Alert archive / Louisiana / Tornado Warnings in 2017

Tornado Warning 10, NWS Shreveport, LA

January 21, 2017Grant Parish, Winn Parish, Louisiana

NWS Shreveport, LA issued this tornado warning at Jan 21, 2017, 6:13 PM CST for Grant Parish, Winn Parish, Louisiana. It was in force for 47 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: Jan 21, 2017, 6:13 PM CST (00:13 UTC)
Expired: Jan 21, 2017, 7:00 PM CST
In force: 47 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

Counties Grant Parish, LA, Winn Parish, LA

The radar

The Ft Polk radar (KPOE), 62 km from the middle of the area, began a volume at 00:15 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
Jan 21, 3:41 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Shreveport, LA (KBAD), launched 00:00Z, 0.2 hours before the alert went out and 118 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: 1144 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 813 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 200 m²/s²
0-3 km storm-relative helicity: 285 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 9.0

Open this sounding in Storm Lab

The text

As transmitted.

858 
WFUS54 KSHV 220013
TORSHV
LAC043-127-220100-
/O.NEW.KSHV.TO.W.0010.170122T0013Z-170122T0100Z/

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

The National Weather Service in Shreveport has issued a

* Tornado Warning for...
  Northwestern Grant Parish in north central Louisiana...
  Southwestern Winn Parish in north central Louisiana...

* Until 700 PM CST
    
* At 612 PM CST, a severe thunderstorm capable of producing a tornado
  was located over Montgomery, or 11 miles east of Natchitoches,
  moving east at 30 mph.

  HAZARD...Tornado and quarter size hail. 

  SOURCE...Radar indicated rotation. A funnel cloud has also been 
           reported with this storm. 

  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...
  Montgomery, Atlanta, Williana and St. Maurice. 

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 3162 9291 3166 9290 3166 9292 3168 9293
      3168 9296 3170 9296 3171 9298 3173 9297
      3178 9297 3178 9295 3180 9295 3190 9262
      3165 9256
TIME...MOT...LOC 0012Z 256DEG 21KT 3170 9291 

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

$$

19

1 follow-up statement

694 
WWUS54 KSHV 220040
SVSSHV

Severe Weather Statement
National Weather Service Shreveport LA
640 PM CST SAT JAN 21 2017

LAC043-127-220100-
/O.CON.KSHV.TO.W.0010.000000T0000Z-170122T0100Z/
Grant LA-Winn LA-
640 PM CST SAT JAN 21 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM CST FOR
NORTHWESTERN GRANT AND SOUTHWESTERN WINN PARISHES...
    
At 640 PM CST, a severe thunderstorm capable of producing a tornado
was located 11 miles northeast of Montgomery, or 13 miles south of
Winnfield, moving east at 25 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...
Atlanta and Williana. 

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 3164 9282 3179 9286 3190 9262 3165 9256
TIME...MOT...LOC 0040Z 256DEG 21KT 3174 9272 

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, 6:04 PM CST	Tornado Warning	SHV	Claiborne	41 min
Jan 21, 6:04 PM CST	Tornado Warning	SHV	Bossier, Caddo	56 min
Jan 21, 6:14 PM CST	Tornado Warning	SHV	Grant, Natchitoches	61 min
Jan 21, 6:16 PM CST	Severe Thunderstorm Warning	SHV	Claiborne, Webster	59 min
Jan 21, 6:22 PM CST	Special Weather Statement	SHV	Claiborne	38 min
Jan 21, 6:32 PM CST	Tornado Warning	SHV	Claiborne, Union	43 min
Jan 21, 6:44 PM CST	Tornado Warning	SHV	Claiborne	46 min
Jan 21, 6:48 PM CST	Tornado Warning	SHV	Bossier, Caddo, Webster	57 min
Jan 21, 6:52 PM CST	Severe Thunderstorm Warning	SHV	LaSalle	23 min
Jan 21, 7:00 PM CST	Tornado Warning	SHV	Grant, LaSalle, Winn	22 min
Jan 21, 7:08 PM CST	Tornado Warning	SHV	Grant	52 min
Jan 21, 7:13 PM CST	Tornado Warning	SHV	Union	47 min
Jan 21, 7:21 PM CST	Tornado Warning	SHV	Claiborne, Union	54 min
Jan 21, 7:34 PM CST	Severe Thunderstorm Warning	SHV	Union	56 min
Jan 21, 7:37 PM CST	Severe Thunderstorm Warning	SHV	Bossier, Claiborne, Webster	68 min
Jan 21, 7:39 PM CST	Tornado Warning	SHV	Union	51 min
Jan 21, 7:56 PM CST	Tornado Warning	SHV	Grant, LaSalle	64 min
Jan 21, 8:03 PM CST	Tornado Warning	SHV	Claiborne, Webster	57 min
Jan 21, 8:21 PM CST	Tornado Warning	SHV	Union	39 min
Jan 21, 8:47 PM CST	Tornado Warning	SHV	Lincoln, Union	43 min
Jan 21, 8:48 PM CST	Special Weather Statement	SHV	Webster	42 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.