Washington: Today - cloudy, high in mid 30s, low in upper 20s. Chance of precipitation is 20 per cent today, 50 per cent tonight. Friday - Chance of rain, high in mid 40s.

Maryland and Virginia: Today - Cloudy, high in the 20s and mid 30s, low in the teens to mid 30s. Friday - Chance of rain, high in upper 30s or low 40s.

Extended Area Forecast for Friday through Sunday: Snow ending early Friday then fair over weekend. Highs will range in the 20s and 30s, lows in the teens to mid 20s. Normal Washington temperatures for this period are a high of 45 and a low of 30.

West Virginia: Today - Mostly cloudy, lows near zero, highs in 20s. Friday - Snow, highs in low 10s.

The National Weather Forecast for Today: Snow will extend from the Virginias across the south and central Appalachians, the Tennessee and Ohio Valleys, the Great Lakes and northern half of the Mississippi Valley, and the northern half of the Plains into the northern Rockies. Rain will continue along the Pacific northwest coast. Temperatures will be very cold over the northern Plains and upper Missouri Valley, and cold from the Atlantic Coast through the northern two-thirds of the Mississippi Valley, across the Plains from north Texas to the Canadian border, over the northern half of the Rockies and the northern half of the Pacific Coast. Temperatures will be mild from the southwest Texas to the southern California coast and cool elsewhere.

Almanac Data for today - Sun rises 7:14 a.m., sets 4:46 p.m.; Moon rises 3:31 a.m., sets 3:27 p.m.; Tides: high 5:18 a.m. and 5:52 p.m., low 12:06 p.m. and 12:50 a.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), 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 2-3 p.m. period was 10 for the pollutant, photochemical oxidants. Index values between 0 and 24 indicate good 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 remain good.

The National Weather Service forecasts the Potomac River stand at Little Falls should fall to 4.8 feet today.

