Alert archive / Louisiana / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 133, NWS New Orleans, LA

December 23, 2020East Feliciana Parish, Pointe Coupee Parish, West Feliciana Parish, Louisiana; Amite County, Wilkinson County, Mississippi

NWS New Orleans, LA issued this severe thunderstorm warning at Dec 23, 2020, 10:55 PM CST for East Feliciana Parish, Pointe Coupee Parish, West Feliciana Parish, Louisiana; Amite County, Wilkinson County, Mississippi. It was in force for 65 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Dec 23, 2020, 10:55 PM CST (04:55 UTC)
Expired: Dec 24, 2020, 12:00 AM CST
In force: 65 min
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties East Feliciana Parish, LA, Pointe Coupee Parish, LA, West Feliciana Parish, LA, Amite County, MS, Wilkinson County, MS

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Dec 23, 8:40 PM CST	Tornado Watch	SPC	5 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 4.9 hours before the alert went out and 167 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: 29 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 705 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 273 m²/s²
0-3 km storm-relative helicity: 337 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS New Orleans, LA wrote its last area forecast discussion before this severe thunderstorm warning went out at Dec 23, 8:57 PM CST, 1 hour 58 minutes earlier.

Area forecast discussion, Dec 23, 8:57 PM CST, 1 hour 58 minutes before

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In the hours before

Special weather statement, Dec 23, 10:41 PM CST, 14 minutes before

Special Weather Statement
National Weather Service New Orleans LA
1041 PM CST Wed Dec 23 2020

LAZ034>036-MSZ068-240615-
East Feliciana-Pointe Coupee-West Feliciana-Wilkinson-
1041 PM CST Wed Dec 23 2020

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT WEST FELICIANA...
NORTHWESTERN POINTE COUPEE...NORTHWESTERN EAST FELICIANA PARISHES IN
SOUTHEASTERN LOUISIANA AND WILKINSON COUNTIES...

At 1041 PM CST, radar indicated strong thunderstorms were located
along a line extending from near Big Bend to near Simmesport.
Movement was northeast at 35 mph.

Winds in excess of 40 mph are possible with these storms.

Locations impacted include...
Jackson, St. Francisville, Centreville, Woodville, Wilson, Norwood,
Wakefield, Spillman, Batchelor, Lettsworth, Fort Adams, Dolorosa and
Crosby.

Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.

A Tornado Watch remains in effect until 200 AM CST for southeastern
Louisiana...and southern Mississippi.

LAT...LON 3132 9110 3128 9106 3084 9106 3073 9175
      3086 9182 3087 9180 3097 9181 3104 9172
      3104 9165 3097 9166 3104 9156 3112 9162
      3122 9158 3124 9155 3122 9153 3123 9149
      3128 9149 3132 9145 3137 9122
TIME...MOT...LOC 0441Z 246DEG 28KT 3112 9175 3090 9182

KLG

The office that day

Everything else NWS New Orleans, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 23, 10:41 PM CST	Special Weather Statement	LIX	West Feliciana	94 min
Dec 23, 11:39 PM CST	Special Weather Statement	LIX	East Feliciana, Saint Helena	51 min
Dec 24, 12:15 AM CST	Tornado Warning	LIX	Saint Helena, Tangipahoa, Washington	13 min
Dec 24, 2:02 AM CST	Special Marine Warning	LIX		58 min
Dec 24, 10:00 AM CST	Small Craft Advisory	LIX		14 hr

Nearby

Severe Thunderstorm Warnings in Louisiana, 2020 Severe Thunderstorm Warnings in Mississippi, 2020 Every severe thunderstorm warning 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.