Severe Thunderstorm Warning 78, NWS Austin/San Antonio, TX

096 
WWUS54 KEWX 111703
SVSEWX

Severe Weather Statement
National Weather Service Austin/San Antonio TX
1203 PM CDT TUE APR 11 2017

TXC031-091-209-259-111730-
/O.CON.KEWX.SV.W.0078.000000T0000Z-170411T1730Z/
Hays TX-Blanco TX-Kendall TX-Comal TX-
1203 PM CDT TUE APR 11 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 PM CDT
FOR WEST CENTRAL HAYS...SOUTH CENTRAL BLANCO...EAST CENTRAL KENDALL
AND NORTHEASTERN COMAL COUNTIES...

At 1201 PM CDT, a severe thunderstorm was located near Twin Sisters,
or 9 miles southeast of Blanco, moving southeast at 15 mph.

HAZARD...Quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Damage to vehicles is expected. 

Locations impacted include...
Canyon Lake, Spring Branch, Twin Sisters, Fischer and U.S. Highway 
281. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3004 9849 3008 9827 2991 9813 2984 9848
TIME...MOT...LOC 1701Z 335DEG 12KT 2998 9835 

HAIL...1.00IN
WIND...<50MPH
 
$$

PLATT

286 
WWUS54 KEWX 111726
SVSEWX

Severe Weather Statement
National Weather Service Austin/San Antonio TX
1226 PM CDT TUE APR 11 2017

TXC031-209-259-111734-
/O.CAN.KEWX.SV.W.0078.000000T0000Z-170411T1730Z/
Hays TX-Blanco TX-Kendall TX-
1226 PM CDT TUE APR 11 2017

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL HAYS...SOUTH
CENTRAL BLANCO AND EAST CENTRAL KENDALL COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 2994 9815 2991 9813 2984 9848 2993 9842
      3003 9829
TIME...MOT...LOC 1724Z 322DEG 9KT 2994 9826 

$$

TXC091-111730-
/O.CON.KEWX.SV.W.0078.000000T0000Z-170411T1730Z/
Comal TX-
1226 PM CDT TUE APR 11 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 PM CDT
FOR NORTHEASTERN COMAL COUNTY...

At 1224 PM CDT, a severe thunderstorm was located over Fischer, or 
near Canyon Lake Dam, moving southeast at 10 mph. Another severe 
thunderstorm was located 2 miles north of Spring Branch. 

HAZARD...Quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Damage to vehicles is expected. 

Locations impacted include...
Canyon Lake, Fischer and Spring Branch. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 2994 9815 2991 9813 2984 9848 2993 9842
      3003 9829
TIME...MOT...LOC 1724Z 322DEG 9KT 2994 9826 

HAIL...1.00IN
WIND...<50MPH
 
$$

PLATT

Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
956 AM CDT Tue Apr 11 2017

.UPDATE...
The weak cold front has moved slightly farther south and is now just
inside the northern CWA. A broad convergence zone has developed
across the northeast Hill Country and is being enhanced by the tail
end of large scale forcing from the mid and upper level shortwave.
Aircraft sounding data out of AUS no longer indicates the presence of
a mid level cap, as was the case late yesterday afternoon and
overnight which helped to limited the potential for on organized
complex to push the front south. With the cap now eroded and deep
moisture pooled over the area the weak front and mid/upper level
forcing has allowed for the generation of scattered showers and
storms through the eastern Hill Country and Central Texas this
morning. These storms will drift east through the morning hours,
possibly near the Austin metro area. A few stronger storms are
possible with small hail and heavy downpours. A quick 1-2 inches is
possibly under any of the heavier storms which could lead to
localized flooding issues. At this time we will hold off on
re-issuing the Flash Flood Watch as the short-term trends suggest
the coverage of excessive rainfall to be isolated in nature.

Going into the afternoon, the front appears to become slightly more
diffuse and mid/upper level forcing begins to pull away. Coverage of
showers and storms should decrease slightly and favor southern and
eastern areas.