Washington data at 7 p.m. (EDT) yesterday.Highest temperature since 7 a.m. yesterday, 34 degrees at 12:35 p.m. Lowest temperature since midnight, 22 degrees at a 6:30 a.m. Excess of temperature since Dec. 1, 23 degrees. Excess of temperature since Jan. 1, 599 degrees. Record high temperature for today, 72 degrees in 1966. Record low temperature for today, 8 degrees in 1882. Relative humidity: Maximum, 46 per cent at 5 a.m.; Minimum, 35 per cent at 2 p.m. 24 hour precipitation, 0 inches. Deficiency of precipitation since Dec. 1, 31 inches. Deficiency of Precipitation since Jan. 1, 4,88 inches. Highest observed wind since 7 a.m. 23 miles per hour from the N.W. at 3 p.m. Peak bust since 8 a.m., 40 miles per hour from the N.W. at 1:41 p.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnight(COLUMN)34(COLUMN)42 1 a.m.(COLUMN)33(COLUMN)40 2 a.m.(COLUMN)31(COLUMN)41 3 a.m.(COLUMN)30(COLUMN)41 4 a.m.(COLUMN)27(COLUMN)44 5 a.m.(COLUMN)25(COLUMN)46 6 a.m.(COLUMN)23(COLUMN)46 7 a.m.(COLUMN)23(COLUMN)46 8 a.m.(COLUMN)23(COLUMN)46 9 a.m.(COLUMN)27(COLUMN)44 10 a.m.(COLUMN)30(COLUMN)39 11 a.m.(COLUMN)31(COLUMN)38 12 noon(COLUMN)32(COLUMN)39 1 p.m.(COLUMN)32(COLUMN)36 2 p.m.(COLUMN)33(COLUMN)35 3 p.m.(COLUMN)33(COLUMN)36 4 p.m.(COLUMN)32(COLUMN)36 5 p.m.(COLUMN)30(COLUMN)41 6 p.m.(COLUMN)29(COLUMN)43 7 p.m.(COLUMN)29(COLUMN)43(END TABLE) Temperatures ending 8 a.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)30(COLUMN)20 Albuquerque(COLUMN)59(COLUMN)28 Amarillo(COLUMN)40(COLUMN)30 Anchorage(COLUMN)10(COLUMN)-7 Ashville(COLUMN)44(COLUMN) 5 Atlanta(COLUMN)47(COLUMN)15 Atlantic City(COLUMN)54(COLUMN)26 Austin(COLUMN)49(COLUMN)32 Baltimore(COLUMN)42(COLUMN)20 Billings(COLUMN) 5(COLUMN) 2 Birmingham(COLUMN)49(COLUMN)19 Bismarck(COLUMN)-2(COLUMN)-8 Boise(COLUMN)48(COLUMN)39 Boston(COLUMN)41(COLUMN)28 Brownsville(COLUMN)71(COLUMN)46 Buffalo(COLUMN)26(COLUMN)17 Burlington(COLUMN)26(COLUMN)20 Casper(COLUMN)40(COLUMN)26 Charleston, S.C.(COLUMN)67(COLUMN)30 Charleston, W.V.(COLUMN)37(COLUMN) 4 Charlotte(COLUMN)53(COLUMN)19 Cheyenne(COLUMN)42(COLUMN)25 Chicago(COLUMN)76(COLUMN)01 Cincinnati(COLUMN)31(COLUMN)-3 Cleveland(COLUMN)29(COLUMN) 7 Columbia, S.C.(COLUMN)58(COLUMN)23 Columbia, S.C.(COLUMN)58(COLUMN)23 Dal. Ft. Worth(COLUMN)41(COLUMN)26 Dayton(COLUMN)28(COLUMN)-1 Denver(COLUMN)54(COLUMN)35 Dos Maines(COLUMN) 9(COLUMN) 4 Detroit(COLUMN)27(COLUMN) 9 Duluth(COLUMN)12(COLUMN) -5 El Paso(COLUMN)62(COLUMN)34 Fairbanks(COLUMN)-21(COLUMN)-34 Fargo(COLUMN) 1(COLUMN)-15 Flagstaff(COLUMN)62(COLUMN)24 Great Falls(COLUMN) 3(COLUMN)-11 Hartford(COLUMN)31(COLUMN)24 Helena(COLUMN)19(COLUMN)10 Honolulu(COLUMN)84(COLUMN)70 Houston(COLUMN)54(COLUMN)40 Indianapolis(COLUMN)30(COLUMN)-2 Jackson, Miss.(COLUMN)46(COLUMN)22 Jacksonville(COLUMN)73(COLUMN)31 Junean(COLUMN)11(COLUMN) 6 Kansas City(COLUMN)13(COLUMN)11 Las Vegas(COLUMN)72(COLUMN)41 Little Rock(COLUMN)34(COLUMN)15 Los Angeles(COLUMN)34(COLUMN) 5 Memphis(COLUMN)36(COLUMN)23 Miami Beach(COLUMN)67(COLUMN)50 Midland-Odessa(COLUMN)48(COLUMN)29 Milwaudee(COLUMN)27(COLUMN) 2 Mpts-St. Paul(COLUMN) 7(COLUMN)-10 Nashville(COLUMN)37(COLUMN)10 New Orleans(COLUMN)61(COLUMN)33 New York(COLUMN)40(COLUMN)36 Norfolk, Va.(COLUMN)64(COLUMN)30 North Platte(COLUMN)17(COLUMN) 5 Oklahoma City(COLUMN)29(COLUMN)21 Omaha(COLUMN)12(COLUMN) 9 Orlando(COLUMN)77(COLUMN)38 Philadelphia(COLUMN)39(COLUMN)22 Phoenix(COLUMN)79(COLUMN)46 Pittsburgh(COLUMN)34(COLUMN) 7 Portland, Me.(COLUMN)24(COLUMN)21 Portland, Ore.