Area Forecast Discussion Issued by NWS Austin/San Antonio, TX
000
FXUS64 KEWX 251121 AAA
AFDEWX
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
621 AM CDT Mon Mar 25 2024
...New AVIATION (12Z TAFS)...
.SHORT TERM...
(Today through Tuesday)
Issued at 200 AM CDT Mon Mar 25 2024
Regional radar imagery shows a line of showers and isolated embedded
thunderstorms pushing southeastward into the Hill Country and
Southern Edwards Plateau early this morning. SPC RAP mesoanalysis
shows a powerful 150 kt jet streak at the 300mb level over South
Central Texas, which is fueling some rather strong 0-6 km bulk shear
in excess of 70 kts across the entire region. Despite the strong
deep layer shear, instability is lacking, so any storms that develop
are unlikely to produce more than perhaps some penny to nickel size
hail. MLCAPE in the 500-1000 J/kg range could aid that hail
development, but due to the time of day, convective inhibition is
quite strong and will remain so through daybreak. Outflow has
already managed to outrun these storms over our western CWA and will
continue to do so through mid morning before storms are out of our
region by midday.
Winds will rapidly increase behind the frontal boundary, with
sustained westerly winds of 20-30 mph, gusting to 45+ at times from
midday through sunset or shortly after before subsiding to less than
10 mph by late evening. A Wind Advisory and a Red Flag Warning are in
effect for the Rio Grande Plains, Southern Edwards Plateau, Western
Hill Country, and Winter Garden where minimum relative humidities
will fall into the 10-20% range, along with dry to critically dry 10
hour fuels in these areas. Factoring in sustained winds of 20-30 mph,
gusting to 45+ at times will lead to critical fire weather
conditions this afternoon and evening for the areas mentioned above.
Elsewhere, an RFD is in place for the Hill Country and I-35/I-37
Corridors where RH values could dip to 15-25%.
Temperatures will warm into the 70s for most today, but cooler and
much drier air will filter in behind the cold front by tonight as we
fall into the 40s area wide. On Tuesday, highs will struggle to get
out of the 60s over the Hill Country and Austin Metro, but lower to
middle 70s can be expected everywhere else. We should see plenty of
sunshine, but some clouds will start to return by later in the day.
&&
.LONG TERM...
(Tuesday night through Sunday)
Issued at 200 AM CDT Mon Mar 25 2024
Fire weather concerns continue on Wednesday into Thursday out west. An
upper level trough moves across the Plains on Wednesday. Forcing by
the trough as well as a surface boundary (dryline/residual front) on
nearly seasonal PWs could produce a few showers and maybe a storm or
two mainly over the Hill Country to along and east of the I-35
corridor. Southerly lower level flow takes hold in response to
deepening surface low pressure in the Plains on Thursday through next
weekend. Moisture increases in the east on Thursday and all areas by
Friday and may lead to patchy drizzle next weekend. After mainly
below normal low temperatures mid week, a warming trend to above
normal temperatures is expected late week through next weekend.
&&
.AVIATION...
(12Z TAFS)
Issued at 557 AM CDT Mon Mar 25 2024
Few changes to the ongoing forecast. The only change is to remove
mention of thunder at AUS as the threat appears to be to the north of
the terminal now rather than along the advancing line of showers.
Winds have already shifted out of WNW and have opted to keep the LLWS
mention in at SAT and SSF through 14Z. Showers should wrap up by 14Z
at SAT and SSF and by 13Z at AUS. Not ruling out the possibility that
some lingering showers stick around after those times, but will go
with the timing mentioned above. Winds will be strong today out of
the west at 15-20 kts sustained, gusting to 25-30 kts. DRT will see
gusts to 40 kts at times. Winds should rapidly drop off and remain
more westerly after 02Z tonight followed by the arrival of a
secondary boundary from the north, resulting in a wind shift to the
north at AUS by 09Z and by 12Z at SAT and SSF. VFR ceilings are
expected after 14-16Z this morning at the I-35 sites.
&&
.FIRE WEATHER...
Issued at 200 AM CDT Mon Mar 25 2024
Critical fire weather conditions will exist today over the Rio
Grande Plains, Southern Edwards Plateau, Western Hill Country, and
Winter Garden where minimum relative humidities will fall to between
10-20% along with gusty westerly winds of 20-30 mph, gusting to 45+
at times. Factoring in 10 hour fuels at less than 3% for a majority
of the area mentioned, a Red Flag Warning is in effect from noon
until 8pm today along with a Wind Advisory from 11am to 7pm. A
Rangeland Fire Danger Statement is in effect for areas east of the
Red Flag Warning, the Hill Country and I-35/I-37 corridor until 8pm.
The dry airmass will persist across many of the same areas on Tuesday
and Wednesday. This further dries the vegetation leading to
increasing fire danger and lowering percentiles of 10 hour and 100
hour fuels. In addition, these regions have had very little rainfall
recently and will only have spotty wetting rains early this morning.
Elevated to near critical fire weather conditions are expected each
day with Rangeland Fire Danger Statements likely for parts of those
areas.
In spite of southerly winds returning on Thursday, moisture recovery
will be poor out west with one more day of elevated to near critical
fire weather conditions likely there. A more significant moisture
recovery is expected on Friday through next weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 78 48 68 48 / 30 0 0 0
Austin Bergstrom Intl Airport 77 43 67 45 / 30 0 0 0
New Braunfels Muni Airport 79 46 71 46 / 30 0 0 0
Burnet Muni Airport 73 42 65 45 / 10 0 0 0
Del Rio Intl Airport 79 53 80 55 / 0 0 0 10
Georgetown Muni Airport 76 43 65 44 / 30 0 0 0
Hondo Muni Airport 78 46 77 48 / 10 0 0 0
San Marcos Muni Airport 78 45 69 45 / 40 0 0 0
La Grange - Fayette Regional 77 47 67 46 / 60 0 0 0
San Antonio Intl Airport 78 48 73 49 / 20 0 0 0
Stinson Muni Airport 80 49 75 50 / 20 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 11 AM this morning to 7 PM CDT this evening for
Bandera-Dimmit-Edwards-Frio-Kerr-Kinney-Maverick-Medina-Real-Uvalde-
Val Verde-Zavala.
&&
$$
Short-Term...MMM
Long-Term...04
Aviation...MMM