Alert archive / Georgia / Mesoscale Discussions in 2012
Mesoscale Discussion 132
The Storm Prediction Center issued this mesoscale discussion at Feb 18, 2012, 7:05 PM CST for 4 counties in Alabama; 22 counties in Florida; 24 counties in Georgia. It was in force for 55 min.
The area
The outline as issued.
The facts
- Issued
- Feb 18, 2012, 7:05 PM CST (01:05 UTC)
- Expired
- Feb 18, 2012, 8:00 PM CST
- In force
- 55 min
- Issued by
- the Storm Prediction Center
All 50 counties
Dale County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Columbia County, FL, Dixie County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Hamilton County, FL, Holmes County, FL, Jackson County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Okaloosa County, FL, Santa Rosa County, FL, Suwannee County, FL, Taylor County, FL, Wakulla County, FL, Walton County, FL, Washington County, FL, Atkinson County, GA, Baker County, GA, Berrien County, GA, Brooks County, GA, Calhoun County, GA, Clay County, GA, Clinch County, GA, Colquitt County, GA, Cook County, GA, Decatur County, GA, Dougherty County, GA, Early County, GA, Echols County, GA, Grady County, GA, Irwin County, GA, Lanier County, GA, Lowndes County, GA, Miller County, GA, Mitchell County, GA, Quitman County, GA, Seminole County, GA, Thomas County, GA, Tift County, GA, Worth County, GA
The radar
The Eglin Afb radar (KEVX), 66 km from the middle of the area, began a volume at 01:08 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 00:00Z, 1.1 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 566 m above ground
- 0-6 km bulk shear
- 66 kt
- 0-1 km storm-relative helicity
- 257 m²/s²
- 0-3 km storm-relative helicity
- 378 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
981
ACUS11 KWNS 190106
SWOMCD
SPC MCD 190105
GAZ000-FLZ000-ALZ000-LAZ000-190200-
MESOSCALE DISCUSSION 0132
NWS STORM PREDICTION CENTER NORMAN OK
0705 PM CST SAT FEB 18 2012
AREAS AFFECTED...PARTS OF SRN GA/NRN FL INCLUDING THE PANHANDLE/SERN
AL/FAR SERN LA
CONCERNING...TORNADO WATCH 30...31...
VALID 190105Z - 190200Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 30...31...CONTINUES.
A NEW WW WILL LIKELY BE NEEDED TO REPLACE WW 30 BY 19/02Z...AND
EXTEND THE SEVERE WEATHER THREAT POTENTIAL EWD ACROSS MORE OF SRN GA
AND NRN FL.
REGIONAL RADAR IMAGERY SHOWED A WELL DEFINED QLCS EXTENDING FROM FAR
SERN AL SWWD THROUGH THE WRN FL PANHANDLE...WHILE ADDITIONAL TSTMS
PERSISTED SWWD ALONG THE TRAILING EXTENT OF THE EFFECTIVE OUTFLOW
BOUNDARY THROUGH FAR SERN PLAQUEMINES PARISH AND ADJACENT MARINE
ZONES. TRENDS IN RADAR DATA INDICATED AN EWD MOVEMENT OF THE QLCS
AT CLOSE TO 40 KT. THE NRN EXTENT OF THIS ACTIVITY WILL EXIT WW 30
AROUND 19/02Z.
VWP DATA PER WSR-88DS VERIFIED THE FORECAST PRESENCE OF A LEAD
STRONG /70-85 KT/ WSWLY MIDLEVEL JET EXTENDING FROM SRN SC-SRN GA TO
THE FL PANHANDLE. THESE WINDS COMBINED WITH A STRENGTHENING SSWLY
LLJ /50+ KT/ ALONG AND IN ADVANCE OF THE QLCS WILL SUPPORT STRONG
EFFECTIVE SRH AND BULK SHEAR TO MAINTAIN THE LINEAR STRUCTURE WITH
AN ATTENDANT THREAT FOR DAMAGING WINDS AND TORNADOES. DESPITE WEAK
DOWNSTREAM LAPSE RATES INTO SRN GA/NRN FL AND RESULTANT MARGINAL
INSTABILITY...THE STRENGTH OF THE KINEMATICS AND PRESENCE OF A WELL
ORGANIZED QLCS WARRANT THE NEED FOR A NEW WW.
..PETERS.. 02/19/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...JAX...TAE...BMX...MOB...LIX...
LAT...LON 28669065 29028952 29588877 29988829 30248768 30668713
30978669 31238619 31648542 31958500 31648491 31688395
31608307 31428257 30788245 30388250 29778290 29428320
29398379 29388430 29228489 29258547 29678627 29868661
29318800 28608892 28458953 28319037 28669065SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 18, 7:24 PM CST | Tornado Watch | SPC | Houston | 6 hr |
| Feb 18, 10:36 PM CST | Mesoscale Discussion | SPC | Baker, Bay, Calhoun, Columbia, Franklin, Gadsden and 11 more | 84 min |
| Feb 19, 11:20 AM CST | Mesoscale Discussion | SPC | Nassau | 85 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; radar from the NEXRAD Level II archive.