Washington: Today -- Increasing cloudiness, high in the 40s, low near 30. The chance of precipitation is 10 percent today increasing to 40 percent tonight. Winds will be from the northwest at 5 to 10 mph. Sunday -- Chance of occasional rain or snow, high in the 40s.

Maryland and Virginia: Today -- Increasing cloudiness with a chance of occasional rain or snow, highs in the 30s and 40s, lows mostly in the 20s. Sunday -- Chance of occasional rain or snow, highs from the 30s to the low 40s.

West Virginia: Today -- Occasional light snow, highs from the mid 20s to the low 30s, low near 20. Sunday -- Partial clearing, highs from the upper 20s to the mid 30s.

Extended Area Forecast for Monday through Wednesday -- Chance of flurries Monday, partly cloudy Tuesday and Wednesday. Highs will average from the 30s to the low 40s, lows in the 20s. Normal Washington temperatures are a high of 44 and a low of 27.

Lower Potomac and Chesapeake Bay -- Chance of occasional rain or snow tonight. Visibility will be 5 miles or more diminishing to less than 3 miles in precipitation. Winds will be from the northwest at 10 to 18 knots. Waves will subside to near 2 feet.

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 3 p.m. period was 21 for the pollutant, photochemical oxidants. Index valuees 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 in the good range.

The national Weather Service forecasts the Potomac River Stage at Little Falls should fall from 8.7 feet to 7.5 feet today.

The national Weather Forecast for today -- Snowshowers are forecast for northern New England across the Great Lakes, the Appalachian Mountains, the Ohio Valley, the upper half of the Mississippi Valley, the plains, from southern Nebraska into the Panhandle and the northern portion of Texas. Rain will be spread from central Texas across the Gulf Coastal states, the Tennessee Valley and the Atlantic Coast states from South Carolina across Florida. Rain will also fall along the Washington and Oregon coasts, changing to snow in the mountains of eastern Washington. Temperatures will be seasonably mild over the northern two thirds of New England. Very cold temperatures will extend from South Dakota through eastern Colorado, and from western Texas across the Plains to Missouri, Arkansas and northern Louisiana. Elsewhere, temperatures across the nation will remain cool or cold.

The Nation Yesterday: Precipitation continued to fall across wide areas of the United States. Snow fall decreased in portions of the plateau region, but persisted from the southern and central Rockies across that portion of the Plains states from the Texas panhandle and Oklahoma to South Dakota, and into the Mississippi Valley. Rain fell from the lower Mississippi Valley into portions of the Florida panhandle, with a thunderstorm reported in southwestern Mississippi. Snow also fell in the Pacific Northwest, with light rain reported near the coastal areas. More snow was reported in the central Geat Lakes and upper Ohio Valley areas. Freezing drizzle was spotted in parts of Ohio and in the extreme lower Great Lakes area. Light rain extended from New York state into New England, with snow falling in portions of central and norther New England. The National Weather Forecast for today -- Snow is forecast from the Pacific Northwest into the northern Rockies and the Great Basin. Snow will also fall from exfreme eastern portions of the northern and central Plains through the Great Lakes and the Ohio Valley. Rain is also likely from eastern Texas across the lower Missippi Valley to the East Coast from Florida through Virginia, and in portions of the Northeast. Very cold temperatures will cover most of the Plains and portions of the lower Mississippi Valley, with cold readings prevailing across the remainder of the nation.

Washington data for yesterday: Highest temperature since midnight yesterday, 44 degrees at 2:30 p.m. Lowest temperature since midnight, 32 degrees at 4:30 a.m. Deficiency of temperature since Jan. 1, 15 degrees. Record high temperature for today, 75 degrees in 1974. Record low temperature for today, 6 degrees in 1935. Relative humidity: miximum, 59 percent at 5 a.m.; minimum, 49 percent at 1 p.m. 24 hour precipitation, trace. Excess of precipitation since Jan. 1, 4.03 inches. Highest observed wind since 7 a.m., 23 miles per hour from the northwest at 1:53 p.m. Peak gust since 7 a.m., 35 miles per hour from the northwest at 1:16 p.m.

