Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX

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FXUS64 KEWX 080713

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
213 AM CDT Thu Jun 8 2023


(Today through Friday)
Issued at 210 AM CDT Thu Jun 8 2023

The MCS and associated MCV along the Rio Grande will continue to
slide southeast into South Texas through the early morning hours,
eventually decaying. Upstream convection in the northwest flow aloft
across West Central Texas should also gradually weaken as it
encounters higher convective inhibition, but could clip portions of
Llano and Burnet Counties during the pre-dawn hours.

A challenging forecast today with where convection re-develops and
how widespread it becomes. The ridge axis remains across eastern NM
and west TX. Downstream impulses in the northwest flow aloft will
continue to assist with convective development across the region
today. Initially in the morning debris cirrus shield, from current
ongoing convection, may limit destabilization in some areas. However,
as we lose some of this cloud cover several CAMs indicate by
afternoon development of showers and storms, but differ on convective
initiation placement and how much coverage and organization takes
place. We have increased PoPs to around 40-50% through portions of
the Hill Country, I-35 corridor, and Coastal Plains today. There is
currently a Level 1 of 5 risk for severe storms this afternoon across
this broad area, with hail and damaging wind gusts the primary
threats. This risk could increase if the more bullish CAM members
verify, such as the HRRR. The more aggressive HRRR is indicating a
pool of 2500-3500 J/kg of MLCAPE coinciding with bulk shear values of
around 40 KT, which would support intense updrafts. DCAPE values of
around 1500 J/kg are also indicated, supporting a risk for some
strong to severe downbursts. In addition, some pockets of heavy
rainfall could occur. HREF probability-matched mean indicates 1-2
inches of rainfall possible and max values of 2-3 inches. This would
be in isolated spots. A Level 1 of 4 risk for excessive rainfall
leading to flooding will be in place today through this region.
Convection should weaken and eventually dissipate after sunset.

The upper level ridge axis does nudge into the area on Friday. There
is a slight chance to see some isolated showers and storms develop
late afternoon on the downstream side of the ridge across Lee,
Fayette, and Lavaca Counties. In addition, upstream of the ridge
axis isolated storms could develop late afternoon and into the
evening across western Val Verde County, where there is a Level 1 of
5 risk for severe storms on Friday. Otherwise, warmer on Friday.


(Friday night through Wednesday)
Issued at 210 AM CDT Thu Jun 8 2023

There is high confidence in temperatures becoming above normal with
mainly dry conditions expected through the long term period.

Weak upper level ridging currently across New Mexico and west Texas
will become more centered over the region for this weekend. This
will allow for temperatures to warm into the mid to upper 90s for
most locations across south-central Texas, with even warmer heat
indices. By Sunday afternoon, temperatures will likely reach the
lower 100s for areas closer to the Rio Grande. The weak ridging will
largely preclude chances for showers and storms through the period,
but we do have isolated chances (~20%) in the forecast for Friday
evening across western Val Verde for any activity that might move
into the area from the dryline further west. We also cannot rule out
some activity across either far northern or western portions of the
CWA on Saturday afternoon as the dryline pushes further east and a
500mb shortwave briefly flattens the ridge, but the NBM is trending
dry for now. Chances may increase some once CAM guidance becomes
available for this time period.

Through early next week, higher heights aloft will push into Mexico
and then much of Texas, resulting in a continuing warming trend and
what will likely be the first 100 degree day(s) for much of the
area. Southerly to southeasterly surface flow in combination with
recent rainfall/relatively moist soils will also help keep dewpoints
fairly elevated, so much so that heat advisories may be needed by
mid-week next week for portions of the area. With the increasing
subsidence and weak flow aloft, dry conditions should prevail.


(06Z TAFS)
Issued at 1236 AM CDT Thu Jun 8 2023

A complex of strong to severe TSRA will impact areas near and west
of a DRT-CZT line over the next few hours. Gusty winds, hail, and
frequent lightning are occurring. In addition, isolated SHRA/TSRA may
clip areas near AQA and BMQ overnight. 00Z models have trended higher
with coverage of SHRA/TSRA during the day on Thursday. Activity is
forecast to develop 15Z-18Z through portions of the Hill Country and
move southeast through the I-35 corridor and into the Coastal Plains
during the afternoon and early evening hours. Some strong to severe
storms are possible, with large hail and wind gusts in excess of
50KT. Away from any SHRA/TSRA activity, VFR conditions are forecast
during the TAF period.


Austin Camp Mabry              91  72  97  74 /  50  10  10  10
Austin Bergstrom Intl Airport  90  70  96  71 /  50  20  10   0
New Braunfels Muni Airport     92  70  94  72 /  50  10   0   0
Burnet Muni Airport            88  70  96  73 /  40  10  10  10
Del Rio Intl Airport           97  74 102  76 /   0   0  10  10
Georgetown Muni Airport        89  70  96  73 /  50  10  10  10
Hondo Muni Airport             92  70  96  71 /  30  10   0   0
San Marcos Muni Airport        90  69  96  71 /  50  20  10   0
La Grange - Fayette Regional   90  70  94  73 /  50  20  20   0
San Antonio Intl Airport       91  71  95  73 /  50  10   0   0
Stinson Muni Airport           93  71  95  73 /  50  10   0   0





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