Alert archive / North Carolina / Mesoscale Discussions in 2004

Mesoscale Discussion 2188

September 8, 200450 counties in North Carolina; Chesterfield County, Lancaster County, Marlboro County, South Carolina; 23 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2004, 8:41 AM EDT for 50 counties in North Carolina; Chesterfield County, Lancaster County, Marlboro County, South Carolina; 23 counties in Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 8, 2004, 8:41 AM EDT (12:41 UTC)
Expired
Sep 8, 2004, 10:45 AM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 76 counties

Alamance County, NC, Anson County, NC, Bladen County, NC, Cabarrus County, NC, Caswell County, NC, Chatham County, NC, Cumberland County, NC, Davidson County, NC, Davie County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Greene County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hoke County, NC, Iredell County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Onslow County, NC, Orange County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Rockingham County, NC, Rowan County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Yadkin County, NC, Chesterfield County, SC, Lancaster County, SC, Marlboro County, SC, Brunswick County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, City of Danville, VA, City of Emporia, VA, City of Galax, VA, City of Martinsville, VA, City of Radford, VA, Dinwiddie County, VA, Floyd County, VA, Franklin County, VA, Greensville County, VA, Halifax County, VA, Henry County, VA, Lunenburg County, VA, Mecklenburg County, VA, Montgomery County, VA, Nottoway County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Wythe County, VA

The radar

The Raleigh/Durham radar (KRAX), 29 km from the middle of the area, began a volume at 12:42 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 0.7 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-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2004-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 835 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, Greensboro/Hi Pt, NC at 12:00Z on 2004-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 225 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
835 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
486 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
225 m²/s²
0-3 km storm-relative helicity
243 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.0

Open this sounding in Storm Lab

The text

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

060 
ACUS11 KWNS 081244
SWOMCD
SPC MCD 081241 
NCZ000-VAZ000-SCZ000-081445-

MESOSCALE DISCUSSION 2188
NWS STORM PREDICTION CENTER NORMAN OK
0741 AM CDT WED SEP 08 2004

AREAS AFFECTED...PORTIONS CENTRAL/ERN NC...SRN VA

CONCERNING...TORNADO WATCH 813...

VALID 081241Z - 081445Z

TORNADO POTENTIAL IS EXPECTED TO INCREASE THROUGH REMAINDER MORNING.
WITH INSOLATION STRONGEST OVER RELATIVELY PRECIP-FREE AREAS OF
NC...DIFFERENTIAL/DIABATIC HEATING WILL CONTRIBUTE TO DIURNAL
REDEVELOPMENT OF BAROCLINIC ZONE OVER ERN SEMICIRCLE OF CYCLONE. 
MOST LIKELY AREA FOR THIS PROCESS WILL BE OVER NRN NC...SHIFTING NWD
INTO SRN VA.  THIS REGION WILL BE IN OPTIMAL OVERLAP OF NRN PORTION
OF STRONGEST BUOYANCY AND SRN PORTION OF RELATIVELY BACKED SFC FLOW
-- WHERE LOW LEVEL HODOGRAPHS ARE MOST ENLARGED.  12Z GSO RAOB SHOWS
200-300 J/KG 0-1 KM SRH AND AROUND 700 J/KG SBCAPE PRIOR TO DIURNAL
HEATING.

VERTICAL SHEAR DECREASES RAPIDLY WITH EWD EXTENT NEAR ERN EDGE OF WW
BASED ON VWP AND RAOBS.  SHEAR DROPS OFF MORE GRADUALLY WITH SWD
EXTENT ACROSS NC.  STILL...AIR MASS S OF DEVELOPING FRONTAL ZONE IN
WW WILL CONTINUE TO SUPPORT MINI-SUPERCELLS AND TORNADO POTENTIAL. 
OVER THIS AREA EXPECT SBCAPE INCREASING TO 1000-1500 J/KG RANGE AND
FAVORABLE SRH -- ESPECIALLY FOR ANY CELLS DEVIATING RIGHTWARD FROM
PREVAILING ORIENTATION OF CONVECTIVE BANDS.

..EDWARDS.. 09/08/2004

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

ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...CAE...GSP...

34547729 34548083 37208112 37227747

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 7, 10:09 PM EDTMesoscale DiscussionSPCAnson, Bladen, Cabarrus, Cleveland, Columbus, Cumberland and 14 more96 min
Sep 8, 12:30 AM EDTTornado WatchSPCAlexander, Anson, Avery, Bladen, Brunswick, Burke and 31 more7 hr
Sep 8, 3:38 AM EDTMesoscale DiscussionSPCAlexander, Anson, Avery, Bladen, Brunswick, Burke and 31 more3 hr
Sep 8, 6:50 AM EDTTornado WatchSPCAlamance, Anson, Bladen, Cabarrus, Caswell, Chatham and 42 more7 hr
Sep 8, 12:00 PM EDTMesoscale DiscussionSPCAlamance, Bladen, Caswell, Chatham, Cumberland, Duplin and 24 more2 hr
Sep 8, 12:50 PM EDTTornado WatchSPCAlamance, Caswell, Chatham, Cumberland, Duplin, Durham and 30 more6 hr
Sep 8, 3:39 PM EDTMesoscale DiscussionSPCBertie, Edgecombe, Franklin, Gates, Greene, Halifax and 8 more2 hr
Sep 8, 6:40 PM EDTTornado WatchSPCAmelia, Arlington, Caroline, Charles City, Chesterfield, Clarke and 52 more5 hr

Nearby

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