Alert archive / Tennessee / Mesoscale Discussions in 2003

Mesoscale Discussion 579

April 25, 200310 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2003, 1:55 PM CDT for 10 counties in Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 25, 2003, 1:55 PM CDT (18:55 UTC)
Expired: Apr 25, 2003, 4:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Cheatham County, TN, Davidson County, TN, Dickson County, TN, Hickman County, TN, Houston County, TN, Lewis County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Williamson County, TN

The radar

The Nashville radar (KOHX), 65 km from the middle of the area, began a volume at 18:55 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.

Severe Thunderstorm Watch 170Apr 25, 4:45 PM CDT

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 6.9 hours before the alert went out and 58 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3 J/kg
Mixed-layer CIN: -232 J/kg
Mixed-layer LCL: 656 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 279 m²/s²
0-3 km storm-relative helicity: 296 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.

Issued	Product	Office	Counties	Lasted
Apr 24, 11:45 PM CDT	Tornado Watch	SPC	Chester, Crockett, Dyer, Fayette, Gibson, Hardeman and 6 more	5 hr
Apr 25, 1:15 AM CDT	Mesoscale Discussion	SPC	Chester, Crockett, Dyer, Fayette, Gibson, Hardeman and 6 more	90 min
Apr 25, 3:05 AM CDT	Mesoscale Discussion	SPC	Chester, Crockett, Fayette, Hardeman, Hardin, Haywood and 5 more	85 min
Apr 25, 11:04 AM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Chester, Decatur, Dickson, Hardin and 12 more	116 min
Apr 25, 11:50 AM CDT	Severe Thunderstorm Watch	SPC	Bedford, Benton, Bledsoe, Bradley, Cannon, Cheatham and 43 more	5 hr
Apr 25, 3:22 PM CDT	Mesoscale Discussion	SPC	Bedford, Cannon, Cheatham, Davidson, DeKalb, Dickson and 20 more	113 min
Apr 25, 4:40 PM CDT	Tornado Watch	SPC	Clay, Macon	4 hr
Apr 25, 4:45 PM CDT	Severe Thunderstorm Watch	SPC	Bedford, Bledsoe, Bradley, Cannon, Clay, Coffee and 28 more	4 hr
Apr 25, 6:48 PM CDT	Mesoscale Discussion	SPC	Bledsoe, Bradley, Clay, Cumberland, DeKalb, Fentress and 13 more	87 min

Nearby

Mesoscale Discussions in Tennessee, 2003 Every 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.