Alert archive / Louisiana / Tornado Watches in 2013
Tornado Watch 4
The Storm Prediction Center issued this tornado watch at Jan 12, 2013, 11:29 PM CST for 4 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 12, 2013, 11:29 PM CST (05:29 UTC)
- Expired
- Jan 13, 2013, 4:50 AM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 65 kt
All 61 counties
Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Cleveland County, AR, Columbia County, AR, Desha County, AR, Drew County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Monroe County, AR, Phillips County, AR, Union County, AR, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Benton County, MS, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Humphreys County, MS, Issaquena County, MS, Lafayette County, MS, Leflore County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tunica County, MS, Washington County, MS, Yalobusha County, MS, Angelina County, TX, Nacogdoches County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX
The radar
The Shreveport radar (KSHV), 147 km from the middle of the area, began a volume at 05:30 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
- 30%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 12, 11:36 PM CST | Severe Thunderstorm Warning | SHV | Angelina, Nacogdoches, San Augustine, Shelby | 54 min |
| Jan 12, 11:50 PM CST | Severe Thunderstorm Warning | SHV | Union | 55 min |
| Jan 12, 11:56 PM CST | Severe Thunderstorm Warning | SHV | Bienville, Bossier, Claiborne, Lincoln, Red River, Webster | 64 min |
| Jan 13, 12:09 AM CST | Severe Thunderstorm Warning | SHV | De Soto | 46 min |
| Jan 13, 12:15 AM CST | Severe Thunderstorm Warning | SHV | Bienville, Bossier, Caddo, De Soto, Red River, Webster | 60 min |
| Jan 13, 12:22 AM CST | Severe Thunderstorm Warning | SHV | Columbia, Union | 26 min |
| Jan 13, 12:33 AM CST | Flash Flood Warning | LZK | Arkansas, Grant, Jefferson, Lincoln, Lonoke, Monroe and 4 more | 3 hr |
| Jan 13, 12:43 AM CST | Severe Thunderstorm Warning | SHV | Union | 62 min |
| Jan 13, 12:52 AM CST | Flash Flood Warning | MEG | Crittenden, Cross, Lee, Poinsett, St. Francis | 2 hr |
| Jan 13, 1:26 AM CST | Severe Thunderstorm Warning | JAN | Ashley | 49 min |
| Jan 13, 1:55 AM CST | Severe Thunderstorm Warning | LZK | Arkansas, Desha, Drew, Lincoln | 35 min |
| Jan 13, 2:49 AM CST | Severe Thunderstorm Warning | JAN | Bolivar, Washington | 45 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 (KSHV), launched 00:00Z, 5.5 hours before the alert went out and 138 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
- 1010 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 620 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 340 m²/s²
- 0-3 km storm-relative helicity
- 398 m²/s²
- Significant tornado parameter
- 1.8
- Supercell composite
- 9.8
The text
As transmitted, in the capitals the NWS used until 2016.
671
WWUS20 KWNS 130531
SEL4
SPC WW 130531
ARZ000-LAZ000-MSZ000-TXZ000-131200-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 4
NWS STORM PREDICTION CENTER NORMAN OK
1130 PM CST SAT JAN 12 2013
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHERN AND EASTERN ARKANSAS
NORTHERN LOUISIANA
NORTHWESTERN MISSISSIPPI
SMALL PART OF EAST TEXAS
EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1130 PM
UNTIL 600 AM CST.
TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 75 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 45 MILES SOUTH SOUTHWEST OF
NATCHITOCHES LOUISIANA TO 40 MILES NORTHWEST OF OXFORD
MISSISSIPPI. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).
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.
OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 3. WATCH NUMBER 3 WILL NOT BE IN EFFECT AFTER 1130
PM CST.
DISCUSSION...BAND OF NEAR-FRONTAL CONVECTION BECOMING BETTER
ORGANIZED ACROSS THIS REGION...WHILE IMPINGING UPON WARM-SECTOR
CAPE-SHEAR PARAMETER SPACE THAT WILL REMAIN FAVORABLE FOR SVR
THROUGH MOST OF PRE-DAWN HOURS. REF MESOSCALE DISCUSSION 21 FOR
MORE INITIAL DETAILS. DAMAGING GUSTS ARE POSSIBLE...AND A TORNADO
THREAT DOES EXIST WITH ANY QLCS MESOVORTICES OR EMBEDDED SUPERCELLS.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 23040.
...EDWARDSSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 12, 6:18 PM CST | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 48 more | 117 min |
| Jan 12, 9:25 PM CST | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Clay, Cleveland and 31 more | 2 hr |
| Jan 12, 10:33 PM CST | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Columbia, Drew, Ouachita and 1 more | 87 min |
| Jan 13, 1:18 AM CST | Mesoscale Discussion | SPC | Ashley, Chicot, Desha, Drew | 87 min |
| Jan 13, 3:53 AM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Chicot, Desha, Drew and 5 more | 97 min |
| Jan 13, 2:30 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, Lafourche, Livingston, Orleans, Saint Charles and 5 more | 90 min |
| Jan 13, 2:46 PM CST | Mesoscale Discussion | SPC | Kemper, Lauderdale, Lowndes, Monroe, Neshoba, Newton and 1 more | 119 min |
Nearby
Tornado Watches in Louisiana, 2013Tornado Watches in Mississippi, 2013Tornado Watches in Arkansas, 2013Every tornado watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.