Alert archive / North Carolina / Mesoscale Discussions in 2003

Mesoscale Discussion 639

April 30, 20034 states

The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2003, 12:50 PM EDT for 4 states. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued: Apr 30, 2003, 12:50 PM EDT (16:50 UTC)
Expired: Apr 30, 2003, 2:45 PM EDT
In force: 115 min
Issued by: the Storm Prediction Center

All 38 counties

Bartow County, GA, Cherokee County, GA, Dawson County, GA, Fannin County, GA, Floyd County, GA, Gilmer County, GA, Gordon County, GA, Lumpkin County, GA, Murray County, GA, Pickens County, GA, Polk County, GA, Rabun County, GA, Towns County, GA, Union County, GA, White County, GA, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Cherokee County, NC, Clay County, NC, Graham County, NC, Haywood County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Swain County, NC, Transylvania County, NC, Watauga County, NC, Yancey County, NC, Carter County, TN, Cocke County, TN, Johnson County, TN, Unicoi County, TN, Washington County, TN, Grayson County, VA

The radar

The Knoxville radar (KMRX), 84 km from the middle of the area, began a volume at 16:51 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 4.8 hours before the alert went out and 269 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: 388 J/kg
Mixed-layer CIN: -87 J/kg
Mixed-layer LCL: 1308 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 46 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 30, 1:22 PM EDT	Mesoscale Discussion	SPC	Bartow, Catoosa, Cherokee, Dade, Dawson, Fannin and 13 more	113 min
Apr 29, 11:04 PM EDT	Mesoscale Discussion	SPC	Benton, Cheatham, Davidson, Decatur, Dickson, Hickman and 10 more	2 hr

Nearby

Mesoscale Discussions in North Carolina, 2003 Mesoscale Discussions in Georgia, 2003 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.