169
FXUS64 KEWX 092256
AFDEWX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
556 PM CDT Thu May 9 2024

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE FOR SEVERE THUNDERSTORM WATCH 224...
Issued at 548 PM CDT Thu May 9 2024

Severe thunderstorms have developed along a cold front and dryline in
Central TX and are moving toward the southeast. We expect additional
storms to develop this evening as the boundaries move toward our CWA.
We have issued a Severe Thunderstorm Watch for most of the Hill
Country and northern I-35 Corridor until midnight tonight.
Thunderstorms will be capable of producing hail up to three inches in
diameter, wind gusts up to 80 mph, and a tornado or two.

&&

.SHORT TERM...
(Tonight through Friday night)
Issued at 340 PM CDT Thu May 9 2024

Early this afternoon a surface cold front stretched from north Texas
into a triple point in west central Texas with the dryline extending
south from there. Very humid and warm conditions exists south of the
cold front and east of the dryline, along with very unstable
conditions above the cap. The cap is still present on ACARS soundings
out of AUS, but has shown initial signs of a weakening trend. The
strong surface heating should continue this trend into the late
afternoon across the Hill Country and Austin metro area. CAMs have
been indicating upstream convection along the aforementioned surface
features to enter Llano and Burnet counties after 5 PM and into the
Austin metro area after 7 PM. A few WoFS members are initiating
convection ahead of the dryline as far south as Medina and Kendall
after 5 PM. MLCAPE values are forecast to be an impressive 3500-4500
J/kg south of the cold front and east of the dryline, and with
sufficient effective bulk shear values isolated storms developing
into or over the Hill Country and into the I-35 corridor near Austin
will be very capable of producing very large hail and damaging
straight-line winds. An isolated tornado can`t be ruled out. A Level
2-3 out of 5 risk for severe storms is still in place for this area.
It`s less certain how far south the storms can make it into the mid
and late evening as convective inhibition begins to build into the
Coastal Plains and San Antonio metro area, but we will watch these
areas closely. The storms are eventually forecast to weaken and
dissipate late evening east of I-35 and north of I-10.

The cold front is forecast slip through most of the central and
eastern areas tonight. Drier and "cooler" air will be in place for
Friday. The front should also help to sweep a lot of the haze out of
the area, which has partially been caused by background residual
smoke in the air originating from seasonal burnings in Mexico and
Central America.

The cold front is forecast to hang up along the Rio Grande Friday
morning. Models have been consistent with developing convection
across this region midday Friday, with downstream development and
propagation back into the western Hill Country and possibly San
Antonio metro area in the afternoon. Isolated strong to severe
storms could be possible Friday afternoon into the early evening.
SPC has placed portions of the Rio Grande, southern Edwards Plateau,
western Hill Country, and San Antonio metro area in a Level 1 out of
5 risk for severe storms Friday, with large hail the primary risk.

Finally, temperatures this afternoon across western areas along the
Rio Grande and south of U.S. 90 will top out around 100-105 degrees,
with mid 90s into the western Hill Country, San Antonio metro, and
inland Coastal Plains. East of the dryline, these temperatures
combined with the humidity may cause heat illness for those that are
not acclimated to the early season heat or are not taking proper
heat precautions. We have issued a Special Weather Statement for
this. High temperatures Friday are forecast to range from the low to
mid 80s north of I-10 to upper 80s to low 90s south.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 340 PM CDT Thu May 9 2024

A period of active weather will likely continue across portions of
the long-term portion of the forecast. However, wide spread chances
for significant severe weather will not be as high this weekend as
in the short-term. A subtle disturbance will move into the area this
weekend providing some lift for a 20-40 percent chance of showers
and isolated storms mainly out west Saturday. This activity will
transition into much of the remainder of the forecast area for
Sunday with increasing PoPs. Overall, instability amounts will be
meager but given the convective season, can`t completely rule out a
strong storm at times during the weekend. Rain amounts for the
weekend will likely average a half an inch or less for most
locations but some isolated higher amounts will also be possible.

For early next week, a weak boundary may bring additional rain
chances to portions of the CWA on Monday. If this were to verify
some severe weather may be possible as instability amounts are
expected to increase. After probable dry weather on Tuesday, another
disturbance could bring additional chances of thunderstorms
Wednesday evening. Highs this weekend will mostly be in the 70s and
80s but will return into the 80s and 90s next week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1242 PM CDT Thu May 9 2024

Most locations are VFR midday, with the exception of some BKN MVFR
ceilings still east of I-35 and I-37, which will scatter our shortly.
The VFR conditions will continue through the afternoon and evening
hours, away from any convection. In addition, haze will continue
across portions of south central Texas south of a cold front and
east of the dryline, at times reducing visibility to 6SM. TSRAs
developing across north and central Texas through the afternoon hours
near where the dryline intersects a southward moving cold front. A
few of these TSRAs could impact areas near and north of a AQO-AUS-3T5
line through the evenings hours. Environmental conditions support
some storms to become severe, producing very large hail and wind
gusts in excess of 50KT.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              70  85  65  82 /  40  10  10  10
Austin Bergstrom Intl Airport  70  83  65  81 /  40  10  10  10
New Braunfels Muni Airport     71  86  67  84 /  20  10  10  20
Burnet Muni Airport            66  81  63  78 /  40  10  10  20
Del Rio Intl Airport           76  89  72  86 /  10  60  40  40
Georgetown Muni Airport        67  81  63  79 /  50  10  10  20
Hondo Muni Airport             72  87  68  83 /   0  20  10  20
San Marcos Muni Airport        70  84  65  82 /  20  10  10  10
La Grange - Fayette Regional   72  86  67  82 /  30  10  10  10
San Antonio Intl Airport       72  86  68  82 /  10  20  10  20
Stinson Muni Airport           74  87  69  84 /  10  20  10  20

&&

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

$$

Mesoscale...05
Short-Term...76
Long-Term...29
Aviation...76