Almanac Data for today: The sun rises 7:19 a.m., sets 5:22 p.m.; The moon rises 6:29 a.m., sets 5:02 p.m. Tides: high 6:39 a.m. and 6:55 p.m., low 12:44 a.m. and 12:41 p.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from the hours above: Annapolis (3 1/4), Bloody Point Light-house (4 1/2), Deale, Md. (4 1/2), Colonial Beach (5 1/2), Norfolk (1), Virginia Beach (3/4), Solomons Island (6 1/4), Point Lookout (7). Local Temp., Humidity (TABLE) Time(COLUMN)T(COLUMN)H 12 imd.(COLUMN)33(COLUMN)54 1 a.m.(COLUMN)33(COLUMN)54 2 a.m.(COLUMN)33(COLUMN)51 3 a.m.(COLUMN)33(COLUMN)54 4 a.m.(COLUMN)33(COLUMN)56 5 a.m.(COLUMN)33(COLUMN)59 9 a.m.(COLUMN)35(COLUMN)56 7 a.m.(COLUMN)34(COLUMN)54 8 a.m.(COLUMN)35(COLUMN)56 6 a.m.(COLUMN)33(COLUMN)59 10 a.m.(COLUMN)37(COLUMN)52 11 a.m.(COLUMN)40(COLUMN)50 12 noon(COLUMN)41(COLUMN)53 1 p.m.(COLUMN)43(COLUMN)49 2 p.m.(COLUMN)42(COLUMN)53 3 p.m.(COLUMN)44(COLUMN)49 4 p.m.(COLUMN)44(COLUMN)49 5 p.m.(COLUMN)42(COLUMN)51 6 p.m.(COLUMN)40(COLUMN)53 7 p.m.(COLUMN)38(COLUMN)55 8 p.m.(COLUMN)37(COLUMN)57 9 p.m.(COLUMN)36(COLUMN)57 10 p.m.(COLUMN)35(COLUMN)59 11 p.m.(COLUMN)34(COLUMN)64(END TABLE) Temperatures ending 7 p.m. (EST) yesterday: (TABLE) City(COLUMN)L(COLUMN)H Albany(COLUMN)33(COLUMN)37 Albuquerque(COLUMN)27(COLUMN)38 Amarillo(COLUMN)19(COLUMN)25 Anchorage(COLUMN)16(COLUMN)29 Asheville(COLUMN)24(COLUMN)45 Atlanta(COLUMN)27(COLUMN)54 Atlantic City(COLUMN)30(COLUMN)42 Austin(COLUMN)45(COLUMN)52 Baltimore(COLUMN)32(COLUMN)45 Billings(COLUMN)6(COLUMN)12 Birmingham(COLUMN)29(COLUMN)51 Bismarck(COLUMN)-1(COLUMN)8 Boise(COLUMN)-8(COLUMN)23 Boston(COLUMN)34(COLUMN)37 Brownsville(COLUMN)65(COLUMN)84 Buffalo(COLUMN)33(COLUMN)34 Burlington, Vt.(COLUMN)33(COLUMN)35 Casper(COLUMN)-1(COLUMN)14 Charleston, S.C.(COLUMN)32(COLUMN)52 Charleston, W.Va.(COLUMN)19(COLUMN)26 Charlotte(COLUMN)19(COLUMN)51 Cheyenne(COLUMN)3(COLUMN)18 Chicago(COLUMN)7(COLUMN)27 Cincinnati(COLUMN)14(COLUMN)25 Cleveland(COLUMN)26(COLUMN)30 Columbia, S.C.(COLUMN)25(COLUMN)61 Columbus(COLUMN)18(COLUMN)27 Dal. Ft. Worth(COLUMN)35(COLUMN)40 Dayton(COLUMN)15(COLUMN)29 Denver(COLUMN)0(COLUMN)17 Des Moines(COLUMN)16(COLUMN)21 Duluth(COLUMN)1(COLUMN)26 El Paso(COLUMN)36(COLUMN)47 Evansville(COLUMN)11(COLUMN)32 Fairbanks(COLUMN)-13(COLUMN)-2 Fargo(COLUMN)9(COLUMN)14 Flagstaff(COLUMN)17(COLUMN)22 Great Falls(COLUMN)-5(COLUMN)21 Hartford(COLUMN)35(COLUMN)37 Helena(COLUMN)-13(COLUMN)8 Honolulu(COLUMN)64(COLUMN)79 Houston(COLUMN)50(COLUMN)56 Indianapolis(COLUMN)5(COLUMN)25 Jackson(COLUMN)33(COLUMN)40 Jacksonville(COLUMN)33(COLUMN)63 Juneau(COLUMN)32(COLUMN)34 Kansas City(COLUMN)29(COLUMN)32 Las Vegas(COLUMN)32(COLUMN)49 Little Rock(COLUMN)28(COLUMN)32 Los Angeles(COLUMN)38(COLUMN)60 Louisville(COLUMN)18(COLUMN)32 Memphis(COLUMN)32(COLUMN)39 Miami Beach(COLUMN)53(COLUMN)68 Midland(COLUMN)35(COLUMN)40 Milwaukee(COLUMN)12(COLUMN)24 Mpls-St. Paul(COLUMN)13(COLUMN)26 Nashville(COLUMN)25(COLUMN)40 New Orleans(COLUMN)43(COLUMN)49 New York(COLUMN)36(COLUMN)44 Norfolk(COLUMN)32(COLUMN)47 North Platte(COLUMN)8(COLUMN)16 Oklahoma City(COLUMN)29(COLUMN)33 Omaha(COLUMN)19(COLUMN)24 Orlando(COLUMN)42(COLUMN)65 Philadelphia(COLUMN)32(COLUMN)43 Phoenix(COLUMN)40(COLUMN)55 Pittsburgh(COLUMN)21(COLUMN)27 Portland, Me.