Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 808

May 14, 201213 counties in North Carolina; 7 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 14, 2012, 2:30 PM EDT for 13 counties in North Carolina; 7 counties in South Carolina. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
May 14, 2012, 2:30 PM EDT (18:30 UTC)
Expired
May 14, 2012, 3:30 PM EDT
In force
60 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Bladen County, NC, Brunswick County, NC, Columbus County, NC, Cumberland County, NC, Duplin County, NC, Jones County, NC, Lenoir County, NC, New Hanover County, NC, Onslow County, NC, Pender County, NC, Robeson County, NC, Sampson County, NC, Wayne County, NC, Berkeley County, SC, Charleston County, SC, Dillon County, SC, Georgetown County, SC, Horry County, SC, Marion County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 60 km from the middle of the area, began a volume at 18:30 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

Charleston AFB, SC (KCHS), launched 12:00Z, 6.5 hours before the alert went out and 137 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, Charleston AFB, SC at 12:00Z on 2012-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 518 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, Charleston AFB, SC at 12:00Z on 2012-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 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
518 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
722 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

101 
ACUS11 KWNS 141831
SWOMCD
SPC MCD 141830
NCZ000-SCZ000-141930-

MESOSCALE DISCUSSION 0808
NWS STORM PREDICTION CENTER NORMAN OK
0130 PM CDT MON MAY 14 2012

AREAS AFFECTED...NC/SC COASTAL PLAIN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 141830Z - 141930Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLD DMGG WIND RISK WILL MOVE EWD AS THE BROKEN TSTM LINE
ADVANCES TOWARDS THE COAST THIS AFTERNOON.

DISCUSSION...RADAR/SURFACE ANALYSIS PLACES A BROKEN LINE OF TSTMS
NEAR THE I-95 CORRIDOR WITH THE AIRMASS CONTINUING TO
WARM/DESTABILIZE AS TEMPS WARM TO AROUND 80 DEG F AHEAD OF IT.  LOW
LEVEL LAPSE RATES IN TURN HAVE STEEPENED CONSIDERABLY /7-8 DEG C PER
KM/ IN THE 0-3 KM LAYER -- BECOMING MORE FAVORABLE FOR ISOLD POCKETS
OF STRONG TO LOWER-END SEVERE WIND GUSTS.  KCLX AND KCAE VAD SHOW
0-6 KM SHEAR RANGING FROM 25-35 KTS...SUPPORTIVE PRIMARILY OF
MULTICELLS/BOWING SEGMENTS WITH OCCASIONAL TRANSIENT SUPERCELL
STRUCTURE...AS THE STORM CONGLOMERATION PUSHES TOWARDS THE COAST AT
25 KTS.

..SMITH/HART.. 05/14/2012

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

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

LAT...LON   32588054 35457870 35417715 34507734 32578008 32588054

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 14, 6:14 PM EDTMesoscale DiscussionSPCAlexander, Burke, Cabarrus, Caldwell, Catawba, Cleveland and 13 more61 min

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.