sydney(COLUMN)pt. cldy(COLUMN)10 p.m.(COLUMN)73 Tel Aviv(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)59 Tokyo(COLUMN)clear(COLUMN)9 p.m.(COLUMN)37 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)68 Vienna(COLUMN)haza(COLUMN)1 p.m.(COLUMN)30 Warsaw(COLUMN)clear(COLUMN)10 p.m.(COLUMN)23(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)cloudy(COLUMN)86(COLUMN)73 Barbados(COLUMN)cloudy(COLUMN)82(COLUMN)73 Bermuda(COLUMN)cloudy(COLUMN)45(COLUMN)57 Calgary(COLUMN)clear(COLUMN)28(COLUMN)00 Edmonton(COLUMN)clear(COLUMN)19(COLUMN)-04 Havana(COLUMN)cloudy(COLUMN)82(COLUMN)70 Kingston(COLUMN)pt. cldy(COLUMN)87(COLUMN)73 Montego Bay(COLUMN)pt. cldy(COLUMN)84(COLUMN)68 Mexico City(COLUMN)cloudy(COLUMN)75(COLUMN)54 Monterrey(COLUMN)clear(COLUMN)64(COLUMN)54 Nassau(COLUMN)cloudy(COLUMN)79(COLUMN)68 Ottawa(COLUMN)snow(COLUMN)23(COLUMN)14 Regina(COLUMN)fg(COLUMN)09(COLUMN)-03 St. Kitts(COLUMN)pt. cldy.(COLUMN)84(COLUMN)82 Tornoto(COLUMN)pt. cldy(COLUMN)27(COLUMN)12 Vancouver(COLUMN)cloudy(COLUMN)46(COLUMN)34 Veracruz(COLUMN)cloudy(COLUMN)73(COLUMN)66 Wimipeg(COLUMN)snow(COLUMN)10(COLUMN)03(END TABLE)