Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Austin/San Antonio Texas
1138 PM CDT Friday Jul 25 2014
VFR skies prevail tonight through Saturday night. Except shallow
moisture depth will allow for periods of stratus with MVFR/IFR
ceilings late tonight into middle morning Saturday and late Saturday
night along Escarpment into Hill Country. S to southeast winds 4 to 8 kts
tonight increase to 10 to 17 kts Saturday due to daytime mixing
and the seabreeze and then decrease to less than 10 kts Saturday
night as the airmass decouples.
Previous discussion... /issued 634 PM CDT Friday Jul 25 2014/
isolated rain showers/thunderstorms and rain S of a kdrt to ksat to kgyb line will move to the
northwest through 02z or 03z and then dissipate. Made no mention in the tafs
due to probs less than 20. However...will monitor radar trends for
possible updates. VFR skies prevail this evening. Stratus with
MVFR/IFR ceilings develops overnight along the Escarpment and into The
Hill Country. Clouds scattered out middle morning Saturday with VFR skies
through afternoon into evening. S to southeast winds 7 to 12 kts this
evening decrease to 7 kts or less overnight and then increase to
10 to 15 kts on Saturday. Wind gusts up to 30 kts are possible in
and near rain showers/thunderstorms and rain this evening.
Previous discussion... /issued 331 PM CDT Friday Jul 25 2014/
Short term (tonight through Saturday night)...
recent mesoscale model runs still show hints of convection over
the southern Rio Grande plains this afternoon into early
evening...but chances are low so we only kept isolated early
evening wording in the text forecasts. Any storms that develop
should dissipate by 02z. Otherwise...the upper level ridge builds
east across Texas and northwest across The Rockies...so expect hot
and dry conditions on Saturday.
Long term (sunday through friday)...
the upper level ridge maintains a strong influence across Texas
through Tuesday. Height/thickness values support slightly above
normal temperatures. The combination of heat and increasing dew
point will produce heat index values of 100-107 for a few hours
each afternoon across the coastal plains. We will highlight this
in the severe weather potential statement and issue an Special Weather Statement...but in reality it/S really not much
hotter than typical conditions for late July.
A deep upper level trough over the Great Lakes...the ridge over
The Rockies...and a trough along the Pacific coast will form an
Omega blocking pattern next week. This will result in an unseasonably
cool air mass for the eastern half of the country...including Texas.
Medium range models have been consistent in pushing a main cold
front and potentially minor outflow boundaries through most of
Texas. Isentropic lift and moist air pooling along these
boundaries (pw approaching 2.4 inches) will create an favorable
environment for at least scattered storm coverage...and potentially
heavy rain. Extensive cloudcover and rain may keep high
temperatures well below normal. Due to uncertainty in specific
placement of features...we will start the trend to increase probability of precipitation
and quantitative precipitation forecast...and decrease high temperatures...for Thursday and Friday.
Expect additional adjustments as model guidance and observations
Preliminary point temps/pops...
Austin Camp Mabry 75 98 75 98 74 / - - - - -
Austin Bergstrom international Airport 73 98 74 98 72 / - - - - -
New Braunfels Muni Airport 73 97 73 97 72 / - - - - -
Burnet Muni Airport 73 97 73 97 73 / - - - - -
del Rio International Airport 78 100 79 100 78 / 20 - - - -
Georgetown Muni Airport 74 97 74 98 74 / - - - - -
Hondo Muni Airport 73 98 73 98 72 / 20 - - - -
San Marcos Muni Airport 73 98 74 98 72 / - - - - -
La Grange - Fayette regional 76 96 77 96 75 / - - - - -
San Antonio International Airport 76 97 75 97 75 / - - - - -
Stinson Muni Airport 75 98 74 98 74 / - - - - -