Alert archive / Georgia / Mesoscale Discussions in 2012
Mesoscale Discussion 1646
The Storm Prediction Center issued this mesoscale discussion at Jul 29, 2012, 6:36 PM EDT for 18 counties in Georgia; 8 counties in South Carolina. It was in force for 24 min.
The area
The outline as issued.
The facts
- Issued
- Jul 29, 2012, 6:36 PM EDT (22:36 UTC)
- Expired
- Jul 29, 2012, 7:00 PM EDT
- In force
- 24 min
- Issued by
- the Storm Prediction Center
All 26 counties
Appling County, GA, Bacon County, GA, Brantley County, GA, Bryan County, GA, Bulloch County, GA, Camden County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Glynn County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Pierce County, GA, Screven County, GA, Tattnall County, GA, Ware County, GA, Wayne County, GA, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dorchester County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC
The radar
The Charleston,SC radar (KCLX), 81 km from the middle of the area, began a volume at 22:36 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, 10.6 hours before the alert went out and 156 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
- 2597 J/kg
- Mixed-layer CIN
- -47 J/kg
- Mixed-layer LCL
- 738 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 63 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
498 ACUS11 KWNS 292236 SWOMCD SPC MCD 292236 SCZ000-GAZ000-292300- MESOSCALE DISCUSSION 1646 NWS STORM PREDICTION CENTER NORMAN OK 0536 PM CDT SUN JUL 29 2012 AREAS AFFECTED...COASTAL SC-GA CONCERNING...SEVERE THUNDERSTORM WATCH 538... VALID 292236Z - 292300Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 538 CONTINUES. SUMMARY...THE SEVERE THREAT HAS LARGELY DIMINISHED ACROSS THE WATCH AREA. AN ISOLD DMGG WIND GUST REMAINS POSSIBLE OVER FAR SERN GA. DISCUSSION...SURFACE ANALYSIS AND RADAR COMPOSITE SHOW THE DISCUSSION AREA HAS CONVECTIVELY OVERTURNED WITH THE BOUNDARY LAYER STABILIZING AS TEMPS HAVE FALLEN INTO THE 70S AND LOWER 80S. ARCING OUTFLOW BOUNDARIES HAVE RADIATED OUTWARD FROM THE COASTAL PLAIN...EFFECTIVELY DIMINISHING ANY REMAINING SEVERE WIND GUST THREAT...EXCEPT IN FAR SERN GA WHERE A SLOW MOVING STORM CLUSTER MAY CONTINUE TO POSE AN ISOLD DMGG WIND HAZARD FOR ANOTHER HR OR SO. OTHERWISE...SEVERE THUNDERSTORM WATCH 538 CAN BE ALLOWED TO BE CANCELLED EARLY. ..SMITH/MEAD.. 07/29/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILM...CHS...CAE...JAX...FFC... LAT...LON 31448105 30878169 31088285 32818179 33987880 31448105
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 29, 2:35 PM EDT | Mesoscale Discussion | SPC | Appling, Atkinson, Bacon, Ben Hill, Berrien, Bleckley and 47 more | 55 min |
| Jul 29, 2:55 PM EDT | Severe Thunderstorm Watch | SPC | Appling, Atkinson, Bacon, Bleckley, Bryan, Bulloch and 25 more | 5 hr |
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.