Alert archive / North Carolina / Mesoscale Discussions in 2004

Mesoscale Discussion 2239

September 17, 200410 counties in North Carolina; Brunswick County, Virginia

The Storm Prediction Center issued this mesoscale discussion at Sep 17, 2004, 7:23 PM EDT for 10 counties in North Carolina; Brunswick County, Virginia. It was in force for 37 min.

The area

The outline as issued.

The facts

Issued: Sep 17, 2004, 7:23 PM EDT (23:23 UTC)
Expired: Sep 17, 2004, 8:00 PM EDT
In force: 37 min
Issued by: the Storm Prediction Center

Counties Duplin County, NC, Edgecombe County, NC, Greene County, NC, Halifax County, NC, Lenoir County, NC, Nash County, NC, New Hanover County, NC, Pender County, NC, Wayne County, NC, Wilson County, NC, Brunswick County, VA

The radar

The Raleigh/Durham radar (KRAX), 66 km from the middle of the area, began a volume at 23:25 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, 11.4 hours before the alert went out and 112 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: 1655 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 550 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 79 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.4

Open this sounding in Storm Lab

The text

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

841 
ACUS11 KWNS 172326
SWOMCD
SPC MCD 172323 
NCZ000-VAZ000-180000-

MESOSCALE DISCUSSION 2239
NWS STORM PREDICTION CENTER NORMAN OK
0623 PM CDT FRI SEP 17 2004

AREAS AFFECTED...SCNTRL VA AND CNTRL NC

CONCERNING...TORNADO WATCH 835...

VALID 172323Z - 180000Z

VALID PORTION OF TORNADO WATCH 835 ACROSS SCNTRL VA AND CNTRL NC
WILL EXPIRE AT 00Z.

LINE OF TSTMS EXTENDING FROM 30 SW KRIC-KGSB-30 SW OF KILM CONTINUES
TO TRANSLATE ENEWD 25-30 KTS.  WIND PROFILES FROM WILMINGTON SUGGEST
THAT THE FLOW HAS VEERED AND BECOME MORE UNIDIRECTIONAL.  IT IS
STILL POSSIBLE THAT SMALL SCALE BOWS MAY EVOLVE WITHIN THE LINE AND
PRODUCE WIND DAMAGE AS SEGMENTS OF THE LINE BECOME ORIENTED
PERPENDICULAR TO THE MEAN FLOW.  THE TORNADO THREATS HAVE SHIFTED
INTO EXTREME NERN NC AND ERN VA.

THE MAIN PART OF THE LINE WILL SHIFT INTO THE NEW TORNADO WATCH 836
BY 00Z.  SRN PORTIONS WILL MOVE ACROSS ECNTRL NC AND THE CAPE
HATTERAS AREA THROUGH LATE EVENING AND MAY PRODUCE ISOLD DAMAGING
WINDS.

..RACY.. 09/17/2004

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

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

34027811 37327794 37167774 35757747 34137769

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 16, 8:45 PM EDT	Tornado Watch	SPC	Cabarrus, Cleveland, Gaston, Lincoln, Mecklenburg, Polk and 1 more	6 hr
Sep 16, 11:42 PM EDT	Mesoscale Discussion	SPC	Gaston, Mecklenburg	2 hr
Sep 17, 1:51 AM EDT	Mesoscale Discussion	SPC	Alexander, Burke, Caldwell, Catawba, Cleveland, Gaston and 6 more	84 min
Sep 17, 9:26 AM EDT	Mesoscale Discussion	SPC	Alamance, Anson, Bladen, Caswell, Chatham, Cumberland and 24 more	2 hr
Sep 17, 10:10 AM EDT	Tornado Watch	SPC	Alamance, Anson, Bladen, Brunswick, Caswell, Chatham and 37 more	7 hr
Sep 17, 11:03 AM EDT	Mesoscale Discussion	SPC	Alamance, Bertie, Caswell, Chatham, Cumberland, Durham and 26 more	87 min
Sep 17, 12:33 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Chowan, Craven, Gates and 8 more	117 min
Sep 17, 1:15 PM EDT	Tornado Watch	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 18 more	7 hr
Sep 17, 1:37 PM EDT	Mesoscale Discussion	SPC	Alamance, Bladen, Brunswick, Caswell, Chatham, Columbus and 29 more	113 min
Sep 17, 3:53 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Chowan, Craven, Edgecombe and 11 more	2 hr
Sep 17, 4:01 PM EDT	Mesoscale Discussion	SPC	Bladen, Brunswick, Columbus, Cumberland, Duplin, Franklin and 6 more	59 min
Sep 17, 4:35 PM EDT	Tornado Watch	SPC	Bladen, Brunswick, Columbus, Duplin, Edgecombe, Franklin and 14 more	3 hr
Sep 17, 6:19 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Chowan, Craven, Currituck and 13 more	116 min
Sep 17, 6:50 PM EDT	Tornado Watch	SPC	Bertie, Camden, Chowan, Currituck, Gates, Hertford and 3 more	5 hr
Sep 17, 3:50 PM EDT	Tornado Watch	SPC	Clarke, Frederick, Loudoun, City of Winchester	4 hr

Nearby

Mesoscale Discussions in North Carolina, 2004 Mesoscale Discussions in Virginia, 2004 Every 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.