Alert archive / Louisiana / Tornado Warnings in 2017

Tornado Warning 5, NWS Shreveport, LA

January 21, 2017Bossier Parish, Claiborne Parish, Webster Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at Jan 21, 2017, 5:33 PM CST for Bossier Parish, Claiborne Parish, Webster Parish, Louisiana. It was in force for 42 min. 2 reports 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: Jan 21, 2017, 5:33 PM CST (23:33 UTC)
Expired: Jan 21, 2017, 6:15 PM CST
In force: 42 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Bossier Parish, LA, Claiborne Parish, LA, Webster Parish, LA

The radar

The Shreveport radar (KSHV), 67 km from the middle of the area, began a volume at 23:34 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
Jan 21, 5:50 PM CST	HAIL 2	6 Wsw Shongaloo, LA	2 HAIL REPORTED IN SEREPTA
Jan 21, 5:55 PM CST	TORNADO	4 Ssw Shongaloo, LA	AN EF-1 TORNADO WITH WINDS ESTIMATED BETWEEN 100-105 MPH TOUCHED DOWN SOUTH OF SHONGALOO ALONG ELMER MOORE ROAD AND CONTINUED NORTHEAST ACROSS RODNEY MARTIN...WORTHAM...AND THOMAS RHONE ROADS BEFORE CROSSING HIGHWAY 159. THE TORNADO FINALLY LIFTED ALONG HEARN

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
Jan 21, 3:41 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Shreveport, LA (KBAD), launched 12:00Z, 11.6 hours before the alert went out and 59 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: 20 J/kg
Mixed-layer CIN: -323 J/kg
Mixed-layer LCL: 1223 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

074 
WFUS54 KSHV 212333
TORSHV
LAC015-027-119-220015-
/O.NEW.KSHV.TO.W.0005.170121T2333Z-170122T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Shreveport LA
533 PM CST SAT JAN 21 2017

The National Weather Service in Shreveport has issued a

* Tornado Warning for...
  Northwestern Webster Parish in northwestern Louisiana...
  Northwestern Claiborne Parish in northwestern Louisiana...
  Northeastern Bossier Parish in northwestern Louisiana...

* Until 615 PM CST
    
* At 532 PM CST, a severe thunderstorm capable of producing a tornado
  was located over Cotton Valley, or 14 miles south of Springhill,
  moving northeast at 30 mph.

  HAZARD...Tornado and quarter size hail. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* Locations impacted include...
  Cotton Valley, Sarepta, Shongaloo and Leton. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 3274 9344 3286 9352 3302 9326 3302 9321
      3291 9314
TIME...MOT...LOC 2332Z 216DEG 24KT 3279 9345 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

19

The office that day

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

Issued	Product	Office	Counties	Lasted
Jan 21, 9:44 AM CST	River Flood Warning	SHV	Caldwell, Grant, LaSalle, Winn	4 days
Jan 21, 2:51 PM CST	Lake Wind Advisory	SHV	Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more	34 hr
Jan 21, 4:21 PM CST	Special Weather Statement	SHV	Caddo	54 min
Jan 21, 4:44 PM CST	Tornado Warning	SHV	Bossier, Caddo	61 min
Jan 21, 4:49 PM CST	Severe Thunderstorm Warning	SHV	Bossier, Caddo, Webster	56 min
Jan 21, 4:56 PM CST	Tornado Warning	SHV	Bossier, Caddo, Webster	49 min
Jan 21, 5:03 PM CST	Severe Thunderstorm Warning	SHV	Caddo	57 min
Jan 21, 5:30 PM CST	Tornado Warning	SHV	Bossier, Webster	60 min
Jan 21, 5:37 PM CST	Tornado Warning	SHV	Grant, Natchitoches, Winn	38 min
Jan 21, 5:41 PM CST	Tornado Warning	SHV	Bossier, Caddo	49 min
Jan 21, 5:46 PM CST	Severe Thunderstorm Warning	SHV	Bossier, Caddo	44 min

Nearby

Tornado Warnings in Louisiana, 2017 Every tornado warning in 2017 Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.