Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX

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FXUS64 KEWX 250444
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1044 PM CST Tue Nov 24 2020

.AVIATION...
The front is already moving through the Hill country, a bit ahead of
schedule. It is producing showers from south of Llano (AQO) to near
Burnet (BMQ), with storms to the northeast of Burnet. While some
development south is possible, think that in general the
precipitation will stay to the north of AUS. Will maintain the VCTS
though for the next few hours at AUS. Will also hang onto the MVFR
cigs building in soon at AUS based on surrounding reports and the
trends in the GOES satellite output over the last half hour showing
an expanding low cloud deck ahead of the front. The front should
arrive between 07z-09z for the I-35 terminals turning winds out of
the north, with winds already northerly at DRT. VFR conditions are
expected behind the front, with winds picking up through the
Wednesday morning hours.

&&

.PREV DISCUSSION... /ISSUED 853 PM CST Tue Nov 24 2020/

UPDATE...
Quick update to expand PoPs slightly across the Hill Country
beginning at 9pm through the overnight hours. The front is already
making its way into Val Verde County having moved through Sonora.
Showers and a few thunderstorms tended from near Brady (to the north
of Mason) to near San Saba and Stephenville. This broken line of
showers and storms will continue to move basically due east.

The best chances for precipitation in the Hill Country and Austin
Metro will be for folks in Llano, Burnet, and Williamson Counties
through the next 6 hours or so. Rain chances do extend down into
Gillespie, Blanco, Travis, Bastrop, and Lee Counties, although
chances are lower the further south you go. Rainfall totals out of
this line so far have averaged 0.05-0.25 of an inch.

PREV DISCUSSION... /ISSUED 539 PM CST Tue Nov 24 2020/

AVIATION...
VFR conditions continue this evening as southerly winds begin to
decrease ahead of the front which is currently moving through the San
Angelo area as of 2330z. The front should arrive at DRT by 03z and by
10z at the I-35 terminals with a northerly wind shift. Some MVFR
ceilings are possible at AUS before the front arrives, with a low but
non-zero chance of some MVFR at SAT/SSF as well. The time window for
this MVFR stratus would be between 06z and the fronts arrival around
10z. AUS also has the greatest chance of seeing some isolated shower
and thunderstorm activity as the front moves through so have included
a VCTS there. There is already several light to moderate showers
along the front. Behind the front skies should clear with VFR
conditions expected through the rest of the TAF period. Winds will go
from southerly to northerly behind the front and be gusty at times
Wednesday morning before decreasing in the afternoon.

PREV DISCUSSION... /ISSUED 312 PM CST Tue Nov 24 2020/

SHORT TERM (Tonight through Wednesday Night)...
Surface low pressure over the Panhandle this afternoon will push
across the Plains and western Great Lakes through this forecast
period. Southerly flow has increased as expected across south-
central TX bringing warm, moist air into the region with
temperatures in the upper 60s to low 80s at 18Z and sticky dew
points in the 60s to near 70. Coverage of drizzle/light showers
through the AM was perhaps a bit higher than expected but most
locations topped out well under a tenth of an inch and showers
should come to an end by mid-afternoon. Cloud cover has been slow to
erode over the east half of the area but will clear out by the
evening, and winds should diminish after sunset though expect a few
25-30 mph gusts in the meantime.

Overnight, the next cold front will push in. Some low clouds and
patchy fog are likely to redevelop over our far southeastern
counties ahead of the front, but are unlikely to reach any further
inland than the Balcones Escarpment. Front should move in from the
far northwest around 02Z, reach the I-35 corridor in the 07-09Z time
frame, and exit to the southeast by about 14Z Wednesday at the
latest. Along the front, some showers may impact locations northeast
of a line from Yoakum to San Marcos to Blanco. An isolated
thunderstorm cannot be ruled out either, but precipitation amounts
aren`t likely to add up to more than a couple tenths in a few lucky
locations.

Any precipitation should end prior to sunrise, with the post-
frontal airmass bringing drier air and more seasonal temperatures
though still slightly above normal for late November. Dew points
will drop into the 30s and 40s, but high temperatures should still
top out in the upper 60s to low 80s. With a dry airmass in place and
light winds, overnight lows for Thanksgiving morning look be much
cooler, in the 40s to low 50s.

LONG TERM (Thursday through Tuesday)...
Partly to mostly cloudy skies are expected across south-central
Texas on Thanksgiving day with highs in the mid 70s across the Hill
Country and upper 70s to lower 80s over the rest of the area. By
Thursday night into Friday morning, an upper level short wave is
forecast to push across the Four Corners region into the Southern
Plains. At the surface a strong cold front is forecast to push across
south-central Texas during the day on Friday. The combination of
these features bring great chances for rain across the area on
Friday into Saturday.

There is also the potential for thunderstorm development ahead and
along the cold front as it pushes to the southeast throughout the day
on Friday. The front is forecast to slow down when it gets to the
Coastal Plains on Friday. All global models (GFS, ECMWF and
Canadian) have the boundary between the middle to upper Texas coast
and the near shore waters from Friday evening into Saturday morning.
During this period, an upper level cutoff low system is forecast to
push across northern Texas to provide enough lift over the area to
keep high chances for showers and isolated to scattered thunderstorms
across south-central Texas.

Storm total rainfall amounts could range from one half to one inch
with isolated spots up to two inches along and east of Highway 281
with one quarter inch or less to the west of Highway 281.

Weather conditions improve late Saturday into Sunday as the upper
level low moves to the east of south-central Texas and the cold front
pushes into the central Gulf of Mexico. A dry and cold airmass
follows the cold front with Sunday`s highs in the 60s areawide. The
cold airmass stays in place for few days across the area with lows in
the lower 30s across the Hill Country and 40s across the rest of the
area on Monday morning. Monday`s highs in the mid 50s to lower 60s.
Under calm and light winds and partly cloudy to clear skies late
Monday night into Tuesday, lows could get into the mid 30s for most
areas and freezing temperatures across the Hill Country.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              81  54  71  43  76 /  30  30   0   0   0
Austin Bergstrom Intl Airport  82  53  72  42  77 /  20  20   0   0   0
New Braunfels Muni Airport     82  58  77  46  79 /  20  -    0   0  -
Burnet Muni Airport            77  48  69  42  76 /  10  30   0   0   0
Del Rio Intl Airport           86  53  77  47  78 /   0   0   0   0   0
Georgetown Muni Airport        80  51  69  42  75 /  20  30   0   0   0
Hondo Muni Airport             85  54  79  48  79 /  10   0   0   0   0
San Marcos Muni Airport        81  55  74  44  78 /  20  20   0   0   0
La Grange - Fayette Regional   81  59  74  46  80 /  20  30   0   0  -
San Antonio Intl Airport       80  57  76  47  77 /  20  -    0   0  -
Stinson Muni Airport           84  58  77  48  77 /  10   0   0   0  -

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

Short-Term/Aviation...Treadway
Long-Term...05


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