Alert archive / North Carolina / Mesoscale Discussions in 2012
Mesoscale Discussion 1963
The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2012, 1:21 PM EDT for 31 counties in North Carolina. It was in force for 84 min.
The area
The outline as issued.
The facts
- Issued
- Sep 18, 2012, 1:21 PM EDT (17:21 UTC)
- Expired
- Sep 18, 2012, 2:45 PM EDT
- In force
- 84 min
- Issued by
- the Storm Prediction Center
All 31 counties
Alamance County, NC, Anson County, NC, Chatham County, NC, Cumberland County, NC, Davidson County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC
The radar
The Raleigh/Durham radar (KRAX), 48 km from the middle of the area, began a volume at 17:24 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
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 5.4 hours before the alert went out and 104 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
- 533 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 545 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 221 m²/s²
- 0-3 km storm-relative helicity
- 313 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 4.1
The text
As transmitted, in the capitals the NWS used until 2016.
759
ACUS11 KWNS 181722
SWOMCD
SPC MCD 181721
NCZ000-VAZ000-SCZ000-181845-
MESOSCALE DISCUSSION 1963
NWS STORM PREDICTION CENTER NORMAN OK
1221 PM CDT TUE SEP 18 2012
AREAS AFFECTED...CNTRL NC
CONCERNING...SEVERE THUNDERSTORM WATCH 641...
VALID 181721Z - 181845Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 641
CONTINUES.
SUMMARY...THE SEVERE THREAT IS INCREASING ACROSS WW 641 AS CELLS
INTENSIFY AND MOVE NEWD ACROSS THE WATCH. A THREAT WILL EXIST FOR
TORNADOES AND WIND DAMAGE ESPECIALLY AS THE STORMS CONTINUE TO
ORGANIZE OVER THE NEXT HOUR OR TWO.
DISCUSSION...SCATTERED THUNDERSTORMS ARE ONGOING ACROSS WW 641
LOCATED ON THE NWRN EDGE OF MODERATE INSTABILITY WITH MESOANALYSIS
ESTIMATING MLCAPE VALUES IN THE 1000 TO 1500 J/KG RANGE. THIS
COMBINED WITH A MOIST BOUNDARY LAYER WITH SFC DEWPOINTS IN THE LOWER
TO MID 70S F...LCL HEIGHTS BELOW 500 METERS AND STRONG LOW-LEVEL
SHEAR PROFILES AS EVIDENCED ON THE RALEIGH WSR-88D VWP WILL BE
FAVORABLE FOR ROTATING STORMS AND POSSIBLY A FEW TORNADOES. SFC
TEMPS ARE NOW AROUND 80 F AND SHOULD CONTINUE TO WARM HELPING TO
STEEP LOW-LEVEL LAPSE RATES A BIT. THIS MAY ALLOW THE WIND DAMAGE
THREAT TO INCREASE ESPECIALLY IF A LINE SEGMENT CAN ORGANIZE ACROSS
THE WATCH AREA.
..BROYLES.. 09/18/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...CAE...GSP...
LAT...LON 34627946 34807966 34808029 35228024 35168041 35218050
35518027 35488013 35728037 35838047 35908033 36038043
36118048 36238039 36227915 36547912 36547783 36487783
36477765 36377752 36327757 36317745 36127725 36017738
35857733 35607779 35187785 35207812 34747819 34697812
34567824 34877851 34837889 34957897 34867913 34857932
34757931 34627946SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 17, 8:14 PM EDT | Mesoscale Discussion | SPC | Cherokee, Clay, Graham, Haywood, Henderson, Jackson and 4 more | 2 hr |
| Sep 18, 12:23 AM EDT | Mesoscale Discussion | SPC | Alexander, Buncombe, Burke, Cabarrus, Caldwell, Catawba and 14 more | 97 min |
| Sep 18, 8:49 AM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Caswell, Chatham, Cumberland, Davidson and 31 more | 116 min |
| Sep 18, 9:45 AM EDT | Tornado Watch | SPC | Alamance, Anson, Chatham, Cumberland, Davidson, Durham and 25 more | 8 hr |
| Sep 18, 10:54 AM EDT | Tornado Watch | SPC | Bertie, Camden, Caswell, Chowan, Currituck, Gates and 4 more | 9 hr |
| Sep 18, 11:19 AM EDT | Mesoscale Discussion | SPC | Alamance, Caswell, Chatham, Cumberland, Durham, Edgecombe and 27 more | 86 min |
| Sep 18, 11:35 AM EDT | Mesoscale Discussion | SPC | Union | 85 min |
| Sep 18, 1:00 PM EDT | Tornado Watch | SPC | Beaufort, Carteret, Craven, Dare, Duplin, Greene and 9 more | 5 hr |
| Sep 18, 1:27 PM EDT | Mesoscale Discussion | SPC | Camden, Chowan, Currituck, Gates, Hertford, Northampton and 2 more | 63 min |
| Sep 18, 3:52 PM EDT | Mesoscale Discussion | SPC | Bertie, Camden, Chowan, Gates, Hertford, Northampton and 2 more | 113 min |
| Sep 18, 4:11 PM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Beaufort, Carteret, Chatham, Craven and 40 more | 94 min |
| Sep 18, 6:15 PM EDT | Mesoscale Discussion | SPC | Camden, Carteret, Chowan, Currituck, Dare, Gates and 5 more | 30 min |
Nearby
Mesoscale 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.