Alert archive / Louisiana / Tornado Warnings in 2013

Tornado Warning 21, NWS Shreveport, LA

February 21, 2013Natchitoches Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at Feb 21, 2013, 3:06 PM CST for Natchitoches Parish, Louisiana. It was in force for 24 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: Feb 21, 2013, 3:06 PM CST (21:06 UTC)
Expired: Feb 21, 2013, 3:30 PM CST
In force: 24 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon

County Natchitoches Parish, LA

What was reported inside it

Time	Report	Where	Remark
Feb 21, 3:07 PM CST	TORNADO	20 Se Provencal, LA	LARGE TREE SNAPPED AND A FEW BROKEN BRANCHES ACROSS KISATCHIE-MORA RD AND WAS RATED AN EF-1

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Feb 21, 1:37 PM CST	Tornado Watch	SPC	5 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 9.1 hours before the alert went out and 140 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 912 m above ground
0-6 km bulk shear: 68 kt
0-1 km storm-relative helicity: 842 m²/s²
0-3 km storm-relative helicity: 990 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

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

899 
WFUS54 KSHV 212106
TORSHV
LAC069-212130-
/O.NEW.KSHV.TO.W.0021.130221T2106Z-130221T2130Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SHREVEPORT LA
306 PM CST THU FEB 21 2013

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN NATCHITOCHES PARISH IN NORTHWEST LOUISIANA...

* UNTIL 330 PM CST

* AT 304 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 6 MILES
  SOUTHWEST OF GORUM...OR 14 MILES NORTH OF SLAGLE...MOVING NORTHEAST
  AT 60 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  CLOUTIERVILLE AND CHOPIN...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WARNING MEANS THAT STRONG ROTATION HAS BEEN DETECTED IN THE
STORM. A TORNADO MAY ALREADY BE ON THE GROUND...OR IS EXPECTED TO
DEVELOP SHORTLY. IF YOU ARE IN THE PATH OF THIS DANGEROUS STORM...
MOVE INDOORS AND TO THE LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM
WINDOWS. IF DRIVING...DO NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

&&

LAT...LON 3135 9300 3136 9303 3136 9313 3141 9318
      3162 9291 3160 9280 3152 9272 3144 9281
      3138 9290 3136 9292 3135 9295 3134 9298
TIME...MOT...LOC 2106Z 230DEG 60KT 3141 9302

$$

14

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 21, 2:22 PM CST	Tornado Warning	SHV	Sabine	23 min
Feb 21, 4:20 PM CST	Severe Thunderstorm Warning	SHV	LaSalle	25 min

Nearby

Tornado Warnings in Louisiana, 2013 Every tornado warning in 2013 Tornadoes in 2013

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.