Alert archive / Georgia / Mesoscale Discussions in 2016
Mesoscale Discussion 663
The Storm Prediction Center issued this mesoscale discussion at May 21, 2016, 2:20 PM EDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- May 21, 2016, 2:20 PM EDT (18:20 UTC)
- Expired
- May 21, 2016, 4:45 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
All 96 counties
Baldwin County, GA, Banks County, GA, Barrow County, GA, Butts County, GA, Clarke County, GA, Clayton County, GA, Columbia County, GA, DeKalb County, GA, Elbert County, GA, Fayette County, GA, Franklin County, GA, Glascock County, GA, Greene County, GA, Gwinnett County, GA, Habersham County, GA, Hancock County, GA, Hart County, GA, Henry County, GA, Jackson County, GA, Jasper 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, Pike County, GA, Putnam County, GA, Richmond County, GA, Rockdale County, GA, Spalding County, GA, Stephens County, GA, Talbot County, GA, Taliaferro County, GA, Upson County, GA, Walton County, GA, Warren County, GA, Wilkes County, GA, Alamance County, NC, Alexander County, NC, Anson County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Gaston County, NC, Guilford County, NC, Henderson County, NC, Iredell County, NC, Lincoln County, NC, Mecklenburg County, NC, Montgomery County, NC, Polk County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Rutherford County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Wilkes County, NC, Yadkin County, NC, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Edgefield County, SC, Fairfield County, SC, Greenville County, SC, Greenwood County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Pickens County, SC, Richland County, SC, Saluda County, SC, Spartanburg County, SC, Union County, SC, York County, SC, Henry County, VA
The radar
The Greer radar (KGSP), 48 km from the middle of the area, began a volume at 18:20 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
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 6.3 hours before the alert went out and 243 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 636 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- -29 m²/s²
- 0-3 km storm-relative helicity
- -5 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
717
ACUS11 KWNS 211821
SWOMCD
SPC MCD 211820
NCZ000-VAZ000-SCZ000-GAZ000-212045-
MESOSCALE DISCUSSION 0663
NWS STORM PREDICTION CENTER NORMAN OK
0120 PM CDT SAT MAY 21 2016
AREAS AFFECTED...NERN GA...NWRN SC...CNTRL/WRN NC...EXTREME SWRN VA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 211820Z - 212045Z
PROBABILITY OF WATCH ISSUANCE...5 PERCENT
SUMMARY...A SLOW INCREASE IN COVERAGE AND INTENSITY OF THUNDERSTORMS
IS EXPECTED THIS AFTERNOON...WITH A PRIMARY THREAT OF LOCALLY
DAMAGING WIND.
DISCUSSION...AT 1815 UTC...A CLUSTER OF THUNDERSTORMS IS ONGOING SE
OF ATL...WITH ADDITIONAL CONVECTION BEGINNING TO DEVELOP ACROSS THE
HIGHER TERRAIN OF WRN NC. COVERAGE IS EXPECTED TO CONTINUE
INCREASING INTO MID-AFTERNOON...AS LARGE-SCALE ASCENT INCREASES
AHEAD OF A STRONG UPPER TROUGH OVER THE OHIO VALLEY.
WHILE LAPSE RATES ARE RELATIVELY POOR...DIURNAL HEATING AND LOW/MID
60S DEWPOINTS ARE RESULTING IN SBCAPE OF 1000-1500 J/KG PER RECENT
MESOANALYSIS. MODERATE WLY FLOW ALOFT IS SUPPORTING EFFECTIVE SHEAR
OF 30-40 KTS...WHICH WILL BE SUFFICIENT FOR A FEW ORGANIZED
STRUCTURES AS THUNDERSTORMS MATURE. WHILE WEAK LOW-LEVEL FLOW WILL
TEMPER THE SEVERE WIND RISK...ISOLATED DAMAGING WIND GUSTS WILL BE
POSSIBLE THIS AFTERNOON...PARTICULARLY WITH ANY SMALL BOWING
SEGMENTS THAT MAY RESULT FROM STORM INTERACTIONS. SMALL HAIL WILL
ALSO BE POSSIBLE...BUT THE SEVERE HAIL RISK IS EXPECTED TO REMAIN
LOW DUE TO WEAK LAPSE RATES AND LACK OF STRONGER INSTABILITY. GIVEN
THE MARGINAL NATURE OF THE THREAT...WW ISSUANCE IS NOT ANTICIPATED.
..DEAN/HART.. 05/21/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RAH...ILM...RNK...CAE...GSP...FFC...
LAT...LON 32918496 34658354 35898173 36578067 36667974 36357930
35667934 34727994 34178053 33548155 33018300 32528472
32918496Nearby
Mesoscale Discussions in Georgia, 2016Mesoscale Discussions in North Carolina, 2016Mesoscale Discussions in South Carolina, 2016Every mesoscale discussion in 2016
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.