&&

.PREV DISCUSSION... /ISSUED 708 AM CDT Tue Apr 11 2017/

UPDATE...
We have let the Severe Thunderstorm and Flash Flood Watches expire
at 12z or 7 AM CDT. There may be some strong storms and locally heavy
downpours as a weakening upper level shortwave moves across South
Central Texas this morning while interacting with a stalled front and
moist and unstable airmass. The downpours may cause some minor
flooding in the small areas that received heavy rains overnight.
However, the threat for severe storms and flash flooding has ended.

PREV DISCUSSION... /ISSUED 627 AM CDT Tue Apr 11 2017/

UPDATE...
See below for the 12z aviation discussion...

AVIATION...
Currently IFR CIGs at AUS and SAT and low-end MVFR CIGs at SSF and
DRT. An isolated shower or two is possible at the Interstate 35
sites through the early afternoon. CIGs are expected to improve to
MVFR at AUS and SAT by 15z with all four TAF sites expected to
improve to VFR by Tuesday afternoon. MVFR CIGs should return by late
Tuesday evening before deteriorating further to IFR by early
Wednesday morning. Winds will generally be out of the east/southeast
at around 5 to 10 knots.

PREV DISCUSSION... /ISSUED 333 AM CDT Tue Apr 11 2017/

SHORT TERM (Today through Wednesday)...
A weak cold front along a Langtry to Lampasas to Waco is only
drifting south and will stall by midday while a weakening upper
level shortwave over western Texas to the Big Bend is moving east.
These features will lift a moist airmass with PWS above 1.4 inches
and unstable airmass with CAPEs above 1000 J/KG to produce isolated
storms that could be strong to severe with locally heavy rains. Have
maintained most of the ongoing severe and flash flood watches, except
for the westernmost counties where the rains have mostly ended. The
forecast is low confidence as models have underperformed for the most
part across South Central Texas. May have to remove other counties
prior to the 12Z expiration based on radar trends. Expect 1 to 3 inch
amounts with very isolated 5 inches totals. Rains will taper off
during the remainder of this morning with only widely scattered
showers and thunderstorms this afternoon. Zonal flow aloft and a
moist airmass will allow for only isolated showers and thunderstorms
tonight into Wednesday as the front dissipates or lifts back north.

LONG TERM (Wednesday Night through Monday)...
The pattern on Wednesday will continue through this weekend into
early next week with isolated showers and thunderstorms expected.
Parts of Val Verde county may see higher coverage due better moisture
convergence with some storms possibly coming off the Serranias del
Burro of northern Mexico. The upper level trough expected Thursday
into Friday has trended further north with more recent model runs
and have lowered POPs to 20 percent.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              76  63  80  64  81 /  50  20  20  10  20
Austin Bergstrom Intl Airport  75  62  80  63  80 /  50  20  20  10  20
New Braunfels Muni Airport     76  63  80  64  80 /  50  20  20  10  20
Burnet Muni Airport            74  61  77  63  77 /  50  20  20  10  20
Del Rio Intl Airport           81  65  81  64  80 /  30  20  20  20  20
Georgetown Muni Airport        75  61  79  63  79 /  50  20  20  10  20
Hondo Muni Airport             79  63  81  64  81 /  40  20  20  10  20
San Marcos Muni Airport        76  63  80  63  80 /  50  20  20  10  20
La Grange - Fayette Regional   76  64  81  64  81 /  50  20  20  10  20
San Antonio Intl Airport       77  64  80  65  80 /  40  20  20  10  20
Stinson Muni Airport           77  64  80  65  81 /  40  20  20  10  20

&&

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

&&

Mesoscale/Aviation...05
Synoptic/Grids...Runyen
Public Service/Data Collection...YB

Hazardous Weather Outlook...UPDATED
National Weather Service Austin/San Antonio TX
155 AM CDT Tue Apr 11 2017

TXZ171>173-183>194-202>209-217>225-228-120700-
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-
155 AM CDT Tue Apr 11 2017

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

.DAY ONE...Rest of tonight.

