Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 16

January 9, 20115 states

The Storm Prediction Center issued this mesoscale discussion at Jan 9, 2011, 10:56 PM CST for 5 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jan 9, 2011, 10:56 PM CST (04:56 UTC)
Expired: Jan 10, 2011, 4:00 AM CST
In force: 5 hr
Issued by: the Storm Prediction Center

All 46 counties

DeKalb County, AL, Jackson County, AL, Banks County, GA, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Dawson County, GA, Fannin County, GA, Franklin County, GA, Gilmer County, GA, Gordon County, GA, Habersham County, GA, Hart County, GA, Lumpkin County, GA, Murray County, GA, Pickens County, GA, Rabun County, GA, Stephens County, GA, Towns County, GA, Union County, GA, Walker 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, Anderson County, SC, Greenville County, SC, Oconee County, SC, Pickens County, SC, Spartanburg County, SC, Bledsoe County, TN, Bradley County, TN, Franklin County, TN, Grundy County, TN, Hamilton County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Polk County, TN, Sequatchie County, TN

The radar

The Knoxville radar (KMRX), 156 km from the middle of the area, began a volume at 04:57 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 00:00Z, 4.9 hours before the alert went out and 171 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2113 m above ground
0-6 km bulk shear: 74 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 239 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.

055 
ACUS11 KWNS 100457
SWOMCD
SPC MCD 100456
SCZ000-NCZ000-GAZ000-TNZ000-ALZ000-101000-

MESOSCALE DISCUSSION 0016
NWS STORM PREDICTION CENTER NORMAN OK
1056 PM CST SUN JAN 09 2011

AREAS AFFECTED...S-CNTRL THROUGH SERN TN...NRN AL AND NRN GA THROUGH
WRN SC AND SWRN NC

CONCERNING...HEAVY SNOW

VALID 100456Z - 101000Z

BANDS OF MODERATE TO HEAVY SNOW WITH RATES LOCALLY 1-1.5 INCHES PER
HOUR WILL CONTINUE DEVELOPING NEWD THROUGH NE AL...NRN GA...S-CNTRL
THROUGH SERN TN...SWRN NC AND WRN SC THROUGH THE EARLY MORNING. SOME
SLEET COULD MIX WITH THE SNOW ACROSS PARTS OF NRN AL AND NRN GA.

STRONG SLY 60+ KT LLJ WILL LIFT NEWD THROUGH AL AND GA INTO THE
EARLY MORNING IN ASSOCIATION WITH AN EJECTING NEGATIVELY TILTED
SHORTWAVE TROUGH CURRENTLY LOCATED OVER MS. STRONG FRONTOGENETIC
FORCING AND ISENTROPIC LIFT ASSOCIATED WITH THIS FEATURE HAS
RESULTED IN BANDS OF WIDESPREAD MODERATE TO LOCALLY HEAVY SNOW FROM
NRN MS...NRN AL AND NRN GA INTO SRN TN. STEEPER MID-LEVEL LAPSE
RATES DEVELOPING WITHIN ZONE OF STRONGER ASCENT HAVE RESULTED IN
SOME CONVECTIVE ENHANCEMENT TO THE SNOW WHERE LIGHTNING HAS RECENTLY
BEEN OBSERVED ACROSS NRN AL. RUC SOUNDINGS INDICATE PRESENCE OF A
DEEP QUASI-ISOTHERMAL LAYER WITH TEMPERATURES FROM 0 TO -5C BETWEEN
THE SURFACE AND 700 MB SUPPORTIVE OF AN EFFICIENT AGGREGATION
PROCESS. ZONE OF HEAVIER SNOW WILL EXPAND NEWD WITH
TIME...EVENTUALLY INTO SERN TN AND THE WRN CAROLINAS.

..DIAL.. 01/10/2011

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

ATTN...WFO...GSP...MRX...FFC...OHX...BMX...HUN...

LAT...LON   34288224 34468585 35358650 35628507 35088186 34288224

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 9, 8:07 PM CST	Mesoscale Discussion	SPC	Colbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more	5 hr
Jan 9, 8:27 PM CST	Mesoscale Discussion	SPC	Autauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 23 more	5 hr
Jan 10, 2:06 AM CST	Mesoscale Discussion	SPC	Barbour, Bullock, Chambers, Lee, Macon, Pike and 2 more	6 hr
Jan 10, 10:27 AM CST	Mesoscale Discussion	SPC	Anson, Bladen, Brunswick, Columbus, Craven, Cumberland and 14 more	6 hr

Nearby

Mesoscale Discussions in Georgia, 2011 Mesoscale Discussions in Tennessee, 2011 Mesoscale Discussions in North Carolina, 2011 Every mesoscale discussion in 2011

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.