FXUS64 KEWX 261122

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
622 AM CDT Wed Sep 26 2018

IFR conditions at San Antonio sites this morning with morning
stratus setting up before improvement to MVFR conditions later this
morning. This afternoon, a cold front reaches all TAF sites with a
chance of thunderstorms between 16-21z. Behind the front, winds out
of the north from 10-12kts with possible gusts up to 20kt.


.PREV DISCUSSION... /ISSUED 419 AM CDT Wed Sep 26 2018/

SHORT TERM (Today through Thursday)...
Surface observations from early this morning show a cold front
located from near Pecos to Abilene. An area of convection stretching
from the southern portion of the Texas Panhandle into the low
rolling plains is noted behind the front. A little closer to home,
current radar data shows a few showers are developing across south
central Texas. The low-level jet is fairly weak, but given plenty of
moisture, we should continue to see shower development through early
this morning.

The above mentioned cold front is set to make steady southward progress
through south central Texas today. As the front moves southward, it
will encounter plenty of moist air. The front and moisture combination
along with a weak trough in the mid and upper levels will lead to a
good chance of showers and storms today. Rain chances in the morning
hours will be favored along the coastal plains, where moisture
levels will be highest. Chances for rain will also be favored across
the western/northern Hill Country where a line of convection should
develop along the front during the late morning hours. The front will
make steady southward progress and will help maintain/initiate a
line of convection through the afternoon into early evening hours.
Some brief heavy rainfall may lead to some minor flooding, especially
over areas that have recently experienced recent heavy rains over
the past several days. High temperatures today will be coolest across
the far northern Hill Country into the southern Edwards Plateau. It
will be warmest along the Rio Grande south of Del Rio into the
coastal plains.

Most of the stronger convection should move south of the coastal
plains by early evening. Rain chances will continue tonight as the
upper trough over the northern half of Texas continues to sharpen. We
should see mostly showers, but a few storms can't be ruled out. The
upper trough axis moves through central and north Texas on Thursday
and with drier air moving in behind the trough, rain chances will
decrease from west to east on Thursday. High temperatures on Thursday
will generally remain in the 70s, likely making this day the coolest
of the forecast period.

LONG TERM (Thursday Night through Tuesday)...
On Friday, surface winds will transition to a more southerly
direction, leading to an increase in low-level moisture. Meanwhile, a
subtropical upper jet will remain overhead. The models continue to
disagree in handling the mid-level flow pattern. Given return flow,
the upper jet and some weak shortwave activity in the mid-levels, we
should see scattered convection Friday through the upcoming weekend.

High pressure in the mid-levels is then expected to build in from the
east early next week. We will begin to lower rain chances for early
next week, but for now have opted to maintain a very low chance for
showers and storms to account for some isolated, diurnally-driven


Austin Camp Mabry 86 61 77 66 82 / 60 40 20 10 20
Austin Bergstrom Intl Airport 86 62 78 66 83 / 60 50 20 10 20
New Braunfels Muni Airport 86 62 78 66 83 / 70 50 20 10 30
Burnet Muni Airport 79 58 75 64 81 / 50 20 20 10 20
Del Rio Intl Airport 85 62 79 67 83 / 50 40 20 10 20
Georgetown Muni Airport 84 60 76 65 82 / 60 30 20 10 20
Hondo Muni Airport 86 62 79 67 83 / 60 40 20 10 20
San Marcos Muni Airport 86 62 78 66 83 / 70 50 20 10 30
La Grange - Fayette Regional 86 66 79 68 84 / 80 60 40 20 40
San Antonio Intl Airport 86 62 78 67 82 / 70 50 20 10 20
Stinson Muni Airport 87 64 78 69 83 / 70 60 20 10 20




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