Washington: Today - Party cloudy, high 54 to 88, low to 70 to 75. Chance of showers is 50 percent; 30 percent tonight. Winds will be light and variable. Monday - Party cloudy, high in mid 80s.

Maryland and Virginia: Today - Partly cloudy and humid, high in 80s, low in mid 70s. There will be a chance of an afternoon or evening thunderstorm. Monday - Partly cloudy, high in mid 80s.

Lower Potomac and Chesapeake Bay: Today - Fair, visibility more than five miles except in rain. Showers or thunderstorms will be from the south 10 knots. Waves in unprotected waters will one foot.

Atlantic Ocean Beaches from New Jersey to North Carolina: Today and Monday will be quite humid and partly cloudy with a chance of afternoon or evening thunderstorms. Water temperatures will be in low to mid 70s north and south.

Extended Area Outlook for Tuesday through Thursday: There will be isolated showers or thunderstorms early in the period, otherwise partly cloudy, warm and humid. Highs will average in the 50s to the low 90s and lows will be from the mid 60s to the mid 70s. Normal Washington temperatures for the period will be a high of 87 and a low of 60.

The Nation Yesterday: A tornado touched down in the industrial area of Plainview, N.Y. during the early of morning hours. There were no serious injuries but a million dollars damage was done by this storm. Showers and occasional thunderstorms continued into the early afternoon, increasing in number as well as strength. Storms extended from the Atlantic Coast across the Ohio Valley and eastern gulf states into the lower half of the Mississippi Valley, and the western end of the Great Lakes. Also, showers were widely scattered through the Rockies, the southern Plateau and the Pacific Coast. Otherwise, skies were sunny over much of the western half of the nation, and temperatures continued to climb.

The National Weather Forecast for today showers will be scattered from Montana across Washington as well as widely scattered over Utah and the central Rockies. Showers and occasional thundershowers will reach from the Atlantic Coast across the Gulf Coast to the northeast Texas Cost. Showers and occasional thunderstorms will also be scattered over the upper Great Lakes into the upper Ohio Valley.Temperatures will be generally mild from the Pacific Coast through the Plateau region into upper Missouri Valley. Hot to very hot temperatures will reach from the Plains states across the upper half of the Mississippi Valley into Wisconsin and much of Illinois. Temperatures elswhere over the nation will remain seasonably warm.

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 12 to 1 p.m. period was 20 for the pollutant, photo-chemical oxidants. Index values between 0 and 25 indicates 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 stage at Little Falls should fall to 4.0 feet today.