A Flash Flood Watch is in effect for most of South Central Texas
through 7 am. Rain totals of 1 to 3 inches with isolated amounts
to 5 inches are possible through Tuesday morning...mainly for
areas along and east of the Edwards escarpment, including the
Interstate 35 corridor. This could lead to flash flooding for
these areas.

In addition...hail up to one inch in diameter and gusty winds up
to 60 mph are possible. A Severe Thunderstorm Watch is also in
effect through 7 am Tuesday, but these threats are secondary to
the main flash flooding threat.

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

No hazardous weather is expected for the extended period.

.SPOTTER INFORMATION STATEMENT...

Please submit any flooding or severe weather reports to the
National Weather Service.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1105 AM CDT TUE APR 11 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1007 AM     HAIL             4 ESE CYPRESS MILL      30.36N 98.18W
04/11/2017  E0.50 INCH       BLANCO             TX   PUBLIC

            REPORTED VIA SOCIAL MEDIA, HALF AN INCH
            HAIL.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1108 AM CDT TUE APR 11 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1104 AM     HAIL             1 NNW DRIPPING SPRINGS  30.20N 98.09W
04/11/2017  E1.00 INCH       HAYS               TX   PUBLIC

            QUARTER SIZE HAIL BEING REPORTED BY DRIPPING
            SPRINGS FIRE DEPT.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1115 AM CDT TUE APR 11 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1105 AM     HAIL             1 NNE LEANDER           30.58N 97.85W
04/11/2017  E0.75 INCH       WILLIAMSON         TX   PUBLIC

            MEDIA VIEWER REPORTED .75 INCH HAIL.

&&

Special Weather Statement
National Weather Service Austin/San Antonio TX
1115 AM CDT TUE APR 11 2017

TXZ191-208-111645-
Caldwell TX-Hays TX-
1115 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CALDWELL AND
SOUTHEASTERN HAYS COUNTIES UNTIL 1145 AM CDT...

At 1115 AM CDT, Doppler radar was tracking a strong thunderstorm over
San Marcos, moving northeast at 25 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
San Marcos, Kyle, Lockhart, Martindale, Uhland, Niederwald, Mountain
City, San Marcos Regional Airport, Maxwell and Reedville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 2978 9781 2979 9782 2978 9783 2979 9783
      2981 9785 2983 9784 2985 9786 2985 9789
      2981 9794 2984 9801 3008 9793 2997 9764
TIME...MOT...LOC 1615Z 202DEG 20KT 2988 9789

Special Weather Statement
National Weather Service Austin/San Antonio TX
1119 AM CDT TUE APR 11 2017

TXZ173-194-111645-
Williamson TX-Lee TX-
1119 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN WILLIAMSON AND
NORTHWESTERN LEE COUNTIES UNTIL 1145 AM CDT...

At 1119 AM CDT, Doppler radar was tracking a strong thunderstorm 9
miles south of Thorndale, or 12 miles west of Lexington, moving
southeast at 20 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Lexington, Tanglewood, Fedor, Knobb Springs and Blue.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3025 9706 3032 9717 3034 9720 3035 9722
      3041 9733 3059 9723 3058 9721 3046 9715
      3054 9700 3052 9691 3051 9690
TIME...MOT...LOC 1619Z 293DEG 18KT 3048 9720

Special Weather Statement
National Weather Service Austin/San Antonio TX
1131 AM CDT TUE APR 11 2017

TXZ191-111700-
Hays TX-
1131 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL HAYS COUNTY UNTIL NOON
CDT...

At 1131 AM CDT, Doppler radar was tracking a strong thunderstorm near
Driftwood, or near Dripping Springs, moving south at 15 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Wimberley, Dripping Springs, Woodcreek, Driftwood, Mount Gainor and
Hays City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3018 9822 3022 9800 3003 9790 2998 9820
TIME...MOT...LOC 1631Z 347DEG 12KT 3013 9810