(COLUMN)33(COLUMN)35 Portland, Ore.(COLUMN)26(COLUMN)34 Providence(COLUMN)32(COLUMN)36 Raleigh(COLUMN)32(COLUMN)50 Rapid City(COLUMN)8(COLUMN)14 Reno(COLUMN)4(COLUMN)32 Richmond(COLUMN)30(COLUMN)51 St. Louis(COLUMN)20(COLUMN)30 St. Prbg.-Tampa(COLUMN)44(COLUMN)62 Salt Lake City(COLUMN)12(COLUMN)28 San Antonio(COLUMN)53(COLUMN)67 San Diego(COLUMN)48(COLUMN)59 San Francisco(COLUMN)47(COLUMN)55 San Juan(COLUMN)71(COLUMN)89 St. Ste. Marie(COLUMN)21(COLUMN)30 Seattle(COLUMN)32(COLUMN)39 Shreveport(COLUMN)36(COLUMN)41 Sioux Falls(COLUMN)16(COLUMN)20 Spokane(COLUMN)10(COLUMN)17 Syracuse(COLUMN)35(COLUMN)38 Topeka(COLUMN)28(COLUMN)34 Tucson(COLUMN)36(COLUMN)49 Tulsa(COLUMN)31(COLUMN)35 Washington(COLUMN)32(COLUMN)44 Wichita(COLUMN)23(COLUMN)25(END TABLE) Temperatures Abroad Yesterday (TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)28 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)36 Athens(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)61 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)32 Brussels(COLUMN)snow(COLUMN)1 p.m.(COLUMN)33 Cairo(COLUMN)clear(COLUMN)5 p.m.(COLUMN)70 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)30 Geneva(COLUMN)rain(COLUMN)1 p.m.(COLUMN)39 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)70 Jerusalem(COLUMN)clear(COLUMN)2 p.m.(COLUMN)57 Lisbon(COLUMN)rain(COLUMN)1 p.m.(COLUMN)61 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)43 Madrid(COLUMN)rain(COLUMN)3 p.m.(COLUMN)48 Manila(COLUMN)clear(COLUMN)8 p.m.(COLUMN)88 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)23 New Delhi(COLUMN)clear(COLUMN)5 p.m.(COLUMN)73 Oslo(COLUMN)clear(COLUMN)1 p.m.(COLUMN)12 Paris(COLUMN)clear(COLUMN)1 p.m.(COLUMN)37 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Stockholm(COLUMN)snow(COLUMN)1 p.m.(COLUMN)23 Tokyo(COLUMN)clear(COLUMN)9 p.m.(COLUMN)61 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)30(END TABLE) Temperatures (Western Hemisphere) (TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)fair(COLUMN)86(COLUMN)69 Barbados(COLUMN)fair(COLUMN)82(COLUMN)75 Bermuda(COLUMN)pt. cldy(COLUMN)74(COLUMN)67 Bogota(COLUMN)cloudy(COLUMN)61(COLUMN)46 Culiacan(COLUMN)pt. cldy(COLUMN)75(COLUMN)61 Havana(COLUMN)pt. cldy(COLUMN)71(COLUMN)59 Kingston(COLUMN)fair(COLUMN)85(COLUMN)72 Montego Bay(COLUMN)pt. cldy(COLUMN)82(COLUMN)72 Mexico City(COLUMN)hazy(COLUMN)72(COLUMN)52 Monterrey(COLUMN)pt. cldy(COLUMN)68(COLUMN)54 Montreal(COLUMN)snow(COLUMN)43(COLUMN)25 Nassau(COLUMN)cloudy(COLUMN)77(COLUMN)55 St. Kitts(COLUMN)fair(COLUMN)82(COLUMN)70 Toronto(COLUMN)rain(COLUMN)34(COLUMN)30 Vancouver(COLUMN)rain(COLUMN)41(COLUMN)30 Veracruz(COLUMN)pt. cldy(COLUMN)85(COLUMN)61(END TABLE)