Alert archive / North Carolina / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 249
The Storm Prediction Center issued this severe thunderstorm watch at May 5, 2012, 2:38 PM EDT for 28 counties in North Carolina; 8 counties in South Carolina. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- May 5, 2012, 2:38 PM EDT (18:38 UTC)
- Expired
- May 5, 2012, 10:00 PM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 36 counties
Beaufort County, NC, Bladen County, NC, Brunswick County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Duplin County, NC, Edgecombe County, NC, Franklin County, NC, Greene County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Jones County, NC, Lenoir County, NC, Nash County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Pitt County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC, Darlington County, SC, Dillon County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Marion County, SC, Marlboro County, SC, Williamsburg County, SC
The radar
The Raleigh/Durham radar (KRAX), 81 km from the middle of the area, began a volume at 18:38 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 5, 6:53 PM EDT | Severe Thunderstorm Warning | RAH | Johnston, Wayne, Wilson | 67 min |
| May 5, 7:33 PM EDT | Severe Thunderstorm Warning | MHX | Duplin, Greene, Lenoir | 27 min |
| May 5, 8:00 PM EDT | Severe Thunderstorm Warning | MHX | Craven, Duplin, Greene, Jones, Lenoir, Onslow and 1 more | 45 min |
| May 5, 8:48 PM EDT | Severe Thunderstorm Warning | ILM | Florence, Georgetown, Horry, Marion, Williamsburg | 57 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Newport, NC (KMHX), launched 12:00Z, 6.6 hours before the alert went out and 132 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
- 918 J/kg
- Mixed-layer CIN
- -65 J/kg
- Mixed-layer LCL
- 976 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 45 m²/s²
- 0-3 km storm-relative helicity
- 57 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
148
WWUS20 KWNS 051836
SEL9
SPC WW 051836
NCZ000-SCZ000-CWZ000-060200-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 249
NWS STORM PREDICTION CENTER NORMAN OK
240 PM EDT SAT MAY 5 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
CENTRAL AND EASTERN NORTH CAROLINA
NORTHEAST SOUTH CAROLINA
COASTAL WATERS
EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 240 PM UNTIL
1000 PM EDT.
HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50
STATUTE MILES EITHER SIDE OF A LINE FROM 35 MILES NORTH OF NEW
BERN NORTH CAROLINA TO 35 MILES SOUTH SOUTHWEST OF FLORENCE SOUTH
CAROLINA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
OTHER WATCH INFORMATION...CONTINUE...WW 248...
DISCUSSION...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND
INTENSITY THIS AFTERNOON AHEAD OF A MIDLEVEL VORTICITY MAXIMUM
TRANSLATING SEWD ACROSS THE REGION. AMBIENT AIR MASS HAS BECOME HOT
AND MODERATELY UNSTABLE THIS AFTERNOON WITH MLCAPE VALUES UPWARDS OF
1000-2000 J/KG. THIS INSTABILITY COMBINED WITH GRADUALLY
STRENGTHENING DEEP-LAYER FLOW ATTENDANT TO IMPULSE WILL SUPPORT
MULTICELL CLUSTERS AND LINE SEGMENTS CAPABLE OF DAMAGING WINDS AND
HAIL.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 29020.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 5, 1:30 PM EDT | Mesoscale Discussion | SPC | Anson, Bertie, Bladen, Chatham, Columbus, Cumberland and 28 more | 2 hr |
| May 5, 6:20 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bladen, Brunswick, Carteret, Columbus, Craven and 22 more | 55 min |
Nearby
Severe Thunderstorm Watches in North Carolina, 2012Severe Thunderstorm Watches in South Carolina, 2012Every severe thunderstorm watch 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.