Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 719

May 5, 201228 counties in North Carolina; 8 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 5, 2012, 6:20 PM EDT for 28 counties in North Carolina; 8 counties in South Carolina. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 5, 2012, 6:20 PM EDT (22:20 UTC)
Expired
May 5, 2012, 7:15 PM EDT
In force
55 min
Issued by
the Storm Prediction Center
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), 93 km from the middle of the area, began a volume at 22:23 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, 10.3 hours before the alert went out and 142 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.

Skew-T log-pSkew-T log-p diagram, Newport, NC at 12:00Z on 2012-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 918 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Newport, NC at 12:00Z on 2012-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
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

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

623 
ACUS11 KWNS 052221
SWOMCD
SPC MCD 052220
NCZ000-SCZ000-052315-

MESOSCALE DISCUSSION 0719
NWS STORM PREDICTION CENTER NORMAN OK
0520 PM CDT SAT MAY 05 2012

AREAS AFFECTED...ERN NC/SC

CONCERNING...SEVERE THUNDERSTORM WATCH 249...

VALID 052220Z - 052315Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 249
CONTINUES.

SUMMARY...THUNDERSTORMS CAPABLE OF DMGG WINDS AND HAIL CONTINUE TO
PROGRESS INTO THE WW AREA. ADDITIONAL STORMS ARE DEVELOPING ALONG
SEVERAL BOUNDARIES.

DISCUSSION...IT APPEARS AS THOUGH EARLIER MIXING HAS LOWERED DEW
POINTS ACROSS MUCH OF THE AREA...GENERALLY LIMITING A MORE POTENTIAL
SEVERE THREAT THUS FAR. HOWEVER...A CLUSTER OF THUNDERSTORMS IS
PROGRESSING INTO THE WW AREA OVER ERN NC. ADDITIONAL STORMS ARE
DEVELOPING ALONG THE OUTFLOW BOUNDARY AHEAD OF THESE STORMS...AND
ALONG A WEAK SURFACE TROUGH THROUGH SC. THESE STORMS MAY BECOME
STRONG TO SEVERE AS THEY APPROACH THE COAST WHERE GREATER
INSTABILITY IS LINGERING. GIVEN A SUBTLE STRENGTHENING IN EFFECTIVE
SHEAR /CURRENTLY ABOUT 30-35 KTS PER SFCOA/...AT LEAST WEAK
ORGANIZATION OF ONGOING/DEVELOPING CONVECTION REMAINS POSSIBLE.

..HURLBUT.. 05/05/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MHX...RAH...ILM...CHS...CAE...

LAT...LON   32967893 33528002 33947994 34348022 34577988 34797992
            34857969 35157949 35557898 35867889 36297836 36027739
            35827731 35697702 35637656 35357654 34917647 34587646
            33817775 32967893

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 5, 1:30 PM EDTMesoscale DiscussionSPCAnson, Bertie, Bladen, Chatham, Columbus, Cumberland and 28 more2 hr
May 5, 2:38 PM EDTSevere Thunderstorm WatchSPCBeaufort, Bladen, Brunswick, Carteret, Columbus, Craven and 22 more7 hr

Nearby

Mesoscale Discussions in North Carolina, 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.