Alert archive / Louisiana / Tornado Watches in 2017

Tornado Watch 2

January 2, 20174 counties in Arkansas; 33 parishes in Louisiana; 27 counties in Texas

The Storm Prediction Center issued this tornado watch at Jan 2, 2017, 6:12 AM CST for 4 counties in Arkansas; 33 parishes in Louisiana; 27 counties in Texas. It was in force for 10 hr.

The area

The outline as issued.

The facts

Issued
Jan 2, 2017, 6:12 AM CST (12:12 UTC)
Expired
Jan 2, 2017, 3:43 PM CST
In force
10 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
65 kt
All 64 counties

Columbia County, AR, Lafayette County, AR, Miller County, AR, Union County, AR, 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, Cameron Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Iberia Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, Lafayette 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, Saint Martin Parish, LA, St. Mary Parish, LA, Union Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Franklin County, TX, Gregg County, TX, Hardin County, TX, Harrison County, TX, Jasper County, TX, Jefferson County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Tyler County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 56 km from the middle of the area, began a volume at 12:15 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.

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
50%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

21 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jan 2, 6:31 AM CSTSevere Thunderstorm WarningSHVCamp, Cherokee, Franklin, Gregg, Morris, Nacogdoches and 6 more59 min
Jan 2, 7:25 AM CSTSevere Thunderstorm WarningLCHJasper, Tyler44 min
Jan 2, 7:28 AM CSTSevere Thunderstorm WarningSHVBowie, Camp, Cass, Franklin, Gregg, Harrison and 7 more62 min
Jan 2, 7:41 AM CSTSevere Thunderstorm WarningSHVSabine34 min
Jan 2, 8:09 AM CSTSevere Thunderstorm WarningSHVHarrison, Panola, Rusk51 min
Jan 2, 8:40 AM CSTSevere Thunderstorm WarningLCHJasper, Tyler65 min
Jan 2, 8:46 AM CSTSevere Thunderstorm WarningSHVSabine44 min
Jan 2, 9:07 AM CSTSevere Thunderstorm WarningLCHHardin, Jasper, Newton, Tyler53 min
Jan 2, 9:11 AM CSTSevere Thunderstorm WarningLCHVernon64 min
Jan 2, 9:28 AM CSTSevere Thunderstorm WarningSHVDe Soto, Natchitoches, Sabine62 min
Jan 2, 9:34 AM CSTSevere Thunderstorm WarningLCHHardin, Jefferson, Orange26 min
Jan 2, 9:46 AM CSTSevere Thunderstorm WarningLCHBeauregard, Vernon59 min
Jan 2, 9:57 AM CSTSevere Thunderstorm WarningLCHCalcasieu, Cameron48 min
Jan 2, 10:10 AM CSTTornado WarningLCHVernon19 min
Jan 2, 10:18 AM CSTSevere Thunderstorm WarningSHVBienville, De Soto, Grant, Natchitoches, Red River, Sabine and 1 more42 min
Jan 2, 10:32 AM CSTSevere Thunderstorm WarningLCHAcadia, Allen, Avoyelles, Beauregard, Evangeline, Rapides and 1 more58 min
Jan 2, 10:53 AM CSTSevere Thunderstorm WarningSHVCaldwell, Grant, LaSalle, Natchitoches, Winn52 min
Jan 2, 11:27 AM CSTSevere Thunderstorm WarningLCHAcadia, Allen, Avoyelles, Evangeline, Jefferson Davis, Rapides and 1 more63 min
Jan 2, 11:33 AM CSTSevere Thunderstorm WarningSHVCaldwell, Grant, Jackson, LaSalle, Winn42 min
Jan 2, 11:59 AM CSTFlash Flood WarningLCHAcadia, Avoyelles, Evangeline, Jefferson Davis, Rapides, Saint Landry4 hr
Jan 2, 12:26 PM CSTSevere Thunderstorm WarningLCHSaint Landry, Saint Martin34 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, 0.2 hours before the alert went out and 60 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-pSkew-T log-p diagram, Shreveport, LA at 12:00Z on 2017-01-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Shreveport, LA at 12:00Z on 2017-01-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 240 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
0 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
240 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.6

Open this sounding in Storm Lab

The text

As transmitted.

838 
WWUS20 KWNS 021210
SEL2  
SPC WW 021210
ARZ000-LAZ000-TXZ000-CWZ000-022000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 2
NWS Storm Prediction Center Norman OK
610 AM CST Mon Jan 2 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern Arkansas
  Louisiana
  East Texas
  Coastal Waters

* Effective this Monday morning and afternoon from 610 AM until
  200 PM CST.

* Primary threats include...
  A few tornadoes possible
  Scattered damaging winds and isolated significant gusts to 75
    mph possible
  Isolated very large hail events to 2 inches in diameter possible

SUMMARY...Multiple bands of strong to severe thunderstorms will
steadily progress east-northeastward across the region this morning,
with the possibility of semi-discrete supercells increasing ahead of
multiple fast-moving convective lines and clusters. Damaging winds
will be the primary risk, but a few tornadoes will be possible as
additional moistening/destabilization occurs by late morning and
midday in conjunction with strengthening low/mid-level winds.

The tornado watch area is approximately along and 85 statute miles
east and west of a line from 5 miles north northeast of Texarkana AR
to 40 miles south southeast of Lake Charles LA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU2).

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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 1...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 25040.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 2, 7:48 AM CSTMesoscale DiscussionSPCColumbia, Lafayette, Miller57 min
Jan 2, 2:06 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 23 more114 min
Jan 2, 5:35 AM CSTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Bienville, Bossier, Caddo and 18 more85 min
Jan 2, 10:17 AM CSTMesoscale DiscussionSPCAscension, Concordia, East Baton Rouge, East Feliciana, Livingston, Orleans and 10 more118 min
Jan 2, 11:09 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Caldwell, Cameron, Evangeline and 12 more96 min
Jan 2, 11:22 AM CSTTornado WatchSPCAscension, Assumption, Catahoula, Concordia, East Baton Rouge, East Feliciana and 21 more9 hr
Jan 2, 2:03 PM CSTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 6 more117 min
Jan 1, 10:11 PM CSTMesoscale DiscussionSPCArcher, Baylor, Bosque, Brown, Callahan, Coleman and 35 more3 hr
Jan 2, 1:04 AM CSTMesoscale DiscussionSPCAnderson, Austin, Bandera, Bastrop, Bell, Bexar and 71 more86 min
Jan 2, 1:39 AM CSTSevere Thunderstorm WatchSPCAnderson, Austin, Bastrop, Bell, Blanco, Bosque and 67 more59 days
Jan 2, 3:36 AM CSTMesoscale DiscussionSPCAnderson, Bastrop, Bell, Blanco, Bosque, Brazos and 44 more54 min

Nearby

Tornado Watches in Louisiana, 2017Tornado Watches in Texas, 2017Tornado Watches in Arkansas, 2017Every tornado watch 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.