Alert archive / Louisiana / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 123, NWS New Orleans, LA

December 1, 2018Ascension Parish, Iberville Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Dec 1, 2018, 1:02 AM CST for Ascension Parish, Iberville Parish, Louisiana. It was in force for 30 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 1, 2018, 1:02 AM CST (07:02 UTC)
Expired
Dec 1, 2018, 1:32 AM CST
In force
30 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Ascension Parish, LA, Iberville Parish, LA

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 7.0 hours before the alert went out and 253 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 00:00Z on 2018-12-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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 00:00Z on 2018-12-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 122 square meters per square second.1939587897Sfc1 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
17 J/kg
Mixed-layer CIN
-174 J/kg
Mixed-layer LCL
942 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
161 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 30, 9:48 PM CSTSpecial Marine WarningLIX42 min
Dec 1, 1:14 AM CSTSpecial Marine WarningLIX91 min
Dec 1, 3:46 AM CSTSpecial Marine WarningLIX59 min
Dec 1, 5:37 AM CSTSpecial Marine WarningLIX53 min
Dec 1, 7:32 AM CSTSpecial Marine WarningLIX43 min
Dec 1, 8:17 AM CSTMarine Dense Fog AdvisoryLIX2 hr
Dec 1, 11:40 AM CSTSpecial Marine WarningLIX35 min
Dec 1, 4:23 PM CSTSpecial Marine WarningLIX37 min
Dec 1, 5:51 PM CSTSpecial Marine WarningLIX39 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2018Every severe thunderstorm warning in 2018

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.