Washington: Today - Partly cloudy, high in the mid 30s, low in the mid 20s. Snow is possible tonight. The chance of precipitation is near zero today and 30 percent tonight. Monday - Snow, high in mid 30s.

Maryland and Virginia: Today - Partly cloudy, high in the 30s, lows in the 20s. Monday - Snow, highs in the 30s.

Lower Potomac and Chesapeake Bay: Today - Partly cloudy, chance of snow late tonight. Visibility will be more than 5 miles today, less than 3 miles tonight. Wind will be from the north at from 10 to 15 knots today, becoming variable tonight. Waves in unprotected waters will be restricted by ice.

Extended Area Forecast for Tuesday through Saturday: Snow will end by Tuesday, than partly cloudy through the period. Highs will be in the 30s, lows in the 20s. Temperatures will be near 10 degrees colder in the mountains. Normal Washington temperatures for the period are a high of 46 and a low of 28.

West Virginia: Today - Partly cloudy, highs from the upper 20 to the upper 30s, lows in the 20s. Monday - Snow, highs in the 30s.

The Nation Yesterday: The winter storm over the Rockies spread snow and freezing drizzle across the central Plains. Snow fell from Montana and Idaho through the New Mexico and central Arizona mountains into the northern Plains. A low pressure center in Colorado was reorganizing and strengthening over the south central Plains and was expected to move eastward. The snowfall from this storm was heavy over the mountains. Heavy snow warnings were posted for eastern Colorado and the mountains, western Kansas and south-western Nebraska. Gusty wind causing blowing and drifting snow were the worst over western Dakotas and Montana. Near blizzard conditions were expected in eastern Montana.

The National Weather Forecast for today: Rain will extend from western Washington through central California, while snows will cover the mountains and extend across the intermountain region. Snow will fall over most of the Rockies reaching through South Dakota, the central Plains and Oklahoma as well as over the mid-Mississippi Valley, Indiana and southwestern Ohio. Snow will be locally heavy over the central Plains. Rain with scattered thunderstorms will cover the eastern half of Texas, in addition to Louisiana and Mississippi. Rain will extend from Arkansas and Tennessee through Kentucky into West Virginia. Snow will fall from western New York into northern Maine. The rest of the nation will have partly cloudy skies. It will be very cold over eastern Montana and much colder over Wyoming and western parts of the Great Plains. It will be quite cold from Arizona through Western Texas, Oklahoma and the eastern Great Plains.

Almanac Data for today - Sun rises 7:03 a.m., sets 5:42 p.m.; moon rises 9:55 a.m., sets 11:23 p.m.; Tides: high 11:43 a.m., low 6:02 a.m. and 6:33 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 9 a.m. to 10 a.m. period was 22 for the pollutant, photochemical oxidants. Index values between zero and 24 indicate good air quality. When the index exceeds 100 the air is considered very unhealthy and individuals with lung, heart and eve ailments are urged to restrict their activity. The forecast for today indicates that the air quality will deteriorate.

The National Weather Service forecasts the Potomac River stage at Little Falls should be near 3.7 feet today.

