Alert archive / Louisiana / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 17, NWS New Orleans, LA

April 9, 2020East Baton Rouge Parish, Iberville Parish, West Baton Rouge Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Apr 9, 2020, 9:08 PM CDT for East Baton Rouge Parish, Iberville Parish, West Baton Rouge Parish, Louisiana. It was in force for 37 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: Apr 9, 2020, 9:08 PM CDT (02:08 UTC)
Expired: Apr 9, 2020, 9:45 PM CDT
In force: 37 min
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties East Baton Rouge Parish, LA, Iberville Parish, LA, West Baton Rouge Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 2.1 hours before the alert went out and 150 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: 2230 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 1009 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: -28 m²/s²
0-3 km storm-relative helicity: 59 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -0.4

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 Apr 9, 7:28 PM CDT, 1 hour 40 minutes earlier.

Area forecast discussion, Apr 9, 7:28 PM CDT, 1 hour 40 minutes before

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In the hours before

Special weather statement, Apr 9, 8:48 PM CDT, 20 minutes before

Special Weather Statement
National Weather Service New Orleans LA
848 PM CDT Thu Apr 9 2020

LAZ034-046-047-100215-
Iberville-Pointe Coupee-West Baton Rouge-
848 PM CDT Thu Apr 9 2020

...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL WEST BATON ROUGE...
SOUTHERN POINTE COUPEE AND NORTHWESTERN IBERVILLE PARISHES...

At 848 PM CDT, a strong thunderstorm was located over Lottie, or 7
miles east of Krotz Springs, moving east at 40 mph.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Livonia, Maringouin, Fordoche, Rosedale, Lottie and Erwinville.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 3064 9174 3062 9138 3043 9141 3046 9144
      3047 9167 3050 9171 3050 9175 3051 9175
      3051 9173 3056 9176 3061 9176
TIME...MOT...LOC 0148Z 277DEG 36KT 3052 9163

KLG

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 9, 8:39 PM CDT	Severe Thunderstorm Warning	LIX	Iberville	36 min
Apr 9, 8:48 PM CDT	Special Weather Statement	LIX	Pointe Coupee	27 min
Apr 9, 9:26 PM CDT	Special Weather Statement	LIX	East Baton Rouge, West Baton Rouge	49 min
Apr 9, 9:43 PM CDT	Severe Thunderstorm Warning	LIX	Ascension, Assumption, East Baton Rouge, Iberville, Lafourche, Livingston and 2 more	47 min
Apr 9, 9:50 PM CDT	Special Weather Statement	LIX	East Baton Rouge, Saint Helena, Tangipahoa	55 min
Apr 9, 10:26 PM CDT	Special Weather Statement	LIX	Ascension, Assumption, Saint James, Saint John the Baptist	49 min
Apr 9, 10:30 PM CDT	Special Weather Statement	LIX	Livingston, Saint Tammany, Tangipahoa, Washington	45 min
Apr 9, 10:33 PM CDT	Special Marine Warning	LIX		87 min
Apr 9, 10:46 PM CDT	Special Weather Statement	LIX	Saint Tammany	59 min
Apr 9, 11:14 PM CDT	Special Weather Statement	LIX	Orleans	46 min
Apr 9, 11:23 PM CDT	Severe Thunderstorm Warning	LIX	Orleans, Saint Tammany	37 min
Apr 9, 11:25 PM CDT	Special Marine Warning	LIX		61 min
Apr 9, 11:32 PM CDT	Severe Thunderstorm Warning	LIX	Orleans, Saint Bernard	43 min
Apr 10, 12:07 AM CDT	Special Marine Warning	LIX		109 min
Apr 10, 4:04 PM CDT	Small Craft Advisory	LIX		54 hr
Apr 9, 11:49 PM CDT	Special Weather Statement	LIX	Hancock, Harrison, Jackson	56 min
Apr 10, 12:04 AM CDT	Special Weather Statement	LIX	Jackson	56 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 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.