Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 823

May 16, 201220 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at May 16, 2012, 12:24 PM EDT for 20 counties in North Carolina. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
May 16, 2012, 12:24 PM EDT (16:24 UTC)
Expired
May 16, 2012, 1:30 PM EDT
In force
66 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Beaufort County, NC, Bladen County, NC, Brunswick County, NC, Camden County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Dare County, NC, Duplin County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Tyrrell County, NC, Washington County, NC

The radar

The Morehead City radar (KMHX), 50 km from the middle of the area, began a volume at 16:29 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, 4.4 hours before the alert went out and 49 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 2012-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2326 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 2012-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 square meters per square second.193958Sfc1 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
2326 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
531 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

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

463 
ACUS11 KWNS 161624
SWOMCD
SPC MCD 161624 
NCZ000-161730-

MESOSCALE DISCUSSION 0823
NWS STORM PREDICTION CENTER NORMAN OK
1124 AM CDT WED MAY 16 2012

AREAS AFFECTED...ERN NC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 161624Z - 161730Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLD WET MICROBURST OR TWO IS POSSIBLE THIS AFTERNOON
AS SCTD TSTMS CONTINUE TO DEVELOP NEAR THE COAST ON SEA BREEZE
BOUNDARIES.

DISCUSSION...LATE MORNING VISIBLE SATELLITE IMAGERY AND LIGHTNING
DATA SHOW SCTD STORMS DEVELOPING FROM THE SC GRAND STRAND NEWD TO
CAPE LOOKOUT WITHIN AN AGITATED CU FIELD.  THE 12Z MHX RAOB
EXHIBITED STRONG POTENTIAL INSTABILITY /2500 J/KG MLCAPE/...AND THE
RAOB/S CONVECTIVE TEMP /77 DEG/ HAS ALREADY BEEN BREACHED AS 16Z
SURFACE OBS RISE INTO THE LOWER 80S.  FURTHER CONVECTIVE-SCALE
COLLISIONS AND SEA BREEZE BOUNDARY CIRCULATIONS WILL PROVIDE
SUFFICIENT FOCUS/LIFT TO CONTINUALLY GENERATE STORMS THROUGH THE
AFTERNOON AS STORMS MOVE NEWD AROUND 25 KTS.  A DEEP/MOISTURE RICH
TROPOSPHERIC PROFILE WITHIN MODEST SWLY FLOW ALOFT WILL FAVOR ISOLD
WET MICROBURSTS WITH THE STRONGER STORMS.  AN ADDITIONAL RISK
/LOW-ISOLD/ FOR MARGINALLY SEVERE HAIL MAY ACCOMPANY THE STRONGER
UPDRAFTS AS WELL.  THE LIMITED SPATIAL/MAGNITUDE OF THE THREAT WILL
PRECLUDE THE NEED FOR A SEVERE WATCH.

..SMITH/HART.. 05/16/2012

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

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

LAT...LON   34357888 36397623 36057520 35207540 33887848 34047874
            34357888

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 8:42 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Anson, Bladen, Brunswick, Burke and 47 more63 min

Nearby

Mesoscale Discussions in North 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.