638
FXUS64 KEWX 121113 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
613 AM CDT Sun May 12 2024

...New AVIATION (12Z TAFS)...

.SHORT TERM...
(Today through Monday)
Issued at 207 AM CDT Sun May 12 2024

The latest GOES 16 IR imagery shows a 500mb closed low over
southwestern Colorado. At the surface, easterly flow has resumed
after a cooler and comfortable day by early to mid-May standards.
Moisture should start to work back in, but dewpoints should start to
rise once again overnight and get back into the 70s by midday
Sunday. Mother`s Day will be a muggy day, but on the cooler side
over the eastern half of the region as cloud cover will be hard to
break. Further west, highs should climb back into the mid to upper
80s and lower 90s once again along the Rio Grande as low clouds
break towards the afternoon hours.

The short term forecast is a messy one, as precip chances look
difficult to predict through Sunday night. Confidence remains low on
timing of any thunderstorms and where they ultimately develop. Light
showers and occasional drizzle should continue through the morning
hours as isentropic ascent is realized with east to southeasterly
flow on the 300k surface. By the afternoon, as instability
increases, some strong to severe storms will be possible. The latest
day 1 outlook from the Storm Prediction Center places the Hill
Country, I-35 Corridor, and Coastal Plains within a Level 1 of 5
Risk, while a small portion of the CWA from east of Austin to La
Grange and northward is in a Level 2 of 5 Risk. All modes of severe
weather are possible, but at this time, the greatest threat appears
to be large hail. Any discrete storm that can tap into rich boundary
layer moisture could also start rotating, with a tornado or two also
possible. Ultimately, the greater severe threat for Sunday lies just
to our east, but conditions should be monitored closely nonetheless.

Monday brings a greater threat for widespread strong to severe
storms as the associated 500mb trough starts to move eastward. On
it`s southern periphery, a potent shortwave will round its base and
move through south Central Texas. A cold front will approach from
the northwest and work through the entire CWA by sunset Monday. SPC
places the eastern Hill Country, I-35/I-37 Corridor, and Coastal
Plains within a Level 2 of 5 Risk on Monday. The primary concern
looks to be large to very large hail along with damaging winds, but
a tornado or two cannot be ruled out along the boundary early in the
afternoon. The RRFS, HRRR, FV3, and NSSL WRF are all on board with
afternoon convection. The real item up in the air is what happens
before the lunch hour. Some members of the HREF develop early
morning convection over the Hill Country and spread it eastward
while others show little to no activity at this time. For now, focus
will be on the afternoon storm chances as instability, shear, lift,
and lapse rates will be highest within this time frame, but morning
storm chances will have to be monitored as well.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 207 AM CDT Sun May 12 2024

A cold front will be moving out of the area with possibly some
showers or thunderstorms Monday night over the Coastal Plains before
pushing east overnight. Dry conditions are then expected for Tuesday
through Wednesday morning as upper ridging moves overhead. Above
normal temperatures are expected Tuesday afternoon from the mid 80s
in the northeastern portion of the area to the upper 90s and 100
degree mark in the west along the Rio Grande. A trough located just
off the southern coast of California on Tuesday will move east
towards the Plains Wednesday and Thursday. This will bring the next
chances for precipitation to the area late Wednesday afternoon
through Thursday night. There remains the potential for some severe
thunderstorms and heavy rainfall with this activity. The current
forecast places the heaviest rain potential over the northeastern
portion of the CWA which is also where WPC has placed a level 2 of 4
risk for excessive rainfall.

For now, the forecast remains on the dry side Friday through the
weekend although there is decent spread in model guidance after the
mid-week system. Some low precipitation chances may be introduced
for next weekend in the coming forecasts. A warming trend is
possible late week into next weekend.

&&

.AVIATION...
(12Z TAFS)
Issued at 602 AM CDT Sun May 12 2024

Very few changes from the going forecast. Confidence remains quite
low on timing and placement of TS today. Will stick with the PROB30
groups at AUS, SAT, and SSF and introduce PROB30s for tomorrow AM at
AUS and SAT. Winds should remain less than 10 kts for the most part
out of the southeast to east-northeast by late tonight. Ceilings
should remain IFR/MVFR through midday before lifting to MVFR/VFR. No
other significant changes at this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              80  72  87  67 /  50  40  60  10
Austin Bergstrom Intl Airport  80  71  87  65 /  50  40  60  10
New Braunfels Muni Airport     85  72  89  67 /  50  20  60  10
Burnet Muni Airport            77  70  85  63 /  50  30  30   0
Del Rio Intl Airport           94  74 101  70 /  20  20  10   0
Georgetown Muni Airport        77  70  86  64 /  50  40  60   0
Hondo Muni Airport             89  73  92  66 /  20  20  30   0
San Marcos Muni Airport        82  71  88  65 /  50  30  60  10
La Grange - Fayette Regional   80  73  86  67 /  50  40  60  20
San Antonio Intl Airport       88  73  90  68 /  40  20  40  10
Stinson Muni Airport           89  74  91  69 /  30  20  40  10

&&

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

$$

Short-Term...MMM
Long-Term...27
Aviation...MMM