Alert archive / North Carolina / Mesoscale Discussions in 2003

Mesoscale Discussion 2175

August 17, 200360 counties in North Carolina; Cherokee County, Union County, York County, South Carolina; 50 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Aug 17, 2003, 6:25 PM EDT for 60 counties in North Carolina; Cherokee County, Union County, York County, South Carolina; 50 counties in Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 17, 2003, 6:25 PM EDT (22:25 UTC)
Expired
Aug 17, 2003, 8:30 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 113 counties

Alamance County, NC, Alexander County, NC, Alleghany County, NC, Anson County, NC, Ashe County, NC, Bertie County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Camden County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Chowan County, NC, Cleveland County, NC, Currituck County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gaston County, NC, Gates County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Iredell County, NC, Johnston County, NC, Lee County, NC, Lincoln County, NC, Martin County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Pasquotank County, NC, Perquimans County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Tyrrell County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Watauga County, NC, Wilkes County, NC, Wilson County, NC, Yadkin County, NC, Cherokee County, SC, Union County, SC, York County, SC, Amelia County, VA, Appomattox County, VA, Bedford County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Danville, VA, City of Emporia, VA, City of Franklin, VA, City of Galax, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Portsmouth, VA, City of Radford, VA, City of Richmond, VA, City of Suffolk, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Greensville County, VA, Halifax County, VA, Henrico County, VA, Henry County, VA, Isle of Wight County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nottoway County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Pulaski County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Wythe County, VA

The radar

The Raleigh/Durham radar (KRAX), 80 km from the middle of the area, began a volume at 22:26 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, 10.4 hours before the alert went out and 79 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 2003-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 994 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 2003-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
994 J/kg
Mixed-layer CIN
-68 J/kg
Mixed-layer LCL
1043 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
1 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

363 
ACUS11 KWNS 172226
SWOMCD
SPC MCD 172225 
NCZ000-VAZ000-SCZ000-TNZ000-180030-

MESOSCALE DISCUSSION 2175
NWS STORM PREDICTION CENTER NORMAN OK
0525 PM CDT SUN AUG 17 2003

AREAS AFFECTED...SRN VA THROUGH NC AND NWRN SC

CONCERNING...SEVERE THUNDERSTORM WATCH 866...

VALID 172225Z - 180030Z

THREAT FOR ISOLATED WET MICRO BURSTS EXPECTED TO PERSIST THROUGH
EARLY EVENING. ACTIVITY SHOULD BEGIN A GRADUAL DECREASE WITH LOSS OF
HEATING.

WV IMAGERY SHOWS AREA OF MID/UPPER DRYING ASSOCIATED WITH LARGER
SCALE SUBSIDENCE SPREADING SEWD THROUGH MUCH OF VA AND INTO NRN NC.
AN UPSTREAM SHORTWAVE TROUGH CONTINUES SEWD THROUGH BASE OF UPPER
TROUGH INTO ERN KY. AT THE SURFACE...NUMEROUS OUTFLOW BOUNDARIES
EXIST IN WARM SECTOR S OF WEAK SURFACE FRONT THAT EXTENDS ACROSS SRN
VA. THE ATMOSPHERE REMAINS MODERATELY UNSTABLE ALONG AND SOUTH OF
THIS BOUNDARY. SLIGHTLY COOLER MID LEVEL TEMPERATURES EXIST ON SRN
PORTION OF UPPER TROUGH ACROSS VA INTO NRN NC.
HOWEVER...THERMODYNAMIC PROFILES ARE STILL SOMEWHAT WARM WITH
MARGINAL LAPSE RATES...AND THIS IS LIMITING UPDRAFT STRENGTH AND
OVERALL HAIL/SEVERE POTENTIAL. LEADING EDGE OF MID LEVEL DRYING
SPREADING SEWD THROUGH SRN VA INTO NRN NC MAY ENHANCE POTENTIAL FOR
ISOLATED WET MICRO BURSTS AS CLUSTERS OF MULTICELL STORMS DEVELOP
SEWD NEXT FEW HOURS. STORMS WILL CONTINUE TO DECREASE FROM THE N
ACROSS VA AS DEEPER DRYING ASSOCIATED WITH STRONGER SUBSIDENCE
DEVELOPS SWD.

..DIAL.. 08/17/2003

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

ATTN...WFO...AKQ...MHX...LWX...RAH...RNK...CAE...GSP...MRX...

36507582 35787564 35507772 35097954 34738119 34498176
35348183 36028180 36728178 37098074 37327961 37657864
37567733 37117636

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 12:06 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Caldwell and 18 more114 min
Aug 17, 1:15 PM EDTSevere Thunderstorm WatchSPCAvery, Buncombe, Cherokee, Clay, Graham, Haywood and 11 more6 hr
Aug 17, 1:52 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Bertie, Cabarrus, Caswell and 40 more113 min
Aug 17, 2:20 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Ashe, Burke, Cabarrus and 40 more6 hr
Aug 17, 4:27 PM EDTMesoscale DiscussionSPCAvery, Buncombe, Cherokee, Clay, Graham, Haywood and 11 more2 hr
Aug 17, 6:16 PM EDTMesoscale DiscussionSPCAvery, Buncombe, Cherokee, Clay, Graham, Haywood and 11 more59 min

Nearby

Mesoscale Discussions in North Carolina, 2003Mesoscale Discussions in Virginia, 2003Mesoscale Discussions in South Carolina, 2003Every mesoscale discussion in 2003

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.