Alert archive / Alabama / Mesoscale Discussions in 2006

Mesoscale Discussion 545

April 18, 200614 counties in Alabama; 8 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 18, 2006, 4:06 PM CDT for 14 counties in Alabama; 8 counties in Tennessee. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Apr 18, 2006, 4:06 PM CDT (21:06 UTC)
Expired
Apr 18, 2006, 6:00 PM CDT
In force
114 min
Issued by
the Storm Prediction Center
All 22 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL, St. Clair County, AL, Giles County, TN, Hickman County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marshall County, TN, Maury County, TN, Moore County, TN

The radar

The Northeast Alabama radar (KHTX), 53 km from the middle of the area, began a volume at 21:08 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

Birmingham, AL (KBMX), launched 12:00Z, 9.1 hours before the alert went out and 162 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, Birmingham, AL at 12:00Z on 2006-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1265 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, Birmingham, AL at 12:00Z on 2006-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.193958Sfc1 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
1265 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
780 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

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 18, 12:30 PM CDTMesoscale DiscussionSPCBarbour, Bullock, Chambers, Clay, Coosa, Dale and 10 more2 hr

Nearby

Mesoscale Discussions in Alabama, 2006Mesoscale Discussions in Tennessee, 2006Every mesoscale discussion in 2006

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.