Alert archive / Tennessee / Mesoscale Discussions in 2006

Mesoscale Discussion 925

May 21, 20064 counties in Alabama; 27 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 21, 2006, 3:12 PM CDT for 4 counties in Alabama; 27 counties in Tennessee. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
May 21, 2006, 3:12 PM CDT (20:12 UTC)
Expired
May 21, 2006, 4:45 PM CDT
In force
93 min
Issued by
the Storm Prediction Center
All 31 counties

Jackson County, AL, Lauderdale County, AL, Limestone County, AL, Madison County, AL, Bedford County, TN, Carroll County, TN, Chester County, TN, Crockett County, TN, Decatur County, TN, Dyer County, TN, Fayette County, TN, Franklin County, TN, Gibson County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Hickman County, TN, Lauderdale County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Madison County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Moore County, TN, Perry County, TN, Tipton County, TN, Wayne County, TN

The radar

The Northeast Alabama radar (KHTX), 118 km from the middle of the area, began a volume at 20:14 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 8.2 hours before the alert went out and 126 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, Nashville Metro, TN at 12:00Z on 2006-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Nashville Metro, TN at 12:00Z on 2006-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 124 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1052 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
May 20, 7:47 PM CDTMesoscale DiscussionSPCDeKalb, Jackson, Madison28 min
May 20, 8:04 PM CDTSevere Thunderstorm WatchSPCDeKalb, Jackson, Limestone, Madison, Marshall9 hr
May 20, 9:28 PM CDTMesoscale DiscussionSPCColbert, Lauderdale, Lawrence, Limestone62 min
May 20, 11:32 PM CDTMesoscale DiscussionSPCColbert, DeKalb, Jackson, Lauderdale, Lawrence, Limestone and 3 more88 min
May 21, 3:35 PM CDTSevere Thunderstorm WatchSPCDeKalb, Jackson, Lauderdale, Limestone, Madison6 hr

Nearby

Mesoscale Discussions in Tennessee, 2006Mesoscale Discussions in Alabama, 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.