Alert archive / North Carolina / Mesoscale Discussions in 2012
Mesoscale Discussion 648
The Storm Prediction Center issued this mesoscale discussion at May 1, 2012, 5:49 PM EDT for 27 counties in North Carolina; 7 counties in Virginia. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- May 1, 2012, 5:49 PM EDT (21:49 UTC)
- Expired
- May 1, 2012, 7:15 PM EDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 60%
All 34 counties
Beaufort County, NC, Bertie County, NC, Camden County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Hertford County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, City of Chesapeake, VA, City of Franklin, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, Isle of Wight County, VA, Southampton County, VA
The radar
The Morehead City radar (KMHX), 118 km from the middle of the area, began a volume at 21:49 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, 9.8 hours before the alert went out and 118 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
- 498 J/kg
- Mixed-layer CIN
- -39 J/kg
- Mixed-layer LCL
- 564 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 141 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.0
The text
As transmitted, in the capitals the NWS used until 2016.
515
ACUS11 KWNS 012150
SWOMCD
SPC MCD 012149
NCZ000-VAZ000-012315-
MESOSCALE DISCUSSION 0648
NWS STORM PREDICTION CENTER NORMAN OK
0449 PM CDT TUE MAY 01 2012
AREAS AFFECTED...SERN VA...ERN NC
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 012149Z - 012315Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...THUNDERSTORM CLUSTERS ARE FORECAST TO MOVE INTO SERN VA
AND ERN NC THROUGH THE EVENING. LARGE HAIL AND DAMAGING WIND GUSTS
WILL BE POSSIBLE. AREA IS BEING MONITORED FOR A WW.
DISCUSSION...AT 2145Z...A CLUSTER OF STRONG TO SEVERE THUNDERSTORMS
WAS LOCATED OVER SRN VA AND NRN NC. AIRMASS AHEAD OF THIS CONVECTION
IS MODERATELY UNSTABLE...WITH TEMPERATURES IN THE 80S...DEWPOINTS IN
THE LOW TO MID 60S...AND MLCAPE VALUES AROUND 1000 J/KG. THIS
ENVIRONMENT SHOULD FAVOR STORM PERSISTENCE AS ACTIVITY MOVES INTO
SERN VA AND ERN NC. GIVEN THE PRESENCE EFFECTIVE BULK WIND
DIFFERENCE NEAR 30 KT...SVR MULTICELL THUNDERSTORMS WILL BE
POSSIBLE...POSING A THREAT FOR LARGE HAIL AND DAMAGING WIND GUSTS.
..GARNER/CORFIDI.. 05/01/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...MHX...RAH...
LAT...LON 35717567 35077621 34947715 35327827 36087841 37037706
36837602 35717567SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 1, 12:43 PM EDT | Mesoscale Discussion | SPC | Alexander, Alleghany, Ashe, Avery, Burke, Caldwell and 13 more | 2 hr |
| May 1, 3:12 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Alexander, Bertie, Burke, Caldwell, Caswell and 34 more | 5 hr |
Nearby
Mesoscale Discussions in North Carolina, 2012Mesoscale Discussions in Virginia, 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.