Alert archive / Georgia / Mesoscale Discussions in 2011
Mesoscale Discussion 448
The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2011, 10:41 PM CDT for 4 states. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Apr 15, 2011, 10:41 PM CDT (03:41 UTC)
- Expired
- Apr 16, 2011, 12:15 AM CDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
All 104 counties
Autauga County, AL, Baldwin County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Chambers County, AL, Chilton County, AL, Clarke County, AL, Clay County, AL, Coffee County, AL, Conecuh County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Tallapoosa County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Baldwin County, GA, Barrow County, GA, Bibb County, GA, Bleckley County, GA, Butts County, GA, Carroll County, GA, Chattahoochee County, GA, Clarke County, GA, Clay County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Crawford County, GA, DeKalb County, GA, Dodge County, GA, Dooly County, GA, Douglas County, GA, Fayette County, GA, Fulton County, GA, Glascock County, GA, Greene County, GA, Gwinnett County, GA, Hancock County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Houston County, GA, Jasper County, GA, Johnson County, GA, Jones County, GA, Lamar County, GA, Laurens County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Morgan County, GA, Muscogee County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Peach County, GA, Pike County, GA, Pulaski County, GA, Putnam County, GA, Quitman County, GA, Randolph County, GA, Rockdale County, GA, Schley County, GA, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taliaferro County, GA, Taylor County, GA, Treutlen County, GA, Troup County, GA, Twiggs County, GA, Upson County, GA, Walton County, GA, Warren County, GA, Washington County, GA, Webster County, GA, Wilkinson County, GA, George County, MS, Greene County, MS
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 3.7 hours before the alert went out and 168 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
- 406 J/kg
- Mixed-layer CIN
- -24 J/kg
- Mixed-layer LCL
- 1138 m above ground
- 0-6 km bulk shear
- 68 kt
- 0-1 km storm-relative helicity
- 373 m²/s²
- 0-3 km storm-relative helicity
- 566 m²/s²
- Significant tornado parameter
- 1.3
- Supercell composite
- 11.3
The text
As transmitted, in the capitals the NWS used until 2016.
000
ACUS11 KWNS 160342
SWOMCD
SPC MCD 160341
GAZ000-ALZ000-FLZ000-MSZ000-160515-
MESOSCALE DISCUSSION 0448
NWS STORM PREDICTION CENTER NORMAN OK
1041 PM CDT FRI APR 15 2011
AREAS AFFECTED...NRN/CNTRL GA...CNTRL/SRN AL...FAR SERN MS...WRN FL
PANHANDLE
CONCERNING...TORNADO WATCH 146...147...
VALID 160341Z - 160515Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 146...147...CONTINUES.
THE PRIMARY CONVECTIVE MODE IS EVOLVING TOWARD A BROKEN
QLCS...CURRENTLY EXTENDING FROM NERN AL INTO CNTRL AL NEAR 30 SE BHM
TO FAR SERN MS NEAR 25 WNW MOB...WITH A FEW LEADING SUPERCELL
STORMS. DURING THE NEXT FEW HOURS...THIS ACTIVITY WILL CONTINUE TO
SHIFT EWD OVER ERN AL AND INTO THE WRN FL PANHANDLE WITHIN
WW146...AND EVENTUALLY INTO CNTRL GA WITHIN WW147 AFTER
0400Z...GIVEN STRONG CLOUD-BEARING W-SWLY FLOW. THE AIR MASS AHEAD
OF THE STORMS IS WEAKLY TO MODERATELY UNSTABLE GIVEN SFC DEWPOINTS
IN THE LOWER TO MIDDLE 60S. BOUNDARY-LAYER MOISTURE AND LOW-LEVEL
PARCEL BUOYANCY WILL BE MAINTAINED BY A CONTINUED INFLUX OF GULF
MOISTURE EVIDENT BY UPPER 60S DEWPOINTS ALONG THE GULF COAST. THESE
FACTORS...COMBINED WITH EFFECTIVE BULK SHEAR MAGNITUDES AOA 50 KT
WILL MAINTAIN ORGANIZED STORM STRUCTURES WITH A MIXED QLCS/SUPERCELL
MODE...AND AN ATTENDANT THREAT FOR DMGG WINDS AND LARGE HAIL. THE
TORNADO THREAT CONTINUES...ALBEIT SOMEWHAT LESS THAN EARLIER...WITH
EFFECTIVE SRH VALUES AOA 400 M2/S2. PERSISTENT SUPERCELLS AND BREAKS
IN CONVECTIVE LINES WILL BE THE PRIMARY FOCI FOR ENHANCED TORNADO
POTENTIAL. HOWEVER...THE STRONG TORNADO THREAT WILL BE LIMITED TO
SOME EXTENT BY DIABATIC COOLING...THE LACK OF STRONG DEEP-LAYER
ASCENT...AND THE EVOLUTION TO A MORE LINEAR MODE.
