
483
FXUS64 KEWX 122251
AFDEWX
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
551 PM CDT Sun Apr 12 2026
...New AVIATION...
.KEY MESSAGES...
- Flood Watch in effect for potentially life-threatening flash flooding
somewhere in the watch area this afternoon and evening over
the I-35 Corridor and Coastal Plains.
- A very humid and unsettled weather pattern continues through the
middle of the upcoming week with daily rain and thunderstorm
chances.
- Another round of strong to severe storms is possible today, with
the greatest threat out west along the Rio Grande.
- The potential for strong to severe storms and locally heavy
rainfall continues into early next week.
&&
.SHORT TERM...
(Tonight through Monday night)
Issued at 101 PM CDT Sun Apr 12 2026
Broad southwesterly flow at 500mb will continue for the foreseeable
future. This will lead to a series of mid-level shortwaves rippling
through this broad SW flow aloft. Each shortwave may fire off
showers and storms, but both storm intensity and coverage are
highly dependent on the timing of these individual shortwave
disturbances. One such shortwave will move through the region this
afternoon/evening, with the HRRR along with HREF indicating the
potential for flash flooding and severe storms with large hail and
damaging winds.
Locally heavy rainfall that could lead to flash flooding is
possible, especially over the I-35 Corridor and Coastal Plains where
a Flood Watch is in effect through Monday morning for potential of 2-
4 inches of rain with some isolated amounts between 5-10
inches. PWATs between 1.25-1.75" are around 150-175% of of normal
for mid-April over South Central Texas. Any storms that form will
likely contain torrential rainfall, with training of storms
being the primary reason for the flooding concerns.
Rainfall rates of up to 2-3" per hour are possible given the
environment in place and a quick 5-10" is possible within the
watch area. Be sure to monitor the weather and have Wireless
Emergency Alerts active on your phone in the event of a Flash
Flood Warning.
Despite dryline storm initiation yesterday, any convection that
forms this afternoon/evening will be tied to the strength of the
mid-level shortwave embedded in this southwesterly flow. Model Theta-
e forecasts indicate the dryline will sharpen well west of our area,
over West Texas, however, 0-6km Bulk Shear of 35-45 kts, in
combination with HREF SBCAPE values in the 2000-3000 J/kg range will
produce a favorable environment for severe storms to form. Large
hail appears to be the primary concern as well given the HRRR
spitting out MUCAPE values >3000 J/kg and 700-500mb lapse rates
between 7-8 C/km. Any storms that can tap into this environment out
west this afternoon may produce golf ball to tennis ball size hail.
Damaging wind and a tornado cannot be ruled out either, but hail
looks to be the biggest threat. The Storm Prediction Center has most
of our area within a Level 2/5 risk today, given the environment
noted above.
Monday will feature yet another threat for strong to severe storms.
SPC has another level 1 of 5 risk for the Edwards Plateau
and Rio Grande Plains. Monday`s storm threat will be focused more on
dryline development than Sunday`s storms. Storms would develop over
west of the Rio Grande and move off higher terrain or the dryline
over west Texas and into the EWX CWA. Once again, the greatest
threat from any storms that form looks to be large hail, but
damaging wind is also a possibility. PWATs are not as high on
Monday out west, so the flooding threat is low.
&&
.LONG TERM...
(Tuesday through next Sunday)
Issued at 101 PM CDT Sun Apr 12 2026
The long term period will remain active, as that persistent
southwesterly 500mb flow continues. An upper level trough that`s
slowly moving inland over California will finally move into the Four
Corners by Tuesday morning. Another round of showers and storms,
some strong to severe is possible Tuesday, again over the Southern
Edwards Plateau and Rio Grande Plains. Another round of showers and
storms, some possibly strong to severe, will occur Wednesday
afternoon and evening, primarily west of I-35, but some of these
storms could work east into the I-35 Corridor late Wednesday
evening.
The upper level trough will eventually eject and open up over the
Plains on Wednesday, bringing an end to our more active stretch of
weather the past week. Thursday and Friday will feature highs back
in the mid to upper 80s with dry conditions. Beyond that, global
models are actually in agreement on the passage of a fairly strong
cold front for mid-April. While the ECMWF has a passage on Saturday
afternoon, the GFS has a frontal passage on Saturday night. Both
models feature rain and thunderstorms developing along this front.
It is too early to say whether severe weather is possible with this
boundary, but keep checking back over the next couple days as the
forecast is further refined and confidence increases.
&&
.AVIATION...
(00Z TAFS)
Issued at 550 PM CDT Sun Apr 12 2026
Mainly VFR to MVFR conditions across the area to start the period
with MVFR ceilings favored to develop again first over I-35 corridor
and Coastal Plains, then spread west across the area into early
Monday morning. Showers may continue over the I-35 terminals for the
next few hours with low chances for thunderstorm redevelopment
tonight that will need to be monitored. Ceilings likely drop to IFR
between 03-06Z at I-35 terminals, then around 12Z for KDRT. Ceilings
may drop to LIFR and patchy dense fog may develop, but confidence is
low and not mentioned in the forecast. Ceilings are slow to lift and
scatter with IFR to MVFR conditions into early Monday afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 70 85 69 86 / 60 10 0 10
Austin Bergstrom Intl Airport 69 85 68 85 / 60 20 0 10
New Braunfels Muni Airport 69 86 68 86 / 50 20 10 10
Burnet Muni Airport 67 83 67 82 / 50 10 10 20
Del Rio Intl Airport 70 87 70 84 / 10 20 40 40
Georgetown Muni Airport 69 82 67 82 / 60 10 0 10
Hondo Muni Airport 67 85 68 85 / 40 20 20 20
San Marcos Muni Airport 69 85 68 85 / 60 20 10 10
La Grange - Fayette Regional 70 85 69 87 / 50 20 0 0
San Antonio Intl Airport 70 85 70 85 / 50 20 10 10
Stinson Muni Airport 71 86 70 86 / 40 20 10 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Monday morning for TXZ173-191>194-206>209-
223>225.
&&
$$
SHORT TERM...MMM
LONG TERM....MMM
AVIATION...27
No recent Short Term Forecast (NOW) has been issued for NWS Austin/San Antonio CWA (EWX).
Special Weather Statement Issued: 04/13/2026 03:42:00 AM UTC