Washington data for yesterday: Highest temperature since midnight yesterday, 87 degrees at 5:15 p.m. Lowest temperature since midnight, 73 degrees at 1:45 a.m. Excess of temperature since Aug. 1, 36 degrees. Deficiency of temperature since Jan. 1, 105 degrees. Record high temperature for today, 101 degrees in 1861. Record low temperature for today, 55 degrees in 1930. Relative humidity: maximum, 94 percent at 7 a.m.; minimum, 68 degrees at 6 p.m. 24-hour precipitation, .68 inch. Excess of precipitation since Aug. 1, .22 inch. Excess of precipitation since Jan. 1, 3.03 inches. Highest observed wind since 8 a.m., 10 miles per hour from the south at 4:54 p.m. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnite(COLUMN)75(COLUMN)88 1 a.m.(COLUMN)74(COLUMN)91 2 a.m.(COLUMN)73(COLUMN)94 3 a.m.(COLUMN)73(COLUMN)94 4 a.m.(COLUMN)74(COLUMN)91 5 a.m.(COLUMN)74(COLUMN)91 6 a.m.(COLUMN)72(COLUMN)90 7 a.m.(COLUMN)74(COLUMN)94 8 a.m.(COLUMN)75(COLUMN)91 9 a.m.(COLUMN)76(COLUMN)88 10 a.m.(COLUMN)76(COLUMN)88 11 a.m.(COLUMN)78(COLUMN)82 12 noon(COLUMN)79(COLUMN)79 1 p.m.(COLUMN)81(COLUMN)74 2 p.m.(COLUMN)83(COLUMN)72 3 p.m.(COLUMN)83(COLUMN)72 4 p.m.(COLUMN)85(COLUMN)68 5 p.m.(COLUMN)85(COLUMN)68 6 p.m.(COLUMN)85(COLUMN)68 7 p.m.(COLUMN)82(COLUMN)77 8 p.m.(COLUMN)82(COLUMN)77 9 p.m.(COLUMN)81(COLUMN)79 10 p.m.(COLUMN)81(COLUMN)82 11 p.m.(COLUMN)80(COLUMN)85(END TABLE) Temperatures ending 8 p.m. (EDT) yesterday(TABLE) City(COLUMN)L.(COLUMN)H. Albany(COLUMN)66(COLUMN)75 Albuquerque(COLUMN)65(COLUMN)96 Amarillo(COLUMN)64(COLUMN)94 Anchorage(COLUMN)57(COLUMN)65 Asheville(COLUMN)64(COLUMN)81 Atlanta(COLUMN)70(COLUMN)76 Atlantic City(COLUMN)71(COLUMN)76 Austin(COLUMN)76(COLUMN)97 Baltimore(COLUMN)69(COLUMN)84 Billings(COLUMN)61(COLUMN)95 Birmingham(COLUMN)71(COLUMN)90 Bismarck(COLUMN)53(COLUMN)100 Boise(COLUMN)56(COLUMN)93 Boston(COLUMN)65(COLUMN)70 Brownsville(COLUMN)81(COLUMN)97 Buffalo(COLUMN)62(COLUMN)81 Burlington(COLUMN)65(COLUMN)71 Casper(COLUMN)63(COLUMN)94 Charleston, S.C.(COLUMN)75(COLUMN)83 Charleston, W.Va.(COLUMN)66(COLUMN)84 Charlotte(COLUMN)70(COLUMN)85 Cheyenne(COLUMN)58(COLUMN)87 Chicago(COLUMN)68(COLUMN)84 Cincinnati(COLUMN)67(COLUMN)76 Cleveland(COLUMN)63(COLUMN)83 Columbia, S.C.(COLUMN)71(COLUMN)90 Columbus(COLUMN)66(COLUMN)79 Dal.-Ft. Worth(COLUMN)76(COLUMN)100 Dayton(COLUMN)67(COLUMN)80 Denver(COLUMN)63(COLUMN)94 Des Moines(COLUMN)64(COLUMN)88 Detroit(COLUMN)67(COLUMN)80 Duluth(COLUMN)66(COLUMN)87 El Paso(COLUMN)75(COLUMN)100 Fairbanks(COLUMN)52(COLUMN)75 Fargo(COLUMN)69(COLUMN)96 Flagstaff(COLUMN)47(COLUMN)73 Great Falls(COLUMN)54(COLUMN)90 Hartford(COLUMN)61(COLUMN)69 Helena(COLUMN)63(COLUMN)90 Houston(COLUMN)78(COLUMN)94 Indianapolis(COLUMN)69(COLUMN)80 Jackson, Miss.(COLUMN)74(COLUMN)92 Jacksonville(COLUMN)70(COLUMN)93 Juneau(COLUMN)51(COLUMN)68 Kansas City(COLUMN)67(COLUMN)90 Las Vegas(COLUMN)73(COLUMN)98 Little Rock(COLUMN)68(COLUMN)93 Los Angeles(COLUMN)66(COLUMN)80 Louisville(COLUMN)68(COLUMN)80 Memphis(COLUMN)72(COLUMN)91 Miami Beach(COLUMN)79(COLUMN)87 Midland-Odessa(COLUMN)69(COLUMN)95 Milwaukee(COLUMN)62(COLUMN)79 Mpls.-St. Paul(COLUMN)67(COLUMN)93 Nashville(COLUMN)69(COLUMN)87 New Orleans(COLUMN)77(COLUMN)90 New York(COLUMN)70(COLUMN)80 Norfolk(COLUMN)73(COLUMN)87 North Platte(COLUMN)62(COLUMN)97 Oklahoma City(COLUMN)77(COLUMN)101 Omaha(COLUMN)64(COLUMN)87 Orlando(COLUMN)74(COLUMN)89 Philadelphia(COLUMN)74(COLUMN)87 Phoenix(COLUMN)78(COLUMN)99 Pittsburgh(COLUMN)65(COLUMN)81 Portland, Me.(COLUMN)59(COLUMN)71 Portland, Ore.