614
FXUS64 KEWX 271834 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
134 PM CDT Sat Apr 27 2024

...New AVIATION...

.SHORT TERM...
(Today through Sunday)
Issued at 147 AM CDT Sat Apr 27 2024

Key Points

* Isolated to scattered strong to severe storms overnight into early
  Sunday
* All hazards possible, including large (possibly very large greater
  than >2 inch) hail, damaging winds, and a tornado or two

Although an upper level trough currently near the Four Corners
region will move over the Central Rockies today, Central High Plains
tonight, and Northern Plains on Sunday, troughiness remains near the
Four Corners region through Sunday. The dryline will mix east into
Val Verde County by midday, perhaps the Winter Garden region late
afternoon, then drift back west this evening. Forcing ahead of these
features along with heating should generate some showers under the
capping inversion with some instability allowing for a few possibly
strong thunderstorms through this evening. Gusty southerly winds
along and east of US 281 could approach advisory levels, at times
today.

As the upper level trough axis lifts into the Plains tonight, a
Pacific front will overtake the dryline and move east into the
Edwards Plateau and Hill Country overnight. Forcing by these
features will generate a line of showers and thunderstorms with
supercells possible ahead of the line. Recent models have trended
slower with this evolution due to the upper level dynamics tracking
a little farther north. This may reduce the severe threat somewhat,
however forecast soundings still show very high CAPE and strong
shear. Thus, all severe hazards are possible, including large
(possibly very large, greater than 2 inches) hail, damaging winds,
and a tornado or two. The line will reach the I-35 corridor early
Sunday morning and then gradually weaken with loss of significant
forcing by late morning into afternoon. Heating may allow for
redevelopment mid afternoon just east of the stalled front near and
east of the I-35 corridor. Forecast soundings indicate a few strong
to perhaps severe storms are still possible in the afternoon.

High temperatures will be near normal east of the front/dryline and
well above normal along/west of the front/dryline. Elevated fire
weather conditions are expected west of the front/dryline each day,
though especially on Sunday as humidities fall into the single
digits and teens along with winds of 10 to 15 mph and gusty. There
is a potential of near critical fire weather conditions around
midday on Sunday across the Rio Grande where winds may peak in the
15 to 20 mph range.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 147 AM CDT Sat Apr 27 2024

A few lingering showers and storms from Sunday`s system will be
possible across our far eastern counties Sunday night, though better
chances for convection will likely be further east by this point.
West-southwesterly flow then sets up for the remainder of the long
term period with embedded disturbances in the 500mb flow resulting
in at least low chances for showers and thunderstorms across
portions of the CWA each day. Only weak ripples in the flow are
noted in the global guidance on Monday and Tuesday, and therefore
PoPs are fairly low and mainly confined to the eastern half of the
CWA. A stronger disturbance is then expected late Wednesday into
Thursday with slightly higher and more widespread chances for
showers and storms. PoPs from Friday onwards are a bit more
uncertain and will be primarily driven by a cold front pushing into
the region. At this point, guidance differs on whether the front
will push completely through south-central Texas or stall near/over
the area. The latter would likely bring cooler and more stable
conditions heading into next weekend, while a stalled front would
likely provide continuing chances for showers and storms.

For the time being, no particular day through the upcoming week
stands out as a favorite for severe weather potential, but it
doesn`t take much for storms to reach that intensity this time of
year so this is something we`ll have to continue to monitor. As far
as temperatures are concerned, above normal temperatures will
prevail through the week with potential for cooler temperatures by
the weekend if the aforementioned front is able to push completely
through the area.

&&

.AVIATION...
(18Z TAFS)
Issued at 1254 PM CDT Sat Apr 27 2024

No significant changes have been made to the latest aviation
forecasts. Clouds will lift above MVFR over the next hour as gusty
southeast winds continue. Some isolated showers will also continue
from the Hill Country into the I-35 corridor. Coverage is too low to
mention in the forecast for today. MVFR cigs return around 02Z to the
I-35 corridor and around 07Z out west at DRT. Gusty southeast winds
will persist through this evening and well into Sunday morning.
Attention turns to a line of storms developing early Sunday across
the southern Edwards Plateau and Hill Country. The I-35 sites stand
the best chance for TSRA in the 11-17Z timeframe, with an earlier
onset at DRT, 07-11Z. We have kept Prob30 groups for now, but suspect
this will go up in subsequent forecasts.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              85  70  82  68 /  20  60  80  10
Austin Bergstrom Intl Airport  85  70  82  68 /  20  40  80  20
New Braunfels Muni Airport     87  71  83  68 /  20  40  70  10
Burnet Muni Airport            83  66  81  65 /  30  80  60  10
Del Rio Intl Airport           97  69  94  67 /  10  50   0   0
Georgetown Muni Airport        84  69  81  66 /  30  70  80  10
Hondo Muni Airport             88  68  87  66 /  20  60  60  10
San Marcos Muni Airport        86  70  82  68 /  20  40  70  20
La Grange - Fayette Regional   85  72  83  70 /  10  20  80  50
San Antonio Intl Airport       85  70  84  69 /  20  50  70  10
Stinson Muni Airport           87  72  85  70 /  20  40  70  10

&&

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

$$

Short-Term...Platt
Long-Term...MMM
Aviation...Platt