FARTHER NORTHEAST INTO NORTH GA...THE 00Z PEACHTREE CITY SOUNDING
DEPICTED MARGINAL INSTABILITY THOUGH A FAVORABLE HODOGRAPH FOR
SUPERCELLS/TORNADOES -- I.E. STRONG CLOCKWISE CURVATURE IN THE LOW
LEVELS YIELDING AN EFFECTIVE SRH VALUE OF 575 M2/S2.
HOWEVER...WIDESPREAD PRECIP ACROSS NRN GA HAS AIDED IN THE
DEVELOPMENT OF A COLD POOL...WITH DEEPER CONVECTION FOUND ON ITS ERN
PERIPHERY. NEVERTHELESS...CONVECTION DEVELOPING UPSTREAM ACROSS NERN
AL CONTINUES TO BE SUSTAINED INVOF MORE NOTABLE SFC PRESSURE FALLS
REFLECTING SOME ASCENT. DESPITE THE STABILIZATION EFFECTS OF THE
COLD POOL OVER NRN GA...THE EFFECT OF STRONG DEEP-LAYER VERTICAL
WIND SHEAR WILL ENHANCE UPDRAFT POTENTIAL IN THIS AREA...AND STRONG
LOW-LEVEL VERTICAL WIND SHEAR WILL YIELD A TORNADO POTENTIAL ACROSS
NRN PORTIONS OF WW147.
..COHEN.. 04/16/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FFC...TAE...BMX...MOB...LIX...
LAT...LON 30698911 32798745 34038462 34128356 33748270 32498240
32118306 31748480 30718630 30298757 30698911SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 15, 7:16 PM CDT | Mesoscale Discussion | SPC | Autauga, Baldwin, Bibb, Blount, Bullock, Butler and 46 more | 59 min |
| Apr 15, 7:48 PM CDT | Tornado Watch | SPC | Autauga, Baldwin, Barbour, Bibb, Bullock, Butler and 34 more | 6 hr |
| Apr 16, 1:43 AM CDT | Mesoscale Discussion | SPC | Coffee, Dale, Geneva, Henry, Houston | 92 min |
| Apr 16, 2:05 AM CDT | Tornado Watch | SPC | Barbour, Bullock, Coffee, Covington, Dale, Geneva and 5 more | 7 hr |
| Apr 16, 6:57 AM CDT | Mesoscale Discussion | SPC | Baker, Columbia, Hamilton, Lafayette, Madison, Nassau and 3 more | 63 min |
| Apr 15, 7:52 PM CDT | Mesoscale Discussion | SPC | Baldwin, Barrow, Bibb, Bleckley, Butts, Clarke and 40 more | 53 min |
| Apr 15, 8:12 PM CDT | Tornado Watch | SPC | Baldwin, Banks, Barrow, Bibb, Bleckley, Butts and 69 more | 9 hr |
| Apr 16, 4:09 AM CDT | Mesoscale Discussion | SPC | Clarke, Columbia, Elbert, Franklin, Glascock, Greene and 12 more | 96 min |
| Apr 16, 4:57 AM CDT | Tornado Watch | SPC | Baldwin, Bibb, Bleckley, Bulloch, Burke, Butts and 56 more | 8 hr |
| Apr 16, 9:39 AM CDT | Mesoscale Discussion | SPC | Bryan, Bulloch, Burke, Candler, Chatham, Effingham and 12 more | 2 hr |
| Apr 15, 7:51 PM CDT | Mesoscale Discussion | SPC | Clarke, Covington, Forrest, Hancock, Jasper, Jefferson Davis and 15 more | 54 min |
Nearby
Mesoscale Discussions in Georgia, 2011Mesoscale Discussions in Alabama, 2011Mesoscale Discussions in Florida, 2011Every mesoscale discussion in 2011
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.