513 
FXUS64 KEWX 160101 AAA
AFDEWX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
801 PM CDT Sat Oct 15 2022

...New UPDATE...

.UPDATE...
Issued at 755 PM CDT Sat Oct 15 2022

Elected to add some patchy fog across the coastal plains from late 
overnight into Sunday morning. Additionally, with a slightly faster
timing of the cold front across the region Sunday evening/night, I
have elected to lower the temperatures during Monday for areas that 
are mainly located along and north of the I-35 corridor, where the
temperatures will fall into the upper 50s and low to mid 60s by the
late afternoon. Kept rain chances the same as the previous package
at this time.

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 157 PM CDT Sat Oct 15 2022

Synopsis/Mesoanalysis: Split flow continues to prevail over much of 
the CONUS. The northern stream, associated with an upper disturbance 
centered just to the southwest of Hudson Bay, swings east-southeast 
from the northern Rocky Mountains into the Ohio and Tennessee River 
Valleys. The accompanying southern stream speed max spreads zonally 
from the base of a cutoff low centered off the Baja California 
coastline into the lower Mississippi Valley and central Gulf Coast. 
The two features will continue to persist through tomorrow afternoon 
and evening, likely beginning to interact to some extent from the 
southern Plains east into the southeastern US. In the lower levels, 
a baroclinic zone is evident across central Oklahoma east into the 
Ozark Plateau. The boundary should serve as a focus for convective 
initiation across this region later today, with attendant outflows 
driving the front into the Edwards Plateau through tomorrow morning 
and afternoon. 

Tonight: Have largely removed previous slight chance mentions of 
showers and thunderstorms predawn over portions of the Rio Grande 
Plains and southern Edwards Plateau. The impulse which will 
facilitate activity should track largely north and west of the 
region, keeping precipitation chances confined mostly to the MAF and 
SJT CWAs. An isolated shower or storm can't be completely ruled out 
over far northern Edwards and Val Verde Counties, where a sliver of 
precip probabilities remain. The vast majority (if not all) of the 
area will remain dry, with low stratus developing nocturnally once 
again. Lows should thus remain in the upper 60s and low 70s across 
the area. 

Tomorrow: Expect highs in the 80s and low 90s. Thanks in large part 
to outflow from tonight's convection over the Red River Valley and 
ArkLaTex, the cold front mentioned above will begin to approach from 
the north by late afternoon/early evening. Likely due to 1) stubborn 
low stratus in the morning and 2) residual mid-upper level cloud 
debris from overnight and early morning thunderstorms to our north, 
convection allowing models continue to suggest little PM surface 
destabilization and attendant shower/storm development along the 
front as it approaches. Have thus trimmed precip probabilities back 
through sunset in light of these trends, though an isolated 
thunderstorm can't be entirely ruled out closest to the likely 
surface position of the boundary from the southern Edwards Plateau 
east into Hill Country. Have continued slight chance thunder 
mentions in these regions. 

Tomorrow Night: This continues to be a period that bears close 
watching. Convective development appears likely near and after 00Z 
over the lower Trans-Pecos as the speed max connected to the Baja 
cutoff begins to overspread the region. Activity should spread east 
into the Rio Grande Plains and Winter Garden moving deeper into the 
overnight hours, with lighter/more scattered precip possible over 
Hill Country and the the I-35 corridor. The cold front will 
concurrently be approaching and entering the southwestern CWA. 
Combined with nocturnally-amplifying east to southeast low level 
flow and attendant moisture advection, the forcing from the front 
and any impulses embedded within the mid level speed max could 
create a favorable setup for multiple episodes of convection over 
portions of the Rio Grande Plains and Winter Garden through the 
predawn hours Monday. Given the presence of 1.50-2.00" precipitable 
water values pooled along the front, as well as a nearly 
antiparallel alignment between the low and mid level flow, heavy 
rainfall and backbuilding/training would be possible in said setup. 
Lots of model spread continues to exist regarding accumulations, 
particularly between the CAMs and global ensembles, so we will 
refrain from suggesting any specific totals in this discussion. WPC 
has included much of the Rio Grande Plains and portions of the 
Winter Garden in a slight risk in its D2 Excessive Rainfall Outlook 
in light of this potential. We will continue to closely monitor 
forecast trends and amend the forecast as necessary.

