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

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856
FXUS64 KEWX 121959
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
159 PM CST Tue Nov 12 2024

...New SHORT TERM, LONG TERM, FIRE WEATHER...

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 106 PM CST Tue Nov 12 2024

Upper air analysis this morning showed the sub-tropical ridge
bulging up from the Gulf with a trough from UT/CO to Baja
California. The flow over Texas was from the southwest. Low level
winds are from the southeast with high pressure centered to the
northeast of the region. The airmass is warm and moist with
temperatures in the 70s and 80s and dewpoints in the 60s. The upper
trough will move into west Texas and then lift out to the northeast
turning the flow to zonal. The low level flow will remain
southeasterly tonight. With the weather pattern staying about the
same tonight will be similar to last night. Temperatures will be
within a couple of degrees of this morning`s lows. A cold front will
move through West Texas tonight reaching our northwestern border by
morning. This front will move across our CWA during the day
Wednesday. Without much moisture or upper support, the front will
move through dry. Winds will shift to the northwest bringing cooler,
drier air. High temperatures Wednesday will be dependent on when
the front passes any particular location. Highs over the northwest
will be a few degrees cooler while the southeast will be a little
warmer. Dewpoints will drop 20-25 degrees from this afternoon to
Wednesday after over the northern and western part of the CWA. See
the Fire Weather discussing below for more on this. The cooler air
will continue to filter in Wednesday night and lows Thursday will be
around 10 degrees cooler.

&&

.LONG TERM...
(Thursday through Tuesday)
Issued at 106 PM CST Tue Nov 12 2024

A surface high will be situated over the Hill Country early Thursday,
resulting in good radiational cooling with dry air in place behind
Wednesday`s cold front. Temperatures will start out in the 40s and
lower 50s with a more comfortable forecast for Thursday afternoon.
Highs should be closer to normal for mid-November, but still some 3-5
degrees above normal with highs in the mid to upper 70s. The
"cooldown" won`t last long as Pacific cold fronts don`t typically
bring as much cool air to the table as Polar fronts do. We`ll get one
more cool/borderline chilly morning Friday before highs climb back
into the upper 70s/lower 80s in the afternoon as southeasterly winds
return on the backside of the departing surface high.

Low level moisture will be on the increase this weekend as we turn
our attention to the west coast. A powerful storm system will plow
through the Desert Southwest, centering as far south as the southern
Arizona/southern New Mexico border late Sunday. Breezy southerly flow
will ramp up ahead of this new storm system, which will initially
send a Pacific front through our CWA on Monday afternoon. Showers and
thunderstorms will develop along this boundary, with a low chance to
be strong to severe. Slightly cooler air filters in behind this
front, but then we wait for the stronger front, this time, of Polar
origin, to push through the region next Tuesday. It is worth noting
that nearly every member of the ECMWF ensemble and GFS ensembles
depict this frontal boundary, so confidence has increased
significantly in a large scale pattern change for the beginning of
next week. While we will certainly take the cooler weather as the
last month+ of heat and dry air has been unwelcome. However, rain
chances look rather slim with this boundary, so we`ll have to wait
longer to see if this newer pattern can bring better rain chances
back into the forecast.

&&

.AVIATION...
(18Z TAFS)
Issued at 1132 AM CST Tue Nov 12 2024

All terminals will have only few to scattered clouds through the next
TAF period. Southeasterly winds at less than 10 kts will continue
through the afternoon and early evening and then become light this
evening. Winds will become southwesterly Wednesday morning. A cold
front will move through the region during the afternoon turning the
winds to the northwest.

&&

.FIRE WEATHER...
Issued at 106 PM CST Tue Nov 12 2024

A dry, Pacific cold front will move through south-central Texas on
Wednesday with fire weather concerns for some areas behind it.
Relative humidity will drop below 30% across the area along and west
of I-35 and below 20% over the southern Edwards Plateau and most of
the Rio Grande Plains. Winds will also be breezy behind the front.
The combination of low RH and breezy winds will likely lead to near
critical fire weather conditions over the west with elevated
conditions over the Hill Country.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              59  86  51  76 /   0   0   0   0
Austin Bergstrom Intl Airport  57  86  51  76 /   0   0   0   0
New Braunfels Muni Airport     60  87  52  78 /   0   0   0   0
Burnet Muni Airport            59  81  48  74 /   0   0   0   0
Del Rio Intl Airport           66  85  50  79 /   0   0   0   0
Georgetown Muni Airport        58  84  49  74 /   0   0   0   0
Hondo Muni Airport             61  85  51  78 /   0   0   0   0
San Marcos Muni Airport        58  85  50  76 /   0   0   0   0
La Grange - Fayette Regional   55  85  50  76 /   0   0   0   0
San Antonio Intl Airport       62  85  54  78 /   0   0   0   0
Stinson Muni Airport           62  87  55  79 /   0   0   0   0

&&

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

$$

Short-Term...05
Long-Term...MMM
Aviation...05