Alert archive / Georgia / Mesoscale Discussions in 2016

Mesoscale Discussion 482

April 28, 201614 counties in Georgia; Beaufort County, Hampton County, Jasper County, South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2016, 2:27 PM EDT for 14 counties in Georgia; Beaufort County, Hampton County, Jasper County, South Carolina. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 28, 2016, 2:27 PM EDT (18:27 UTC)
Expired
Apr 28, 2016, 5:00 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Appling County, GA, Bacon County, GA, Bryan County, GA, Bulloch County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Jeff Davis County, GA, Liberty County, GA, Long County, GA, Tattnall County, GA, Toombs County, GA, Wayne County, GA, Beaufort County, SC, Hampton County, SC, Jasper County, SC

The radar

The Charleston,SC radar (KCLX), 83 km from the middle of the area, began a volume at 18:29 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, 6.5 hours before the alert went out and 182 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 2016-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 613 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 2016-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
613 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
960 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

395 
ACUS11 KWNS 281827
SWOMCD
SPC MCD 281827 
SCZ000-GAZ000-282100-

MESOSCALE DISCUSSION 0482
NWS STORM PREDICTION CENTER NORMAN OK
0127 PM CDT THU APR 28 2016

AREAS AFFECTED...SOUTHEAST GA INTO SOUTHERN SC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 281827Z - 282100Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED STRONG WIND GUSTS CANNOT BE RULED OUT FROM
THUNDERSTORMS TRACKING TO THE EAST THIS AFTERNOON ACROSS SOUTHEAST
GA INTO SOUTHERN SC.

DISCUSSION...SIMILAR TO STORMS THAT HAVE FORMED IN SOUTHWEST
GA...THE SHORT/ARCED BAND OF TSTMS EXTENDING FROM EMANUEL TO JEFF
DAVIS COUNTIES IN SOUTHEAST GA APPEAR TO BE DEVELOPING ALONG
EASTWARD-MOVING GRAVITY WAVES...WHICH EMANATED FROM THE MCS LOCATED
ACROSS AND OFFSHORE OF THE CENTRAL GULF COAST.  THE SOUTHEAST BAND
OF STORMS IS CURRENTLY MOVING TO THE EAST INTO A DESTABILIZED
ENVIRONMENT...WHERE SURFACE HEATING IS SUPPORTING STEEPENING
LOW-LEVEL LAPSE RATES.  THIS COMBINED WITH RICH BOUNDARY-LAYER
MOISTURE IS RESULTING IN MLCAPE THUS FAR UP TO AROUND 1500 J/KG. 
ALTHOUGH MIDLEVEL LAPSE RATES ARE RELATIVELY WEAK...DEEP
UNIDIRECTIONAL WESTERLY FLOW FIELD WILL MAINTAIN EASTWARD MOVEMENT
INTO THE MODERATE INSTABILITY AND STEEPENING LOW-LEVEL LAPSE RATES. 
SHORT-TERM MODELS INCLUDING THE HRRR DO NOT PROVIDE CLEAR GUIDANCE
WITH THE TIMING...INTENSITY...AND/OR COVERAGE OF CONVECTIVE
DEVELOPMENT IN SOUTHERN GA TO SOUTHERN SC TODAY.  HOWEVER...BASED ON
THE OBSERVED AFOREMENTIONED DESTABILIZING ENVIRONMENT...LOCALLY
STRONG WIND GUSTS SHOULD BE THE PRIMARY THREAT...WITH NO NEED FOR
WATCH ISSUANCE.

..PETERS/CORFIDI.. 04/28/2016

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

ATTN...WFO...CHS...JAX...FFC...

LAT...LON   32808135 32938091 32558048 31878117 31338162 31378232
            31618297 32118255 32478245 32588220 32808135

Nearby

Mesoscale Discussions in Georgia, 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.