Special Weather Statement, NWS Austin/San Antonio, TX

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1243 AM CDT Thu May 14 2020

.AVIATION...
Low clouds moving in from the southeast and from Hill Country slowly
enveloping the I-35 corridor at this hour. MVFR conditions should
last several hours into the morning before a brief period of IFR.
Mostly cloudy skies prevail at all terminals tomorrow at VFR
categories.

&&

.PREV DISCUSSION... /ISSUED 1027 PM CDT Wed May 13 2020/

UPDATE...
The Severe Thunderstorm Watch for Val Verde County issued early
through 10 PM this evening was allowed to expire. There is strong to
severe thunderstorm moving across north central Val Verde County as
of this writing and we issued a Severe Thunderstorm Warning for it
through 11 PM. The storm is entering to an area where conditions are
less favorable to keep current status. Therefore, we think the storm
should begin to weaken within the next several volume scans.

Also with this update, removed the slight chances for showers and
thunderstorms over parts of south central Texas and kept showers
mentioned over two-thirds of the area in case some light shower
activity develops overnight as an upper level short wave moves over
the area. Still showing isolated thunderstorms over parts of the
western part of the Hill Country overnight where the better lift may
be present.

PREV DISCUSSION... /ISSUED 332 PM CDT Wed May 13 2020/

UPDATE...
Updated to add Severe Thunderstorm Watch 180 for Val Verde county
until 10 PM CDT.

PREV DISCUSSION... /ISSUED 228 PM CDT Wed May 13 2020/

SHORT TERM (Tonight through Thursday Night)...
Low stratus deck has struggled to scatter and lift this morning. SSE
wind have begun to pick up this afternoon which will encourage
boundary layer mixing and promote additional clearing. Scattered
streamer showers are depicted by several high res models over the
coastal plains and areas east of I-35 for this afternoon. Low-end
POPs in for this activity till 21Z.

Attention will then turn to west TX and the Big Bend region where
storms are expected to initiate along the dryline. Convective
initiation should be around 21Z when a shortwave makes it's way over
the state. Convective allowing models diverge on how this evening
activity is handled. General consensus is that shortly after sunset,
storms begin a downward trend and reach our far western counties as
they dissipate. Some outliers, like the ARW, carry this line of
potentially strong to severe storms a bit further into the interior
Hill Country and our central counties. One outlier, the 06Z and 12Z
3km NAM dissipates storms over the Rio Grande but carries a line of
storms into the northeastern Hill Country and over the Austin metro
all the way from northwest TX that developed along the dryline in
the late afternoon. Again this is an outlier but run to run
consistency has gained some attention. There will be a pretty strong
cap in place over our eastern counties this evening and overnight so
there is confidence that if any storms do make it as far as the I-35
corridor, it would be fairly weak. SPC does have our western 1/3
under a slight risk and a marginal risk stretching to the I-35
corridor. Main threats being large hail and damaging winds.

Overnight Wednesday, temperatures will remain warm, only dropping to
the low 70s for much of the region. Dewpoints will remain elevated
in the upper 60s to low 70s, so a warm and muggy night is in store.
Some fog development could take place for the interior Hill Country
with the absence of any rainfall but would remain confined to rural
areas of the Hill Country.

On Thursday, shower activity should be confined mostly along the
coast and over the Gulf as this latest disturbance continues
eastward. Kept low-end POPs in for our southeastern counties for
this. Slight warm up for Thursday with afternoon highs a couple of
degrees above what they were Wednesday and a brief break from rain
chances Thursday night.

