Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Austin/San Antonio Texas
559 am CST Sat Dec 20 2014
Aviation... /12z taf cycle/
low end MVFR ceilings ongoing this morning for ksat/kaus/kssf with
kdrt bouncing between low MVFR and VFR as bkn010 to sct010 keep
being observed. Will go on pessimistic side for kdrt through
17-20z before eventual break out to VFR occurs this afternoon. For
central sites however, feel MVFR will rule through the afternoon
per rap/NAM soundings and hrrr output. Top of stratus cloud deck
looks to be around 3.5-4 kft, resulting in a 1-1.5 kft thick
stratus cloud layer. Overnight, IFR is likely for all sites with
another slow improvement to MVFR/VFR on Sunday afternoon.
Surface winds will be north/north-northeast at 10 kts through the day and then
become light and variable overnight tonight. /Allen/
Previous discussion... /issued 357 am CST Sat Dec 20 2014/
Short term (today through sunday)...
an upper level trough slowly develops over the plains states. A
series of weak upper level short-waves traverse the trough to
generate weak isentropic lift. Moisture depth only sufficient for
maintenance of stratus/stratocumulus deck with no rain expected.
Below average daytime and above average nighttime temperatures are
expected due to the cloud cover. Patchy fog will persist across
higher elevations of The Hill Country through around 9 am this
Long term (sunday night through friday)...
the upper level trough shifts east by Tuesday. Southwesterly lower
level flow develops allowing skies to mostly clear with well above
average temperatures Monday. A middle level short-wave moving through
the trough forces a cold front to move across south central Texas
Tuesday morning. There is sufficient moisture for isolated showers
along the front across far eastern areas and have introduced
mention. Zonal flow aloft for middle to late week with an upper level
trough moving across the plains forcing another cold front across
south central Texas Friday. No rain is expected as moisture depth
will be minimal. Cooler temperatures Tuesday into Wednesday...then
warmer Thursday Christmas day.
Preliminary point temps/pops...
Austin Camp Mabry 56 44 60 48 70 / - - - - -
Austin Bergstrom international Airport 56 42 59 46 70 / - - - - -
New Braunfels Muni Airport 56 45 61 48 71 / - - - - -
Burnet Muni Airport 54 40 58 46 69 / - - - - -
del Rio International Airport 60 45 62 46 73 / - - - - -
Georgetown Muni Airport 54 40 58 47 69 / - - - - -
Hondo Muni Airport 59 45 62 46 72 / - - - - -
San Marcos Muni Airport 57 43 61 46 70 / - - - - -
La Grange - Fayette regional 57 45 61 48 71 / - - - - -
San Antonio International Airport 57 45 61 49 72 / - - - - -
Stinson Muni Airport 58 46 62 49 72 / - - - - -