Alert archive / Georgia / Mesoscale Discussions in 2011

Mesoscale Discussion 291

March 27, 201146 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 27, 2011, 3:03 AM EDT for 46 counties in Georgia. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Mar 27, 2011, 3:03 AM EDT (07:03 UTC)
Expired
Mar 27, 2011, 4:00 AM EDT
In force
57 min
Issued by
the Storm Prediction Center
All 46 counties

Appling County, GA, Atkinson County, GA, Bacon County, GA, Ben Hill County, GA, Bibb County, GA, Bleckley County, GA, Brantley County, GA, Candler County, GA, Chattahoochee County, GA, Coffee County, GA, Crawford County, GA, Crisp County, GA, Dodge County, GA, Dooly County, GA, Evans County, GA, Harris County, GA, Houston County, GA, Irwin County, GA, Jeff Davis County, GA, Johnson County, GA, Laurens County, GA, Lee County, GA, Long County, GA, Macon County, GA, Marion County, GA, Montgomery County, GA, Muscogee County, GA, Peach County, GA, Pierce County, GA, Pulaski County, GA, Schley County, GA, Sumter County, GA, Talbot County, GA, Tattnall County, GA, Taylor County, GA, Telfair County, GA, Toombs County, GA, Treutlen County, GA, Turner County, GA, Twiggs County, GA, Upson County, GA, Wayne County, GA, Webster County, GA, Wheeler County, GA, Wilcox County, GA, Wilkinson County, GA

The radar

The Robins AFB radar (KJGX), 57 km from the middle of the area, began a volume at 07:04 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, 7.1 hours before the alert went out and 175 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.

278 
ACUS11 KWNS 270703
SWOMCD
SPC MCD 270703 
GAZ000-270800-

MESOSCALE DISCUSSION 0291
NWS STORM PREDICTION CENTER NORMAN OK
0203 AM CDT SUN MAR 27 2011

AREAS AFFECTED...WRN/CNTRL GA

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 270703Z - 270800Z

STORMS ARE EXPECTED TO PERSIST ACROSS CNTRL GA OVER THE NEXT FEW
HOURS...WITHIN A MARGINALLY FAVORABLE ENVIRONMENT FOR AN ISOLATED
TORNADO. A NEW WW MAY BE REQUIRED MAINLY FOR CNTRL/SRN GA.

AN E-W ORIENTED BAND OF STORMS...NEARLY PARALLEL TO THE DEEP LAYER
SHEAR VECTOR...CONTINUES TO DRIFT SLOWLY SEWD. COMPOSITE RADAR
IMAGERY SHOWS A WELL DEFINED OUTFLOW BOUNDARY AHEAD OF THE ERN GA/SC
ACTIVITY...CURLING BACK NWWD INTO CNTRL/WRN GA WHERE STORMS ARE
LIKELY MORE SURFACE BASED.

STRONG DEEP LAYER SHEAR/LONG HODOGRAPHS REMAIN IN PLACE ACROSS THE
REGION...AND SEWD STORM MOTIONS ARE CREATING ENOUGH STORM RELATIVE
HELICITY FOR ROTATION WITHIN SOME CELLS. ONE OF THE BEST DEVELOPED
MESOCYCLONES AS INDICATED BY RADAR WAS RECENTLY NOTED OVER TROUP
COUNTY GA...WHICH WILL BE MOVING INTO MERIWETHER COUNTY AND PERHAPS
NRN TALBOT/UPSON COUNTIES. GIVEN SUCH STRONG SHEAR AND SURFACE BASED
INSTABILITY...A BRIEF TORNADO MAY OCCUR AND A WATCH WILL BE ISSUED
SOON.

..JEWELL.. 03/27/2011

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

ATTN...WFO...CHS...JAX...FFC...TAE...

LAT...LON   32668503 33058492 32988420 32888332 32748267 32328176
            31938153 31478149 31158190 31078226 31398318 31888431
            32098469 32668503

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, 12:43 AM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Burke, Catoosa, Chattooga and 38 more62 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, 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.