Alert archive / Texas / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 16, NWS Shreveport, LA

March 25, 2002Nacogdoches County, Texas

NWS Shreveport, LA issued this severe thunderstorm warning at Mar 25, 2002, 8:29 PM CST for Nacogdoches County, Texas. It was in force for 61 min. 1 report 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: Mar 25, 2002, 8:29 PM CST (02:29 UTC)
Expired: Mar 25, 2002, 9:30 PM CST
In force: 61 min
Issued by: NWS Shreveport, LA
Area: Counties, with a storm outline in the text

County Nacogdoches County, TX

The radar

The Shreveport radar (KSHV), 117 km from the middle of the area, began a volume at 02:32 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
Mar 25, 8:38 PM CST	Hail 1	Nacogdoches, TX

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

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

Shreveport, LA (KSHV), launched 00:00Z, 2.5 hours before the alert went out and 125 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: 1114 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 504 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 49 m²/s²
0-3 km storm-relative helicity: 125 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.7

Open this sounding in Storm Lab

The text

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

000 
WUUS54 KSHV 260229
SVRSHV
TXC347-260330-
/NEW.KSHV.SV.W.0039.260228-260330/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
828 PM CST MON MAR 25 2002

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NACOGDOCHES COUNTY IN EASTERN TEXAS

* UNTIL 930 PM CST

* AT 828 PM CST...THE SHREVEPORT NATIONAL WEATHER SERVICE DOPPLER
  RADAR INDICATED A SEVERE THUNDERSTORM 12 MILES SOUTH OF
  NACOGDOCHES...OR ABOUT 8 MILES NORTH OF LUFKIN...MOVING NORTHEAST
  AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  NACOGDOCHES AT 845 PM CST

THIS THUNDERSTORM WILL PRODUCE LARGE HAIL UP TO AN INCH AND A HALF 
IN DIAMETER.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE STORM IN A STRONG
BUILDING.

REPEATING...THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE
THUNDERSTORM WARNING FOR...
  NACOGDOCHES COUNTY IN EASTERN TEXAS
UNTIL 930 PM CST.

LAT...LON 3153 9483 3147 9458 3161 9437 3170 9442
          3183 9454

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 Shreveport, LA wrote its last area forecast discussion before this severe thunderstorm warning went out at Mar 25, 6:45 PM CST, 1 hour 44 minutes earlier.

Area forecast discussion, Mar 25, 6:45 PM CST, 1 hour 44 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
645 PM CST MON MAR 25 2002

UPDATED ZONES FOR SEVERE THUNDERSTORM WATCH UNTIL MIDNIGHT ACROSS LA
PORTIONS...AS WELL AS EXTREME SW TIER OF AR...AND EAST TX LAKES.
SCATTERED LINE OF RAPIDLY DEVELOPING THUNDERSTORMS...FROM MAGNOLIA
AR TO SHV TO LFK...ALREADY BECOMING SEVERE...AND LINE MAY FILL IN.
DEVELOPING LINE OF THUNDERSTORMS TO THE WEST AS WELL IN COLD AIR.
THIS LINE NOT EXPECTED TO BE SEVERE...BUT SMALL COLD AIR HAIL IS
POSSIBLE.

VII

.SHV...NONE.

The office that day

Everything else NWS Shreveport, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 25, 7:27 PM CST	Severe Thunderstorm Warning	SHV	Shelby	63 min
Mar 25, 8:21 PM CST	Severe Thunderstorm Warning	SHV	Angelina	39 min
Mar 25, 9:04 PM CST	Severe Thunderstorm Warning	SHV	Shelby	56 min

Nearby

Severe Thunderstorm Warnings in Texas, 2002 Every severe thunderstorm warning in 2002

Sources

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