Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 2226

December 25, 20127 counties in Alabama; 9 counties in Florida; 22 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Dec 25, 2012, 11:10 PM CST for 7 counties in Alabama; 9 counties in Florida; 22 counties in Georgia. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Dec 25, 2012, 11:10 PM CST (05:10 UTC)
Expired
Dec 26, 2012, 12:45 AM CST
In force
95 min
Issued by
the Storm Prediction Center
All 38 counties

Barbour County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Lee County, AL, Russell County, AL, Bay County, FL, Calhoun County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Liberty 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, Marion County, GA, Miller County, GA, Mitchell 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, Terrell County, GA, Webster County, GA

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 5.2 hours before the alert went out and 176 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 00:00Z on 2012-12-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2012-12-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 232 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1109 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
232 m²/s²
0-3 km storm-relative helicity
410 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.

658 
ACUS11 KWNS 260510
SWOMCD
SPC MCD 260510 
GAZ000-FLZ000-ALZ000-260645-

MESOSCALE DISCUSSION 2226
NWS STORM PREDICTION CENTER NORMAN OK
1110 PM CST TUE DEC 25 2012

AREAS AFFECTED...SERN AL...SWRN GA...WRN FL PANHANDLE

CONCERNING...TORNADO WATCH 698...

VALID 260510Z - 260645Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 698 CONTINUES.

SUMMARY...A RISK FOR ISOLATED DAMAGING WINDS/TORNADOES SHOULD
PERSIST BUT GRADUALLY WANE WITHIN A QLCS MOVING EWD AT 30-35 KT.

DISCUSSION...THE NUMBER AND INTENSITY OF EMBEDDED
SUPERCELLS/MESOVORTEX STRUCTURES HAVE DECREASED OVERALL WITHIN THE
QLCS THAT EXTENDED FROM MACON COUNTY GA TO OKALOOSA COUNTY FL AS OF
05Z. THIS DIMINISHING TREND SHOULD CONTINUE INTO THE OVERNIGHT
PERIOD AS BUOYANCY FROM SURFACE-BASED PARCELS FURTHER WANES WITH
MLCAPE REMAINING AOB 750 J/KG. STILL...SCANT DOWNSTREAM
DESTABILIZATION IS EXPECTED TO BE COINCIDENT JUST AHEAD OF THE QLCS
AS MODEST SURFACE PRESSURE FALLS OCCUR. WHERE SURFACE DEW POINTS ARE
ABLE TO ROUGHLY REACH 60 DEG F AMIDST INTENSE LOW/MID-LEVEL
FLOW...THE DAMAGING WIND/TORNADO RISK SHOULD EXIST FOR SEVERAL HOURS
ALBEIT IN A MORE SPATIALLY CONFINED/TRANSIENT FASHION.

..GRAMS.. 12/26/2012

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

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

LAT...LON   32548546 32878528 32818464 32588428 32028392 30958426
            29698515 30348655 32098558 32548546

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 25, 6:05 PM CSTMesoscale DiscussionSPCBibb, Chambers, Chilton, Clay, Coosa, Elmore and 5 more85 min
Dec 25, 7:08 PM CSTMesoscale DiscussionSPCAutauga, Baldwin, Butler, Chilton, Clarke, Clay and 14 more67 min
Dec 25, 8:49 PM CSTMesoscale DiscussionSPCBarbour, Bullock, Coffee, Covington, Crenshaw, Dale and 9 more56 min
Dec 25, 9:23 PM CSTTornado WatchSPCBaldwin, Barbour, Bullock, Chambers, Coffee, Covington and 12 more6 hr
Dec 26, 2:55 AM CSTMesoscale DiscussionSPCCalhoun, Gadsden, Gulf, Liberty65 min

Nearby

Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in Florida, 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.