Alert archive / Texas / Special Weather Statements in 2017

Special Weather Statement, NWS Austin/San Antonio, TX

July 23, 2017Williamson County, Texas

NWS Austin/San Antonio, TX issued this special weather statement at Jul 23, 2017, 2:02 PM CDT for Williamson County, Texas. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 23, 2017, 2:02 PM CDT (19:02 UTC)
Expired: Jul 23, 2017, 2:30 PM CDT
In force: 28 min
Issued by: NWS Austin/San Antonio, TX

County Williamson County, TX

The radar

The Ft Hood radar (KGRK), 40 km from the middle of the area, began a volume at 19:04 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.

The nearest sounding before it

Del Rio, TX (KDLF), launched 12:00Z, 7.0 hours before the alert went out and 327 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: 501 J/kg
Mixed-layer CIN: -233 J/kg
Mixed-layer LCL: 1356 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Austin/San Antonio, TX wrote its last area forecast discussion before this special weather statement went out at Jul 23, 12:33 PM CDT, 1 hour 29 minutes earlier.

Area forecast discussion, Jul 23, 12:33 PM CDT, 1 hour 29 minutes before

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Hazardous weather outlook, Jul 23, 4:34 AM CDT, 9 hours 28 minutes before

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In the hours before

Special weather statement, Jul 23, 2:02 PM CDT, 0 minutes before

Special Weather Statement
National Weather Service Austin/San Antonio TX
202 PM CDT SUN JUL 23 2017

TXZ173-231930-
Williamson TX-
202 PM CDT SUN JUL 23 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN WILLIAMSON COUNTY
UNTIL 230 PM CDT...

At 202 PM CDT, Doppler radar was tracking a strong thunderstorm near
Sun City, or near Serenada, moving southwest at 15 mph.

Pea size hail and winds up to 40 mph will be possible with this
storm.

Locations impacted include...
Cedar Park, Georgetown, Serenada, Leander, Liberty Hill, Georgetown
Dam, Sun City, Seward Junction and Brushy Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3076 9779 3071 9767 3051 9777 3064 9796
TIME...MOT...LOC 1902Z 037DEG 15KT 3069 9778

RUNYEN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 2:04 PM CDT	Special Weather Statement	EWX	Burnet	26 min
Jul 23, 2:21 PM CDT	Special Weather Statement	EWX	Llano	24 min
Jul 23, 2:51 PM CDT	Special Weather Statement	EWX	Llano	39 min
Jul 23, 3:01 PM CDT	Special Weather Statement	EWX	Travis	29 min
Jul 23, 3:17 PM CDT	Special Weather Statement	EWX	Gillespie	28 min
Jul 23, 3:27 PM CDT	Special Weather Statement	EWX	Hays	33 min
Jul 23, 3:36 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Hays	38 min
Jul 23, 3:42 PM CDT	Special Weather Statement	EWX	Gillespie	48 min

Nearby

Special Weather Statements in Texas, 2017 Every special weather statement in 2017

Sources

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