Washington: Today - Sunny and warm, high near 80, low near 50. The chance of rain is near zero through tonight. Tuesday - Fair, high in the 80s.

Maryland: Today - Sunny and warm, high near 80, low in the upper 40s. Tuesday - Fair, high in the 80s.

Virginia: Today - Sunny and warm, high near 80, low in the low 50s. Tuesday - Fair, high in the 80s.

Extended Area Forecast for Wednesday through Friday: Fair and warm through the period. Highs will be in the low 80s, low in the 50s. Normal Washington temperatures for the period are a high of 66 and a low of 45.

Lower Potomac and Chesapeake Bay: Today - Fair with winds from the southwest at 12 to 20 knots subsiding to less than 10 knots by nightfall. Visibility will be 5 miles or more. Waves in unprotected waters will average near 2 feet.

West Virginia: - Sunny and warm through Tuesday, highs will range from the mid 70s to mid 80s and lows from the mid 40s to mid 50s.

The National Weather forecast for today - Widely scattered showers and thundershowers are likely in the southern Rockies, Colorado and the southern and central Great Plains into South Dakota and Iowa. There is a slight chance of showers from northern Maine into New York state and northeastern Michigan. Showers will be scattered across the Pacific northwest and the northern Rockies. Elsewhere, it will be mostly sunny. Seasonably cool temperatures are expected in New England and west of the Continental Divide, except for California. Elsewhere, it will be mild to warm.

ALMANAC DATA fOR APRIL 11, 1977. Sun rises 5:38 a.m., sets 6:47 p.m.; moon rises 1:36 a.m. sets 12:18 p.m.. Tides: High 1:53 a.m. and 4:21 p.m., low 8:43 a.m. and 9:18 p.m.. High and low tides at the following locations can be obtained by subtracting the hours indicated from the tides above. Annapolis (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' Alr Quality Index for yesterday showed the high reading in the Washington area during the 10 a.m. period was 18 for the pollutant, photochemical oxidants. Index values between 0 and 24 indicate good air quality. When the index exceeds 100 the air becomes hazardous and persons with lung, heart and eye problems shoudl restrict their activity. The forecast for today indicates the air quality will remain good.