(COLUMN)59(COLUMN)70 Providence(COLUMN)64(COLUMN)72 Raleigh(COLUMN)70(COLUMN)87 Rapid City(COLUMN)61(COLUMN)102 Reno(COLUMN)42(COLUMN)87 Richmond(COLUMN)71(COLUMN)89 St. Louis(COLUMN)66(COLUMN)87 St. Prbg.-Tampa(COLUMN)77(COLUMN)87 Salt Lake City(COLUMN)71(COLUMN)85 San Antonio(COLUMN)74(COLUMN)93 San Diego(COLUMN)71(COLUMN)78 San Francisco(COLUMN)56(COLUMN)66 San Juan(COLUMN)91(COLUMN)81 St. Ste. Marie(COLUMN)55(COLUMN)83 Seattle(COLUMN)57(COLUMN)72 Shreveport(COLUMN)75(COLUMN)100 Sioux Falls(COLUMN)67(COLUMN)89 Spokane(COLUMN)58(COLUMN)61 Syracuse(COLUMN)68(COLUMN)83 Topeka(COLUMN)65(COLUMN)95 Tucson(COLUMN)72(COLUMN)91 Tulsa(COLUMN)76(COLUMN)105 Washington(COLUMN)73(COLUMN)87 Wichita(COLUMN)75(COLUMN)106(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp Aberdeen(COLUMN) haze(COLUMN) 1 p.m(COLUMN)57 Amsterdam(COLUMN) cloudy(COLUMN) 1 p.m.(COLUMN)66 Ankara(COLUMN)pt. cldy(COLUMN) 3 p.m.(COLUMN)84 Athens(COLUMN) clear(COLUMN) 2 p.m.(COLUMN)84 Auckland(COLUMN) clear(COLUMN)12 a.m.(COLUMN)50 Berlin(COLUMN) cloudy(COLUMN) 1 p.m.(COLUMN)57 Birmingham(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)57 Bonn(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)63 Brussels(COLUMN)pt.cldy(COLUMN) 1 p.m.(COLUMN)66 Casablanca(COLUMN)pt.cldy(COLUMN)12 p.m.(COLUMN)57 Copenhagen(COLUMN)pt.cldy(COLUMN) 1 p.m.(COLUMN)68 Dublin(COLUMN)pt.cldy(COLUMN) 1 p.m.(COLUMN)63 Geneva(COLUMN)pt.cldy(COLUMN) 1 p.m.(COLUMN)68 Hong Kong(COLUMN)Pt.cldy(COLUMN) 8 p.m.(COLUMN)82 Jerusalem(COLUMN)clear(COLUMN) 2 p.m.(COLUMN)82 Lisbon(COLUMN)clear(COLUMN)12 p.m.(COLUMN)82 Landon(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)63 Madrid(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)82 Malta(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)82 Manila(COLUMN)rain(COLUMN) 8 p.m.(COLUMN)73 Moscow(COLUMN)rain(COLUMN) 3 p.m.(COLUMN)63 New Delhi(COLUMN)cloudy(COLUMN) 6 p.m.(COLUMN)82 Nice(COLUMN)pt.cldy(COLUMN) 1 p.m.(COLUMN)73 Oslo(COLUMN)pt.cldy(COLUMN) 1 p.m.(COLUMN)63 Paris(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)79 Peking(COLUMN)pt.cldy(COLUMN) 8 P.m.(COLUMN)72 Rome(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)77 Saigon(COLUMN)rain(COLUMN) 8 p.m.(COLUMN)81 Sofia(COLUMN)cloudy(COLUMN) 2 p.m.(COLUMN)57 Stockholm(COLUMN)rain(COLUMN) 1 p.m.(COLUMN)61 Sydney(COLUMN)pt.cldy(COLUMN)10 p.m.(COLUMN)46 Tokyo(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)88 Tunis(COLUMN)clear(COLUMN) 1 p.m.(COLUMN)79 Vienna(COLUMN)cloudy(COLUMN) 1 p.m.(COLUMN)63 Warsaw(COLUMN)storm(COLUMN) 1 p.m.(COLUMN)63(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt.cldy(COLUMN)92(COLUMN)79 Barbados(COLUMN)pt.cldy(COLUMN)86(COLUMN)74 Be rmuda(COLUMN)rain(COLUMN)87(COLUMN)75 Bogota(COLUMN)cloudy(COLUMN)64(COLUMN)35 Calgary(COLUMN)cloudy(COLUMN)73(COLUMN)50 Culiacan(COLUMN)fair(COLUMN)90(COLUMN)74 Edmonton(COLUMN)cloudy(COLUMN)73(COLUMN)52 Havana(COLUMN)pt.cldy(COLUMN)90(COLUMN)73 Kingston(COLUMN)pt.cldy(COLUMN)92(COLUMN)79 Mexico City(COLUMN)haze(COLUMN)77(COLUMN)57 Monterrey(COLUMN)pt.cldy(COLUMN)95(COLUMN)75 Montreal(COLUMN)cloudy(COLUMN)79(COLUMN)57 Nassau(COLUMN)pt.cldy(COLUMN)90(COLUMN)79 Ottawa(COLUMN)clear(COLUMN)79(COLUMN)57 Regina(COLUMN)clear(COLUMN)90(COLUMN)55 St. Kitts(COLUMN)pt.cldy(COLUMN)89(COLUMN)78 St. Thomas(COLUMN)pt.cldy(COLUMN)90(COLUMN)75 Toronto(COLUMN)clear(COLUMN)75(COLUMN)54 Vancouver(COLUMN)pt.cldy(COLUMN)63(COLUMN)55 Veracruz(COLUMN)pt.cldy(COLUMN)90(COLUMN)75 Winnipeg(COLUMN)clear(COLUMN)95(COLUMN)59(END TABLE)