Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 285

March 26, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2011, 8:55 PM EDT for 4 states. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Mar 26, 2011, 8:55 PM EDT (00:55 UTC)
Expired
Mar 26, 2011, 10:30 PM EDT
In force
95 min
Issued by
the Storm Prediction Center
All 57 counties

Banks County, GA, Barrow County, GA, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Columbia County, GA, Dade County, GA, Dawson County, GA, Elbert County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Gilmer County, GA, Gordon County, GA, Greene County, GA, Habersham County, GA, Hall County, GA, Hart County, GA, Jackson County, GA, Lincoln County, GA, Lumpkin County, GA, Madison County, GA, McDuffie County, GA, Morgan County, GA, Murray County, GA, Oconee County, GA, Oglethorpe County, GA, Pickens County, GA, Rabun County, GA, Stephens County, GA, Taliaferro County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, Warren County, GA, White County, GA, Whitfield County, GA, Wilkes County, GA, Cherokee County, NC, Clay County, NC, Macon County, NC, Abbeville County, SC, Anderson County, SC, Edgefield County, SC, Greenville County, SC, Greenwood County, SC, Laurens County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Pickens County, SC, Saluda County, SC, Polk County, TN

The radar

The Atlanta radar (KFFC), 137 km from the middle of the area, began a volume at 00:57 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 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, 0.9 hours before the alert went out and 132 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 2011-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 120 joules per kilogram.LCLLFCEL10008507005003002001001 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, Peachtre/Fal Fld, GA at 00:00Z on 2011-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 343 square meters per square second.19395878Sfc1 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
120 J/kg
Mixed-layer CIN
-166 J/kg
Mixed-layer LCL
635 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
343 m²/s²
0-3 km storm-relative helicity
404 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

539 
ACUS11 KWNS 270056
SWOMCD
SPC MCD 270055
SCZ000-GAZ000-NCZ000-TNZ000-270230-

MESOSCALE DISCUSSION 0285
NWS STORM PREDICTION CENTER NORMAN OK
0755 PM CDT SAT MAR 26 2011

AREAS AFFECTED...NRN GA...FAR SE TN...NW SC..SW NC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 270055Z - 270230Z

ELEVATED CONVECTION HAS INCREASED UPSTREAM ACROSS NRN MS AND
AL...INCLUDING SOME ELEVATED SUPERCELLS CAPABLE OF PRODUCING LARGE
HAIL. THIS ACTIVITY IS BEING FUELED BY A STRONG LOW-LEVEL JET AND A
COMPACT VORTICITY MAXIMUM MOVING QUICKLY EAST ACROSS THE OHIO
VALLEY. 00Z FFC SOUNDING INDICATES SUBSTANTIAL ELEVATED BUOYANCY /MU
CAPE AROUND 1500 J/KG/ AND SUFFICIENT EFFECTIVE SHEAR FOR
SUPERCELLS. A SEVERE HAIL THREAT WILL EXIST FOR SEVERAL MORE HOURS
ACROSS NRN GA...WITH A SOMEWHAT LESSER THREAT ACROSS FAR SE TN...NW
SC...AND SW NC...WHERE AVAILABLE BUOYANCY BECOMES WEAKER AND
INCREASINGLY ELEVATED.

IF ONGOING ACTIVITY MAINTAINS ITS INTENSITY AS IT MOVES EAST...A
SEVERE THUNDERSTORM WATCH MAY BECOME NECESSARY IN THE NEXT 1-2
HRS...ESPECIALLY ACROSS NRN GA.

..DEAN.. 03/27/2011

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

ATTN...WFO...CAE...GSP...MRX...FFC...

LAT...LON   34118511 34228540 34518547 34868557 34998516 35278458
            35348394 35278332 35158275 34898213 34548165 34358148
            33978145 33618176 33428198 33368231 33428272 33508316
            33548355 33978399 34218426 34128446 34108470 34118511

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 8:47 PM EDTTornado WatchSPCBaldwin, Ben Hill, Bibb, Bleckley, Butts, Carroll and 61 more7 hr
Mar 26, 9:19 PM EDTSevere Thunderstorm WatchSPCBanks, Barrow, Bartow, Burke, Catoosa, Chattooga and 39 more8 hr
Mar 26, 11:10 PM EDTMesoscale DiscussionSPCBryan, Bulloch, Candler, Chatham, Effingham, Evans and 3 more65 min
Mar 27, 12:21 AM EDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Butts, Carroll, Chattahoochee and 55 more54 min
Mar 27, 12:43 AM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Burke, Catoosa, Chattooga and 38 more62 min
Mar 27, 3:03 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Ben Hill, Bibb, Bleckley and 40 more57 min
Mar 27, 3:25 AM EDTTornado WatchSPCAppling, Baldwin, Bibb, Bleckley, Bryan, Bulloch and 46 more3 hr
Mar 27, 8:33 AM EDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Bulloch, Burke, Butts and 48 more117 min
Mar 27, 9:55 AM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 87 more7 hr
Mar 27, 11:51 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 64 more84 min
Mar 27, 3:49 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 44 more56 min
Mar 27, 4:27 PM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 38 more5 hr
Mar 27, 7:24 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 34 more2 hr

Nearby

Mesoscale Discussions in Georgia, 2011Mesoscale Discussions in South Carolina, 2011Mesoscale Discussions in North Carolina, 2011Every 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.