Alert archive / Louisiana / Heat Advisories in 2026
Heat Advisory 21, NWS New Orleans, LA
NWS New Orleans, LA issued this heat advisory at Aug 18, 2026, 11:14 AM CDT for 22 parishes in Louisiana; 8 counties in Mississippi. It took effect at Aug 19, 2026, 11:00 AM CDT. It was in force for 9 hr.
The area
The counties it named.
The facts
- Issued
- Aug 18, 2026, 11:14 AM CDT (16:14 UTC)
- In effect from
- Aug 19, 2026, 11:00 AM CDT
- Expired
- Aug 19, 2026, 8:00 PM CDT
- In force
- 9 hr
- Issued by
- NWS New Orleans, LA
All 30 counties
Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Pike County, MS, Walthall County, MS, Wilkinson County, MS
The radar
The Hammond radar (KHDC), 15 km from the middle of the area, began a volume at 16:17 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.
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 12:00Z, 4.2 hours before the alert went out and 74 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.
- Mixed-layer CAPE
- 1648 J/kg
- Mixed-layer CIN
- -109 J/kg
- Mixed-layer LCL
- 1035 m above ground
- 0-6 km bulk shear
- 6 kt
- 0-1 km storm-relative helicity
- -37 m²/s²
- 0-3 km storm-relative helicity
- 11 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 17, 6:35 PM CDT, 16 hours 39 minutes earlier.
Area forecast discussion, Aug 17, 6:35 PM CDT, 16 hours 39 minutes before
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</html>The office that day
Everything else NWS New Orleans, LA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 2:07 PM CDT | Special Weather Statement | LIX | Washington | 38 min |
| Aug 18, 2:48 PM CDT | Special Weather Statement | LIX | Washington | 42 min |
| Aug 18, 3:39 PM CDT | Special Weather Statement | LIX | Tangipahoa | 36 min |
| Aug 18, 4:04 PM CDT | Special Weather Statement | LIX | Tangipahoa | 41 min |
| Aug 18, 4:18 PM CDT | Special Weather Statement | LIX | Tangipahoa | 42 min |
| Aug 18, 4:19 PM CDT | Special Weather Statement | LIX | Tangipahoa | 26 min |
| Aug 18, 2:19 PM CDT | Special Weather Statement | LIX | Pearl River | 26 min |
| Aug 18, 3:01 PM CDT | Special Weather Statement | LIX | Pike, Walthall | 44 min |
| Aug 18, 4:25 PM CDT | Special Weather Statement | LIX | Amite | 35 min |
| Aug 18, 5:05 PM CDT | Special Weather Statement | LIX | Amite | 40 min |
Nearby
Heat Advisories in Louisiana, 2026Heat Advisories in Mississippi, 2026Every heat advisory in 2026
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.