Triple Digit Heat in the Forecast - NBC Bay Area

Triple Digit Heat in the Forecast

Monday is the hottest day of the forecast with triple digit temps possible inland.



    Summer-like Sunday Ahead

    SUNDAY: High pressure building through the day will warm inland temps through the 80s into the upper 90s near Livermore. This will be quite the temperature swing with many areas starting the day in the 40s and 50s, then about 40 to 45 degrees of warming through the afternoon! A weak sea breeze not only will lead to our warming temperatures but limit the mixing out of air pollution around the Bay Area = a Spare the Air alert for Sunday, with poor air quality likely for Monday as well with slightly warmer temperatures. AHEAD: Temps will begin cooling midweek and drop to slightly below average into the weekend with highs only in the upper 70s to low 80s inland by Saturday. There's a slight risk of some mountain showers around that time as well, so stay tuned! - Rob Mayeda VIDEO: Weather Team 7 Day (Published Sunday, Sept. 30, 2012)

    The calendar says its fall, but the forecast sure sounds like summer.

    Temperatures in the high 90s are possible both today and tomorrow with a cool down not expected until after Tuesday, according NBC Bay Area meteorologist Rob Mayeda.

    It's enough for the National Weather Service to issue an excessive heat watch for Sunday and Monday.

    Mayeda says the reason for the high temps is a high pressure system that is building over the Bay Area.

    He says high pressure causes the winds to basically stop and shut down the Bay Area's natural air conditioning system.

    Inland temps will sore to the 80s and into the upper 90s in parts of the East and South Bay.

    There is a possibility of triple digits in some places on Monday. The heatwave is not expected to break until midweek.

    Rob's forecast highs for Sunday:

    • San Jose - 90
    • Gilroy - 97
    • Los Gatos - 94
    • Walnut Creek - 98
    • Antioch - 99
    • Napa - 90
    • Santa Cruz - 86
    • San Francisco - 75

    Those numbers will be even higher for Monday. 

    Both weekend days were declared spare the air days. A third spare the air day is expected for Monday.

    Because of the heat, Morgan Hill police posted an on line notice about a cooling center that will open all weekend at the Centennial Recreation Senior Center at 171 W. Edmundson Ave. in Morgan Hill.

    So far there is no statewide power alert, although the heatwave is a statewide event.

    The National Weather Service issued both and excessive heat watch and a fire weather alert for inland and valley areas of Southern California through Tuesday.

    Offshore winds are also gusting up to 30 mph which is making for high fire danger is SoCal.