Washington: Today - Partly cloudy, high in mid to upper 80s, lows in mid 60s. Chance of rain is 10 per cent through tonight. Monday - Partly cloud, highs in mid to upper 80s.

Maryland and Virginia: Today - Partly cloudy, highs in mid to upper 80s, lows in 60s. Chance of afternoon or evening showers in west. Monday - Partly cloudy, highs in mid to upper 80s.

Lower Potomac and Chesapeake Bay: Today - Partly cloudy skies with far visibility through tonight. Winds should be southerly 7 to 12 knots this afternoon, otherwise southerly at about 7 knots through tonight.

Extended Area Outlook: For Tuesday through Thursday - Rain likely Tuesday with highs in 80s and lows in 60s. Skies should be fair Wednesday and Thursday with highs in mid 70s and lows in 50s.

West Virginia: Today - Mostly sunny, highs in 80s to low 90s, lows in upper 50s to mid 60s. Monday - Partly cloudy and humid with chance of rain, highs in 80s to low 90s.

The National Weather Forecast for Today - Scattered showels and thunderstorms are likely from northern California through Washington state, from Washington State through Western Montana, from the middle Mississippi Valley and the eastern part of the northern Plains through the Great Lakes and Ohio Valley and from southern South Carolina and Florida through southern Lousiana. Isolated snowers are possible over eastern Montana, portions of the southern Plains and lower Mississippi Valley, the north Atlantic Coast states and over portions of North Carolina and northern South Carolina. Temperatures will be mostly cool from the northern and central Pacific Coast through the northern and central Rocky Mountain region and over most of the northern Plains. Warm conditions will prevail from the lower Mississippi Valley through the Central and south Atlantic Coast region. Most of the remainder of the nation will be seasonably mild.

The Council of Government's Air Quality Index for yesterday snowed the high reading in the Washington area during the noon to 1 p.m. period was 25 for the pollutant, photochemical oxidants. 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 eve ailments are urged to restrict their activity.

The National Weather Service forecasts the Potomac River stage at Little Falls should remain near 2.6 feet through today.

Almanac data for Sunday, Sept. 18. Sun rises 6:53 a.m., set 7:10 p.m.; moon rises 1:33 p.m. sets 11:52 p.m. Tides: High 12:22 p.m. and 12:53 a.m.

(TABLE) Time(COLUMN)T.(COLUMN)H. Local Temp., Humidity 12 mid.(COLUMN)69(COLUMN)93 1 a.m.(COLUMN)69(COLUMN)95 2 a.m.(COLUMN)70(COLUMN)95 3 a.m.(COLUMN)70(COLUMN)94 4 a.m.(COLUMN)70(COLUMN)96 5 a.m.(COLUMN)70(COLUMN)95 6 a.m.(COLUMN)69(COLUMN)97 7 a.m.(COLUMN)68(COLUMN)90 8 a.m.(COLUMN)71(COLUMN)90 9 a.m.(COLUMN)71(COLUMN)87 10 a.m.(COLUMN)76(COLUMN)82 12 noon(COLUMN)81(COLUMN)72 1 p.m.(COLUMN)79(COLUMN)79 2 p.m.(COLUMN)81(COLUMN)77 3 p.m.(COLUMN)81(COLUMN)72 4 p.m.(COLUMN)82(COLUMN)69 5 p.m.(COLUMN)82(COLUMN)69(END TABLE)

