Alert archive / Texas / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 4, NWS Austin/San Antonio, TX

February 20, 2003Bexar County, Wilson County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Feb 20, 2003, 6:44 AM CST for Bexar County, Wilson County, Texas. It was in force for 46 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: Feb 20, 2003, 6:44 AM CST (12:44 UTC)
Expired: Feb 20, 2003, 7:30 AM CST
In force: 46 min
Issued by: NWS Austin/San Antonio, TX
Area: Counties, with a storm outline in the text

Counties Bexar County, TX, Wilson County, TX

The radar

The Austin/San Antonio radar (KEWX), 49 km from the middle of the area, began a volume at 12:47 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 0.7 hours before the alert went out and 199 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: 353 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 638 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

519 
WUUS54 KEWX 201244
SVRSAT
TXC029-493-201330-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
644 AM CST THU FEB 20 2003

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR THE FOLLOWING COUNTIES IN TEXAS...
  BEXAR
  WILSON

* UNTIL 730 AM CST

* AT 644 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 14 MILES SOUTHWEST OF ELMENDORF...OR ABOUT 9
  MILES NORTH OF POTEET...MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE...
  2 MILES NORTHWEST OF ELMENDORF AT 705 AM
  6 MILES SOUTHEAST OF CHINA GROVE AT 715 AM
  5 MILES NORTHWEST OF LA VERNIA AT 730 AM

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 55 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.


LAT...LON 2913 9845 2922 9861 2953 9822 2948 9813
          2937 9812 2938 9798

$$

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Feb 20, 5:30 AM CST, 1 hour 14 minutes earlier.

Area forecast discussion, Feb 20, 5:30 AM CST, 1 hour 14 minutes before

SOUTH CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
530 AM CST THU FEB 20 2003

A FRONTAL FLASH FLOOD EVENT IS LIKELY TODAY EVOLVING INTO A
FRONTAL/SYNOPTIC SCALE FLASH FLOOD EVENT TONIGHT INTO EARLY FRIDAY
MORNING.  OVERRUNNING GULF MOISTURE (RICH AND CONDITIONALLY
UNSTABLE) WILL LIFT OVER SHALLOW COOL DOME ACROSS SOUTH CENTRAL
TEXAS TODAY.  IMPULSES WILL EJECT FROM THE UPPER LOW TO THE WEST
WHICH BECOMING INCREASINGLY DIFFLUENT ALOFT.  THE RESULT WILL BE
INCREASING CHANCES THROUGHOUT THE DAY OF SHOWERS AND HEAVY
THUNDERSTORMS.  BY EVENING...SATURATED GROUND CONDITIONS MAY
EXIST...PARTICULARLY OVER THE EASTERN HALF OF THE REGION.
TONIGHT..THE UPPER LOW WILL MAKE ITS ENTRANCE WITH ADDITIONAL
SHOWERS AND THUNDERSTORMS...INCREASING DIFFLUENCE AND COLDER AIR
ALOFT WILL RESULT IN THE ADDITIONAL POSSIBILITY OF LARGE HAIL...THIS
MAY ALSO OCCUR AS EARLY AS THIS AFTERNOON SO INCLUDED SEVERE
POSSIBILITY FOR TODAY AS WELL.

SHOWERS AND THUNDERSTORMS SHOULD END FROM THE WEST BY LATE FRIDAY
MORNING...THEN CLEARING FROM THE WEST FRIDAY AFTERNOON INTO THE
EVENING.  A NICE WEEKEND IN STORE AS NORTHWEST TO WEST FLOW ALOFT
DOMINATES.

CLOUDS WILL RETURN EARLY NEXT WEEK AS RETURN FLOW BRINGS GULF
MOISTURE.  A STRONG COLD FRONT WILL PUSH INTO THE AREA BY MIDWEEK.

PRELIMINARY NUMBERS...
AUS  057/055 062/046 066 8+92
DRT  060/058 065/048 074 8+90
SAT  059/056 069/052 068 8+90=

.EWX...FLASH FLOOD WATCH TODAY AND TONIGHT FOR ALL OF SOUTH CENTRAL
TEXAS.

02/06

02/06

Hazardous weather outlook, Feb 20, 6:00 AM CST, 44 minutes before

TXZ171>173-183>194-202>209-217>225-228-211200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
600 AM CST THU FEB 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY...EXCESSIVE RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE
EXPECTED OVER ALL OF SOUTH CENTRAL TEXAS TODAY.  AS A WINTER STORM
SYSTEM APPROACHES SOUTH TEXAS TONIGHT, AN ADDITIONAL 2 TO 3 INCHES
OF RAIN IS POSSIBLE AND FLASH FLOODING BECOMES LIKELY.  ALSO THERE
IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WITH LARGE HAIL.

.DAYS TWO THROUGH SEVEN...
AN ADDITIONAL ONE INCH OF RAIN FRIDAY IS POSSIBLE BEFORE THE WINTER
STORM EXITS SOUTH TEXAS.  FLASH FLOODING AND A FEW SEVERE
THUNDERSTORMS WILL REMAIN UNTIL AROUND NOON FRIDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON.

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 20, 7:29 AM CST	Flash Flood Warning	EWX	Blanco, Comal, Hays, Kendall	6 hr
Feb 20, 7:34 AM CST	Flash Flood Warning	EWX	Travis, Williamson	6 hr
Feb 20, 9:14 AM CST	Flash Flood Warning	EWX	Bastrop, Caldwell, Lee	4 hr
Feb 20, 9:23 AM CST	Severe Thunderstorm Warning	EWX	Gonzales	52 min
Feb 20, 11:15 AM CST	Severe Thunderstorm Warning	EWX	Lavaca	45 min
Feb 20, 1:25 PM CST	Flash Flood Warning	EWX	Bastrop, Blanco, Caldwell, Comal, Guadalupe, Hays and 3 more	4 hr
Feb 20, 4:33 PM CST	Flash Flood Warning	EWX	Fayette, Gonzales	57 min
Feb 20, 5:20 PM CST	Flash Flood Warning	EWX	Blanco, Caldwell, Comal, Guadalupe, Hays, Travis and 1 more	3 hr
Feb 20, 5:25 PM CST	Flash Flood Warning	EWX	Bastrop, DeWitt, Fayette, Gonzales, Lavaca, Lee	3 hr

Nearby

Severe Thunderstorm Warnings in Texas, 2003 Every severe thunderstorm warning in 2003

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.