Alert archive / Texas / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 10, NWS Austin/San Antonio, TX

March 18, 2003Llano County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Mar 18, 2003, 4:03 AM CST for Llano County, Texas. It was in force for 27 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
Mar 18, 2003, 4:03 AM CST (10:03 UTC)
Expired
Mar 18, 2003, 4:30 AM CST
In force
27 min
Issued by
NWS Austin/San Antonio, TX
Area
Counties, with a storm outline in the text

County Llano County, TX

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

Del Rio, TX (KDRT), launched 00:00Z, 10.1 hours before the alert went out and 252 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-pSkew-T log-p diagram, Del Rio, TX at 00:00Z on 2003-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 00:00Z on 2003-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2977 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
132 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

301 
WUUS54 KEWX 181003
SVRSAT
TXC299-181100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
402 AM CST TUE MAR 18 2003

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR THE FOLLOWING COUNTIES IN TEXAS...
  LLANO

* UNTIL 430 AM CST

* AT 400 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS OVER SOUTHWEST LLANO COUNTY...MOVING NORTHEAST
  AT 30 MPH.  SOME OF THESE THUNDERSTORMS COULD BE SEVERE.

LARGE HAIL IS POSSIBLE WITH THESE THUNDERSTORMS...SOME THAT
ARE SEVERE.  IF YOU ARE IN THE PATH OF THE STORM...PUT YOUR CAR IN A 
GARAGE AND MOVE TO A SUBSTANTIAL SHELTER.  

STRONG GUSTY WINDS ARE ALSO POSSIBLE WITH THESE THUNDERSTORMS.

INTENSE LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...STAY
AWAY FROM HIGH AREAS...METAL OBJECTS...AND TALL ISOLATED TREES. MOVE
INDOORS IF POSSIBLE BUT STAY AWAY FROM WINDOWS AND DOORS AND AVOID
USING THE TELEPHONE UNLESS IT IS AN EMERGENCY.

LAT...LON 3060 9886 3060 9851 3086 9845 3086 9891

$$

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 Mar 18, 2:39 AM CST, 1 hour 24 minutes earlier.

Area forecast discussion, Mar 18, 2:39 AM CST, 1 hour 24 minutes before
SOUTH CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
239 AM CST TUE MAR 18 2003

CONVECTION FIRING OVER NORTHWEST HILL COUNTRY MOVING RAPIDLY
NORTHEAST WITH THE STEERING WINDS.  DRY LINE HAS MOVED INTO AREA AND
WAS LAST SEEN MOVING SOUTHEAST AT 24 KTS.  ORIENTATION OF WINDS
ALOFT WILL KEEP DRY LINE MOVING EAST BUT NOT MUCH TO THE SOUTH.
ALSO BECAUSE OF WESTERLY WINDS ALOFT, DOWNSLOPE OFF THE ROCKIES WILL
LOWER THE P.W.S OUT WEST, SO WILL NOT MENTION POPS OVER THERE
WITH THIS PACKAGE.  THE SEVERE WX THREAT LOOKS GOOD FOR THE
NORTHEAST COUNTIES AS THIS PART WILL BE IN THE LEFT FRONT QUAD OF
THE UPPER LEVEL JET WITH GOOD VEERING IN THE LOW LEVELS.  LOWER
THICKNESS ADVECTION AND SFC GRADIENT BEHIND DRY LINE WILL KEEP WEST
AND SOUTHWEST WINDS GUSTING TODAY.

TONIGHT...DRY LINE/PACIFIC FRONT IS NOW EAST OF OUR CWA AND HANGING
NEAR THE MIDDLE TX COAST.  SOME LIMITED WRAP AROUND CLOUDINESS
TONIGHT WITH TEMPS SLIGHTLY BELOW NORMAL.

WEDNESDAY...CAA ENDS DURING THE MORNING AND SOUTHWEST TO WEST WINDS
LIGHTEN UP.  DAYTIME HIGHS SHUD BE WELL ABOVE NORMAL.

WEDNESDAY NIGHT...THE CANADIAN AIR IS NOW READY TO FLOW SOUTH INTO
TEXAS BEHIND THE EXITING UPPER LOW.  SFC WINDS WILL SHIFT TO THE
NORTHWEST AT 10 TO 15 MPH WITH GUSTS TO 25 MPH.  TEMPS ABOUT THE
SAME AS TONIGHT.

THURSDAY...STRONG SHORT WAVE TROUGH MOVES THROUGH TEXAS WITH A LOW
POP FOR SPRINKLES EASTERN SECTIONS.  LIGHT NORTH WINDS PREVAIL UNDER
MOSTLY SUNNY SKIES.  TEMPS NEAR SEASONAL NORMS.

THURSDAY NIGHT...LIGHT WINDS AND SUBSIDENT REGIME WILL ALLOW GOOD
RADIATIONAL COOLING.  EXPECT MINS 10 DEGREES BELOW NORM.

FRIDAY THROUGH MONDAY...CLOUDS AND FOG RETURN FRIDAY AS THE
NEXT UPPER LOW DIGS SOUTHEAST ACROSS THE ROCKIES AND MOVES INTO
WEST TEXAS SATURDAY MORNING. ATMOSPHERIC DESTABILIZATION SATURDAY
WILL SET US UP FOR A ROUND OF SHOWERS AND THUNDERSTORMS ENDING
SUNDAY AS THE UPPER LOW MOVES ACROSS NORTH TEXAS.  A CLEAR DRY
MONDAY IN STORE.

PRELIM NUMBER...
AUS 76 45 77 45 71  40001
SAT 78 48 80 50 75  40001
DRT 82 51 84 51 78  -0000

.EWX...SLGT RISK SVR TSTMS TODAY KERRVILLE TO SAN ANTONIO TO CUERO
AND EASTWARD.

06/08

.

.EWX...NONE.
Hazardous weather outlook, Mar 18, 3:32 AM CST, 31 minutes before
TXZ171>173-183>194-202>209-217>225-228-181200-

HAZARDOUS WEATHER OUTLOOK UPDATED
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
332 AM CST TUE MAR 18 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...
A CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT OVER PARTS OF THE HILL
COUNTRY.  SOME THUNDERSTORMS COULD BE CLOSE TO SEVERE...
CAUSING STRONG WINDS AND HAIL.

SPOTTER ACTIVATION MAY BE REQUIRED.

.DAYS TWO THROUGH SEVEN...

A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY OVER THE HILL COUNTRY
TO PARTS OF CENTRAL TEXAS.

RAIN IS NOT EXPECTED WEDNESDAY THROUGH FRIDAY.  ON SATURDAY AND
SUNDAY...AN EARLY SPRING WEATHER SYSTEM WILL APPROACH PARTS OF
CENTRAL AND SOUTH CENTRAL TEXAS FROM THE WEST...CAUSING A CHANCE OF
SHOWERS OR THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TUESDAY.

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 18, 4:23 AM CSTSevere Thunderstorm WarningEWXBurnet37 min

Nearby

Severe Thunderstorm Warnings in Texas, 2003Every 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.