Alert archive / Tennessee / Mesoscale Discussions in 2004

Mesoscale Discussion 447

April 23, 200440 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 23, 2004, 11:09 AM CDT for 40 counties in Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 23, 2004, 11:09 AM CDT (16:09 UTC)
Expired
Apr 23, 2004, 1:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 40 counties

Bedford County, TN, Bledsoe County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Hickman County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Meigs County, TN, Moore County, TN, Overton County, TN, Perry County, TN, Putnam County, TN, Rhea County, TN, Rutherford County, TN, Sequatchie County, TN, Smith County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, White County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 56 km from the middle of the area, began a volume at 16:09 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

Nashville Metro, TN (KBNA), launched 12:00Z, 4.2 hours before the alert went out and 42 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 2004-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 226 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, Nashville Metro, TN at 12:00Z on 2004-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 187 square meters per square second.19395878Sfc1 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
226 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
630 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
187 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

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, 11:25 PM CDTMesoscale DiscussionSPCCrockett, Dyer, Fayette, Haywood, Lake, Lauderdale and 3 more65 min
Apr 22, 11:40 PM CDTSevere Thunderstorm WatchSPCCrockett, Dyer, Fayette, Gibson, Hardeman, Haywood and 7 more6 hr
Apr 23, 3:12 AM CDTMesoscale DiscussionSPCCrockett, Dyer, Fayette, Gibson, Hardeman, Haywood and 7 more93 min
Apr 23, 7:33 AM CDTMesoscale DiscussionSPCFayette, Hardeman, Shelby, Tipton87 min

Nearby

Mesoscale Discussions in Tennessee, 2004Every mesoscale discussion in 2004

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.