Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Austin/San Antonio Texas
623 PM CDT Friday Sep 19 2014
Aviation...the previous set of tafs appeared sound in reasoning
and therefore the only changes that were made were to initial
conditions and the removal of the vcsh for the drt taf. Overall...
VFR conditions right now will degrade to IFR for majority of the
Aerodrome sites as low stratus and reduced visibilities develop.
VFR will return on Saturday only to degrade to MVFR or possible
IFR again Saturday night.
Previous discussion... /issued 326 PM CDT Friday Sep 19 2014/
Short term (tonight through Saturday night)...
rain continues to extend from Llano southeast towards San
Marcos down through and Cuero. Parts of The Hill
Country have already seen 3-5 inches of rainfall through the early
afternoon hours. The remnants of Odile are currently near Midland
while a middle to upper level convergence zone remains draped across
south central Texas.
The tropical moisture over our area...from what is left of Odile
and some upper level moisture from Tropical Storm Polo...continues
to produce precipitable water values of 2-2.5 inches. The morning
sounding at del Rio had a precipitable water value of 1.98 inches. While models
show the remnant circulation of Odile staying to our north the
moisture and lift will combine with the convergence zone over the
area and ample moisture to continue chances for showers and a few
thunderstorms this afternoon into the evening hours. Coverage
should be less than the last two days so the Flash Flood Watch
will not be reissued. That said locally heavy rainfall is still
possible...as we saw this morning...so some areas could get 1-2
inches of rainfall with 3-4 inch totals possible. High resolution
models suggest that overnight the upper level convergence will
shift closer to the Rio Grande plains increasing their chance for
As the tropical airmass remains over Texas and the remnants of
Odile are slow to push out of West Texas rain chances continue
into Saturday. Models suggest that the best chance of rain
Saturday will be along and west of Highway 281...although the
eastern half of central Texas could still see some scattered
Long term (sunday through friday)...
the drying trend begins on Sunday as high pressure develops over
southern New Mexico and West Texas. Drier low level air will
result in only isolated showers and thunderstorms on Sunday and
Monday. Models still show the front that was expected early next
week will remain to our north and only produce a wind shift on
Monday and aid in drier air move in across south central Texas for
the middle of the week. Behind the front the upper level ridge
continues to build across much of Texas. Both long range
models...the GFS and European model (ecmwf)...show a trough across the Central
Plains by Thursday of next week. This could weaken the ridge
enough to promote some sea breeze activity but with the main
forcing to the north no significant precipitation is expected.
Highs will remain at or just above seasonal normals while low
temperatures will cool slightly into next week due to the dry air
and lower dewpoints.
Preliminary point temps/pops...
Austin Camp Mabry 74 90 73 92 73 / 30 30 20 20 20
Austin Bergstrom international Airport 72 90 71 92 71 / 30 30 20 20 20
New Braunfels Muni Airport 73 90 73 94 72 / 30 30 20 30 20
Burnet Muni Airport 73 86 72 92 71 / 30 30 20 30 20
del Rio International Airport 76 89 74 88 74 / 40 40 30 40 30
Georgetown Muni Airport 74 89 73 92 72 / 30 30 20 20 20
Hondo Muni Airport 74 89 74 93 73 / 40 40 30 30 20
San Marcos Muni Airport 73 90 73 92 71 / 30 30 20 20 20
La Grange - Fayette regional 74 89 74 93 72 / 30 30 20 20 20
San Antonio International Airport 75 89 75 93 74 / 30 30 20 30 20
Stinson Muni Airport 75 90 74 93 74 / 30 40 20 30 20