Alert archive / Georgia / Mesoscale Discussions in 2012
Mesoscale Discussion 802
The Storm Prediction Center issued this mesoscale discussion at May 13, 2012, 2:41 PM CDT for 8 counties in Alabama; 12 counties in Georgia. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 13, 2012, 2:41 PM CDT (19:41 UTC)
- Expired
- May 13, 2012, 4:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Barbour County, AL, Bullock County, AL, Chambers County, AL, Elmore County, AL, Lee County, AL, Macon County, AL, Russell County, AL, Tallapoosa County, AL, Calhoun County, GA, Chattahoochee County, GA, Clay County, GA, Dougherty County, GA, Harris County, GA, Marion County, GA, Muscogee County, GA, Quitman County, GA, Randolph County, GA, Stewart County, GA, Terrell County, GA, Webster County, GA
The nearest sounding before it
Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 7.7 hours before the alert went out and 138 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 563 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 202 m²/s²
- 0-3 km storm-relative helicity
- 405 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
073
ACUS11 KWNS 131942
SWOMCD
SPC MCD 131941
GAZ000-ALZ000-132145-
MESOSCALE DISCUSSION 0802
NWS STORM PREDICTION CENTER NORMAN OK
0241 PM CDT SUN MAY 13 2012
AREAS AFFECTED...SERN AL THROUGH SWRN GA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 131941Z - 132145Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...STORMS DEVELOPING ACROSS SERN AL THROUGH SWRN GA WILL
CONTINUE TO POSE A LIMITED THREAT FOR ISOLATED DOWNBURSTS AND
PERHAPS A COUPLE OF BRIEF TORNADOES INTO THE EARLY EVENING. OVERALL
THREAT DOES NOT APPEAR SUFFICIENT TO WARRANT A WW AT THIS TIME...BUT
AREA WILL CONTINUE TO BE MONITORED.
DISCUSSION...THIS AFTERNOON A WARM FRONT EXTENDS FROM SWRN GA NWWD
THROUGH SERN AND CNTRL AL WHERE IT INTERSECTS A ZONE OF PRE-FRONTAL
CONVERGENCE THAT EXTENDS SWWD INTO THE WRN FL PANHANDLE. DESPITE
RICH LOW LEVEL MOISTURE...THE WARM SECTOR REMAINS MARGINALLY
UNSTABLE /500-1000 J/KG/ MLCAPE DUE TO WEAK MID LEVEL LAPSE RATES. A
WEAK UPPER LOW CIRCULATION CENTERED NEAR THE TN VALLEY IS MOVING
EAST. UPPER WINDS IN ASSOCIATION WITH THIS FEATURE ARE RELATIVELY
WEAK WITH 20-25 KT AT 500 MB SUPPORTING ONLY MODEST /20-30 KT/
VERTICAL SHEAR THROUGH A DEEP LAYER. HOWEVER...NEAR SFC WINDS REMAIN
BACKED TO SELY ALONG AND NORTH OF THE WARM FRONT FROM E-CNTRL
THROUGH SERN AL AND SWRN GA...SUPPORTING SLIGHTLY GREATER LOW LEVEL
SHEAR PROFILES. YET 0-1 KM HODOGRAPHS REMAIN FAIRLY SMALL IN
VICINITY OF THE BOUNDARY DUE TO WEAK LOW LEVEL WINDS. LARGER
HODOGRAPHS EXIST FARTHER EAST INTO GA...BUT THE BOUNDARY LAYER IS
STABLE IN THAT AREA. STORMS DEVELOPING ALONG AND EAST OF THE
PRE-FRONTAL CONVERGENCE BANDS MAY POSE A LIMITED THREAT FOR AN
ISOLATED TORNADO OR TWO FROM E-CNTRL AND SERN AL INTO SWRN GA AS
THEY INTERACT WITH THE WARM FRONT. ISOLATED WET DOWNBURSTS MAY ALSO
BE POSSIBLE WITHIN THE STRONGER CORES.
..DIAL/HART.. 05/13/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FFC...TAE...BMX...
LAT...LON 32578617 33178578 33158516 32678465 31538410 31238473
31848578 32578617Nearby
Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Alabama, 2012Every 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.