The National Weather Service forecasts that the Potomac River stage at Little Falls will fall to near 5.2 feet. Stages about 5 feet are considered hazardous for recreational purposes. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midn.(COLUMN)40(COLUMN)60 1 a.m.(COLUMN)39(COLUMN)65 2 a.m.(COLUMN)37(COLUMN)70 3 a.m.(COLUMN)36(COLUMN)70 4 a.m.(COLUMN)36(COLUMN)64 5 a.m.(COLUMN)36(COLUMN)70 6 a.m.(COLUMN)35(COLUMN)73 7 a.m.(COLUMN)39(COLUMN)65 8 a.m.(COLUMN)44(COLUMN)55 9 a.m.(COLUMN)47(COLUMN)53 10 a.m.(COLUMN)51(COLUMN)52 11 a.m.(COLUMN)55(COLUMN)26 12 noon(COLUMN)58(COLUMN)30 1 p.m.(COLUMN)60(COLUMN)28 2 p.m.(COLUMN)62(COLUMN)27 3 p.m.(COLUMN)64(COLUMN)26 4 p.m.(COLUMN)63(COLUMN)27 5 p.m.(COLUMN)64(COLUMN)26 6 p.m.(COLUMN)62(COLUMN)30 7 p.m.(COLUMN)57(COLUMN)39(END TABLE) Temperatures ending 7 a.m. (EST) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)38(COLUMN)26 Albuquerque(COLUMN)82(COLUMN)51 Amarillo(COLUMN)79(COLUMN)54 Anchorage(COLUMN)42(COLUMN)35 Asheville(COLUMN)68(COLUMN)35 Atlanta(COLUMN)72(COLUMN)46 Atlantic City(COLUMN)44(COLUMN)31 Austin(COLUMN)78(COLUMN)50 Baltimore(COLUMN)50(COLUMN)32 BiHings(COLUMN)70(COLUMN)42 Birmingham(COLUMN)80(COLUMN)46 Bismarck(COLUMN)87(COLUMN)45 Boise(COLUMN)59(COLUMN)33 Boston(COLUMN)42(COLUMN)33 Brownsville(COLUMN)84(COLUMN)63 Buffalo(COLUMN)37(COLUMN)29 Burlington, Vt.(COLUMN)38(COLUMN)21 Casper(COLUMN)78(COLUMN)35 Charleston, S.C.(COLUMN)68(COLUMN)54 Charl'ton, W.Va.(COLUMN)53(COLUMN)34 Charlotte(COLUMN)61(COLUMN)40 Cheyenne(COLUMN)75(COLUMN)42 Chicago(COLUMN)62(COLUMN)48 Cincinnati(COLUMN)57(COLUMN)43 Cleveland(COLUMN)46(COLUMN)30 Columbia, S.C.(COLUMN)70(COLUMN)36 Columbus(COLUMN)50(COLUMN)36 Dal.-Ft. Worth(COLUMN)83(COLUMN)48 Dayton(COLUMN)55(COLUMN)39 Denver(COLUMN)81(COLUMN)53 Des Moines(COLUMN)86(COLUMN)61 Detroit(COLUMN)53(COLUMN)35 Duluth(COLUMN)58(COLUMN)36 El Paso(COLUMN)90(COLUMN)54 Fairbanks(COLUMN)42(COLUMN)29 Fargo(COLUMN)85(COLUMN)45 Flagstaff(COLUMN)69(COLUMN)24 Great Falls(COLUMN)58(COLUMN)35 Hartford(COLUMN)42(COLUMN)28 Helena(COLUMN)59(COLUMN)36 Honolulu(COLUMN)84(COLUMN)72 Houston(COLUMN)81(COLUMN)47 Indianapolis(COLUMN)58(COLUMN)41 Jackson(COLUMN)83(COLUMN)45 Jacksonville(COLUMN)72(COLUMN)40 Juneau(COLUMN)42(COLUMN)37 Kansas City(COLUMN)83(COLUMN)36 Las Vagas(COLUMN)81(COLUMN)50 Little Rock(COLUMN)85(COLUMN)59 Los Angeles(COLUMN)67(COLUMN)51 Louisville(COLUMN)59(COLUMN)43 Memphis(COLUMN)82(COLUMN)58 Miami Beach(COLUMN)78(COLUMN)70 Midland(COLUMN)77(COLUMN)48 Milwaukee(COLUMN)53(COLUMN)41 Mpls. St. Paul(COLUMN)73(COLUMN)54 Nashville(COLUMN)70(COLUMN)47 New Orleans(COLUMN)84(COLUMN)52 New York(COLUMN)43(COLUMN)35 Norfolk(COLUMN)50(COLUMN)35 North Platte(COLUMN)84(COLUMN)44 Oklahoma City(COLUMN)81(COLUMN)57 Omaha(COLUMN)88(COLUMN)57 Orlando(COLUMN)87(COLUMN)56 Philadelphia(COLUMN)47(COLUMN)30 Phoenix(COLUMN)94(COLUMN)64 Pittsburgh(COLUMN)45(COLUMN)25 Portland, Me.(COLUMN)35(COLUMN)17 Portland, Or.