Aviation Forecasts Discussions (AFD) INFO

(EXTRACTED FROM FXUS66 KSEW 181815)


    A warm front will meander across southern WA today, then
    lift north across the area this evening ahead of the next low. Rain
    at times with persistent widespread MVFR cigs, and areas of IFR
    (especially KPWT/KOLM/KHQM). Light westerly flow aloft becoming
    strong southwesterly flow later tonight and Tuesday associated with
    a deepening 995 mb low tracking into central Washington. Moist at
    all levels and stable.
    
    KSEA...The convergence zone is stalled around KSEA/KBFI, and this
    could continue for several hours wind some variable wind shifts at
    KSEA. KBFI should mostly stay northeast 5 kt or less then go south
    early this evening. The NE wind at KSEA is around 13-16 kt w/ gusts
    to 20 kt at 10 am, but these speeds are expected to weaken
    significantly over the next 1-2 hours. By 20z easterly winds may be
    around 5-8 kt then going south early this evening. Rain today with
    IFR cigs, possible improving to low MFR this afternoon.
    
    Colder air arrives late Tuesday night and Wednesday. Snow levels
    falling to 1500 feet after midnight Tuesday night and down to 1000
    feet Wednesday morning. Snow accumulation is not expected at KSEA
    but period of wet mixed precipitation cannot be ruled out Wednesday
    morning. Cold rain is most likely.