Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 361

March 25, 201213 counties in North Carolina; Horry County, Marion County, South Carolina

The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2012, 5:56 PM EDT for 13 counties in North Carolina; Horry County, Marion County, South Carolina. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Mar 25, 2012, 5:56 PM EDT (21:56 UTC)
Expired: Mar 25, 2012, 7:30 PM EDT
In force: 94 min
Issued by: the Storm Prediction Center

Counties Bladen County, NC, Brunswick County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Dare County, NC, Hyde County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Tyrrell County, NC, Washington County, NC, Horry County, SC, Marion County, SC

The radar

The Morehead City radar (KMHX), 42 km from the middle of the area, began a volume at 21:57 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, 9.9 hours before the alert went out and 42 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 234 J/kg
Mixed-layer CIN: -68 J/kg
Mixed-layer LCL: 840 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 74 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

515 
ACUS11 KWNS 252156
SWOMCD
SPC MCD 252156 
NCZ000-SCZ000-252330-

MESOSCALE DISCUSSION 0361
NWS STORM PREDICTION CENTER NORMAN OK
0456 PM CDT SUN MAR 25 2012

AREAS AFFECTED...ERN NC...NERN SC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 252156Z - 252330Z

A FEW STORMS MAY CONTINUE TO POSE A THREAT FOR MARGINALLY SVR HAIL
THROUGH 00Z ACROSS ERN NC AND NERN SC...WITH THE THREAT DECREASING
DURING THE EVENING HOURS. ANY INSTANCES OF SVR STORMS WILL BE
SPORADIC...AT MOST...AND A WW IS NOT WARRANTED.

PULSE STORMS CONTINUE BETWEEN A DIFFUSE SFC FRONT /EXTENDING FROM
THE OUTER BANKS WWD INTO PARTS OF CNTRL NC/ AND A SFC TROUGH
/EXTENDING FROM A SUB-SYNOPTIC-SCALE LOW CENTERED INVOF THE FRONT NW
OF CAPE HATTERAS SWWD ALONG THE ATLANTIC COAST/. MARGINAL
INSTABILITY OWING TO EARLIER INSOLATION...AND MODESTLY STEEP
MID-LEVEL LAPSE RATES IN CONJUNCTION WITH A MID-LEVEL COLD CORE OVER
THE AREA...WILL CONTINUE TO SUPPORT CONVECTION UNTIL NOCTURNAL
STABILIZATION STRENGTHENS. THIS ACTIVITY WILL REMAIN LARGELY
DISORGANIZED OWING TO WEAK VERTICAL SHEAR PER REGIONAL VWP DATA. THE
STRONGEST STORMS MAY BE CAPABLE OF PRODUCING BRIEF INSTANCES OF
QUARTER-SIZE HAIL ON AN ISOLATED BASIS...MAINLY OVER SERN NC AND
NERN SC. ALSO...AMBIENT VERTICAL VORTICITY IN ASSOCIATION WITH THE
AFOREMENTIONED LOW JUXTAPOSED WITH SUFFICIENT BUOYANCY MAY SUPPORT A
FEW WEAKLY ROTATING STORMS OVER E-CNTRL SECTIONS OF THE NC COASTAL
PLAIN. HOWEVER...EVEN HERE...THE MARGINAL DEGREE OF BUOYANCY IS NOT
EXPECTED TO SUPPORT ANYTHING MORE THAN MARGINALLY SVR HAIL OR
PERHAPS GUSTY SFC WINDS.

..COHEN.. 03/25/2012

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

ATTN...WFO...MHX...RAH...ILM...

LAT...LON   33887791 33587878 33687936 34137951 34797889 34967745
            35307686 35857668 35997620 35897588 35737549 35197557
            34617637 34517720 33887791

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 24, 8:43 PM EDT	Severe Thunderstorm Watch	SPC	Bladen, Columbus, Robeson	5 hr
Mar 24, 10:20 PM EDT	Mesoscale Discussion	SPC	Brunswick, Columbus, Robeson	115 min
Mar 24, 10:23 PM EDT	Mesoscale Discussion	SPC	Bertie, Edgecombe, Franklin, Greene, Halifax, Hertford and 8 more	97 min
Mar 25, 12:33 AM EDT	Mesoscale Discussion	SPC	Bladen, Brunswick, Columbus, Robeson	57 min
Mar 25, 12:31 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Carteret, Chowan and 26 more	2 hr

Nearby

Mesoscale Discussions in North Carolina, 2012 Mesoscale Discussions in South Carolina, 2012 Every 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.