Alert archive / South Carolina / Mesoscale Discussions in 2012
Mesoscale Discussion 2229
The Storm Prediction Center issued this mesoscale discussion at Dec 26, 2012, 6:20 AM EST for Brunswick County, Columbus County, New Hanover County, North Carolina; 5 counties in South Carolina. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Dec 26, 2012, 6:20 AM EST (11:20 UTC)
- Expired
- Dec 26, 2012, 7:45 AM EST
- In force
- 85 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Brunswick County, NC, Columbus County, NC, New Hanover County, NC, Berkeley County, SC, Charleston County, SC, Georgetown County, SC, Horry County, SC, Williamsburg County, SC
The radar
The Wilmington radar (KLTX), 65 km from the middle of the area, began a volume at 11:22 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Charleston AFB, SC (KCHS), launched 00:00Z, 11.3 hours before the alert went out and 129 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
- 44 J/kg
- Mixed-layer CIN
- -71 J/kg
- Mixed-layer LCL
- 560 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 237 m²/s²
- 0-3 km storm-relative helicity
- 387 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
232
ACUS11 KWNS 261121
SWOMCD
SPC MCD 261120
NCZ000-SCZ000-261245-
MESOSCALE DISCUSSION 2229
NWS STORM PREDICTION CENTER NORMAN OK
0520 AM CST WED DEC 26 2012
AREAS AFFECTED...COASTAL SECTIONS OF NERN SC AND EXTREME SRN NC
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 261120Z - 261245Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...TSTMS OFFSHORE S OF THE SRN NC COAST WERE SHOWING
OCCASIONAL SIGNS OF ORGANIZATION/TRANSIENT ROTATION WHILE MOVING NWD
WITHIN A WARM FRONTAL ZONE. THESE TSTMS MAY EXHIBIT ORGANIZATION
WHILE APCHG THE COAST OVER THE NEXT FEW HOURS. A WW IS NOT
ANTICIPATED IN THE SHORT TERM HOWEVER CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED.
DISCUSSION...TSTMS LOCATED JUST OFFSHORE OF THE NC/SC COASTS WERE
MOVG NWD AND INTERACTING WITH A WARM FRONT THAT EXTENDED FROM JUST
SOUTH OF ILM TO NEAR MYR AND OGB. THE ENVIRONMENT ALONG AND JUST
NORTH OF THE WARM-FRONTAL ZONE IS CHARACTERIZED BY A LOCAL INCREASE
IN 0-1 KM SRH TO OVER 500 M2/S2 AS SAMPLED BY THE KILM AND KLTX
VWPS. TSTMS WITHIN THE WARM FRONTAL ZONE HAVE SHOWN OCCASIONAL
SIGNS OF ROTATION AND THIS TREND MAY CONTINUE FOR THE NEXT FEW HOURS
AS THESE STORMS APCH THE COAST. LATEST MESOANALYSIS REVEALS AN
INSTABILITY GRADIENT ALONG THE COAST WITH MUCAPES RANGING FROM
500-1000 J/KG ALONG AND SOUTH OF THE WARM FRONT TO AROUND 100 J/KG
INLAND. AS A RESULT...STORMS MAY CONTINUE TO EXHIBIT OCCASIONAL
ROTATION WHILE APCHG THE COAST BUT SHOULD WEAKEN WITH NWD MOVEMENT
ONSHORE. LATER THIS MORNING AS THE WARM FRONT CONTINUES TO MOVE
NWD...THE THREAT FOR SUPERCELL STRUCTURES MAY INCREASE FARTHER
INLAND. WHILE A WW IS NOT ANTICIPATED IN THE SHORT TERM...CONVECTIVE
TRENDS WILL CONTINUE TO BE MONITORED.
..BUNTING/MEAD.. 12/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MHX...ILM...CHS...
LAT...LON 32248001 32998021 33797962 34237892 34537761 34487742
34117733 33537789 32787901 32248001SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 26, 8:07 AM EST | Mesoscale Discussion | SPC | Anson, Beaufort, Bladen, Brunswick, Carteret, Columbus and 24 more | 83 min |
| Dec 26, 10:08 AM EST | Tornado Watch | SPC | Beaufort, Bladen, Brunswick, Carteret, Columbus, Craven and 23 more | 6 hr |
| Dec 26, 2:20 PM EST | Mesoscale Discussion | SPC | Beaufort, Bladen, Brunswick, Carteret, Columbus, Craven and 19 more | 85 min |
| Dec 26, 6:11 PM EST | Mesoscale Discussion | SPC | Beaufort, Bertie, Camden, Chowan, Currituck, Dare and 12 more | 2 hr |
Nearby
Mesoscale Discussions in South Carolina, 2012Mesoscale Discussions in North 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.