Alert archive / Tennessee / Mesoscale Discussions in 2003

Mesoscale Discussion 418

April 6, 200324 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2003, 3:02 PM CDT for 24 counties in Tennessee. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued
Apr 6, 2003, 3:02 PM CDT (20:02 UTC)
Expired
Apr 6, 2003, 5:00 PM CDT
In force
118 min
Issued by
the Storm Prediction Center
All 24 counties

Bedford County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hickman County, TN, Houston County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Rutherford County, TN, Smith County, TN, Trousdale County, TN, Warren County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 54 km from the middle of the area, began a volume at 20:02 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, 8.0 hours before the alert went out and 41 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 2003-04-06Temperature 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 2003-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 140 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1528 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
140 m²/s²
0-3 km storm-relative helicity
304 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.

000 
ACUS11 KWNS 062003
SWOMCD
SPC MCD 062002 
TNZ000-ALZ000-062200-

MESOSCALE DISCUSSION 0418
NWS STORM PREDICTION CENTER NORMAN OK
0302 PM CDT SUN APR 06 2003

AREAS AFFECTED...MIDDLE TN

CONCERNING...SEVERE THUNDERSTORM WATCH 104...

VALID 062002Z - 062200Z

...MAIN THREAT FROM SEVERE THUNDERSTORMS WILL BE LARGE HAIL...



SFC WARM FRONT EXTENDED FROM SOUTHEAST OF MEMPHIS THROUGH MIDDLE
TN TO JUST SOUTHEAST OF KNOXVILLE AT 06/20Z. LATEST OBSERVATIONAL
ANALYSIS FIELDS INDICATE ELEVATED CAPE VALUES ARE AROUND 1000
J/KG...WITH DEEP LAYER SHEAR VALUES OVER 50 KTS PER THE LATEST
VAD WIND PROFILE FROM MEMPHIS. DEEP LAYER SHEAR WILL INCREASE
FROM WEST TO EAST AS MID LEVEL SPEED MAX APPROACHES...SUPPORTING
THE DEVELOPMENT OF SUPERCELL TSTMS. AS STORMS MOVE NORTH AWAY
FROM THE WARM FRONT AND BECOME MORE ELEVATED...THE MAIN THREAT
WITH STORMS WILL BE LARGE HAIL. 

..TAYLOR.. 04/06/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MRX...OHX...HUN...

36338775 36438575 35128569 34938740

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 9:19 AM CDTMesoscale DiscussionSPCBedford, Benton, Carroll, Cheatham, Davidson, Dickson and 18 more116 min
Apr 6, 11:05 AM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Chester, Crockett, Decatur, Dyer and 11 more5 hr
Apr 6, 12:27 PM CDTMesoscale DiscussionSPCCrockett, Dyer, Fayette, Gibson, Hardeman, Haywood and 4 more2 hr
Apr 6, 1:07 PM CDTMesoscale DiscussionSPCBedford, Bledsoe, Bradley, Cannon, Cheatham, Coffee and 33 more113 min
Apr 6, 1:20 PM CDTSevere Thunderstorm WatchSPCBedford, Cannon, Cheatham, Coffee, Davidson, DeKalb and 28 more6 hr

Nearby

Mesoscale Discussions in Tennessee, 2003Every mesoscale discussion in 2003

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.