Alert archive / North Carolina / Mesoscale Discussions in 2004

Mesoscale Discussion 2148

August 29, 200424 counties in North Carolina; 5 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Aug 29, 2004, 9:13 PM EDT for 24 counties in North Carolina; 5 counties in South Carolina. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Aug 29, 2004, 9:13 PM EDT (01:13 UTC)
Expired
Aug 29, 2004, 10:45 PM EDT
In force
92 min
Issued by
the Storm Prediction Center
All 29 counties

Bladen County, NC, Brunswick County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Duplin County, NC, Franklin County, NC, Greene County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Nash County, NC, New Hanover County, NC, Onslow County, NC, Pender County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC, Chesterfield County, SC, Dillon County, SC, Horry County, SC, Marion County, SC, Marlboro County, SC

The radar

The Wilmington radar (KLTX), 55 km from the middle of the area, began a volume at 01:14 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 00:00Z, 1.2 hours before the alert went out and 152 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 00:00Z on 2004-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1120 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 00:00Z on 2004-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 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
1120 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
742 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.7

Open this sounding in Storm Lab

The text

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

132 
ACUS11 KWNS 300115
SWOMCD
SPC MCD 300113 
NCZ000-SCZ000-300245-

MESOSCALE DISCUSSION 2148
NWS STORM PREDICTION CENTER NORMAN OK
0813 PM CDT SUN AUG 29 2004

AREAS AFFECTED...ERN NC

CONCERNING...TORNADO WATCH 796...

VALID 300113Z - 300245Z

MARGINAL TORNADO POTENTIAL WILL REMAIN THROUGH REMAINDER OF TONIGHT
AND SPREAD NEWD ACROSS NERN NC.  HOWEVER...THREAT SHOULD CONTINUE TO
DIMINISH SUCH THAT WW CAN BE ALLOWED TO EXPIRE WITHOUT ADDITIONAL
ISSUANCE.  PARTIAL SPIRAL BAND NOW EVIDENT FROM OFFSHORE ONSLOW
COUNTY NWWD TOWARD JOHNSTON COUNTY SHOULD CONTINUE TO BE PRIMARY
CONVECTIVE FOCUS AWAY FROM CIRCULATION CORE...THROUGH AT LEAST 04Z. 
VERTICAL SHEAR REMAINS FAVORABLE OVER NERN QUADRANT OF CIRCULATION
OF GASTON -- I.E. 0-1 KM SRH 100-250 J/KG BASED ON MHX RAOB AND VWP
FROM RDU/MHX REGIONS.  MAIN AREA OF INTEREST REMAINS SFC TROUGH/WIND
SHIFT LINE AND PRESSURE FALL AXIS NEAR POB...LHZ...60 E DAN
LINE...PARTICULARLY IF ANY DISCRETE STORMS OR MINI-SUPERCELLS
EMBEDDED WITHIN SPIRAL BAND MOVE THROUGH THAT CORRIDOR.  THIS SHOULD
SERVE AS AXIS OF ANY REMAINING TORNADO PROBABILITIES.  MAIN NEGATIVE
FACTOR IS WEAKENING SFC-BASED INSTABILITY AND RESULTANT DECREASE
COVERAGE/INTENSITY OF DISCRETE CONVECTION ACROSS FAVORABLY SHEARED
SECTOR OF GASTON.

..EDWARDS.. 08/30/2004

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

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

33237865 34638017 36337828 34967676

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 30, 12:07 PM EDTMesoscale DiscussionSPCCamden, Chowan, Currituck, Gates, Hertford, Pasquotank and 3 more113 min
Aug 30, 12:50 PM EDTTornado WatchSPCCurrituck7 hr

Nearby

Mesoscale Discussions in North Carolina, 2004Mesoscale Discussions in South Carolina, 2004Every mesoscale discussion in 2004

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.