Alert archive / North Carolina / Mesoscale Discussions in 2003

Mesoscale Discussion 2018

July 29, 200331 counties in North Carolina; 6 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Jul 29, 2003, 7:42 PM EDT for 31 counties in North Carolina; 6 counties in South Carolina. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jul 29, 2003, 7:42 PM EDT (23:42 UTC)
Expired
Jul 29, 2003, 9:15 PM EDT
In force
93 min
Issued by
the Storm Prediction Center
All 37 counties

Anson County, NC, Beaufort County, NC, Bladen County, NC, Chatham County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Duplin County, NC, Greene County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Montgomery County, NC, Moore County, NC, New Hanover County, NC, Onslow County, NC, Pender County, NC, Pitt County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Union County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC, Chesterfield County, SC, Darlington County, SC, Dillon County, SC, Kershaw County, SC, Lancaster County, SC, Marlboro County, SC

The radar

The Raleigh/Durham radar (KRAX), 116 km from the middle of the area, began a volume at 23:43 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, 11.7 hours before the alert went out and 148 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 2003-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 681 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 2003-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 square meters per square second.1939Sfc1 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
681 J/kg
Mixed-layer CIN
-58 J/kg
Mixed-layer LCL
1045 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
54 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

676 
ACUS11 KWNS 292343
SWOMCD
SPC MCD 292342 
NCZ000-SCZ000-300115-

MESOSCALE DISCUSSION 2018
NWS STORM PREDICTION CENTER NORMAN OK
0642 PM CDT TUE JUL 29 2003

AREAS AFFECTED...NRN SC...CENTRAL/ERN NC

CONCERNING...SEVERE THUNDERSTORM WATCH 812...

VALID 292342Z - 300115Z

ISOLATED DAMAGING WINDS WILL REMAIN POSSIBLE WHERE CONVECTIVE
LINE/INDIVIDUAL STORM MERGERS OCCUR...ESPECIALLY OVER SERN NC/FAR
NERN SC. ALTHOUGH THE OVERALL SEVERE THREAT APPEARS TO BE
DIMINISHING...THE HEAVY RAIN THREAT WILL REMAIN OVER PORTIONS OF ERN
NC ALONG/NORTH OF A STATIONARY BOUNDARY.

LATEST IR IMAGERY SHOWS CLOUD TOP WARMING SUGGESTING A WEAKENING
TREND IN CONVECTIVE LINE MOVING THROUGH CENTRAL NC. THUS THE
ORGANIZED DAMAGING WIND THREAT SHOULD BE MITIGATED OVER WW 812
THROUGH THE REMAINDER OF THE WATCH VALID TIME...30/01Z. THE BEST
POTENTIAL FOR SHORT LIVED DOWNBURSTS/DAMAGING WIND THREAT WILL OCCUR
OVER OVER SERN NC/NERN SC...WHERE CONVECTIVE LINE/INDIVIDUAL STORM
MERGERS WILL LOCALLY ENHANCE UPDRAFT STRENGTH IN AN AIRMASS THAT HAS
NOT BEEN PREVIOUSLY CONVECTIVELY CONTAMINATED SOUTH OF A STATIONARY
BOUNDARY. INCREASING SWLY LOW LEVEL JET...GENERATED FROM CONVECTIVE
COMPLEX...INTO THIS STATIONARY BOUNDARY EXTENDING FORM 30 S OF SOP
EWD 25 N OF EWN MAY SHOULD AID IN CONTINUED STRONG CONVECTIVE
DEVELOPMENT ALONG AND NORTH OF THE BOUNDARY OVER ERN/NERN NC. WLY
MEAN WIND FIELDS SHOULD AID IN SOME ECHO TRAINING/HEAVY RAIN THREAT
WITH HOURLY RAINFALL RATES UP TO 2 INCHES FOR THE NEXT 3-4 HOURS.

..CROSBIE.. 07/29/2003

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

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

34278112 35877987 35687658 34167772

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 29, 2:14 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Anson, Buncombe, Burke, Cabarrus and 30 more2 hr
Jul 29, 3:00 PM EDTSevere Thunderstorm WatchSPCAlexander, Anson, Bladen, Burke, Cabarrus, Caldwell and 31 more6 hr
Jul 29, 4:51 PM EDTMesoscale DiscussionSPCAlamance, Anson, Cabarrus, Catawba, Chatham, Cleveland and 30 more114 min

Nearby

Mesoscale Discussions in North Carolina, 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.