Alert archive / Louisiana / Tornado Watches in 2016
Tornado Watch 501
The Storm Prediction Center issued this tornado watch at Nov 28, 2016, 11:08 AM CST for 27 parishes in Louisiana; 9 counties in Texas. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 28, 2016, 11:08 AM CST (17:08 UTC)
- Expired
- Nov 28, 2016, 5:00 PM CST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 36 counties
Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Harrison County, TX, Jasper County, TX, Marion County, TX, Newton County, TX, Orange County, TX, Panola County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX
The radar
The Shreveport radar (KSHV), 70 km from the middle of the area, began a volume at 17:10 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 50%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 28, 2:01 PM CST | Severe Thunderstorm Warning | SHV | De Soto, Sabine | 21 min |
| Nov 28, 2:02 PM CST | Severe Thunderstorm Warning | SHV | Natchitoches, Sabine | 31 min |
| Nov 28, 2:38 PM CST | Severe Thunderstorm Warning | SHV | Grant, LaSalle, Winn | 25 min |
| Nov 28, 2:41 PM CST | Tornado Warning | SHV | Grant, LaSalle, Winn | 19 min |
| Nov 28, 2:59 PM CST | Tornado Warning | SHV | Caldwell, Grant, LaSalle, Winn | 16 min |
| Nov 28, 3:56 PM CST | Tornado Warning | LCH | Avoyelles, Rapides | 20 min |
| Nov 28, 4:18 PM CST | Tornado Warning | LCH | Avoyelles | 27 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Shreveport, LA (KBAD), launched 12:00Z, 5.1 hours before the alert went out and 66 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.
- Mixed-layer CAPE
- 14 J/kg
- Mixed-layer CIN
- -326 J/kg
- Mixed-layer LCL
- 701 m above ground
- 0-6 km bulk shear
- 70 kt
- 0-1 km storm-relative helicity
- 499 m²/s²
- 0-3 km storm-relative helicity
- 482 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
393 WWUS20 KWNS 281706 SEL1 SPC WW 281706 ARZ000-LAZ000-TXZ000-282300- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 501 NWS STORM PREDICTION CENTER NORMAN OK 1105 AM CST MON NOV 28 2016 THE NWS STORM PREDICTION CENTER HAS ISSUED A * TORNADO WATCH FOR PORTIONS OF EXTREME SOUTHERN ARKANSAS MUCH OF WESTERN AND NORTHERN LOUISIANA EXTREME EAST TEXAS * EFFECTIVE THIS MONDAY MORNING AND AFTERNOON FROM 1105 AM UNTIL 500 PM CST. * PRIMARY THREATS INCLUDE... A FEW TORNADOES POSSIBLE SCATTERED DAMAGING WIND GUSTS TO 70 MPH LIKELY ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE SUMMARY...THUNDERSTORMS WILL SLOWLY INCREASE IN COVERAGE AND INTENSITY THROUGH THE AFTERNOON WHILE SPREADING EASTWARD FROM TEXAS INTO LOUISIANA. THE STORM ENVIRONMENT WILL BECOME MORE FAVORABLE FOR SUPERCELLS WITH THE POTENTIAL TO PRODUCE A FEW TORNADOES THIS AFTERNOON...ESPECIALLY WITH THE MORE ISOLATED NOW FORMING NEAR THE SABINE RIVER. ALSO...A LINE OF STORMS ACROSS NORTHEAST TEXAS AND SOUTHERN ARKANSAS WILL LIKELY BECOME BETTER ORGANIZED THROUGH THE AFTERNOON AND POSE A RISK FOR DAMAGING WINDS. THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE MILES EAST AND WEST OF A LINE FROM 65 MILES NORTHEAST OF SHREVEPORT LA TO 45 MILES SOUTH OF FORT POLK LA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. && AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION VECTOR 24055. ...THOMPSON
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 28, 7:40 AM CST | Mesoscale Discussion | SPC | Bossier, Caddo, Claiborne, De Soto, Red River, Sabine and 1 more | 3 hr |
| Nov 28, 10:10 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 16 more | 2 hr |
| Nov 28, 1:02 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 22 more | 118 min |
| Nov 28, 2:23 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 27 more | 2 hr |
| Nov 28, 2:49 PM CST | Tornado Watch | SPC | Ascension, Catahoula, Concordia, East Baton Rouge, East Carroll, East Feliciana and 13 more | 6 hr |
| Nov 28, 5:07 PM CST | Mesoscale Discussion | SPC | East Baton Rouge, East Feliciana, Saint Helena, Tangipahoa, Washington, West Baton Rouge and 1 more | 83 min |
| Nov 27, 11:34 PM CST | Mesoscale Discussion | SPC | Archer, Clay, Collin, Cooke, Delta, Denton and 14 more | 2 hr |
| Nov 27, 11:52 PM CST | Severe Thunderstorm Watch | SPC | Clay, Collin, Cooke, Denton, Fannin, Grayson and 5 more | 6 hr |
Nearby
Tornado Watches in Louisiana, 2016Tornado Watches in Texas, 2016Every tornado watch in 2016
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.