Alert archive / Louisiana / Dense Fog Advisories in 2021

Dense Fog Advisory 13, NWS New Orleans, LA

February 26, 2021Saint Bernard Parish, Saint John the Baptist Parish, Louisiana

NWS New Orleans, LA issued this dense fog advisory at Feb 26, 2021, 3:44 PM CST for Saint Bernard Parish, Saint John the Baptist Parish, Louisiana. It took effect at Feb 26, 2021, 10:00 PM CST. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued
Feb 26, 2021, 3:44 PM CST (21:44 UTC)
In effect from
Feb 26, 2021, 10:00 PM CST
Expired
Feb 27, 2021, 9:00 AM CST
In force
11 hr
Issued by
NWS New Orleans, LA

Counties Saint Bernard Parish, LA, Saint John the Baptist Parish, LA

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 9.7 hours before the alert went out and 258 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, Jackson, MS at 12:00Z on 2021-02-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 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, Jackson, MS at 12:00Z on 2021-02-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 217 square meters per square second.1939587897117Sfc1 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
13 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
486 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
217 m²/s²
0-3 km storm-relative helicity
262 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 26, 3:43 PM CSTMarine Dense Fog AdvisoryLIX20 hr

Nearby

Dense Fog Advisories in Louisiana, 2021Dense Fog Advisories in Mississippi, 2021Every dense fog 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.