Aviation Forecasts Discussions (AFD) INFO

(EXTRACTED FROM FXUS66 KSEW 130424)


    High pressure is over the region and the air is stable
    with patchy moisture--there are some clouds near the Olympics and
    KCLM was showing OVC050 at 7pm. The HRRR shows some fog getting into
    Hoquiam before midnight, earlier than the current forecast so that
    is one spot to watch tonight. Also, the HRRR is also showing a patch
    of fog forming at KBLI before midnight. Interestingly, the HRRR does
    not show fog in the metro area, while the 12z 1km WRFGFS makes a
    good case for widespread fog all around the Puget Sound area, over
    a good part of SW Washington, plus areas up through Whidbey Island
    and the San Juans and all through the Admiralty Inlet area and the
    east entrance to the Strait of Juan de Fuca--plus that blob on the
    central coast that the HRRR also showed. Areas of fog should give
    way to sunshine Wednesday afternoon--except perhaps for a few
    patches near the water and Olympia that might last all day.
    
    KSEA...The forecast has fog starting at 13z/5am so we will watch the
    dewpoints and obs tonight and go with that idea unless the moisture
    starts to frost out--lowering the dew point.