Alert archive / Louisiana / Tornado Watches in 2020

Tornado Watch 138

April 23, 202011 parishes in Louisiana

The Storm Prediction Center issued this tornado watch at Apr 23, 2020, 12:02 AM CDT for 11 parishes in Louisiana. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Apr 23, 2020, 12:02 AM CDT (05:02 UTC)
Expired
Apr 23, 2020, 4:00 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Evangeline Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA

The radar

The Ft Polk radar (KPOE), 78 km from the middle of the area, began a volume at 05:00 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
30%
Ten or more severe wind reports
40%
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
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 23, 12:33 AM CDTSevere Thunderstorm WarningLCHAllen, Calcasieu, Jefferson Davis57 min
Apr 23, 1:02 AM CDTTornado WarningLCHAvoyelles, Evangeline, Rapides43 min
Apr 23, 1:24 AM CDTSevere Thunderstorm WarningLCHAcadia, Allen, Evangeline, Jefferson Davis, Saint Landry50 min
Apr 23, 1:52 AM CDTTornado WarningLCHAcadia, Saint Landry42 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 00:00Z, 5.0 hours before the alert went out and 121 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, Lake Charles Mun, LA at 00:00Z on 2020-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2355 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lake Charles Mun, LA at 00:00Z on 2020-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 220 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
2355 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
548 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
220 m²/s²
0-3 km storm-relative helicity
302 m²/s²
Significant tornado parameter
4.7
Supercell composite
15.7

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 7:01 PM CDTMesoscale DiscussionSPCBeauregard, Vernon89 min
Apr 22, 7:41 PM CDTMesoscale DiscussionSPCVernon34 min
Apr 22, 8:26 PM CDTMesoscale DiscussionSPCDe Soto, Natchitoches, Sabine94 min
Apr 22, 9:31 PM CDTMesoscale DiscussionSPCAvoyelles, Concordia, East Feliciana, Pointe Coupee, Saint Helena, Washington and 1 more89 min
Apr 22, 9:47 PM CDTTornado WatchSPCAscension, Catahoula, Concordia, East Baton Rouge, East Feliciana, Franklin and 12 more9 hr
Apr 22, 10:17 PM CDTMesoscale DiscussionSPCCaldwell, Grant, LaSalle, Natchitoches, Sabine, Winn88 min
Apr 22, 11:16 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 15 more89 min
Apr 23, 2:28 AM CDTMesoscale DiscussionSPCAcadia, Ascension, Avoyelles, Concordia, East Baton Rouge, East Feliciana and 17 more92 min
Apr 23, 1:37 PM CDTMesoscale DiscussionSPCAscension, East Baton Rouge, East Feliciana, Iberville, Livingston, Saint Helena and 3 more113 min

Nearby

Tornado Watches in Louisiana, 2020Every tornado watch in 2020

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.