Alert archive / Georgia / Mesoscale Discussions in 2015

Mesoscale Discussion 1237

June 30, 201510 counties in Alabama; 47 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2015, 7:59 AM CDT for 10 counties in Alabama; 47 counties in Georgia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 30, 2015, 7:59 AM CDT (12:59 UTC)
Expired
Jun 30, 2015, 10:00 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 57 counties

Bullock County, AL, Chambers County, AL, Clay County, AL, Cleburne County, AL, Elmore County, AL, Lee County, AL, Macon County, AL, Randolph County, AL, Russell County, AL, Tallapoosa County, AL, Barrow County, GA, Bartow County, GA, Bibb County, GA, Butts County, GA, Carroll County, GA, Chattahoochee County, GA, Cherokee County, GA, Clayton County, GA, Cobb County, GA, Coweta County, GA, Crawford County, GA, DeKalb County, GA, Douglas County, GA, Fayette County, GA, Forsyth County, GA, Fulton County, GA, Gwinnett County, GA, Haralson County, GA, Harris County, GA, Heard County, GA, Henry County, GA, Jasper County, GA, Jones County, GA, Lamar 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, Paulding County, GA, Peach County, GA, Pike County, GA, Polk County, GA, Rockdale County, GA, Schley County, GA, Spalding County, GA, Stewart County, GA, Sumter County, GA, Talbot County, GA, Taylor County, GA, Troup County, GA, Upson County, GA, Walton County, GA, Webster County, GA

The radar

The Atlanta radar (KFFC), 41 km from the middle of the area, began a volume at 13:01 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 nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 1.0 hours before the alert went out and 45 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, Peachtre/Fal Fld, GA at 12:00Z on 2015-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 713 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 12:00Z on 2015-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
713 J/kg
Mixed-layer CIN
-96 J/kg
Mixed-layer LCL
1029 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
97 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

368 
ACUS11 KWNS 301300
SWOMCD
SPC MCD 301259 
GAZ000-ALZ000-301500-

MESOSCALE DISCUSSION 1237
NWS STORM PREDICTION CENTER NORMAN OK
0759 AM CDT TUE JUN 30 2015

AREAS AFFECTED...E-CNTRL AL / N-CNTRL AND W-CNTRL GA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 301259Z - 301500Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE FORECAST TO INTENSIFY DURING THE NEXT 2-4 HOURS
AND A SEVERE THUNDERSTORM WATCH IS POSSIBLE LATER THIS MORNING.

DISCUSSION...RADAR MOSAIC SHOWS A MCV LOCATED 35 MI ENE CBM MOVING
ESEWD AND EXPECTED TO TRACK ACROSS N-CNTRL AL THIS MORNING.  A BELT
OF STRONGER MID-LEVEL FLOW ASSOCIATED WITH THIS FEATURE /30 KT AT
H5/ SAMPLED ON THE 12Z BMX RAOB WILL SUPPORT ORGANIZED MULTICELLS. 
MODERATE BUOYANCY /1500 J PER KG MLCAPE/ WITH AMPLE PW OBSERVED ON
THE BMX RAOB WILL INCREASE THIS MORNING AS SURFACE TEMPS WARM
THROUGH THE 70S AND INTO THE 80S BY THE LATE MORNING HOURS. 
UPSTREAM OF THE MCV...AN UPPER TROUGH OVER THE LOWER TN/OH VALLEYS
WILL PIVOT INTO THE TN VALLEY BY EARLY AFTERNOON AND LEND AT LEAST
LARGE-SCALE SUPPORT FOR A CONTINUATION OF VIGOROUS CONVECTIVE
ACTIVITY AS THIS STORM CLUSTER MOVES EWD TOWARDS THE AL/GA VICINITY.
THEREFORE A GRADUAL UPTICK IN STORM INTENSITY IS FORECAST WITH
PRIMARILY A WIND DAMAGE THREAT DEVELOPING LATER THIS MORNING. 
CONVECTIVE TRENDS WILL BE MONITORED OVER THE NEXT SEVERAL HOURS IF
STORMS CAN DEVELOP/STRENGTHEN ON THE LEADING EDGE OF THE EVOLVING
CLUSTER.

..SMITH/EDWARDS.. 06/30/2015

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

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

LAT...LON   32368628 33928564 34348504 34318381 33758327 32718361
            32008422 31878529 32368628

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 30, 11:17 AM CDTMesoscale DiscussionSPCGeneva, Henry, Houston88 min
Jun 30, 11:38 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 4 more97 min
Jun 30, 1:06 PM CDTSevere Thunderstorm WatchSPCBaldwin, Coffee, Covington, Crenshaw, Dale, Escambia and 4 more6 hr
Jun 30, 11:55 AM CDTMesoscale DiscussionSPCFannin, Rabun, Towns, Union3 hr
Jun 30, 12:01 PM CDTMesoscale DiscussionSPCBaldwin, Banks, Barrow, Bibb, Bleckley, Bulloch and 66 more89 min
Jun 30, 12:37 PM CDTSevere Thunderstorm WatchSPCElbert, Franklin, Habersham, Hart, Rabun, Stephens7 hr
Jun 30, 12:53 PM CDTSevere Thunderstorm WatchSPCBaldwin, Banks, Barrow, Bibb, Bleckley, Bryan and 64 more6 hr
Jun 30, 12:57 PM CDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Brantley, Charlton, Clinch and 6 more7 hr
Jun 30, 3:33 PM CDTMesoscale DiscussionSPCBaldwin, Banks, Barrow, Bibb, Bleckley, Bulloch and 53 more117 min
Jun 30, 3:51 PM CDTMesoscale DiscussionSPCBaker, Brooks, Colquitt, Decatur, Grady, Miller and 3 more114 min
Jun 30, 6:08 PM CDTMesoscale DiscussionSPCCatoosa, Fannin, Franklin, Gilmer, Habersham, Hart and 7 more67 min

Nearby

Mesoscale Discussions in Georgia, 2015Mesoscale Discussions in Alabama, 2015Every mesoscale discussion in 2015

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.