Alert archive / North Carolina / Mesoscale Discussions in 2012
Mesoscale Discussion 866
The Storm Prediction Center issued this mesoscale discussion at May 22, 2012, 2:29 PM EDT for 44 counties in North Carolina; 6 counties in South Carolina; 7 counties in Virginia. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- May 22, 2012, 2:29 PM EDT (18:29 UTC)
- Expired
- May 22, 2012, 4:00 PM EDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 57 counties
Beaufort County, NC, Bertie County, NC, Bladen County, NC, Brunswick County, NC, Camden County, NC, Chatham County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Currituck County, NC, Duplin County, NC, Edgecombe County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Hyde County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Onslow County, NC, Pamlico County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Pitt County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Tyrrell County, NC, Wake County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Dillon County, SC, Georgetown County, SC, Horry County, SC, Marion County, SC, Marlboro County, SC, Williamsburg County, SC, City of Chesapeake, VA, City of Franklin, VA, City of Norfolk, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, Isle of Wight County, VA
The radar
The Raleigh/Durham radar (KRAX), 66 km from the middle of the area, began a volume at 18:31 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
Newport, NC (KMHX), launched 12:00Z, 6.5 hours before the alert went out and 110 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
- 89 J/kg
- Mixed-layer CIN
- -68 J/kg
- Mixed-layer LCL
- 747 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- -26 m²/s²
- 0-3 km storm-relative helicity
- 32 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
477
ACUS11 KWNS 221829
SWOMCD
SPC MCD 221829
NCZ000-VAZ000-SCZ000-222000-
MESOSCALE DISCUSSION 0866
NWS STORM PREDICTION CENTER NORMAN OK
0129 PM CDT TUE MAY 22 2012
AREAS AFFECTED...NERN SC...CENTRAL/ERN NC AND SERN VA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 221829Z - 222000Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...WIDESPREAD CONVECTIVE DEVELOPMENT IS EXPECTED TO PERSIST
THROUGH THE AFTERNOON ACROSS NERN SC THROUGH CENTRAL AND ERN NC INTO
SERN VA. WEAK WINDS/DEEP SHEAR ARE EXPECTED TO LIMIT OVERALL STORM
ORGANIZATION...THOUGH PW VALUES 1.3-1.5 INCH WILL PROMOTE HEAVY
RAINFALL RATES WITH SOME POTENTIAL FOR LOCALLY STRONG WIND GUSTS
ATTENDANT TO PULSE-TYPE ACTIVITY. A FEW STRONGER CORES MAY SUPPORT
AN ADDITIONAL THREAT FOR HAIL APPROACHING 1 INCH IN DIAMETER.
DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY/LIGHTNING DATA
INDICATED ONGOING WIDESPREAD TSTMS FROM NERN SC THROUGH CENTRAL/ERN
NC INTO SERN VA. A MODERATELY UNSTABLE ENVIRONMENT WILL CONTINUE TO
SUPPORT THE STORMS THROUGH THE AFTERNOON. GREATEST CONCENTRATION OF
ACTIVITY SHOULD PERSIST WITHIN A ZONE OF WEAK LOW LEVEL CONVERGENCE
EXTENDING SWWD FROM SERN VA THROUGH ERN NC. INTERMITTENT STRONGER
CORES HAVE OCCURRED OVER NERN SC INTO SERN NC ATTENDANT TO UPWARD
VERTICAL MOTION ALONG THE TRACK OF AN UPPER VORT...PER WATER VAPOR
IMAGERY...TRACKING NNEWD ALONG THE SRN NC COAST. THE FORCING FOR
ASCENT WITH THIS FEATURE SHOULD SUPPORT ADDITIONAL SUSTAINED
UPDRAFTS...BUT WEAK DEEP LAYER WIND FIELDS SUGGEST STORM
ORGANIZATION SHOULD BE LIMITED...RESULTING IN A LOW PROBABILITY FOR
WATCH ISSUANCE.
..PETERS/WEISS.. 05/22/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...MHX...RAH...ILM...GSP...
LAT...LON 37067652 36917595 36017564 35087626 34647697 34287781
33787866 33337926 33407977 34277959 34917988 35508019
35897867 36287772 36757692 37067652SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 22, 1:46 PM EDT | Mesoscale Discussion | SPC | Abbeville, Edgefield, McCormick | 59 min |
| May 22, 3:32 PM EDT | Severe Thunderstorm Watch | SPC | Allendale, Beaufort, Berkeley, Charleston, Colleton, Dorchester and 2 more | 5 hr |
| May 22, 6:58 PM EDT | Mesoscale Discussion | SPC | Beaufort, Berkeley, Charleston, Clarendon, Colleton, Dorchester and 2 more | 62 min |
Nearby
Mesoscale Discussions in North Carolina, 2012Mesoscale Discussions in Virginia, 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.