Special Weather Statement, NWS Austin/San Antonio, TX

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
426 AM CDT Tue Jul 20 2021

.UPDATE...
Made two slight changes to the recent forecast package. Added some
areas of fog across portions of the Hill Country with mainly calm
winds and low-levels near saturation with the temperatures falling
down to near the dew points. A few reporting stations currently
reporting visibilities down to a quarter mile across that region.

Additionally, raised the PoPS out ahead of the current convective
line from highway 90 down to Dimmit County as the line advances
southward. Heavy rainfall with rainfall rates up to 1 to 2 inches
remains possible. Doppler estimates of 2 to 3 inches of rain have
fallen to the east of Spofford. Gusty winds could accompany this
activity as well.

&&

.PREV DISCUSSION... /ISSUED 321 AM CDT Tue Jul 20 2021/

SHORT TERM (Today through Wednesday)...
After convection had moved through the area during late yesterday
afternoon and evening in association with an outflow boundary in
advance of the rare mid to late July front, activity had quickly
tapered off and has left remnant mid to high level clouds over the
region. A group of showers and isolated thunderstorm activity have
rejuvenated along the Rio Grande overnight and are moving southward.
Otherwise, latest water vapor imagery shows drier air is working
into the region from the north, where PWATs are dropping below 1.25
inches. While this drier air helps suppress rain chances, still
expect some redevelopment of isolated to widely scattered convection
during Tuesday afternoon with a weak vort max pivoting around the
trough axis that sits across the Mid-South into Texas. The rain
chances remain highest towards the south across the Coastal Plains
and Winter Garden regions where the higher PWATs and greatest
surface convergence resides.

Any activity that is able to establish Tuesday afternoon likely
wanes into Tuesday night with loss of daytime heating but will
continue to keep in some low end chances for any rouge isolated
activity. Isolated to widely scattered activity should develop
Wednesday with daytime heating as the center of the cutoff upper
level low moves more directly over North-Central Texas.

Beyond the rainfall chances, conditions are to feel quite
comfortable across the region for middle to late July, with
temperatures running several degrees below average as afternoon
highs range from the upper 80s into the lower 90s. With some
slightly lower dew points as well, overnight lows should trend
slightly cooler as well, especially across the Hill Country.

LONG TERM (Wednesday Night through Monday)...
As the upper level low moves to the west while passing just to our
north on Thursday, isolated to scattered showers and thunderstorms
are expected. The threat for heavy rainfall has decreased as moisture
levels are now forecast to be only slightly above normal. However,
cannot rule out a few brief heavy downpours.

The upper level low moves off to the west as the Subtropical Ridge
begins to build over our area on Friday with only isolated showers
and thunderstorms expected as near normal moisture levels linger.

The Subtropical Ridge builds in fully this weekend and then is the
dominant influence for next week and likely beyond. Subsidence and a
drier airmass keep rain out of the forecast. However, an isolated
afternoon shower or thunderstorm is possible over western Val Verde
county this weekend.

Below normal temperatures on Thursday will gradually warm to near
normal this weekend into next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              89  72  90  72  90 /  30  20  30  10  30
Austin Bergstrom Intl Airport  88  71  89  71  90 /  30  20  30  10  40
New Braunfels Muni Airport     90  72  90  72  90 /  30  20  30  20  40
Burnet Muni Airport            87  70  87  71  89 /  20  20  20  -   20
Del Rio Intl Airport           95  74  93  75  95 /  20  10  20  10  20
Georgetown Muni Airport        87  70  89  71  90 /  20  20  30  -   30
Hondo Muni Airport             91  72  89  72  90 /  20  10  30  20  40
San Marcos Muni Airport        89  71  89  71  90 /  30  20  30  10  40
La Grange - Fayette Regional   89  74  90  75  91 /  30  20  30  10  40
San Antonio Intl Airport       90  73  89  73  89 /  30  20  30  20  50
Stinson Muni Airport           91  74  90  75  90 /  30  20  30  20  40

&&

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

Short-Term/Aviation...Brady
Long-Term...04

Hazardous Weather Outlook...UPDATED
National Weather Service Austin/San Antonio TX
914 AM CDT Mon Jul 19 2021

TXZ171>173-183>194-202>209-217>225-228-201415-
Llano-Burnet-Williamson-Val Verde-Edwards-Real-Kerr-Bandera-
Gillespie-Kendall-Blanco-Hays-Travis-Bastrop-Lee-Kinney-Uvalde-
Medina-Bexar-Comal-Guadalupe-Caldwell-Fayette-Maverick-Zavala-
Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-Dimmit-
914 AM CDT Mon Jul 19 2021

This Hazardous Weather Outlook is for South-Central Texas..

.DAY ONE...Today And Tonight.

Locally heavy rainfall and isolated minor flash flooding may be
possible from this afternoon into tonight with scattered to
numerous showers and thunderstorms associated with a rare July
front moving into and across the region. Some of these storms
could be strong to marginally severe with thunderstorm damaging
winds being the main threat.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Wet pattern continues with scattered to numerous showers and
thunderstorms from Tuesday through Friday. In addition to cloud-
to-ground lightning, locally heavy rainfall and minor flash
flooding may be possible.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report any flooding to the National
Weather Service.

Special Weather Statement
National Weather Service Austin/San Antonio TX
451 AM CDT Tue Jul 20 2021

TXZ202-217-218-228-201045-
Maverick TX-Kinney TX-Dimmit TX-Zavala TX-
451 AM CDT Tue Jul 20 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN KINNEY...MAVERICK...
DIMMIT AND WESTERN ZAVALA COUNTIES UNTIL 545 AM CDT...

At 450 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 16 miles northwest of Quemado to 8 miles
southeast of Paloma to 8 miles northwest of Las Colonias. Movement
was south at 30 mph.

Wind gusts up to 50 mph and heavy rains up to 3 inches will be
possible with these storms.

Locations impacted include...
Eagle Pass, Crystal City, Carrizo Springs, Spofford, Quemado, La
Pryor, El Indio, Asherton, Chula Vista, Chula Vista-River Spur,
Darling, Las Colonias, Brundage, Carrizo Hill, Gilson Groves, Rosita,
Paloma, Winter Haven, Cometa and Radar Base.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 2840 10035 2845 10034 2848 10037 2850 10033
      2852 10039 2858 10040 2866 10050 2880 10053
      2891 10064 2909 10067 2917 10078 2929 10073
      2902 9985 2821 9947 2820 10021
TIME...MOT...LOC 0950Z 013DEG 17KT 2907 10086 2883 10029 2882 9990

CP