&&

.LONG TERM...
(Monday through Saturday)
Issued at 157 PM CDT Sat Oct 15 2022

Active southwest flow aloft along with some forcing along a cold
front will result in active weather along with a good chance of 
rainfall for portions of south central Texas. With a fairly shallow 
cold front near the surface and southeasterly winds initially in 
place around 850mb early Monday morning, scattered to numerous 
showers and thunderstorms are expected. The models continue to show 
the most favorable setup for rainfall will occur out west across the 
southern Edwards Plateau and Rio Grande plains. We will keep rain 
chances generally at or above 70% for the mentioned areas throughout 
the daytime hours on Monday. With marginal shear and instability in 
place, a strong to severe storm or two can't be completely ruled out 
mainly over the Rio Grande plains south of Del Rio. Gusty winds and 
marginally severe hail are the main concerns. In addition, some 
locally heavy rainfall may occur across the Rio Grande plains as 
moist southeast to easterly flow just above the frontal layer 
continues through most of the daytime hours. Farther east into the 
Hill Country and along/east of the I-35 corridor, the setup for heavy
rainfall does not appear too favorable at this time. We do expect 
some scattered showers and storms, but forecast rainfall amounts will
be significantly lower compared to values along the Rio Grande. 

For Monday night, northeasterly flow in the low-levels begins to
deepen and this will result in drier and more stable air being
advected into the region. We will begin to show much lower rain
chances over our northern areas, with higher rain chances farther
south into the Winter Garden region. In addition, the focus for any
strong storms and locally heavy rainfall should be mostly south of
our region by late evening. Most areas will remain dry on Tuesday as
gusty northeast winds behind the cold front spread across all of 
south central Texas. Much cooler high temperatures are in store with
highs only in the lower 60s to near 70s. Cloud cover will also
decrease from north to south as the day progresses. 

Low temperatures for Tuesday night into Wednesday morning will be
quite chilly with some upper 30s likely in the Hill Country and
mainly 40s expected elsewhere. Surface high pressure remains over 
the area Wednesday and this will result in highs in the upper 60s to
lower 70s. South to southwesterly winds in the low-levels return on
Thursday and highs will rebound back into the lower 70s to lower 80s.
Southerly flow in the low-levels continues to strengthen on Friday
and Saturday, with temperatures getting back closer to climatological
normals. 

&&

.AVIATION...
(00Z TAFS)
Issued at 640 PM CDT Sat Oct 15 2022

VFR flight conditions continue into tonight before deteriorating to 
IFR to MVFR levels during the overnight into Sunday morning with low
ceilings. Couldn't rule out some patchy fog for the I-35 sites but
likely will be more concentrated across the coastal plains. Ceilings
improve to VFR levels from Sunday afternoon into Sunday evening. A
stronger autumn cold front moves into South-Central Texas in the 24
to 30 hour TAF range and have inserted a PROB30 group at KAUS for
introduction for possible -TSRA. Otherwise, I have elected to keep
any precipitation mentions out of the rest of the TAF sites through
this TAF period. Light to moderate southeasterly winds continue with
winds then turning more easterly to northeasterly Sunday evening at 
KAUS and KSAT with the approach and passage of the aforementioned 
front. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              72  91  64  68 /   0  20  50  60 
Austin Bergstrom Intl Airport  68  90  62  69 /   0  20  50  60 
New Braunfels Muni Airport     71  92  66  71 /   0  10  50  60 
Burnet Muni Airport            69  87  60  65 /   0  30  60  60 
Del Rio Intl Airport           71  87  67  70 /   0  20  80  90 
Georgetown Muni Airport        70  88  61  66 /   0  20  50  60 
Hondo Muni Airport             70  92  69  72 /   0   0  60  70 
San Marcos Muni Airport        70  91  66  70 /   0  10  50  60 
La Grange - Fayette Regional   69  92  67  74 /   0  20  50  50 
San Antonio Intl Airport       71  91  68  71 /   0  10  50  60 
Stinson Muni Airport           72  93  70  73 /   0  10  50  60 

&&

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

$$

Short-Term...Brady
Long-Term...Platt
Aviation...Brady