Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 1111

June 10, 201220 counties in Alabama; 8 counties in Florida; 25 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Jun 10, 2012, 10:27 AM CDT for 20 counties in Alabama; 8 counties in Florida; 25 counties in Georgia. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jun 10, 2012, 10:27 AM CDT (15:27 UTC)
Expired
Jun 10, 2012, 12:00 PM CDT
In force
93 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 53 counties

Autauga County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Chambers County, AL, Coffee County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Elmore County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Montgomery County, AL, Pike County, AL, Russell County, AL, Tallapoosa County, AL, Bay County, FL, Calhoun County, FL, Holmes County, FL, Jackson County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Chattahoochee County, GA, Clay County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Harris County, GA, Lee County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Miller County, GA, Muscogee County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Seminole County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taylor County, GA, Terrell County, GA, Troup County, GA, Webster County, GA

The radar

The Eglin Afb radar (KEVX), 56 km from the middle of the area, began a volume at 15:29 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 3.5 hours before the alert went out and 187 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, Tallahassee Rgnl, FL at 12:00Z on 2012-06-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1717 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, Tallahassee Rgnl, FL at 12:00Z on 2012-06-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 155 square meters per square second.193958Sfc1 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
1717 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
478 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.8

Open this sounding in Storm Lab

The text

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

881 
ACUS11 KWNS 101527
SWOMCD
SPC MCD 101527 
GAZ000-FLZ000-ALZ000-101700-

MESOSCALE DISCUSSION 1111
NWS STORM PREDICTION CENTER NORMAN OK
1027 AM CDT SUN JUN 10 2012

AREAS AFFECTED...SRN/ERN AL...FL PNHDL AND PARTS OF WRN GA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 101527Z - 101700Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...IT IS NOT CERTAIN THAT A WW WILL BE NEEDED...PARTICULARLY
IN THE NEAR TERM...BUT TRENDS ARE BEING MONITORED FOR AN INCREASING
SEVERE THREAT THAT COULD REQUIRE A WW LATER THIS AFTERNOON.  SEVERE
PROBABILITIES WILL BE INCREASED TO A CATEGORICAL SLIGHT RISK IN THE
UPCOMING 1630Z OUTLOOK FOR PORTIONS OF THE REGION.

DISCUSSION...SATELLITE IMAGERY SUPPORTS MODEL PROGS IN SUGGESTING
THAT ANOTHER MID-LEVEL CIRCULATION IS IN THE PROCESS OF GRADUALLY
MIGRATING INLAND ACROSS LOUISIANA/MISSISSIPPI COASTAL AREAS. 
ASSOCIATED WITH THIS FEATURE...A LINE OF THUNDERSTORMS IS SLOWLY
INTENSIFYING EAST OF MOBILE BAY INTO THE NORTH CENTRAL GULF OF
MEXICO...WITH ADDITIONAL CONVECTIVE ACTIVITY EAST OF THE
LINE...ALONG A ZONE OF ENHANCED LOW-LEVEL CONVERGENCE JUST INLAND OF
THE COAST...ACROSS PARTS OF SOUTHERN ALABAMA AND THE WESTERN FLORIDA
PANHANDLE.  THE COASTAL CONVERGENCE ZONE...COUPLED WITH MODESTLY
LARGE AND CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS...MAY CONTINUE TO
SUPPORT AT LEAST LOW POTENTIAL FOR ISOLATED...BRIEF TORNADOES
THROUGH THE MIDDAY HOURS.  

THERMODYNAMIC PROFILES APPEAR CHARACTERIZED BY A HIGH DEGREE OF
SATURATION IN LOWER LEVELS...ALONG WITH SIZABLE CAPE.  AND INLAND
ADVECTION OF LOWER/MID 70S SURFACE DEW POINTS MAY CONTINUE ACROSS
THE FLORIDA PANHANDLE THROUGH EASTERN ALABAMA AND WESTERN
GEORGIA...AS A 30-40 KT SOUTHERLY 850 MB JET LIFTS NORTHWARD OUT OF
THE GULF OF MEXICO.  

HEAVY PRECIPITATION LOADING AND THE DOWNWARD TRANSPORT OF HIGHER
MOMENTUM AIR TO THE SURFACE MAY CONTRIBUTE TO A MORE SUBSTANTIVE
RISK FOR POTENTIALLY DAMAGING WIND GUSTS LATER THIS AFTERNOON... AS
THE BOUNDARY LAYER CONTINUES TO DESTABILIZE ACROSS EASTERN ALABAMA
AND WESTERN GEORGIA.  IT IS ALSO POSSIBLE THAT THE RISK FOR
TORNADOES COULD INCREASE...BOTH WITHIN THE LINE...AND IN A WEAK
LOW-LEVEL WARM ADVECTION REGIME DEVELOPING NORTHEASTWARD JUST AHEAD
OF IT.

..KERR/MEAD.. 06/10/2012

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

ATTN...WFO...FFC...TAE...BMX...MOB...

LAT...LON   30248718 31178694 32608670 33098600 33188463 32388376
            31098440 29418566 28838698 29238775 30248718

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 10, 11:41 AM CDTTornado WatchSPCBarbour, Bullock, Coffee, Covington, Crenshaw, Dale and 8 more6 hr
Jun 10, 2:02 PM CDTMesoscale DiscussionSPCHenry, Houston, Lee, Russell88 min
Jun 10, 12:05 AM CDTMesoscale DiscussionSPCTaylor25 min
Jun 10, 5:35 PM CDTMesoscale DiscussionSPCGadsden, Gulf, Jefferson, Leon, Liberty, Wakulla55 min

Nearby

Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Florida, 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; radar from the NEXRAD Level II archive.