Alert archive / Louisiana / Heat Advisories in 2021

Heat Advisory 20, NWS New Orleans, LA

August 31, 202115 parishes in Louisiana; 5 counties in Mississippi

NWS New Orleans, LA issued this heat advisory at Aug 31, 2021, 4:06 AM CDT for 15 parishes in Louisiana; 5 counties in Mississippi. It took effect at Sep 1, 2021, 10:00 AM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Aug 31, 2021, 4:06 AM CDT (09:06 UTC)
In effect from: Sep 1, 2021, 10:00 AM CDT
Expired: Sep 1, 2021, 6:00 PM CDT
In force: 8 hr
Issued by: NWS New Orleans, LA

Counties Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Pearl River County, MS, Pike County, MS, Walthall County, MS, Wilkinson County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 9.1 hours before the alert went out and 100 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: 914 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 811 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 125 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 heat advisory 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 heat advisory went out at Aug 31, 3:56 AM CDT, 10 minutes earlier.

Area forecast discussion, Aug 31, 3:56 AM CDT, 10 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 10:02 AM CDT	Special Marine Warning	LIX		118 min
Aug 31, 1:21 PM CDT	Special Weather Statement	LIX	Saint Bernard	39 min
Aug 31, 1:58 PM CDT	Special Weather Statement	LIX	Saint Bernard	32 min
Aug 31, 2:49 PM CDT	Flash Flood Warning Considerable damage threat	LIX	Jefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles	88 min
Aug 31, 3:52 PM CDT	Special Weather Statement	LIX	Saint Charles	53 min
Aug 31, 4:23 PM CDT	Special Marine Warning	LIX		2 hr
Aug 31, 4:36 PM CDT	Special Weather Statement	LIX	Lafourche	24 min
Aug 31, 4:44 PM CDT	Flash Flood Warning Considerable damage threat	LIX	Lafourche, Saint James, Saint John the Baptist	3 hr
Aug 31, 5:05 PM CDT	Special Weather Statement	LIX	Lafourche	25 min
Aug 31, 5:22 PM CDT	Special Weather Statement	LIX	Assumption	53 min
Aug 31, 6:20 PM CDT	Flash Flood Warning Considerable damage threat	LIX	Saint Charles, Saint John the Baptist	49 min
Aug 31, 6:50 PM CDT	Flash Flood Warning	LIX	Assumption, Lafourche, Terrebonne	42 min
Aug 30, 9:28 PM CDT	Flash Flood Warning	LIX	Hancock, Harrison, Jackson, Pearl River	9 hr
Aug 30, 9:55 PM CDT	River Flood Warning	LIX	Jackson	61 hr

Nearby

Heat Advisories in Louisiana, 2021 Heat Advisories in Mississippi, 2021 Every heat advisory in 2021

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.