Alert archive / Georgia / Mesoscale Discussions in 2008

Mesoscale Discussion 939

May 15, 200829 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at May 15, 2008, 5:44 PM EDT for 29 counties in Georgia. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: May 15, 2008, 5:44 PM EDT (21:44 UTC)
Expired: May 15, 2008, 6:45 PM EDT
In force: 61 min
Issued by: the Storm Prediction Center

All 29 counties

Bibb County, GA, Butts County, GA, Chattahoochee County, GA, Clayton County, GA, Coweta County, GA, Crawford County, GA, Fayette County, GA, Harris County, GA, Henry County, GA, Houston County, GA, Jasper County, GA, Jones County, GA, Lamar County, GA, Macon County, GA, Marion County, GA, Meriwether County, GA, Monroe County, GA, Muscogee County, GA, Newton County, GA, Peach County, GA, Pike County, GA, Rockdale County, GA, Schley County, GA, Spalding County, GA, Talbot County, GA, Taylor County, GA, Troup County, GA, Twiggs County, GA, Upson County, GA

The radar

The Atlanta radar (KFFC), 47 km from the middle of the area, began a volume at 21:45 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, 9.7 hours before the alert went out and 47 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 770 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 146 m²/s²
0-3 km storm-relative helicity: 109 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.

000 
ACUS11 KWNS 152144
SWOMCD
SPC MCD 152144 
GAZ000-ALZ000-152245-

MESOSCALE DISCUSSION 0939
NWS STORM PREDICTION CENTER NORMAN OK
0444 PM CDT THU MAY 15 2008

AREAS AFFECTED...W-CNTRL GA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 152144Z - 152245Z

THE THREAT FOR LOW-TOPPED SUPERCELLS CAPABLE OF AN ISOLATED TORNADO
APPEARS TO BE INCREASING AND CONVECTIVE TRENDS ARE BEING MONITORED
FOR A WW.

RECENT TRENDS IN RADAR DATA SHOW AN INCREASE IN STORM INTENSITY OVER
E-CNTRL AL AND W-CNTRL GA.  THIS ACTIVITY APPEARS TO BE COLOCATED
WITH A MIDLEVEL VORTICITY MAXIMUM /MCV/ AND ATTENDANT SURFACE LOW. 
LATEST SURFACE OBSERVATIONS OVER ERN AL INDICATE A WELL-DEFINED
PRESSURE FALL CENTER WITH THIS LOW IN ADDITION TO AN OUTFLOW
BOUNDARY WHICH EXTENDS FROM THIS LOW ENEWD TO NEAR MCN TO N OF AGS. 
MODIFICATION OF A RUC PROXIMITY SOUNDING FOR CURRENT SURFACE
CONDITIONS INVOF THIS LOW YIELDS SBCAPES OF 400-700 J/KG. 
MOREOVER...ACCOMPANYING FORECAST WIND PROFILE AND MAXWELL AFB VWP
INDICATE STRONG LOW-LEVEL SHEAR WITH 0-1 KM SRH OF 300-350 M2/S2. 
GIVEN THE MOIST BOUNDARY LAYER AND RESULTANT LOW LCL HEIGHTS...THE
POTENTIAL WILL EXIST FOR A COUPLE OF LOW-TOPPED SUPERCELLS CAPABLE
OF A TORNADO.

..MEAD.. 05/15/2008

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

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

32768545 33358506 33778425 33578349 32888320 32338351
32198509

Nearby

Mesoscale Discussions in Georgia, 2008 Every mesoscale discussion in 2008

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.