LONG TERM (Friday through Wednesday)...
Models continue to be consistent with an upper level trough moving
across Texas for the end of the week. This will be a trigger for
showers and thunderstorms starting Friday and continuing through
Sunday. In the low levels warm, moist flow from the Gulf will prime
the atmosphere for a potential heavy rain event. PW values will
increase to 1.5 to 2.0 inches which is sufficient for heavy rain at
this time of year. At this time, the best chance for heavy rain looks
to be across the eastern half of our CWA. Rainfall totals from Friday
through Sunday morning will be generally two to four inches with
isolated amounts to six inches possible. Exact locations are hard to
determine at this time. This amount of rain will likely lead to
localized flooding and our confidence is growing that a Flash Flood
Watch will be needed for this time period. The upper system will move
slowly away from the region during the first part of next week and
low chances for showers will linger over the area Monday through
Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              86  71  86  68  79 /  20  -   50  60  80
Austin Bergstrom Intl Airport  86  70  86  67  79 /  20  -   50  60  80
New Braunfels Muni Airport     87  70  86  68  79 /  20  -   40  60  80
Burnet Muni Airport            85  69  84  66  77 /  10   0  40  60  70
Del Rio Intl Airport           93  74  90  68  90 /   0  -   40  70  30
Georgetown Muni Airport        86  70  86  67  78 /  10  -   40  60  80
Hondo Muni Airport             90  71  90  67  84 /  10   0  40  70  60
San Marcos Muni Airport        86  70  86  67  79 /  20  -   40  60  80
La Grange - Fayette Regional   86  72  86  69  80 /  30  10  40  50  90
San Antonio Intl Airport       88  72  87  69  82 /  20   0  50  70  70
Stinson Muni Airport           89  73  88  70  82 /  20   0  50  70  70

&&

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

Short-Term/Aviation...YB
Long-Term...Runyen

Hazardous Weather Outlook
National Weather Service Austin/San Antonio TX
415 AM CDT Wed May 13 2020

TXZ171>173-183>194-202>209-217>225-228-141000-
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-
415 AM CDT Wed May 13 2020

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

.DAY ONE...Today And Tonight.

Isolated severe storms are possible late this afternoon and
evening along the Rio Grande and southern Edwards Plateau. Large
hail and damaging straight-line winds are the primary threats.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Locally heavy rainfall is possible Friday night through Saturday
across South Central Texas. Between 2 and 4 inches of rainfall is
currently forecast, with isolated amounts of 6 inches. Dangerous
flash flood impacts and river flooding could occur. Further
details on timing, locations, and rainfall amounts will be refined
through the week.

.SPOTTER INFORMATION STATEMENT...

Spotter are encouraged to submit storm reports and rainfall
amounts to the National Weather Service.

Special Weather Statement
National Weather Service Austin/San Antonio TX
853 PM CDT Wed May 13 2020

TXZ183-140245-
Val Verde TX-
853 PM CDT Wed May 13 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN VAL VERDE COUNTY
UNTIL 945 PM CDT...

At 853 PM CDT, Doppler radar was tracking a strong thunderstorm 10
miles northwest of Pandale, moving east at 25 mph.

Nickel size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Pandale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm 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.

&&

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
south central Texas.

LAT...LON 3028 10176 3029 10161 3028 10136 3009 10140
      3018 10176
TIME...MOT...LOC 0153Z 271DEG 23KT 3027 10172

CP

Special Weather Statement
National Weather Service Austin/San Antonio TX
937 PM CDT Wed May 13 2020

TXZ183-140315-
Val Verde TX-
937 PM CDT Wed May 13 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN VAL VERDE COUNTY
UNTIL 1015 PM CDT...

At 937 PM CDT, Doppler radar was tracking a strong thunderstorm 10
miles southeast of Pandale, or 18 miles north of Langtry, moving east
at 25 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Juno and Bakers Crossing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm 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.

&&

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
south central Texas.

LAT...LON 3001 10155 3012 10153 3020 10103 2973 10114
TIME...MOT...LOC 0237Z 282DEG 22KT 3006 10147

CP

Special Weather Statement
National Weather Service Austin/San Antonio TX
1054 PM CDT Wed May 13 2020

TXZ183-184-140500-
Val Verde TX-Edwards TX-
1054 PM CDT Wed May 13 2020

...SIGNIFICANT WEATHER ADVISORY FOR EDWARDS AND NORTHEASTERN VAL
VERDE COUNTIES UNTIL MIDNIGHT CDT...

