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

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FXUS64 KEWX 030521

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1221 AM CDT Fri Jul 3 2020

Models are still showing some decent chances of MVFR coming into at
least SAT/SSF before dawn. Kept with this trend and also adding in
some SCT clouds at both AUS and DRT as some guidance points to lower
cigs as well. Confidence is low overall as satellite showing plenty
of mid-high clouds moving in from the north and northeast. If skies
clear just a bit, might get some patches of MVFR by early morning at
AUS. Already seeing some patches develop near Gonzales. And down to
the southwest, lamp guidance is pointing toward maybe some decks
along the Rio Grande in the mid morning hours. Input some SCT decks
to start the trend. These DRT low clouds will also depend on how
thick the mid-high clouds move in overnight. Winds will be generally
from the south and southeast through the period. High clouds should
scatter out during the day on Friday but still be present. The
building upper ridge should do a good job of keeping lower clouds at
a minimum during Friday afternoon.


.PREV DISCUSSION... /ISSUED 633 PM CDT Thu Jul 2 2020/

Upper level high pressure will build over South Central Texas
tonight and Friday. This will weaken the southeasterly flow into the
region and reduce the amount of low level cloud cover overnight. All
terminals are currently VFR and will remain that way through the
evening. MVFR ceilings will develop in the San Antonio area overnight
and only last until mid-morning. DRT and AUS will remain VFR. Winds
will be generally less than 10 kts in Austin and San Antonio during
the day Friday.


SHORT TERM (Today through Friday)...
Weakness in the ridge and the piece of vorticity that brought storms
to the Trans Pecos and Val Verde county last night/early this
morning has since dissipated. The remnant MCV has taken a dive
southwestward further into Mexico and our CWA look to remain rain
free for the remainder of the short term. There is a slim chance
that storms could redevelop over the Del Burros/Trans Pecos and
attempt to make it into western Val Verde county late this afternoon
but latest high resolution guidance has backed off on any convection
later today. Took mention of slight chances for storms out of the
forecast for this reason.

Subtropical ridge builds and expands over the region and will be the
dominant feature driving our weather pattern. While temperatures
will be on the increase for late this week, dewpoints will be well
mixed at the surface and should keep heat indices from climbing to
advisory criteria. Temperatures will run in the upper 90s both today
and tomorrow with a few locations reaching the century mark out
along the Rio Grande.

LONG TERM (Friday Night through Wednesday)...
The upper level ridge will continue to dominate the weather through
the July 4th weekend. With the ridge extending well into the Central
Plains afternoon highs will climb to near 100 degrees for most areas,
including the I-35 corridor. The Rio Grande Plains will see highs
103-105 for the Saturday through Monday time frame. This could also
produce the first 100 degree day at San Antonio for 2020. The ridge
will also keep the weather dry due to sinking air (subsidence) across
South Central Texas.

A weak upper level low across the Southeast U.S. will help weaken
the ridge and push it back across the Desert Southwest for the start
of next week. This will result in northerly flow aloft and help
funnel a disturbance south across Texas during the day on Monday. Due
to the moist environment in place the added lift of the disturbance
along with daytime heating could spark off some isolated showers and
thunderstorms during the afternoon and evening hours. The upper level
low mentioned above will strengthen slightly and move north across
Arkansas on Tuesday. It will interact with increased moisture and
could produce shower and thunderstorm activity across East Texas,
some of which could impact the HWY 77 corridor Tuesday afternoon from
Elgin to Bastrop to Gonzales and Cuero and points east. The ridge
builds back in on Wednesday cutting off rain chances for the middle
and end of next week.

Heat index values each day through the holiday weekend and into next
week will range from 99 to 105 so if you are out and about
celebrating be sure to drink plenty of water, wear light colored
clothing, and hang out in the shade.


Austin Camp Mabry              74 100  76 100  76 /   0   0   0   0  -
Austin Bergstrom Intl Airport  72  99  75 100  75 /   0   0   0   0  -
New Braunfels Muni Airport     72  99  73 100  75 /   0   0   0   0  -
Burnet Muni Airport            72 100  74  99  75 /   0   0  -    0  -
Del Rio Intl Airport           76 104  78 105  79 /   0   0   0   0  -
Georgetown Muni Airport        74 101  76  99  76 /   0   0  -   -   -
Hondo Muni Airport             72 102  73 102  74 /   0   0   0   0   0
San Marcos Muni Airport        71 100  73 100  74 /   0   0   0   0  -
La Grange - Fayette Regional   74  99  75  99  76 /   0   0  -   -   -
San Antonio Intl Airport       74 100  75 100  76 /   0   0   0   0  -
Stinson Muni Airport           73 100  75 101  76 /   0   0   0   0   0




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