Alert archive / Georgia / Mesoscale Discussions in 2017

Mesoscale Discussion 1237

July 5, 20174 states

The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2017, 5:46 PM CDT for 4 states. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Jul 5, 2017, 5:46 PM CDT (22:46 UTC)
Expired
Jul 5, 2017, 7:15 PM CDT
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 121 counties

Chambers County, AL, Clay County, AL, Cleburne County, AL, Randolph County, AL, Talladega County, AL, Tallapoosa County, AL, Baldwin County, GA, Banks County, GA, Barrow County, GA, Bibb County, GA, Burke County, GA, Butts County, GA, Carroll County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Columbia County, GA, Coweta County, GA, Crawford County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fayette County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Glascock County, GA, Greene County, GA, Gwinnett County, GA, Hall County, GA, Hancock County, GA, Haralson County, GA, Harris County, GA, Hart County, GA, Heard County, GA, Henry County, GA, Jackson County, GA, Jasper County, GA, Jefferson County, GA, Johnson County, GA, Jones County, GA, Lamar County, GA, Lincoln County, GA, Madison County, GA, McDuffie County, GA, Meriwether County, GA, Monroe County, GA, Morgan County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Peach County, GA, Pike County, GA, Putnam County, GA, Richmond County, GA, Rockdale County, GA, Spalding County, GA, Stephens County, GA, Talbot County, GA, Taliaferro County, GA, Taylor County, GA, Troup County, GA, Twiggs County, GA, Upson County, GA, Walton County, GA, Warren County, GA, Washington County, GA, Wilkes County, GA, Wilkinson County, GA, Anson County, NC, Bladen County, NC, Cabarrus County, NC, Columbus County, NC, Cumberland County, NC, Gaston County, NC, Hoke County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Richmond County, NC, Robeson County, NC, Scotland County, NC, Stanly County, NC, Union County, NC, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Bamberg County, SC, Barnwell County, SC, Calhoun County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Greenville County, SC, Greenwood County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Orangeburg County, SC, Pickens County, SC, Richland County, SC, Saluda County, SC, Spartanburg County, SC, Sumter County, SC, Union County, SC, York County, SC

The radar

The Columbia radar (KCAE), 90 km from the middle of the area, began a volume at 22:46 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

Charleston AFB, SC (KCHS), launched 12:00Z, 10.8 hours before the alert went out and 227 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, Charleston AFB, SC at 12:00Z on 2017-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1417 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 12:00Z on 2017-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.1939Sfc1 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
1417 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
1071 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
13 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

661 
ACUS11 KWNS 052247
SWOMCD
SPC MCD 052246 
NCZ000-SCZ000-GAZ000-ALZ000-060015-

Mesoscale Discussion 1237
NWS Storm Prediction Center Norman OK
0546 PM CDT Wed Jul 05 2017

Areas affected...Portions of the Southeast

Concerning...Severe potential...Watch unlikely 

Valid 052246Z - 060015Z

Probability of Watch Issuance...5 percent

SUMMARY...Scattered thunderstorms will continue to pose a threat of
strong, gusty winds capable of localized damage through mid evening.
However, they should lack sufficient organization to require a
Severe Thunderstorm Watch.

DISCUSSION...Scattered strong to marginally severe storms are
evolving eastward across the Southeast early this evening, aided by
propagation along cold pools and enhanced by any mergers of outflow.
A well-mixed (i.e., steep low-level lapse rates) and moist boundary
layer will continue to offer a localized damaging wind potential
with stronger downdrafts. Forecast soundings also suggest drier
mid-level air over parts of the region may enhance cold-pool
generation and the resultant wind threat briefly this evening.
However, modest/weak tropospheric flow will likely keep storms
rather disorganized, with movement driven by a combination of weak
westerly mid-level winds and propagation along localized corridors
of greater instability. Therefore, watch issuance is not
anticipated. Storms should gradually weaken later this evening, as
surface-based buoyancy wanes and inhibition increases.

..Picca/Thompson.. 07/05/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...RAH...ILM...CHS...CAE...GSP...FFC...BMX...

LAT...LON   33348668 34118480 35338154 35418019 35367919 34827849
            34127844 33837908 33797925 32648274 32448409 32818605
            33348668

Nearby

Mesoscale Discussions in Georgia, 2017Mesoscale Discussions in South Carolina, 2017Mesoscale Discussions in North Carolina, 2017Every mesoscale discussion in 2017

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.