(COLUMN)54(COLUMN)41 Providence(COLUMN)40(COLUMN)24 Raleigh(COLUMN)58(COLUMN)20 Rapid City(COLUMN)11(COLUMN) 5 Reno(COLUMN)65(COLUMN)36 Richmond(COLUMN)57(COLUMN)24 St. Louis(COLUMN)18(COLUMN) 5 St. Prog. Tampa(COLUMN)74(COLUMN)35 Salt Lake City(COLUMN)52(COLUMN)48 San Antonio(COLUMN)53(COLUMN)30 San Diego(COLUMN)72(COLUMN)57 San Francisco(COLUMN)64(COLUMN)55 San Juan(COLUMN)87(COLUMN)74 St. Ste. Marie(COLUMN)19(COLUMN)11 Seattle(COLUMN)50(COLUMN)39 Shreveport(COLUMN)45(COLUMN)21 Sioux Falls(COLUMN) 5(COLUMN) 1 Spokane(COLUMN)41(COLUMN)32 Syracuse(COLUMN)31(COLUMN)20 Topeka(COLUMN)19(COLUMN)14 Tucson(COLUMN)77(COLUMN)44 Tulsa(COLUMN)28(COLUMN)18 Washington(COLUMN)45(COLUMN)22 Wichita(COLUMN)24(COLUMN)17(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)43 Amsterdam(COLUMN)haze(COLUMN) 1 p.m.(COLUMN)28 Ankara(COLUMN)clear(COLUMN) 3 p.m.(COLUMN)30 Athens(COLUMN)rain(COLUMN) 2 p.m.(COLUMN)50 Auckland(COLUMN)pt. cldy.(COLUMN)mdnt.(COLUMN)63 Berlin(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN) Birmingham(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)39 Brussels(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)37 Casablanca(COLUMN)cloudy(COLUMN)noon(COLUMN)66 Copenhagen(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)34 Dublin(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)43 Geneva(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)36 Hong Kong(COLUMN)clear(COLUMN) 8 p.m.(COLUMN)66 Lisbon(COLUMN)rain(COLUMN)noon(COLUMN)61 London(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)39 Madrid(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)46 Malta(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)63 Manita(COLUMN)clear(COLUMN) 8 p.m.(COLUMN)19 Moscow(COLUMN)cloudy(COLUMN) 3 p.m.(COLUMN)12 New Delhi(COLUMN)clear(COLUMN) 5 p.m.(COLUMN)70 Nice(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)43 Oslo(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)36 Paris(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)48 Peking(COLUMN)cloudy(COLUMN) 8 p.m.(COLUMN)34 Rome(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)52 Saigon(COLUMN)clear(COLUMN) 8 p.m.(COLUMN)79 Sofia(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)30 Stockholm(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)27 Sydney(COLUMN)cloudy(COLUMN)10 p.m.(COLUMN)66 Tel Aviv(COLUMN)pt. cldy.(COLUMN) 2 p.m.(COLUMN)66 Tokyo(COLUMN)clear(COLUMN) 9 p.m.(COLUMN)50 Tunis(COLUMN)pt. cldy.(COLUMN) 1 p.m.(COLUMN)64 Vienna(COLUMN)snow(COLUMN) 1 p.m.(COLUMN) Warsaw(COLUMN)snow(COLUMN) 1 p.m.(COLUMN)28(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)clear(COLUMN)90(COLUMN)75 Barbados(COLUMN)pt. cldy.(COLUMN)85(COLUMN)78 Bermuda(COLUMN)pt. cldy.(COLUMN)75(COLUMN)67 Culiacan(COLUMN)clear(COLUMN)70(COLUMN)54 Edmonton(COLUMN)snow(COLUMN)-18(COLUMN)-22 Havana(COLUMN)cloudy(COLUMN)88(COLUMN)64(KEY OFF)ingston clear(COLUMN)90(COLUMN)75 Montego Bay(COLUMN)cloudy(COLUMN)86(COLUMN)72 Mexico City(COLUMN)haze(COLUMN)72(COLUMN)45 Monterry(COLUMN)haze(COLUMN)59(COLUMN)48 Montreal(COLUMN)snow(COLUMN)23(COLUMN)19 Nassau(COLUMN)clear(COLUMN)86(COLUMN)72 Ottawa(COLUMN)snow(COLUMN)21(COLUMN)18 Regina(COLUMN)snow(COLUMN)-13(COLUMN)-36 St. KItts(COLUMN)cloudy(COLUMN)85(COLUMN)75 St. Thomas(COLUMN)clear(COLUMN)86(COLUMN)80 Toronto(COLUMN)cloudy(COLUMN)19(COLUMN)16 Vancouver(COLUMN)rain(COLUMN)46(COLUMN)H32 Veracruz(COLUMN)clear(COLUMN)82(COLUMN)72 Winnipeg(COLUMN)clear(COLUMN) 0(COLUMN)-13(END TABLE)(KEYWORD)