363
FXUS64 KEWX 171726
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1226 PM CDT Mon Jun 17 2024

...New AVIATION...

.UPDATE...
Issued at 647 AM CDT Mon Jun 17 2024

We`re seeing some streamer showers across the CWA this morning. These
should continue for another few hours, and we have updated the
forecast to add a mention of intermittent light rain until mid-
morning.

&&

.SHORT TERM...
(Today through Tuesday)
Issued at 216 AM CDT Mon Jun 17 2024

A mid-level trough over the western Gulf has pushed the subtropical
ridge toward the west over northern Mexico. Southeasterly flow in
the low levels has continued over the last 24 hours. A warm, moist
airmass remains in place over South Central Texas. The upper trough
over the Gulf will continue to push slowly to the west while the low
level flow continues from the southeast. The weakening of the ridge
will allow for possible showers and thunderstorms over the Coastal
Plains counties today. A little more cloudiness today will keep
temperatures a few degrees lower than yesterday. Convection should
end with the loss of daytime heating. There is a small chance for
some streamer showers overnight, but chances are so low that we will
not include any mention in the forecast. Overnight lows will be
similar to today. As the Gulf trough approaches the coast rain
chances will push farther inland Tuesday. Slight chances for showers
and thunderstorms will reach I-35 during the afternoon with better
chances over the Coastal Plains. Temperatures will drop another
couple of degrees.

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 216 AM CDT Mon Jun 17 2024

The latest NHC forecast for the formation of a tropical system in
the southwestern Gulf of Mexico has a 60 percent chance in the next
48 hours, and a 70 percent chance over the next 7 days. PWATS
continue to increase overnight Tuesday into Wednesday with all of
the area seeing values over 2 inches by Wednesday afternoon. This
moisture and disturbance will bring increasing shower and
thunderstorm chances to the area from east to west through the day
on Wednesday with these chances continuing through much of the day
Friday. There still remains considerable differences in exactly how
this system will track, which in turn leads to many solutions for
rainfall amounts from mid to late week.

The NBM gives roughly a 30 to 60 percent chance for all of South
Central Texas to see two inches or greater rainfall through Friday
which remains similar to the GEFS ensemble probabilities. The latest
ECMWF ensemble guidance gives only about a 40 to 60 percent chance
for an inch or more for our southernmost tiers of counties at this
time, so quite a difference from other guidance. GEFS probabilities
for 4 or more inches of rain during this time along and east of I-35
remain at 30 to 40 percent. Taking all of this into consideration,
there looks to be a high potential most of the area will see some
rain mid to late week, with a medium potential for heavy rain which
could lead to flooding or flash flooding. WPC has increased the the
potential for excessive rainfall to a level 3 of 4 for portions of
the coastal plains and I-35 corridor, with a level 2 of 4 elsewhere
for Wednesday into Thursday morning. The day 4 forecast (Thursday
into Friday morning) remains similar to yesterday with the level 2 of
4 risk shifting across the western half of the area.

Cloudy conditions will lead to much cooler than normal temperatures
during this time with highs mainly in the 80s Wednesday and
Thursday. A warming trend may be seen again Friday into the weekend,
although forecast temperatures still remain below 100 degrees for
this timeframe. Rain chances decrease Friday night into Saturday
morning for much of the area, with chances returning for the coastal
plains each afternoon this weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 1223 PM CDT Mon Jun 17 2024

VFR conditions are prevailing across most locations at the present
time and should remain so through the remainder of the afternoon and
evening. There are some showers primarily east of the I35 corridor
and will not mention anything in the TAFs for now. Another round of
MVFR ceilings is expected overnight tonight into tomorrow morning.
Winds will remain out of the south/southeast with speeds up to 15-20
knots at times.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              94  76  92  74 /  10   0  20  20
Austin Bergstrom Intl Airport  94  75  92  74 /  10   0  20  20
New Braunfels Muni Airport     96  76  94  74 /  10   0  20  20
Burnet Muni Airport            93  75  90  73 /  10   0  10  10
Del Rio Intl Airport          103  80 101  78 /   0   0   0   0
Georgetown Muni Airport        93  74  90  72 /  10   0  10  20
Hondo Muni Airport             98  76  95  75 /   0   0  10  10
San Marcos Muni Airport        94  74  92  73 /  10   0  20  20
La Grange - Fayette Regional   91  76  90  74 /  30  10  30  30
San Antonio Intl Airport       95  77  94  74 /  10   0  20  20
Stinson Muni Airport           98  78  95  76 /  10   0  20  20

&&

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

$$

Short-Term...05
Long-Term...27
Aviation...29