Alert archive / Georgia / Mesoscale Discussions in 2017

Mesoscale Discussion 918

May 29, 201758 counties in Georgia; Cabarrus County, Mecklenburg County, Union County, North Carolina; 22 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 29, 2017, 7:30 PM EDT for 58 counties in Georgia; Cabarrus County, Mecklenburg County, Union County, North Carolina; 22 counties in South Carolina. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
May 29, 2017, 7:30 PM EDT (23:30 UTC)
Expired
May 29, 2017, 8:30 PM EDT
In force
60 min
Issued by
the Storm Prediction Center
All 83 counties

Baldwin County, GA, Banks County, GA, Barrow County, GA, Bibb County, GA, Burke County, GA, Butts County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Columbia County, GA, Crawford County, GA, DeKalb 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, Hart County, GA, Henry County, GA, Houston County, GA, Jackson County, GA, Jasper County, GA, Jefferson County, GA, Jones County, GA, Lamar County, GA, Lincoln County, GA, Macon County, GA, Madison County, GA, Marion County, GA, McDuffie County, GA, Meriwether County, GA, Monroe County, GA, Morgan County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Peach County, GA, Pike County, GA, Putnam County, GA, Richmond County, GA, Rockdale County, GA, Schley County, GA, Spalding County, GA, Talbot County, GA, Taliaferro County, GA, Taylor County, GA, Twiggs County, GA, Upson County, GA, Walton County, GA, Warren County, GA, Washington County, GA, Wilkes County, GA, Wilkinson County, GA, Cabarrus County, NC, Mecklenburg County, NC, Union County, NC, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Barnwell County, SC, Calhoun County, SC, Cherokee County, SC, Chester County, SC, Edgefield County, SC, Fairfield County, SC, Greenwood County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Spartanburg County, SC, Union County, SC, York County, SC

The radar

The Greer radar (KGSP), 135 km from the middle of the area, began a volume at 23:30 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, 11.5 hours before the alert went out and 151 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 2017-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 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, Peachtre/Fal Fld, GA at 12:00Z on 2017-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -82 square meters per square second.19395878Sfc1 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
27 J/kg
Mixed-layer CIN
-236 J/kg
Mixed-layer LCL
1043 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-82 m²/s²
0-3 km storm-relative helicity
-88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

194 
ACUS11 KWNS 292331
SWOMCD
SPC MCD 292330 
SCZ000-NCZ000-GAZ000-300030-

Mesoscale Discussion 0918
NWS Storm Prediction Center Norman OK
0630 PM CDT Mon May 29 2017

Areas affected...Eastern GA...SC

Concerning...Severe Thunderstorm Watch 298...

Valid 292330Z - 300030Z

The severe weather threat for Severe Thunderstorm Watch 298
continues.

SUMMARY...Scattered severe thunderstorms will be concentrated
primarily over the eastern half of WW298.

DISCUSSION...An apparent weak short-wave trough has shifted to near
the GA/SC border.  Deep convection is concentrated ahead of this
feature with several severe storms located from Columbia County GA
east into Richland County SC.  This activity is moving east at
roughly 35kt and the more robust convection is likely producing
large hail and locally damaging winds.  Greatest corridor of strong
convection should extend along an axis from near AGS to FLo over the
next few hours.

If it appears thunderstorms will maintain their
intensity/organization there may be a need for a WW downstream into
portions of ILM CWA.

..Darrow.. 05/29/2017

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

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

LAT...LON   34108468 35498042 33488044 32078467 34108468

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 2:27 PM EDTMesoscale DiscussionSPCBaldwin, Barrow, Bibb, Burke, Butts, Clarke and 53 more3 hr
May 29, 3:15 PM EDTSevere Thunderstorm WatchSPCBaldwin, Banks, Barrow, Bartow, Bibb, Bleckley and 66 more7 hr
May 29, 4:59 PM EDTMesoscale DiscussionSPCBaldwin, Banks, Barrow, Bibb, Bleckley, Burke and 56 more2 hr
May 28, 8:20 PM EDTMesoscale DiscussionSPCBladen, Brunswick, Columbus, New Hanover, Pender85 min

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.