Alert archive / Louisiana / Tornado Warnings in 2017

Tornado Warning 53, NWS Shreveport, LA

April 10, 2017Bossier Parish, Webster Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at Apr 10, 2017, 7:41 PM CDT for Bossier Parish, Webster Parish, Louisiana. It was in force for 34 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: Apr 10, 2017, 7:41 PM CDT (00:41 UTC)
Expired: Apr 10, 2017, 8:15 PM CDT
In force: 34 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.25 in

Counties Bossier Parish, LA, Webster Parish, LA

The radar

The Shreveport radar (KSHV), 55 km from the middle of the area, began a volume at 00:42 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.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 10, 2:26 PM CDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 0.7 hours before the alert went out and 47 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: 741 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 1114 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 72 m²/s²
0-3 km storm-relative helicity: 123 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 4.2

Open this sounding in Storm Lab

The text

As transmitted.

329 
WFUS54 KSHV 110041
TORSHV
LAC015-119-110115-
/O.NEW.KSHV.TO.W.0053.170411T0041Z-170411T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Shreveport LA
741 PM CDT MON APR 10 2017

The National Weather Service in Shreveport has issued a

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

* Until 815 PM CDT
    
* At 741 PM CDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles southwest of Sarepta, or 12 miles southwest of
  Springhill, moving east at 20 mph.

  HAZARD...Tornado and half dollar 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...
  Cullen, Cotton Valley, Sarepta and Ivan. 

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 3277 9358 3290 9363 3300 9337 3280 9331
TIME...MOT...LOC 0041Z 251DEG 14KT 3284 9356 

TORNADO...RADAR INDICATED
HAIL...1.25IN

$$

19

1 follow-up statement

005 
WWUS54 KSHV 110106
SVSSHV

Severe Weather Statement
National Weather Service Shreveport LA
806 PM CDT MON APR 10 2017

LAC015-119-110115-
/O.CON.KSHV.TO.W.0053.000000T0000Z-170411T0115Z/
Webster LA-Bossier LA-
806 PM CDT MON APR 10 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
NORTHWESTERN WEBSTER AND NORTHEASTERN BOSSIER PARISHES...
    
At 805 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Sarepta, or 9 miles south of Springhill, moving east
at 15 mph.

HAZARD...Tornado and half dollar 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 and Sarepta. 

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 3278 9348 3291 9353 3300 9337 3280 9331
TIME...MOT...LOC 0105Z 251DEG 14KT 3287 9345 

TORNADO...RADAR INDICATED
HAIL...1.25IN

$$

19

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 10, 7:36 PM CDT	Severe Thunderstorm Warning	SHV	Bossier, Claiborne, Webster	54 min
Apr 10, 8:31 PM CDT	Severe Thunderstorm Warning	SHV	Claiborne, Webster	59 min
Apr 11, 12:21 AM CDT	Special Weather Statement	SHV	Lincoln, Union	39 min
Apr 11, 5:14 AM CDT	Special Weather Statement	SHV	Bossier	61 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.