Severe Thunderstorm Warning 77, NWS Austin/San Antonio, TX

995 
WWUS54 KEWX 111609
SVSEWX

Severe Weather Statement
National Weather Service Austin/San Antonio TX
1109 AM CDT TUE APR 11 2017

TXC209-111630-
/O.CON.KEWX.SV.W.0077.000000T0000Z-170411T1630Z/
Hays TX-
1109 AM CDT TUE APR 11 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 AM CDT
FOR CENTRAL HAYS COUNTY...

At 1108 AM CDT, a severe thunderstorm was located over Dripping
Springs, moving southeast at 15 mph.

HAZARD...Quarter size hail. 

SOURCE...Trained weather spotters reported quarter size hail in 
         Dripping Springs. 

IMPACT...Damage to vehicles is expected. 

Locations impacted include...
Wimberley, Dripping Springs, Woodcreek, Bear Creek, Driftwood and
Mount Gainor.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Austin San Antonio.

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.

&&

LAT...LON 3018 9824 3029 9808 3014 9788 2999 9810
TIME...MOT...LOC 1608Z 318DEG 13KT 3015 9806 

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

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.

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

TXZ189-206-111045-
Comal TX-Kendall TX-
457 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN KENDALL AND WEST
CENTRAL COMAL COUNTIES UNTIL 545 AM CDT...

At 457 AM CDT, Doppler radar was tracking a strong thunderstorm over
Bergheim, or 7 miles east of Boerne, moving east at 15 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Guadalupe River State Park, Kreutzberg, Bergheim and Anhalt.

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.

&&

LAT...LON 2980 9869 2986 9869 2991 9843 2979 9843
TIME...MOT...LOC 0957Z 268DEG 15KT 2983 9863

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

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

0555 AM     FLASH FLOOD      5 NW BOERNE             29.85N 98.80W
04/11/2017                   KENDALL            TX   LAW ENFORCEMENT

            NUMEROUS ROAD CLOSURES ACROSS SOUTHWESTERN KENDALL COUNTY
            NEAR BOERNE DUE TO WATER OVER THE ROADWAY.

&&

BMW

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

TXZ172-111345-
Burnet TX-
819 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BURNET COUNTY UNTIL
845 AM CDT...

At 819 AM CDT, Doppler radar was tracking a strong thunderstorm near
Kempner, or 7 miles south of Copperas Cove, moving east at 25 mph.

Nickel size hail will be possible with this storm.

This storm will remain over mainly rural areas of northeastern Burnet
County.

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 3099 9788 3092 9783 3092 9784 3091 9799
      3103 9802 3104 9801 3103 9791
TIME...MOT...LOC 1319Z 260DEG 21KT 3101 9793

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

TXZ173-111515-
Williamson TX-
931 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN WILLIAMSON COUNTY
UNTIL 1015 AM CDT...

At 930 AM CDT, Doppler radar was tracking a strong thunderstorm over
Jarrell, or 10 miles northeast of Serenada, moving east at 60 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Granger, Bartlett, Jarrell, Granger Dam, Theon, Laneport, Walburg and
Schwertner.

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 3087 9762 3074 9727 3068 9725 3075 9771
      3088 9769
TIME...MOT...LOC 1430Z 276DEG 50KT 3084 9761

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

TXZ190>192-111530-
Blanco TX-Hays TX-Travis TX-
943 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN HAYS...WEST CENTRAL
TRAVIS AND NORTHEASTERN BLANCO COUNTIES UNTIL 1030 AM CDT...

At 943 AM CDT, Doppler radar was tracking a strong thunderstorm over
Pedernales Falls State Park, or 8 miles southeast of Round Mountain,
moving east at 25 mph.

Nickel size hail will be possible with this storm.

Locations impacted include...
Austin, Dripping Springs, Lakeway, Lago Vista, Bee Cave, The Hills,
Bear Creek, Hudson Bend, Cypress Mill, Pedernales Falls State Park,
Mansfield Dam, Shady Hollow, Jonestown and Briarcliff.

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 3043 9813 3043 9812 3047 9809 3046 9787
      3015 9791 3026 9834 3047 9830
TIME...MOT...LOC 1443Z 278DEG 24KT 3034 9825

Special Weather Statement
National Weather Service Austin/San Antonio TX
1031 AM CDT TUE APR 11 2017

TXZ173-111615-
Williamson TX-
1031 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR WILLIAMSON COUNTY UNTIL 1115 AM
CDT...

At 1030 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Leander to near Thrall. Movement was
southeast at 55 mph.

Nickel size hail will be possible with these storms.

Locations impacted include...
Round Rock, Cedar Park, Georgetown, Taylor, Granger, Serenada, Hutto,
Bartlett, Liberty Hill, Thrall, Weir, Georgetown Dam, Granger Dam,
Coupland, Andice, Sun City, Mahomet, Laneport, Waterloo and Jonah.

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 3080 9744 3074 9727 3046 9716 3041 9730
      3042 9738 3046 9744 3046 9746 3049 9751
      3048 9755 3050 9758 3048 9764 3048 9768
      3046 9769 3046 9771 3077 9797 3082 9793
TIME...MOT...LOC 1530Z 333DEG 49KT 3058 9781 3056 9725