Alert archive / North Carolina / Mesoscale Discussions in 2004

Mesoscale Discussion 1978

August 12, 20045 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at Aug 12, 2004, 5:55 PM EDT for 5 counties in North Carolina. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Aug 12, 2004, 5:55 PM EDT (21:55 UTC)
Expired
Aug 12, 2004, 7:00 PM EDT
In force
65 min
Issued by
the Storm Prediction Center

Counties Brunswick County, NC, Carteret County, NC, New Hanover County, NC, Onslow County, NC, Pender County, NC

The radar

The Wilmington radar (KLTX), 19 km from the middle of the area, began a volume at 21:58 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 159 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 2004-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 926 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 2004-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
926 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
584 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

624 
ACUS11 KWNS 122155
SWOMCD
SPC MCD 122155 
NCZ000-SCZ000-122300-

MESOSCALE DISCUSSION 1978
NWS STORM PREDICTION CENTER NORMAN OK
0455 PM CDT THU AUG 12 2004

AREAS AFFECTED...EXTREME SERN NC IN TORNADO WATCH 743

CONCERNING...TORNADO WATCH 743...

VALID 122155Z - 122300Z

TORNADO WATCH 743 EXPIRES AT 22Z AND WILL NOT BE REISSUED. 
HOWEVER...THE FORECAST OFFICE IN WILMINGTON NC WILL LIKELY LOCALLY
EXTEND THE TORNADO WATCH FOR A FEW COUNTIES IN SERN NC FOR A COUPLE
OF HOURS.

BANDS OF TSTMS CONTINUE TO TRANSLATE ENEWD ACROSS SERN NC AND WILL
BE MOVING OFF THE COAST IN A COUPLE OF HOURS.  SURFACE WINDS BEHIND
THE LINES HAVE VEERED WEST OF INTERSTATE 40...BUT REMAIN SSELY ALONG
THE COAST FROM WRIGHTSVILLE BEACH UP INTO THE MOREHEAD CITY AREA.
ENHANCED LOW LEVEL SHEAR MAY BE SUFFICIENT FOR AN ISOLD TORNADO AS
THE STORMS MOVE ACROSS THE AREA.

THE PRIMARY RISK OF TORNADOES...HOWEVER...SEEMS TO BE LOCATED
FARTHER TO THE NORTH ACROSS NERN NC AND SERN VA WITHIN TORNADO WATCH
745.

GIVEN THAT THE TORNADO THREAT AREA IS SMALL AND SHORT-LIVED ACROSS
SERN NC...ANOTHER WW WILL NOT BE ISSUED...BUT RATHER LOCALLY
EXTENDED BY THE WFO ILM.

..RACY.. 08/12/2004

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

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

33437912 34937794 34847615 33417826 33407889

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 10:02 AM EDTMesoscale DiscussionSPCBladen, Columbus, Pender, Robeson88 min
Aug 12, 11:45 AM EDTTornado WatchSPCAnson, Bladen, Brunswick, Columbus, Craven, Cumberland and 12 more6 hr
Aug 12, 1:34 PM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Camden, Caswell, Chatham and 28 more86 min
Aug 12, 2:25 PM EDTTornado WatchSPCAlamance, Beaufort, Bertie, Cabarrus, Camden, Caswell and 39 more6 hr
Aug 12, 4:06 PM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Camden and 49 more84 min
Aug 12, 6:47 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Chowan, Currituck, Gates and 7 more58 min

Nearby

Mesoscale Discussions in North 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.