Alert archive / Louisiana / Tornado Watches in 2014

Tornado Watch 64

April 6, 201416 parishes in Louisiana; Jefferson County, Newton County, Orange County, Texas

The Storm Prediction Center issued this tornado watch at Apr 6, 2014, 3:27 PM CDT for 16 parishes in Louisiana; Jefferson County, Newton County, Orange County, Texas. It was in force for 14 hr.

The area

The outline as issued.

The facts

Issued: Apr 6, 2014, 3:27 PM CDT (20:27 UTC)
Expired: Apr 7, 2014, 5:34 AM CDT
In force: 14 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Jefferson County, TX, Newton County, TX, Orange County, TX

The radar

The Lake Charles radar (KLCH), 49 km from the middle of the area, began a volume at 20:27 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: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 20%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 60%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 6, 11:19 PM CDT	Severe Thunderstorm Warning	LCH	Iberia, Saint Martin	41 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.5 hours before the alert went out and 49 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: 3 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 401 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 526 m²/s²
0-3 km storm-relative helicity: 574 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

270 
WWUS20 KWNS 062026
SEL4  
SPC WW 062026
LAZ000-TXZ000-CWZ000-070400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 64
NWS STORM PREDICTION CENTER NORMAN OK
325 PM CDT SUN APR 6 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  CENTRAL AND SOUTHWEST LOUISIANA
  FAR SOUTHEAST TEXAS
  COASTAL WATERS

* EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 325 PM UNTIL
  1100 PM CDT.

* PRIMARY THREATS INCLUDE...
  SEVERAL TORNADOES POSSIBLE
  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  A FEW LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 30 MILES NORTH OF PORT
ARTHUR TEXAS TO 20 MILES NORTHEAST OF LAFAYETTE LOUISIANA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU4).

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 63...

DISCUSSION...THUNDERSTORMS DEVELOPING ALONG THE SABINE RIVER VALLEY
ARE EXPECTED TO BECOME PROGRESSIVELY SURFACE BASED AS THEY MOVE EAST
AND ENCOUNTER A WARM FRONT LIFTING NORTHWARD. THE AIR MASS TO THE
SOUTH OF THIS FRONT IS MOIST AND UNSTABLE...AND GIVEN THE STRONG
VERTICAL SHEAR ALONG THE FRONT...SUPERCELLS ARE POSSIBLE WITH A RISK
FOR TORNADOES AND DAMAGING WINDS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 24035.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 6, 6:26 AM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 23 more	12 hr
Apr 6, 9:39 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 17 more	66 min
Apr 6, 1:31 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 15 more	59 min
Apr 6, 6:24 PM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 18 more	2 hr
Apr 6, 6:56 PM CDT	Tornado Watch	SPC	Ascension, Assumption, Concordia, East Baton Rouge, East Feliciana, Iberville and 17 more	8 hr
Apr 6, 4:34 AM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Austin, Bastrop, Bell, Blanco and 57 more	2 hr

Nearby

Tornado Watches in Louisiana, 2014 Tornado Watches in Texas, 2014 Every tornado watch in 2014

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.