Washington data at 7 p.m. (EST) yesterday: since 7 a.m. yesterday, 40 degrees at 3:45 p.m. Lowest temperature since midnight, 20 degrees at 6:20 a.m. Deficiency of temperature since Feb. 1, 96 degrees. Deficiency of temperature since Jan. 1, 186 degrees. Record high temperature for today, 67 degrees in 1898. Record low temperature for today, 4 degrees in 1899. Relative humidity: Maximum, 57 per cent at 7 a.m.; Minimum, 25 per cent at 2 p.m. Deficiency of precipitation since Feb. 1, .64 Excess of precipitation since Jan. 1, 3.85 inches. Highest observed wind since 7 a.m. 20 miles per hour from the west at 2:53 p.m. Peak gust since of a.m. 26 miles per hour from the northwest at 11:15 a.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnight(COLUMN)26(COLUMN)50 1 a.m.(COLUMN)26(COLUMN)50 2 a.m.(COLUMN)26(COLUMN)48 3 a.m.(COLUMN)25(COLUMN)50 4 a.m.(COLUMN)23(COLUMN)52 5 a.m.(COLUMN)23(COLUMN)55 6 a.m.(COLUMN)(COLUMN) 7 a.m.(COLUMN)22(COLUMN)57 8 a.m.(COLUMN)23(COLUMN) 9 a.m.(COLUMN)28(COLUMN)30 10 a.m.(COLUMN)31(COLUMN)36 11 a.m.(COLUMN)33(COLUMN)32 12 noon(COLUMN)35(COLUMN)27 1 p.m.(COLUMN)37(COLUMN)28 2 p.m.(COLUMN)38(COLUMN)25 3 p.m.(COLUMN)39(COLUMN)27 4 p.m.(COLUMN)40(COLUMN)26 5 p.m.(COLUMN)39(COLUMN)29 6 p.m.(COLUMN)37(COLUMN)28 7 p.m.(COLUMN)36(COLUMN)28 8 p.m.(COLUMN)35(COLUMN)29 9 p.m.(COLUMN)34(COLUMN)30 10 p.m.(COLUMN)32(COLUMN)33 11 p.m.(COLUMN)32(COLUMN)33(END TABLE) Temperatures ending 8 p.m. (EST) yesterday:(TABLE) City(COLUMN)L.(COLUMN)H. Albany(COLUMN)zero(COLUMN)33 Albuquerque(COLUMN)36(COLUMN)50 Amarillo(COLUMN)25(COLUMN)35 Anchorage(COLUMN)19(COLUMN)29 Asheville(COLUMN)20(COLUMN)49 Atlanta(COLUMN)27(COLUMN)58 Atlantic City(COLUMN)19(COLUMN)32 Austin(COLUMN)34(COLUMN)54 Baltimore(COLUMN)14(COLUMN)35 Billings(COLUMN) 9(COLUMN)10 Birmingham(COLUMN)21(COLUMN)54 Bismarck(COLUMN) 7(COLUMN)12 Boise(COLUMN)32(COLUMN)34 Boston(COLUMN)11(COLUMN)28 Brownsville(COLUMN)51(COLUMN)75 Buffalo(COLUMN)12(COLUMN)19 Burlington(COLUMN)13(COLUMN)20 Casper(COLUMN)12(COLUMN)14 Charleston, S.C.(COLUMN)34(COLUMN)48 Charleston, W.Va.(COLUMN) 5(COLUMN)30 Charlotte(COLUMN)21(COLUMN)51 Cheyenne(COLUMN)15(COLUMN)25 Chicago(COLUMN) 2(COLUMN)30 Cincinnati(COLUMN) 2(COLUMN)27 Cleveland(COLUMN) 3(COLUMN)28 Columbia, S.C.(COLUMN)19(COLUMN)55 Dallas-Ft. Worth(COLUMN)29(COLUMN)35 Dayton(COLUMN) 3(COLUMN)27 Denver(COLUMN)21(COLUMN)27 Des Monies(COLUMN)13(COLUMN)26 Detroit(COLUMN) 4(COLUMN)31 Duluth(COLUMN) 3(COLUMN)23 El Paso(COLUMN)45(COLUMN)57 Fairbanks(COLUMN)18(COLUMN) 1 Fargo(COLUMN) 1(COLUMN) 6 Flagstaff(COLUMN)20(COLUMN)32 Great Falls(COLUMN) 7(COLUMN) 9 Hartford(COLUMN) 4(COLUMN)29 Helena(COLUMN)12(COLUMN)13 Honolulu(COLUMN)65(COLUMN)84 Houston(COLUMN)38(COLUMN)51 Indianapolis(COLUMN) 2(COLUMN)27 Jackson, Miss.