Alert archive / Georgia / Mesoscale Discussions in 2012
Mesoscale Discussion 769
The Storm Prediction Center issued this mesoscale discussion at May 9, 2012, 7:04 PM EDT for 6 counties in Georgia; Beaufort County, Jasper County, South Carolina. It was in force for 26 min.
The area
The outline as issued.
The facts
- Issued
- May 9, 2012, 7:04 PM EDT (23:04 UTC)
- Expired
- May 9, 2012, 7:30 PM EDT
- In force
- 26 min
- Issued by
- the Storm Prediction Center
Counties Bryan County, GA, Chatham County, GA, Effingham County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Beaufort County, SC, Jasper County, SC
The radar
The Charleston,SC radar (KCLX), 59 km from the middle of the area, began a volume at 23:06 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, 11.1 hours before the alert went out and 139 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
- 484 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 666 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 39 m²/s²
- 0-3 km storm-relative helicity
- 50 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
559
ACUS11 KWNS 092304
SWOMCD
SPC MCD 092304
SCZ000-GAZ000-092330-
MESOSCALE DISCUSSION 0769
NWS STORM PREDICTION CENTER NORMAN OK
0604 PM CDT WED MAY 09 2012
AREAS AFFECTED...PORTIONS OF SRN SC...SERN GA
CONCERNING...SEVERE THUNDERSTORM WATCH 269...
VALID 092304Z - 092330Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 269
CONTINUES.
SUMMARY...THE SVR THREAT IS DIMINISHING ACROSS REMAINING VALID
PORTIONS OF WW269...AND THE WW SHOULD BE ALLOWED TO EXPIRE BY 01Z.
DISCUSSION...A DISORGANIZED BAND OF CONVECTION INVOF A
NE-SW-ORIENTED SFC COLD FRONT CROSSING THE REGION WILL POSE A THREAT
FOR STRONG WIND GUSTS...AND PERHAPS A MARGINALLY SVR WIND GUST...AS
IT APPROACHES THE COAST. AIR MASS RECOVERY IN THE WAKE OF CONVECTION
THAT EARLIER MOVED OFF THE COAST HAS BEEN VERY LIMITED...AND INFLOW
INTO ONGOING INLAND CONVECTION IS ONLY MARGINALLY UNSTABLE.
HOWEVER...WITH 33 KT OF 0-6-KM BULK SHEAR PER CHARLESTON SC VWP
DATA...OCCASIONALLY ORGANIZED STORM STRUCTURES MAY ENSUE DURING THE
NEXT HOUR PRIOR TO CONVECTION MOVING OFF THE COAST. HOWEVER...THE
LACK OF MORE APPRECIABLE BUOYANCY...AND THE DEVELOPMENT OF THE
NOCTURNAL BOUNDARY LAYER...WILL LIKELY YIELD A DOWNWARD TREND IN
CONVECTIVE INTENSITY.
..COHEN.. 05/09/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CHS...JAX...
LAT...LON 32638101 32428041 31918060 31428125 31578171 32098183
32408153 32638101SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 11:32 AM EDT | Mesoscale Discussion | SPC | Burke, Richmond | 88 min |
| May 9, 12:59 PM EDT | Mesoscale Discussion | SPC | Appling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 49 more | 2 hr |
| May 9, 2:00 PM EDT | Severe Thunderstorm Watch | SPC | Bryan, Bulloch, Candler, Chatham, Effingham, Evans and 4 more | 5 hr |
| May 9, 4:54 PM EDT | Mesoscale Discussion | SPC | Bryan, Chatham, Liberty, Long, McIntosh, Wayne | 96 min |
| May 9, 6:01 PM EDT | Mesoscale Discussion | SPC | Atkinson, Bacon, Brantley, Brooks, Camden, Charlton and 6 more | 89 min |
Nearby
Mesoscale Discussions in Georgia, 2012Mesoscale Discussions in South Carolina, 2012Every mesoscale discussion in 2012
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.