Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Austin/San Antonio Texas
617 am CDT Thu Oct 17 2019
12z aviation forecast below.
VFR conditions through the taf period with broken cloud decks around
8-12k along with high cirrus through the morning. An upper level low
will move across the region today. While moisture is relatively
limited, there may be enough just enough mid level moisture, combined
with the upper level forcing, to produce isolated elevated shras.
A few showers have occurred overnight north and west of drt. The
greatest chances for shras through the morning and early afternoon
will be between drt and Sat, however coverage will remain sparse. Due
to the low probabilities and minimal coverage we have not included
mention in taf sites. Light and variable winds early this morning,
becoming NE around 5kt after 15z along and east of I-35 and southeast along
the Rio Grande. Winds could veer to east-southeast at Sat/ssf after 21z.
Previous discussion... /issued 307 am CDT Thu Oct 17 2019/
Short term (today through friday)...
an upper low over West Texas shift shift east to between San Antonio and
LaGrange by 00z Friday. NE winds in the lowest 5000 ft over eastern
counties will keep conditions dry over most areas, but areas closest
to and just south of the low could see a few showers and perhaps an
isolated storm. Isolated convection should remain possible through
noon over the Rio Grande plains and srn Edwards Plateau, and then
shift sewd to areas S/southeast of San Antonio this afternoon. Light east/NE
low level winds should initially succeed the low and with mostly
clear skies dropping temps to a few degrees below morning normals.
Near normal highs follow for Friday with mostly sunny skies and weak
ridging aloft building east across Texas.
Long term (friday night through wednesday)...
a shallow upper trough moves through OK Friday night. The surface
pressure gradient south of this system is tightened Friday afternoon
and evening, then relaxed by early Saturday morning. With minimal
elevated cloud cover expected, some low clouds and patchy fog are
anticipated for areas east of I-35 Saturday morning. A weak front is
partially pushed into south central Texas for Saturday while moisture
remains mostly shallow, so models are calling for another day where
temps manage to climb into the upper 80s to low 90s. More moisture
pooling at low levels will be possible for some fog late Saturday
night over the coastal prairies.
Broad troughing develops to the west of Texas Sunday, so an isolated
round of convection is depicted to account for slightly deeper
moisture over the eastern half of the forecast area. The upper
troughing sharpens over Texas as an upper low deepens over the
central/northern plains by Sunday night. A polar front is depicted to
collect enough moisture for a scattered round of storms late Sunday
night into midday Monday. Blended guidances show limited rain
potential with this system over the Rio Grande, but there is also a
Pacific tropical disturbance forecast to be near the Gulf of California by a
significant amount of the deterministic runs. Pops are capped mainly
at chance for now, but further confidence in a Pacific tropical tap
could trend chances toward likely in later forecasts.
Dry weather and near normal temps will follow the Monday front
through the middle of next week, but another front forecast for next
Thursday could send US a couple days of below normal temps heading
into next weekend.
Preliminary point temps/pops...
Austin Camp Mabry 55 82 65 91 65 / 0 0 0 - -
Austin Bergstrom Intl Airport 51 82 64 91 63 / 0 0 0 - -
New Braunfels Muni Airport 54 83 64 91 64 / - 0 0 0 0
Burnet Muni Airport 53 82 63 88 60 / 0 0 0 - 0
del Rio Intl Airport 57 85 64 92 64 / 0 0 0 0 0
Georgetown Muni Airport 51 82 64 89 62 / 0 0 0 - 0
Hondo Muni Airport 56 85 64 93 66 / 0 0 0 0 0
San Marcos Muni Airport 53 82 63 91 63 / 0 0 0 0 0
La Grange - Fayette regional 54 83 64 90 66 / 0 10 0 0 -
San Antonio Intl Airport 56 83 66 91 67 / 0 0 0 0 0
Stinson Muni Airport 56 85 66 91 67 / - 0 0 0 0