Alert archive / Louisiana / Tornado Watches in 2022

Tornado Watch 49

March 17, 202229 parishes in Louisiana; 5 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Mar 17, 2022, 11:42 PM CDT for 29 parishes in Louisiana; 5 counties in Mississippi. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Mar 17, 2022, 11:42 PM CDT (04:42 UTC)
Expired
Mar 18, 2022, 7:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 34 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Franklin County, MS, Pike County, MS, Wilkinson County, MS

The radar

The Ft Polk radar (KPOE), 85 km from the middle of the area, began a volume at 04:45 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
80%
One or more EF2 to EF5 tornadoes
50%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 18, 5:05 AM CDTSevere Thunderstorm WarningLIXSaint Helena, Tangipahoa, Washington25 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, 4.7 hours before the alert went out and 111 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 2022-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 428 joules per kilogram.LCLLFCEL10008507005003002001001 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 2022-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 225 square meters per square second.19395878Sfc1 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
428 J/kg
Mixed-layer CIN
-168 J/kg
Mixed-layer LCL
754 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
225 m²/s²
0-3 km storm-relative helicity
273 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted.

537 
WWUS20 KWNS 180438
SEL9  
SPC WW 180438
LAZ000-MSZ000-CWZ000-181200-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 49
NWS Storm Prediction Center Norman OK
1140 PM CDT Thu Mar 17 2022

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern Louisiana
  Southwest Mississippi
  Coastal Waters

* Effective this Thursday night and Friday morning from 1140 PM
  until 700 AM CDT.

* Primary threats include...
  Several tornadoes likely with a couple intense tornadoes
    possible
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Thunderstorms are expected to intensify overnight and
spread across much of southern Louisiana.  Strengthening winds aloft
and increasing moisture will pose a risk of supercell storms capable
of tornadoes.  A strong tornado or two is possible.

The tornado watch area is approximately along and 60 statute miles
north and south of a line from 20 miles northwest of Lake Charles LA
to 25 miles south of Mc Comb MS. For a complete depiction of the
watch see the associated watch outline update (WOUS64 KWNS WOU9).

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 2 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 22035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 17, 8:30 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 4 more2 hr
Mar 17, 10:47 PM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 19 more3 hr
Mar 18, 1:40 AM CDTMesoscale DiscussionSPCEast Baton Rouge, Evangeline, Pointe Coupee, Saint Landry, West Baton Rouge, West Feliciana95 min
Mar 18, 3:12 AM CDTMesoscale DiscussionSPCAscension, East Baton Rouge, East Feliciana, Iberville, Livingston, Pointe Coupee and 7 more2 hr
Mar 18, 3:55 AM CDTTornado WatchSPCSaint Tammany, Washington8 hr
Mar 18, 5:48 AM CDTMesoscale DiscussionSPCWashington87 min
Mar 18, 7:16 AM CDTMesoscale DiscussionSPCForrest, George, Greene, Hancock, Harrison, Jackson and 4 more89 min

Nearby

Tornado Watches in Louisiana, 2022Tornado Watches in Mississippi, 2022Every tornado watch in 2022

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.