Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 359

March 25, 201232 counties in North Carolina; 4 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2012, 12:31 PM EDT for 32 counties in North Carolina; 4 counties in South Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Mar 25, 2012, 12:31 PM EDT (16:31 UTC)
Expired: Mar 25, 2012, 3:00 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 36 counties

Beaufort County, NC, Bertie County, NC, Bladen County, NC, Brunswick County, NC, Carteret County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Dare County, NC, Duplin County, NC, Edgecombe County, NC, Greene County, NC, Harnett County, NC, Hoke County, NC, Hyde County, NC, Johnston County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Perquimans County, NC, Pitt County, NC, Robeson County, NC, Sampson County, NC, Tyrrell County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Dillon County, SC, Florence County, SC, Horry County, SC, Marion County, SC

The radar

The Morehead City radar (KMHX), 99 km from the middle of the area, began a volume at 16:33 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, 4.5 hours before the alert went out and 98 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.

177 
ACUS11 KWNS 251632
SWOMCD
SPC MCD 251631
NCZ000-SCZ000-251900-

MESOSCALE DISCUSSION 0359
NWS STORM PREDICTION CENTER NORMAN OK
1131 AM CDT SUN MAR 25 2012

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

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 251631Z - 251900Z

SCATTERED TSTMS SHOULD DEVELOP FROM NERN SC INTO ERN NC THIS
AFTERNOON. DESPITE WEAK SHEAR...MODERATELY STEEP MID-LEVEL LAPSE
RATES WILL SUPPORT A RISK OF MARGINALLY SEVERE HAIL IN PULSE TO
LOOSELY ORGANIZED MULTICELL CLUSTERS. THE PROBABILITY OF A SEVERE
TSTM WATCH ISSUANCE IS 20 PERCENT.

16Z SURFACE ANALYSIS PLACED A 1006 MB CYCLONE AROUND 35 NE FLO.
LOW/MID-LEVEL CIRCULATION IMMEDIATELY W IN THE PEE DEE REGION WAS
QUITE APPARENT IN VISIBLE SATELLITE IMAGERY WITH THIS FEATURE
EXPECTED TO TRACK NEAR THE NC/SC BORDER DURING THE AFTERNOON.
ISOLATED SHOWERS AND A THUNDERSTORM HAVE FORMED INVOF THIS
CIRCULATION...WITH ADDITIONAL AREAS OF AGITATED CU ACROSS ERN NC.
CONVECTION-ALLOWING AND SREF MODEL GUIDANCE ARE CONSISTENT IN
INCREASING TSTM COVERAGE THROUGH THE DAY AS SURFACE HEATING
CONTINUES...CONTRIBUTING TO POCKETS OF MLCAPE REACHING 600-1200
J/KG.

MID-LEVEL LAPSE RATES AROUND 7 DEG C/KM WILL SUPPORT A RISK FOR
HAIL. BUT FLOW FIELDS WILL REMAIN VERY WEAK INVOF THE MID-LEVEL LOW
WITH EFFECTIVE SHEAR AOB 10 KTS. STRONGER SLYS AOA 600 MB SHOULD BE
CONFINED TO COASTAL NC. AS SUCH...PULSE CONVECTION WILL BE THE
DOMINANT MODE NEAR THE CIRCULATION CENTER WITH PRIMARILY SUB-SEVERE
HAIL...WITH A GREATER RISK FOR A FEW MARGINALLY SEVERE EVENTS INTO
FAR ERN NC.

..GRAMS.. 03/25/2012

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

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

LAT...LON   34117981 34647959 35207914 35577865 36187717 36197637
            36007581 35687533 35197535 34537645 33787801 33567877
            33547936 33797972 34117981

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, 5:56 PM EDT	Mesoscale Discussion	SPC	Bladen, Brunswick, Carteret, Columbus, Craven, Dare and 7 more	94 min

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.