Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 955

May 29, 201229 counties in Georgia; 16 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 29, 2012, 12:20 PM EDT for 29 counties in Georgia; 16 counties in South Carolina. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued: May 29, 2012, 12:20 PM EDT (16:20 UTC)
Expired: May 29, 2012, 1:15 PM EDT
In force: 55 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 45 counties

Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Chatham County, GA, Columbia County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glascock County, GA, Greene County, GA, Hancock County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Liberty County, GA, Lincoln County, GA, Long County, GA, McDuffie County, GA, McIntosh County, GA, Oglethorpe County, GA, Richmond County, GA, Screven County, GA, Taliaferro County, GA, Tattnall County, GA, Toombs County, GA, Warren County, GA, Washington County, GA, Wilkes County, GA, Abbeville County, SC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Colleton County, SC, Edgefield County, SC, Greenwood County, SC, Hampton County, SC, Jasper County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Saluda County, SC

The radar

The Charleston,SC radar (KCLX), 91 km from the middle of the area, began a volume at 16:20 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

Charleston AFB, SC (KCHS), launched 12:00Z, 4.3 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-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: 1148 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 525 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 23 m²/s²
0-3 km storm-relative helicity: 46 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.

782 
ACUS11 KWNS 291620
SWOMCD
SPC MCD 291620 COR
SCZ000-GAZ000-291715-

MESOSCALE DISCUSSION 0955
NWS STORM PREDICTION CENTER NORMAN OK
1120 AM CDT TUE MAY 29 2012

AREAS AFFECTED...ERN GA...WRN SC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 291620Z - 291715Z

CORRECTED FOR SPELLING AND GRAPHIC

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED TORNADO THREAT WILL LIKELY EXIST THIS
AFTERNOON AND MAY INCREASE GRADUALLY WITH TIME. A TORNADO OR TWO MAY
OCCUR ACROSS ERN GA AND WRN SC WHERE WW ISSUANCE CAN NOT BE RULED
OUT.

DISCUSSION...THE NATIONAL HURRICANE CENTER PLACES TROPICAL
DEPRESSION BERYL ABOUT 50 STATUTE MILES EAST OF ALBANY GA. RAINBANDS
ARE WRAPPING AROUND THE SRN AND ERN SIDES OF BERYL. A PROMINENT LINE
OF THUNDERSTORMS IN THE NERN QUADRANT OF BERYL CURRENTLY EXTENDS
NWWD FROM JUST WEST OF SAVANNAH GA NWWD TO JUST SOUTH OF AUGUSTA GA.
THIS LINE IS LOCATED ALONG THE AXIS OF STRONGEST LOW-LEVEL SHEAR
WITH REGIONAL WSR-88D VWPS SHOWING 30 KT OF 0-1 KM SHEAR ACROSS ERN
GA. THIS COMBINED WITH PRECIPITABLE WATER VALUES OF GREATER THAN 2
INCHES SHOULD BE FAVORABLE FOR LOW-ROTATING CLOUD BASES AND POSSIBLY
A TORNADO OR TWO. AS TROPICAL STORM BERYL MOVES NWD THIS AFTERNOON
AND DESTABILIZATION CONTINUES TO OCCUR IN THE NERN QUADRANT...THE
THREAT FOR ROTATING STORMS SHOULD CONTINUE WITH AT LEAST A MARGINAL
TORNADO THREAT EXTENDING NWD INTO THE ATHENS GA AND EWD INTO THE
CHARLESTON AND COLUMBIA SC AREAS LATER THIS AFTERNOON.

..BROYLES.. 05/29/2012

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

ATTN...WFO...CHS...CAE...GSP...JAX...FFC...

LAT...LON   31798084 32708018 33508076 34198103 34378144 34378188
            34308224 34158270 33878313 33608324 33118312 32498262
            31698203 31228137 31798084

Nearby

Mesoscale Discussions in Georgia, 2012 Mesoscale Discussions in South Carolina, 2012 Every mesoscale discussion in 2012

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.