Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 290

March 27, 201144 counties in Georgia; 7 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Mar 27, 2011, 12:43 AM EDT for 44 counties in Georgia; 7 counties in South Carolina. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued
Mar 27, 2011, 12:43 AM EDT (04:43 UTC)
Expired
Mar 27, 2011, 1:45 AM EDT
In force
62 min
Issued by
the Storm Prediction Center
All 51 counties

Banks County, GA, Barrow County, GA, Bartow County, GA, Burke 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, Gwinnett 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, Richmond 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, Abbeville County, SC, Aiken County, SC, Barnwell County, SC, Edgefield County, SC, Greenwood County, SC, McCormick County, SC, Saluda County, SC

The radar

The Greer radar (KGSP), 118 km from the middle of the area, began a volume at 04:43 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, 4.7 hours before the alert went out and 173 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.

361 
ACUS11 KWNS 270444
SWOMCD
SPC MCD 270443
SCZ000-GAZ000-NCZ000-ALZ000-270545-

MESOSCALE DISCUSSION 0290
NWS STORM PREDICTION CENTER NORMAN OK
1143 PM CDT SAT MAR 26 2011

AREAS AFFECTED...NRN GA AND WRN SC

CONCERNING...SEVERE THUNDERSTORM WATCH 66...

VALID 270443Z - 270545Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 66
CONTINUES.

OVERALL SEVERE WEATHER THREAT...DAMAGING WINDS AND HAIL...REMAINS
MAINLY ACROSS WRN AND SRN PARTS OF WW 66.  THE NERN EXTENT OF THIS
WATCH HAS BEEN CONVECTIVELY OVERTURNED...LIMITING THE THREAT FOR
SEVERE OVERNIGHT...SUCH THAT AREA WILL LIKELY BE REMOVED FROM THE
WATCH BY THE LOCAL WFO.

AT 04Z...SURFACE ANALYSIS SHOWED AN AREA OF LOW PRESSURE OVER EAST
CENTRAL/NERN AL /INVOF ANB/ WITH A WARM FRONT EXTENDING ESEWD
THROUGH CENTRAL GA TO FAR SRN SC.  STRONG SURFACE BASED INHIBITION N
OF THE WARM FRONT SUGGESTS THE ORGANIZED LINES/BOWING SEGMENTS
TRACKING SEWD THROUGH WRN AND SRN PARTS OF WW 66 ARE LIKELY
ELEVATED.  DESPITE THIS FACT...EXPANDING AND COOLING CLOUD TOPS PER
IR SATELLITE IMAGERY OVER NERN AL/NWRN GA SUGGESTS AN MCS IS
POTENTIALLY DEVELOPING.  THIS WITH AN ATTENDANT COLD POOL AND SEWD
MOVEMENT OF THE LEADING LINE OF STORMS AT 35-40 KT AND A 50 KT SWLY
LLJ EXTENDING INTO CENTRAL GA SUGGESTS SOME OF THIS HIGHER MOMENTUM
AIR COULD REACH THE SURFACE OVERNIGHT.  THIS THREAT FOR DAMAGING
WINDS WOULD BE ALONG THE SRN TIER OF WW 66...AND POTENTIAL INTO SRN
SC/EAST CENTRAL GA WHERE ACTIVITY WOULD BECOME CLOSER TO SURFACE
BASED AS IT REACHES THIS PORTION OF THE WARM FRONT AFTER 07Z.

..PETERS.. 03/27/2011

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

ATTN...WFO...CHS...CAE...GSP...MRX...FFC...BMX...HUN...

LAT...LON   33618114 33198129 32828215 33248232 33528359 34078426
            34138545 34988559 34998381 34528288 34228195 34128152
            33868150 33618114

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, 8:55 PM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Catoosa, Chattooga, Cherokee and 36 more95 min
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, 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, 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.