(TABLE) City(COLUMN)H.(COLUMN)T. Temperatures ending 8 a.m. (EDT) Yesterday Albany(COLUMN)60(COLUMN)58 Albuquerque(COLUMN)81(COLUMN)56 Amarillo(COLUMN)91(COLUMN)67 Anchorage(COLUMN)60(COLUMN)41 Asheville(COLUMN)76(COLUMN)66 Atlanta(COLUMN)81(COLUMN)68 Atlantic City(COLUMN)73(COLUMN)71 Austin(COLUMN)91(COLUMN)72 Baltimore(COLUMN)74(COLUMN)70 Billings(COLUMN)68(COLUMN)48 Birmingham(COLUMN)81(COLUMN)70 Bismarck(COLUMN)74(COLUMN)45 Boise(COLUMN)59(COLUMN)49 Boston(COLUMN)67(COLUMN)57 Brownsville(COLUMN)94(COLUMN)76 Buffalo(COLUMN)68(COLUMN)65 Burlington Vt.(COLUMN)62(COLUMN)59 Casper(COLUMN)78(COLUMN)40 Charleston, S.C.(COLUMN)86(COLUMN)76 Chiston, W. Va.(COLUMN)77(COLUMN)67 Charlotte, N.C.(COLUMN)81(COLUMN)69 Cheyenne(COLUMN)74(COLUMN)49 Chicago(COLUMN)72(COLUMN)61 Cincinnati(COLUMN)78(COLUMN)66 Cleveland(COLUMN)69(COLUMN)62 Columbia, S.C.(COLUMN)89(COLUMN)69 Columbus, Ohio(COLUMN)73(COLUMN)65 Dal. Ft. Worth(COLUMN)92(COLUMN)71 Dayton(COLUMN)77(COLUMN)66 Denver(COLUMN)82(COLUMN)57 Des Moines(COLUMN)73(COLUMN)65 Detroit(COLUMN)77(COLUMN)62 Duluth(COLUMN)62(COLUMN)50 ElPaso(COLUMN)83(COLUMN)66 Fairbanks(COLUMN)52(COLUMN)41 Fargo(COLUMN)70(COLUMN)60 Flagstaff(COLUMN)67(COLUMN)51 Great Falls(COLUMN)54(COLUMN)43 Hartford(COLUMN)61(COLUMN)60 Helena(COLUMN)61(COLUMN)40 Honolulu(COLUMN)89(COLUMN)78 Houston(COLUMN)83(COLUMN)77 Indianapolis(COLUMN)81(COLUMN)63 Jackson, Miss.(COLUMN)85(COLUMN)71 Jacksonville(COLUMN)89(COLUMN)72 Juneau(COLUMN)60(COLUMN)46 Kansas City(COLUMN)82(COLUMN)70 Las Vegas(COLUMN)83(COLUMN)62 Little Rock(COLUMN)82(COLUMN)63 Los Angeles(COLUMN)72(COLUMN)59 Louisville(COLUMN)79(COLUMN)66 Memphis(COLUMN)86(COLUMN)71 Miami Beach(COLUMN)86(COLUMN)76 Midland(COLUMN)95(COLUMN)69 Milwaukee(COLUMN)69(COLUMN)59 Mpls. St. Paul(COLUMN)67(COLUMN)55 Nashville(COLUMN)80(COLUMN)66 New Orleans(COLUMN)87(COLUMN)72 New York(COLUMN)66(COLUMN)63 Norfolk(COLUMN)87(COLUMN)74 North Platte(COLUMN)81(COLUMN)57 Oklahoma City(COLUMN)89(COLUMN)71 Omaha(COLUMN)78(COLUMN)62 Orlando(COLUMN)93(COLUMN)76 Philadelphia(COLUMN)74(COLUMN)70 Phoenix(COLUMN)98(COLUMN)74 Pittsburgh(COLUMN)67(COLUMN)64 Portland, me.(COLUMN)65(COLUMN)53 Portland, Ore.(COLUMN)66(COLUMN)53 Providence(COLUMN)65(COLUMN)60 Raleigh(COLUMN)87(COLUMN)69 Rapid City(COLUMN)77(COLUMN)50 Reno(COLUMN)59(COLUMN)35 Richmond(COLUMN)85(COLUMN)69 St. Louis(COLUMN)82(COLUMN)65 St. Prbg-Tampa(COLUMN)92(COLUMN)76 Salt Lake City(COLUMN)79(COLUMN)52 San Antonio(COLUMN)88(COLUMN)75 San Diego(COLUMN)73(COLUMN)64 San Francisco(COLUMN)63(COLUMN)60 San. Juan, P.R.(COLUMN)87(COLUMN)76 St Ste. Marie(COLUMN)58(COLUMN)54 Seattle(COLUMN)65(COLUMN)50 Shreveport(COLUMN)88(COLUMN)69 Sioux Falls(COLUMN)65(COLUMN)60 Spokane(COLUMN)52(COLUMN)47 Syracuse(COLUMN)65(COLUMN)63 Topeka(COLUMN)88(COLUMN)72 Tucson(COLUMN)92(COLUMN)71 Tulsa(COLUMN)87(COLUMN)70 Washington(COLUMN)73(COLUMN)68 Wichita(COLUMN)84(COLUMN)69(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time.