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

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
000
FXUS64 KEWX 232342 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
642 PM CDT Mon Oct 23 2017

.AVIATION.../00Z TAF CYCLE/

VFR will prevail through the entire TAF period with no aviation
weather impacts expected. Only weather feature of note will be a
surface wind shift from the current south/VRB wind to a stronger 10
knot north wind 05-07Z overnight with the passage of a weak cold
front. No appreciable weather will occur with the frontal passage
other than the wind shift. North winds will increase in the late
morning Tuesday through the afternoon with 10-15 knots sustained and
gusts in the low 20 knot range.

&&

.PREV DISCUSSION... /ISSUED 229 PM CDT Mon Oct 23 2017/

SHORT TERM (Tonight through Tuesday Night)...
The primary concern for the short term period is the passage of a
weak cold front overnight tonight and its effects on fire weather
potential for the CWA.

HRRR/RAP both bring the wind shift into the northern CWA around 03Z
this evening and exiting to the south by 11-12Z tomorrow morning.
Behind the front, sustained 15-25 mph winds with gust potential to 30
mph is possible. This front will also serve to maintain low dewpoints
and thus very low RH values, likely in the teens and low 20 percent
range across the CWA. The early passage of the front may be fortunate
for fire weather concerns as the pressure gradient is progged to
relax by early afternoon, lowering winds gradually throughout the
afternoon. However, there may be some locations where RH values fall
to near 20 percent while winds are still breezy. Thus have included
elevated fire weather wording in the FWF.

Guidance continues to drop the lows for Wednesday morning, and when
coupled with another excellent radiational cooling set up, this looks
like the right trend. Could see some mid thirties in the river
valleys and other low lying areas Wednesday morning, especially in
the Hill Country.

LONG TERM (Wednesday through Monday)...
The focus for the long term is similar to the short in that we will
have yet another cold front passage, however this one looks to be
significant enough to give South Central Texas its first real taste
of fall-like conditions as highs may struggle to reach 70 degrees
this weekend. There are still some disagreements in timing, but
models have been consistently advertising the cold front to begin
reaching the northern CWA overnight Thursday night.

The ECMWF, with respect to QPF/PoP chances, continues to be the
wetter of the two deterministic solutions, but again unable to
ascertain the source of the moisture availability to warrant its
output. There doesn`t seem to be a contiguous moisture conveyor for
efficient moistening of the column prior to fropa Friday morning, or
at least as far west as it does. The better alignment of upper level
RER with LLJ is well east, more along the TX/LA border. The GFS is
completely rain free and at present, believe it is more reasonable.

The coldest day of the next 7 may be Sunday morning as the center of
the surface high behind the front builds and settles over South
Central Texas. This should also be a clear night to go with calm
winds and could be enough to tank some locations in the Hill Country into
the lower 30s. Still some considerable spread in ensemble members
though so did not go too aggressive just yet. Maintained mid 30s for
Sunday morning in Hill Country with low 40s elsewhere.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              54  78  46  78  50 /   0   0   0   0   0
Austin Bergstrom Intl Airport  50  77  44  77  46 /   0   0   0   0   0
New Braunfels Muni Airport     52  77  44  78  46 /   0   0   0   0   0
Burnet Muni Airport            51  74  42  76  48 /   0   0   0   0   0
Del Rio Intl Airport           56  78  48  80  51 /   0   0   0   0   0
Georgetown Muni Airport        51  75  42  77  48 /   0   0   0   0   0
Hondo Muni Airport             52  79  43  80  46 /   0   0   0   0   0
San Marcos Muni Airport        51  77  43  77  46 /   0   0   0   0   0
La Grange - Fayette Regional   53  76  42  76  46 /   0   0   0   0   0
San Antonio Intl Airport       55  78  46  79  50 /   0   0   0   0   0
Stinson Muni Airport           56  78  47  80  49 /   0   0   0   0   0

&&

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

$$

Mesoscale/Aviation...Allen
Synoptic/Grids...Treadway



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.