(COLUMN)56(COLUMN)38 Providence(COLUMN)42(COLUMN)30 Raleigh(COLUMN)58(COLUMN)31 Rapid City(COLUMN)88(COLUMN)50 Reno(COLUMN)59(COLUMN)28 Richmond(COLUMN)56(COLUMN)20 St. Louis(COLUMN)77(COLUMN)60 St. Prbg. Tampa(COLUMN)85(COLUMN)57 Salt Lake City(COLUMN)78(COLUMN)41 San Antonio(COLUMN)79(COLUMN)58 San Diego(COLUMN)66(COLUMN)56 San Francisco(COLUMN)56(COLUMN)48 San Juan(COLUMN)87(COLUMN)74 St. Ste. Marie(COLUMN)43(COLUMN)22 Seattle(COLUMN)55(COLUMN)58 Shereveport(COLUMN)85(COLUMN)49 Sioux Falls(COLUMN)88(COLUMN)61 Spokane(COLUMN)52(COLUMN)34 Syracuse(COLUMN)41(COLUMN)26 Topeka(COLUMN)85(COLUMN)64 Tucson(COLUMN)91(COLUMN)53 Tulsa(COLUMN)84(COLUMN)52 Washington(COLUMN)52(COLUMN)33 Witchita(COLUMN)81(COLUMN)56(END TABLE) Temperature Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)T. Aberdeen(COLUMN)rain(COLUMN)1 p.m.(COLUMN)41 Amsterdam(COLUMN)clear(COLUMN)1 p.m.(COLUMN)43 Ankara(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)72 Athens(COLUMN)cloudy(COLUMN)2 p.m.(COLUMN)66 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)61 Berlin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)36 Birmingham(COLUMN)rain(COLUMN)1 p.m.(COLUMN)43 Brussels(COLUMN)clear(COLUMN)1 p.m.(COLUMN)41 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)95 Casablanca(COLUMN)cloudy(COLUMN)noon(COLUMN)64 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)36 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)50 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)41 Hong Kong(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)72 Lisbon(COLUMN)clear(COLUMN)noon(COLUMN)57 London(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)45 Madrid(COLUMN)clear(COLUMN)1 p.m.(COLUMN)50 Malta(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Manila(COLUMN)clear(COLUMN)8 p.m.(COLUMN)82 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)63 New Delhi(COLUMN)clear(COLUMN)5 p.m.(COLUMN)91 Nice(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)52 Oslo(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)34 Paris(COLUMN)clear(COLUMN)1 p.m!(COLUMN)43 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)63 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Saigon(COLUMN)clear(COLUMN)8 p.m.(COLUMN)82 Sofia(COLUMN)rain(COLUMN)2 p.m.(COLUMN)57 Stockholm(COLUMN)snow(COLUMN)1 p.m.(COLUMN)32 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)55 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)84 Tokyo(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)57 Tunis(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Vienna(COLUMN)Cloudy(COLUMN)1 p.m.(COLUMN)39 Warsaw(COLUMN)cloudy(COLUMN)10 p.m.(COLUMN)37(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco clear(COLUMN)90(COLUMN)73 Barbados(COLUMN)pt. cldy.(COLUMN)83(COLUMN)77 Bermuda(COLUMN)pt. cldy.(COLUMN)70(COLUMN)61 Bogota(COLUMN)pt. cldy.(COLUMN)67(COLUMN)39 Calgary(COLUMN)clear(COLUMN)61(COLUMN)27 Cullacan(COLUMN)pt. cldy.(COLUMN)94(COLUMN)55 Edmonton(COLUMN)clear(COLUMN)57(COLUMN)28 Havana(COLUMN)clear(COLUMN)79(COLUMN)72 Kingston(COLUMN)clear(COLUMN)88(COLUMN)73 Montego Bay(COLUMN)clear(COLUMN)86(COLUMN)73 Mexico City(COLUMN)haze(COLUMN)76(COLUMN)44 Monterry(COLUMN)cloudy(COLUMN)79(COLUMN)61 Montreal(COLUMN)clear(COLUMN)34(COLUMN)16 Ottawa(COLUMN)pt. cldy.(COLUMN)39(COLUMN)23 Regina(COLUMN)cloudy(COLUMN)79(COLUMN)30 St. Kitts(COLUMN)pt. cldy.(COLUMN)85(COLUMN)71 St. Thomas(COLUMN)pt. cldy.(COLUMN)83(COLUMN)72 Toronto(COLUMN)cloudy(COLUMN)43(COLUMN)28 Vancouver(COLUMN)rain(COLUMN)54(COLUMN)43 Veracruz(COLUMN)pt. cldy.(COLUMN)77(COLUMN)66 Winnipeg(COLUMN)cloudy(COLUMN)81(COLUMN)41(END TABLE)