Aviation Forecasts Discussions (AFD) INFO

(EXTRACTED FROM FXUS64 KHGX 200144)


    VFR for the 20/00Z TAFs with lots of cirrus streaming across the area
    overnight. Light N to NE winds tonight will shift around to the S and
    SE during the day tomorrow.  42
    
    PREV DISCUSSION... /ISSUED 306 PM CST Sun Nov 19 2017/
    
    NEAR TERM [Through Tonight]...
    
    Since I cannot take my AWIPS workstation outside in the cool
    crisp fall air to enjoy, I'm left writing my discussion looking
    out the window at it. But at least I have a window to look out to
    see some thin cirrus moving across the sky. Satellite imagery
    shows this as well and water vapor imagery showing a weak short
    wave trough enhancing the cloud cover. High pressure over Texas
    today will move east over the Tennessee river valley tonight. Axis
    of high pressure will still support calm winds tonight. Cirrus
    may be an issue for the low temperature forecast but do not think
    it will be that thick enough to make an impact. Look for
    temperatures Monday morning in the upper 30s to low 40s for much
    of the area.
    
    SHORT TERM [Monday Through Tuesday Night]...
    
    Short range models are in pretty good agreement with some weak
    return flow on Monday going into Tuesday. Rain chances increase
    mainly in the Gulf and just along the coast on Tuesday. Vorticity
    from a trough now approaching the Pacific NW should continue its
    movement around the upper level ridge and reach Texas late
    Tuesday. A cold front will be moving into the area about the same
    time so will keep some low end rain chances in the forecast. Best
    chances of rain and higher rainfall totals should remain off the
    Gulf coast. The cold front should push off the coast by Wednesday
    morning with high pressure building over the Plains.
    
    LONG TERM [Wednesday Through Sunday]...
    
    Surface high pressure should remain over the area in some shape
    or fashion through the end of the week. This will allow for
    temperatures to be about 5 degrees below normal for Thanksgiving.
    You can be thankful we will not have any record breaking high
    temperatures that day or even record high minimum temperatures.
    Temperatures then push maybe 5 degrees above normal for the
    holiday weekend as upper level ridge begins to expand over the
    Desert SW and Southern Rockies causing 500mb height rises. Even
    then, the NW flow aloft may help push a weak front through the
    area next Sunday taking the edge off those slightly above normal
    temperatures.
    
    Overpeck
    
    
    
    VFR conditions expected. Breezy conditions will continue to
    diminish through the afternoon. High pressure will then bring
    light winds from the north tonight and northeast to east on
    Monday.
    
    40
    
    MARINE...
    
    The winds have steadily diminished this afternoon. This in turn
    has led to subsiding seas as well. Expect the small craft advisory
    that was in effect between 20 and 60 nm offshore of the coast to
    end at 4:00 PM. With the surface high pressure ridge over North
    Texas expected to build into East and Southeast Texas, winds and
    seas should continue to diminish. Onshore winds will return on
    Monday. Still looks like a cold front will move off of the coast
    late Tuesday. Caution or advisory conditions are possible behind
    this front Tuesday night and Wednesday.
    
    The low water advisory will continue through the remainder of
    this afternoon. Water levels in some locations of Galveston Bay
    were down to one foot below the predicted levels. With diminishing
    winds, should see the water levels to begin returning to near
    normal levels this evening.
    
    40
    
    FIRE WEATHER...
    
    Elevated fire weather conditions will continue through the
    remainder of this afternoon. Some locations have seen the relative
    humidity values to drop to around 25 percent so far this
    afternoon. However, wind speeds have dropped below 15 mph and many
    of the driest locations were already below 10 mph. On Monday the
    lowest relative humidity values should range from 35 to 40
    generally north of the Interstate 10 corridor. With easterly and
    then southeasterly winds developing, the elevated fire weather
    threat should diminish as the afternoon progresses.
    
    40