Alert archive / Louisiana / Mesoscale Discussions in 2005

Mesoscale Discussion 674

April 22, 2005Ascension Parish, Iberville Parish, Livingston Parish, Louisiana; Pearl River County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 22, 2005, 11:20 PM CDT for Ascension Parish, Iberville Parish, Livingston Parish, Louisiana; Pearl River County, Mississippi. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Apr 22, 2005, 11:20 PM CDT (04:20 UTC)
Expired
Apr 23, 2005, 12:15 AM CDT
In force
55 min
Issued by
the Storm Prediction Center

Counties Ascension Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Pearl River County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 4.3 hours before the alert went out and 111 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, Slidell Radar S, LA at 00:00Z on 2005-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1138 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, Slidell Radar S, LA at 00:00Z on 2005-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.1939587897117136Sfc1 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
1138 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
1314 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 10:29 PM CDTMesoscale DiscussionSPCAscension, Concordia, East Baton Rouge, East Feliciana, Iberville, Livingston and 7 more91 min
Apr 22, 8:28 PM CDTMesoscale DiscussionSPCClarke, Forrest, George, Greene, Jasper, Jones and 4 more2 hr
Apr 22, 8:50 PM CDTSevere Thunderstorm WatchSPCGeorge, Greene, Jones, Perry, Wayne5 hr
Apr 22, 11:14 PM CDTMesoscale DiscussionSPCGreene, Wayne91 min

Nearby

Mesoscale Discussions in Louisiana, 2005Mesoscale Discussions in Mississippi, 2005Every mesoscale discussion in 2005

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.