Alert archive / Georgia / Mesoscale Discussions in 2020

Mesoscale Discussion 369

April 12, 202019 counties in Georgia; 6 counties in North Carolina; Polk County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2020, 8:41 PM EDT for 19 counties in Georgia; 6 counties in North Carolina; Polk County, Tennessee. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Apr 12, 2020, 8:41 PM EDT (00:41 UTC)
Expired
Apr 12, 2020, 9:45 PM EDT
In force
64 min
Issued by
the Storm Prediction Center
All 26 counties

Bartow County, GA, Catoosa County, GA, Cherokee County, GA, Dawson County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Gilmer County, GA, Gordon County, GA, Habersham 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, Whitfield County, GA, Cherokee County, NC, Clay County, NC, Graham County, NC, Jackson County, NC, Macon County, NC, Transylvania County, NC, Polk County, TN

The radar

The Northeast Alabama radar (KHTX), 163 km from the middle of the area, began a volume at 00:41 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.7 hours before the alert went out and 167 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, Peachtre/Fal Fld, GA at 00:00Z on 2020-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 404 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 00:00Z on 2020-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 733 square meters per square second.1939587897Sfc1 km3 km6 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
404 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
804 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
733 m²/s²
0-3 km storm-relative helicity
874 m²/s²
Significant tornado parameter
1.3
Supercell composite
10.8

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 8:57 PM EDTTornado WatchSPCRabun6 hr
Apr 12, 11:17 PM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Catoosa, Chattooga, Cherokee and 36 more88 min
Apr 12, 11:28 PM EDTMesoscale DiscussionSPCButts, Carroll, Chattahoochee, Clay, Clayton, Cobb and 30 more92 min
Apr 12, 11:45 PM EDTTornado WatchSPCBaker, Baldwin, Banks, Barrow, Bartow, Bibb and 86 more8 hr
Apr 13, 1:51 AM EDTTornado WatchSPCElbert, Franklin, Habersham, Hart, Rabun, Stephens6 hr
Apr 13, 2:39 AM EDTMesoscale DiscussionSPCBaker, Baldwin, Ben Hill, Bleckley, Burke, Calhoun and 37 more96 min
Apr 13, 3:20 AM EDTTornado WatchSPCAppling, Atkinson, Bacon, Ben Hill, Berrien, Bleckley and 54 more8 hr
Apr 13, 6:17 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Brantley, Brooks, Bryan and 15 more88 min
Apr 13, 4:40 AM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Camden and 51 more95 min
Apr 13, 5:01 AM EDTTornado WatchSPCAlamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 53 more7 hr
Apr 13, 6:46 AM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Chowan, Columbus, Craven and 32 more89 min
Apr 13, 9:56 AM EDTMesoscale DiscussionSPCCarteret, Dare, Hyde, Pamlico, Tyrrell, Washington64 min
Apr 12, 8:56 PM EDTMesoscale DiscussionSPCFayette, Lauderdale, Shelby, Tipton2 hr
Apr 12, 9:19 PM EDTSevere Thunderstorm WatchSPCBenton, Carroll, Chester, Crockett, Decatur, Dyer and 15 more4 hr
Apr 12, 10:44 PM EDTMesoscale DiscussionSPCCarroll, Chester, Crockett, Decatur, Dyer, Fayette and 10 more91 min
Apr 13, 12:19 AM EDTMesoscale DiscussionSPCBenton, Carroll, Chester, Crockett, Decatur, Dickson and 21 more86 min

Nearby

Mesoscale Discussions in Georgia, 2020Mesoscale Discussions in North Carolina, 2020Mesoscale Discussions in Tennessee, 2020Every mesoscale discussion in 2020

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.