Alert archive / Texas / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 35, NWS Austin/San Antonio, TX

April 6, 2018Burnet County, Williamson County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Apr 6, 2018, 7:34 PM CDT for Burnet County, Williamson County, Texas. It was in force for 41 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 6, 2018, 7:34 PM CDT (00:34 UTC)
Expired: Apr 6, 2018, 8:15 PM CDT
In force: 41 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Burnet County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 58 km from the middle of the area, began a volume at 00:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Apr 6, 7:51 PM CDT	TORNADO	8 Nw Briggs, TX	TRAINED SPOTTER REPORTS TORNADO NW OF BRIGGS JUST NORTH OF US 183 IN NORTHEASTERN BURNET COUNTY.
Apr 6, 7:55 PM CDT	HAIL 1.75	8 N Briggs, TX	DELAYED REPORT OF GOLF BALL SIZED HAIL IN NORTHEASTERN BURNET COUNTY.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 0.6 hours before the alert went out and 220 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 690 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 1896 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -40 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

392 
WUUS54 KEWX 070034
SVREWX
TXC053-491-070115-
/O.NEW.KEWX.SV.W.0035.180407T0034Z-180407T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Austin/San Antonio TX
734 PM CDT FRI APR 6 2018

The National Weather Service in Austin San Antonio has issued a

* Severe Thunderstorm Warning for...
  Northwestern Williamson County in south central Texas...
  Northeastern Burnet County in south central Texas...

* Until 815 PM CDT

* At 734 PM CDT, a severe thunderstorm was located near Watson, or 8
  miles southeast of Lampasas, moving east at 35 mph.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees. 

* Locations impacted include...
  Georgetown, Florence, Mahomet, Sunnylane, Joppa, Watson, Andice and
  Briggs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail, damaging winds, and continuous cloud to ground lightning
are 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 3103 9791 3091 9783 3087 9763 3065 9783
      3099 9824 3104 9820
TIME...MOT...LOC 0034Z 291DEG 32KT 3098 9806 

HAIL...1.50IN
WIND...60MPH
 
$$

PLATT

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 6, 7:29 PM CDT	Special Weather Statement	EWX	Burnet	46 min
Apr 6, 7:50 PM CDT	Tornado Warning	EWX	Burnet	25 min
Apr 6, 8:16 PM CDT	Special Weather Statement	EWX	Williamson	44 min
Apr 6, 8:51 PM CDT	Special Weather Statement	EWX	Williamson	24 min
Apr 6, 11:12 PM CDT	Special Weather Statement	EWX	Williamson	48 min
Apr 6, 11:32 PM CDT	Severe Thunderstorm Warning	EWX	Travis, Williamson	43 min
Apr 7, 12:16 AM CDT	Special Weather Statement	EWX	Bastrop	44 min

Nearby

Severe Thunderstorm Warnings in Texas, 2018 Every severe thunderstorm warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.