Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 197

March 1, 201217 counties in Alabama; Holmes County, Jackson County, Florida; 20 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 1, 2012, 10:24 AM CST for 17 counties in Alabama; Holmes County, Jackson County, Florida; 20 counties in Georgia. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Mar 1, 2012, 10:24 AM CST (16:24 UTC)
Expired: Mar 1, 2012, 12:00 PM CST
In force: 96 min
Issued by: the Storm Prediction Center

All 39 counties

Barbour County, AL, Bullock County, AL, Butler County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Monroe County, AL, Pike County, AL, Russell County, AL, Washington County, AL, Holmes County, FL, Jackson County, FL, Baker County, GA, Calhoun County, GA, Chattahoochee County, GA, Clay County, GA, Crisp County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Lee County, GA, Miller County, GA, Mitchell County, GA, Quitman County, GA, Randolph County, GA, Schley County, GA, Seminole County, GA, Stewart County, GA, Sumter County, GA, Terrell County, GA, Webster County, GA, Worth County, GA

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 4.4 hours before the alert went out and 193 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: 240 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 499 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 170 m²/s²
0-3 km storm-relative helicity: 158 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

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

825 
ACUS11 KWNS 011625
SWOMCD
SPC MCD 011624
GAZ000-FLZ000-ALZ000-011800-

MESOSCALE DISCUSSION 0197
NWS STORM PREDICTION CENTER NORMAN OK
1024 AM CST THU MAR 01 2012

AREAS AFFECTED...SRN AL INTO SRN GA...PARTS OF ADJACENT FL PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 011624Z - 011800Z

TRENDS ARE BEING MONITORED FOR THE POSSIBILITY OF AN INCREASING
SEVERE WEATHER THREAT...BUT POTENTIAL STILL APPEARS LIMITED AT THE
PRESENT TIME.

SUSTAINED VIGOROUS CONVECTIVE DEVELOPMENT...NOW PROGRESSING NEAR/
SOUTH THROUGH EAST OF THE EVERGREEN AL AREA...APPEARS LARGELY
SUPPORTED BY FORCING ASSOCIATED WITH A FOCUSED LOWER/MID
TROPOSPHERIC WARM ADVECTION FIELD...ON THE NORTHERN PERIPHERY OF
FLAT SUBTROPICAL RIDING CENTERED OVER THE SOUTHERN GULF OF MEXICO.
THIS IS ALSO ROUGHLY NEAR THE REMNANTS OF A STALLING/ WEAKENING
LOW-LEVEL FRONTAL ZONE...ALONG WHICH LIFTED MOIST UNSTABLE AIR
APPEARS CHARACTERIZED BY CAPE OF 500+ K/KG.  WESTERLY 850 MB WIND
FIELDS ARE RATHER MODERATE IN STRENGTH AT 20-30 KT...BUT WESTERLY
DEEP LAYER FLOW AND SHEAR REMAIN STRONG...ON THE ORDER OF 50+ KT.

FAVORABLE FOR AT LEAST SIGNIFICANT MID-LEVEL ROTATION AND MODEST
STORM MOTION AROUND 30 KT...THIS IS PROBABLY ENHANCING
ACTIVITY...WHICH COULD STRENGTHEN SUFFICIENTLY FOR PERHAPS A
MARGINAL SEVERE HAIL/WIND GUST THREAT THROUGH MID DAY.  MODELS ARE
UNCLEAR HOW MUCH LONGER BEYOND THE 17-19Z TIME FRAME THIS FORCING
WILL PERSIST...BUT IT IS NOT OUT OF THE QUESTION THAT FURTHER
BOUNDARY LAYER DESTABILIZATION AND STORM SCALE DYNAMIC FORCING
ASSOCIATED WITH THE SHEAR COULD OVERCOME THIS LIMITING FACTOR.

..KERR.. 03/01/2012

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

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

LAT...LON   31778831 32098671 32228564 32388504 32318424 31988363
            31598367 31178380 30678461 30868599 31198821 31778831

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 1, 3:00 AM CST	Mesoscale Discussion	SPC	Autauga, Bibb, Chambers, Chilton, Clay, Cleburne and 9 more	90 min
Mar 1, 12:44 PM CST	Mesoscale Discussion	SPC	Bryan, Bulloch, Candler, Chatham, Dodge, Effingham and 8 more	91 min

Nearby

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