At 1054 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 22 miles northwest of Rocksprings to 22 miles
south of Sonora to 10 miles west of Loma Alta. Movement was east at
35 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Rocksprings, Loma Alta, Carta Valley, Vinegarone, Devils River State
Nat Area Del Norte, Us-277 Near The Sutton-
Edwards County Line, Kickapoo Cavern State Park and Devil's Sinkhole
State Natural Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3029 10089 3029 10004 2963 10029 2962 10048
      2984 10109
TIME...MOT...LOC 0354Z 266DEG 30KT 3022 10050 3025 10072 2993 10096

CP

Special Weather Statement
National Weather Service Austin/San Antonio TX
1223 AM CDT Thu May 14 2020

TXZ184>186-140615-
Kerr TX-Edwards TX-Real TX-
1223 AM CDT Thu May 14 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN KERR...CENTRAL
EDWARDS AND NORTHERN REAL COUNTIES UNTIL 115 AM CDT...

At 1223 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles south of Telegraph to 14 miles
northeast of Vance to 9 miles east of Carta Valley. Movement was east
at 25 mph.

Nickel size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Vance, Kerr Wildlife Management Area, Barksdale, Devil's Sinkhole
State Natural Area and Prade Ranch.

LAT...LON 3027 9943 2995 9947 2965 10022 2975 10069
      3004 10011 3026 10003
TIME...MOT...LOC 0523Z 278DEG 20KT 3019 9990 3001 9992 2977 10052

RUNYEN

Special Weather Statement
National Weather Service Austin/San Antonio TX
103 AM CDT Thu May 14 2020

TXZ184>188-202-203-140700-
Uvalde TX-Gillespie TX-Kerr TX-Kinney TX-Edwards TX-Real TX-
Bandera TX-
103 AM CDT Thu May 14 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN BANDERA...KERR...
NORTHEASTERN KINNEY...NORTHWESTERN UVALDE...SOUTHWESTERN GILLESPIE...
SOUTHEASTERN EDWARDS AND REAL COUNTIES UNTIL 200 AM CDT...

At 102 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles northwest of Mountain Home to 8 miles
southwest of Kerr Wildlife Management Area to 16 miles north of Alamo
Village. Movement was east at 25 mph.

Half inch hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Medina, Kerrville, Fredericksburg, Leakey, Vanderpool, Ingram, Hunt,
Camp Wood, Camp Verde, Barksdale, Tuff, Tivydale, Kerrville-Schreiner
Park, Vance, Waltonia, Kerr Wildlife Management Area, Center Point,
Reagan Wells, Rio Frio and Harper.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2989 9898 2943 10005 2967 10059 3002 9982
      3029 9968 3030 9889
TIME...MOT...LOC 0602Z 278DEG 23KT 3024 9952 2998 9958 2967 10043

RUNYEN

Special Weather Statement
National Weather Service Austin/San Antonio TX
157 AM CDT Thu May 14 2020

TXZ185>189-203-204-140800-
Uvalde TX-Gillespie TX-Kerr TX-Medina TX-Real TX-Bandera TX-
Kendall TX-
157 AM CDT Thu May 14 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MEDINA...BANDERA...
EASTERN KERR...NORTHERN UVALDE...SOUTHWESTERN GILLESPIE...
NORTHWESTERN KENDALL AND SOUTHERN REAL COUNTIES UNTIL 300 AM CDT...

At 156 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Mountain Home to Kerrville to near Medina
to Camp Wood. Movement was east at 25 mph.

Half inch hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Medina, Kerrville, Comfort, Bandera, Leakey, Vanderpool, Tarpley,
Ingram, Camp Wood, Camp Verde, Tuff, Tivydale, Kerrville-Schreiner
Park, Waltonia, Welfare, Nelson City, Center Point, Reagan Wells,
Utopia and Waring.

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.

&&

LAT...LON 3006 9867 2978 9885 2958 9927 2947 10009
      2956 10012 2962 10011 2963 10001 2966 10003
      2968 10002 2971 10006 2972 10002 2976 10003
      2986 9951 3006 9932 3023 9944 3028 9897
TIME...MOT...LOC 0656Z 269DEG 21KT 3019 9930 3006 9913 2978 9930 2966
10001

RUNYEN