(COLUMN)24(COLUMN)60 Jacksonville(COLUMN)30(COLUMN)64 Juneau(COLUMN)35(COLUMN)34 Kansas City(COLUMN)28(COLUMN)35 Las Vegas(COLUMN)37(COLUMN)50 Little Rock(COLUMN)21(COLUMN)43 Los Angeles(COLUMN)43(COLUMN)59 Louisville(COLUMN)10(COLUMN)32 Memphis(COLUMN)24(COLUMN)52 Miami Beach(COLUMN)46(COLUMN)66 Midland-Odessa(COLUMN)36(COLUMN)60 Milwaukee(COLUMN)13(COLUMN)27 Mpls.-St. Paul(COLUMN)10(COLUMN)26 Nashville(COLUMN)21(COLUMN)42 New Orleans(COLUMN)30(COLUMN)57 New York(COLUMN)17(COLUMN)34 Norfolk(COLUMN)28(COLUMN)41 North Platte(COLUMN)17(COLUMN)22 Oklahoma City(COLUMN)27(COLUMN)34 Omaha(COLUMN)22(COLUMN)29 Orlando(COLUMN)36(COLUMN)67 Philadelphia(COLUMN)12(COLUMN)31 Phoenix(COLUMN)48(COLUMN)60 Pittsburgh(COLUMN) 8(COLUMN)30 Portland, Me.(COLUMN)10(COLUMN)28 Portland, Oreg.(COLUMN)32(COLUMN)44 Providence(COLUMN)zero(COLUMN)27 Raleigh(COLUMN)14(COLUMN)47 Rapid City(COLUMN)14(COLUMN)16 Reno(COLUMN)22(COLUMN)36 Richmond(COLUMN)13(COLUMN)44 St. Louis(COLUMN)11(COLUMN)29 St. Prbg.-Tampa(COLUMN)37(COLUMN)63 Salt Lake City(COLUMN)36(COLUMN)46 San Antonio(COLUMN)35(COLUMN)56 San Diego(COLUMN)53(COLUMN)60 San Francisco(COLUMN)47(COLUMN)55 San Juan(COLUMN)73(COLUMN)83 St. Ste. Marie(COLUMN) 5(COLUMN)20 Seattle(COLUMN)36(COLUMN)46 Shreveport(COLUMN)22(COLUMN)58 Sioux Falls(COLUMN)19(COLUMN)23Spokane 30(COLUMN)32 Syracuse(COLUMN)32(COLUMN)26 Topeka(COLUMN)29(COLUMN)37 Tucson(COLUMN)40(COLUMN)55 Tulsa(COLUMN)28(COLUMN)40 Washington(COLUMN)20(COLUMN)40(END TABLE) Temperature (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)low Acapuloco(COLUMN) clear(COLUMN)86(COLUMN)68 Bermuda(COLUMN) cloudy(COLUMN)65(COLUMN)59 Bogota(COLUMN)pt. cldy(COLUMN)70(COLUMN)40 Calgary(COLUMN) show(COLUMN)10(COLUMN) 3 Culiacan(COLUMN) fair(COLUMN)82(COLUMN)70 Edmonton(COLUMN) clear(COLUMN)12(COLUMN)17 Havana(COLUMN)pt. cldy(COLUMN)68(COLUMN)61 Kingston(COLUMN) fair(COLUMN)90(COLUMN)68 Montego Bay(COLUMN) fair(COLUMN)82(COLUMN)71 mexico City(COLUMN)fair(COLUMN)75(COLUMN)48 Monterrey(COLUMN)pt. cldy(COLUMN)47(COLUMN)42 Montreal(COLUMN) snow(COLUMN)14(COLUMN) 3 Nassau(COLUMN) fair(COLUMN)70(COLUMN)62 Ottawa(COLUMN) clear(COLUMN)16(COLUMN) 1 Regina(COLUMN) clear(COLUMN)16(COLUMN)15 St. Kitts(COLUMN) cloudy(COLUMN)84(COLUMN)73 St. Thomas(COLUMN)pt. cldy(COLUMN)82(COLUMN)76 Toronto(COLUMN) snow(COLUMN)27(COLUMN)16 Vancouver(COLUMN) clear(COLUMN)45(COLUMN)28 Veracruz(COLUMN)pt. cldy(COLUMN)73(COLUMN)59 Winnipeg(COLUMN) clear(COLUMN)10(COLUMN)11(END TABLE)