Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/13/19
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
717 PM CDT Thu Sep 12 2019
See below for the 00z aviation discussion...
A few showers and thunderstorms are lingering this evening near AUS
and SAT, but these should avoid both terminals. This activity should
come to an end in an hour or two with the loss of daytime heating.
Otherwise, expect MVFR CIGs to develop at SAT/SSF by around 9z Friday
morning, and at DRT by 11z Friday morning. MVFR CIGs will be possible
at AUS Friday morning, but for now have kept them at VFR (but show
SCT015 for the possibility of MVFR CIGs). CIGs should improve to VFR
by late Friday morning. Winds will generally be out of the southeast
around 5 to 10 knots throughout the TAF period.
.PREV DISCUSSION... /ISSUED 234 PM CDT Thu Sep 12 2019/
SHORT TERM (Tonight through Friday Night)...
Afternoon water vapor imagery shows the mid/upper level disturbance
that has been lingering over the region the past few days has begun
to shear out as upper ridging spreads farther into the region from
the east. Area radars show scattered thunderstorms lifting into
Atascosa, Karnes, DeWitt, and Lavaca Counties along the sea breeze.
Aircraft soundings from Austin and San Antonio as well as 2 PM
surface observations show the environment ahead of the sea breeze has
a fairly dry sub-cloud layer in place (surface dew point depressions
of around 30 degrees). This will mean stronger thunderstorms this
afternoon and evening are again capable of a localized gusty wind
threat. Unlike the past few days though, drier air was noted between
900-500 MB and this will likely help erode showers and thunderstorms
as they move farther north. High resolution guidance has remained
fairly consistent in bringing the sea breeze towards the Interstate
35 corridor by sunset, so expect at least a few showers and
thunderstorms to make a run towards the Austin and San Antonio metros
but decrease in coverage upon approach. Loss of heating will allow
for convection to quickly dissipate by 8-9 PM.
Clearing skies this evening may allow for enough radiational cooling
to promote some light or patchy fog development early Friday morning
in the Coastal Plains and into Central Texas, especially in areas
that saw rain yesterday. Some pre-dawn stratus is also expected near
and west of the Interstate 35 corridor. Surface flow backing ahead
of a cold front stalling across North Texas may also result in enough
orographic lift to produce an isolated shower or two across the Hill
Country, but with weak winds through 900 MB confidence in this
happening is low. Otherwise, expect overnight lows in the upper 60s
to mid 70s.
Expect highs to climb into the lower 90s in the Hill Country and mid
90s to near 100 tomorrow afternoon. Have trended temperatures above
blended and MOS guidance as models have struggled to capture how
efficiently the region has been heating the past few days. Another
round of showers and thunderstorms possible again along the sea
breeze, with backed low level flow likely limiting inland extent of
the sea breeze and keeping rain chances only in the Coastal Plains.
Loss of heating will again result in this activity dissipating Friday
evening with overnight lows in the mid 60s to low 70s.
LONG TERM (Saturday through Thursday)...
Upper ridging sprawls across the southern US on Saturday through
Monday while an inverted mid-level trough retrogrades underneath it
towards northern Mexico. This will keep rain chances nil for the
region on Saturday and allow for high temperatures to remain in the
mid 90s to near 100 for most of the region this weekend. The
inverted trough may come close enough to the region to allow for the
southern and southeastern counties to see a passing shower or storm
on Sunday and Monday afternoons, but still expect most areas to
remain dry into early next week. An upper trough sliding into the
western United States from the Pacific on Tuesday and Wednesday
begins to dampen the ridging over Texas, which may allow for
increasing (albeit still low) rain chances to spread farther into
South Central Texas along the sea breeze each afternoon.
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 72 99 73 99 73 / 20 10 0 0 0
Austin Bergstrom Intl Airport 71 97 72 99 71 / 20 10 0 0 0
New Braunfels Muni Airport 71 97 71 98 71 / 20 10 0 0 0
Burnet Muni Airport 70 95 71 95 70 / 20 10 0 0 0
Del Rio Intl Airport 74 97 72 97 71 / 20 10 - 0 0
Georgetown Muni Airport 71 97 72 99 71 / 20 10 0 0 0
Hondo Muni Airport 72 98 71 100 70 / 20 10 0 0 0
San Marcos Muni Airport 70 97 71 98 70 / 20 10 0 0 0
La Grange - Fayette Regional 72 98 73 99 72 / 20 10 0 0 0
San Antonio Intl Airport 73 97 73 98 73 / 20 10 0 0 0
Stinson Muni Airport 74 96 73 97 73 / 20 10 0 0 0
Public Service/Data Collection...EWilliams