(COLUMN)T. Aberdeen(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)50 Amsterdam(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)59 Ankara(COLUMN)pt, cldy(COLUMN) 3 p.m.(COLUMN)77 Athens(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)81 Auckland(COLUMN)clear(COLUMN)midnight(COLUMN)48 Berlin(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)54 Birmingham(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)54 Brussels(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)57 Cairo(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)83 Casablanca(COLUMN)cloudy(COLUMN)noon(COLUMN)75 Copenhagen(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)54 Dublin(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)54 Geneva(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)57 Hong Kong(COLUMN)pt. cldy(COLUMN) 8 p.m.(COLUMN)84 Lisbon(COLUMN)cloudy(COLUMN)noon(COLUMN)66 London(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)57 Madrid(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)81 Malta(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)81 Manila(COLUMN)rain(COLUMN) 8 p.m.(COLUMN)77 Moscow(COLUMN)cloudy(COLUMN) 3 p.m.(COLUMN)45 New Delhi(COLUMN)cloudy(COLUMN) 5 p.m.(COLUMN)82 Nice(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)73 Oslo(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)57 Paris(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)59 Peking(COLUMN)clear(COLUMN) 8 p.m.(COLUMN)66 Rome(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)77 Saigon(COLUMN)storm(COLUMN) 8 p.m.(COLUMN)81 Sofia(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)64 Stockholm(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)46 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)72 Tunis(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)88 Vienna(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)55 Warsaw(COLUMN)pt. cldy(COLUMN) 1 p.m.(COLUMN)55(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)sunny(COLUMN)[WORD ILLEGIBLE](COLUMN)77 Barbados(COLUMN)sunny(COLUMN)88(COLUMN)78 Bermuda(COLUMN)pt. cldy(COLUMN)82(COLUMN)77 Bogota(COLUMN)pt. cldy(COLUMN)64(COLUMN)45 Calgary(COLUMN)rain(COLUMN)46(COLUMN)39 Culiacan(COLUMN)fair(COLUMN)95(COLUMN)80 Edmonton(COLUMN)cloudy(COLUMN)50(COLUMN)41 Havana(COLUMN)pt. cldy(COLUMN)90(COLUMN)77 Kingston(COLUMN)pt. cldy(COLUMN)92(COLUMN)78 Montego Bay(COLUMN)pt. cldy(COLUMN)88(COLUMN)76 Mexico City(COLUMN)haze(COLUMN)73(COLUMN)59 Monterrey(COLUMN)pt. cldy(COLUMN)92(COLUMN)72 Montreal(COLUMN)cloudy(COLUMN)61(COLUMN)57 Nassau(COLUMN)pt. cldy(COLUMN)90(COLUMN)76 Ottawa(COLUMN)fog(COLUMN)59(COLUMN)55 Regina(COLUMN)cloudy(COLUMN)55(COLUMN)43 St. Kitts(COLUMN)fair(COLUMN)89(COLUMN)74 Toronto(COLUMN)pt. cldy(COLUMN)64(COLUMN)61 Vancouver(COLUMN)cloudy(COLUMN)63(COLUMN)50 Veracruz(COLUMN)cloudy(COLUMN)88(COLUMN)74 Winnipeg(COLUMN)cloudy(COLUMN)73(COLUMN)54(END TABLE)