Alert archive / South Carolina / Mesoscale Discussions in 2004

Mesoscale Discussion 1449

June 30, 2004Richmond County, Georgia; 12 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2004, 1:27 PM EDT for Richmond County, Georgia; 12 counties in South Carolina. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jun 30, 2004, 1:27 PM EDT (17:27 UTC)
Expired: Jun 30, 2004, 4:30 PM EDT
In force: 3 hr
Issued by: the Storm Prediction Center

Counties Richmond County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Georgetown County, SC, Orangeburg County, SC, Williamsburg County, SC

The radar

The Columbia radar (KCAE), 108 km from the middle of the area, began a volume at 17:28 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

Charleston AFB, SC (KCHS), launched 12:00Z, 5.5 hours before the alert went out and 57 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: 2262 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 799 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 62 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

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

228 
ACUS11 KWNS 301728
SWOMCD
SPC MCD 301727 
SCZ000-GAZ000-302030-

MESOSCALE DISCUSSION 1449
NWS STORM PREDICTION CENTER NORMAN OK
1227 PM CDT WED JUN 30 2004

AREAS AFFECTED...FAR E-CENTRAL GA...AND CENTRAL/ERN SC

CONCERNING...HEAVY RAINFALL 

VALID 301727Z - 302030Z

FAVORABLE MESOSCALE ENVIRONMENT EXISTS FOR LOCALLY HEAVY RAINFALL
ALONG AN AXIS FROM AGS TO NEAR CRE. RAIN RATES EXPECTED TO LOCALLY
EXCEED 2/HR DURING THIS AFTERNOON.

AT 17Z...A LINE OF SLOW-MOVING STRONG THUNDERSTORMS EXTENDED FROM
NEAR AGS ENEWD TO THE NERN SC COAST. ADDITIONAL DEVELOPMENT WAS
OCCURRING IN VICINITY OF THE SEA BREEZE BOUNDARY ENEWD OF CHS.
ANTICYCLONIC ARC TO CIRRUS CLOUDS ACROSS GA/FL WITH MORE ZONAL UPPER
FLOW SUGGESTED IN UPPER CLOUDS OVER NC SUGGEST STRONG UPPER
DIFFLUENCE/DIVERGENCE ACROSS CENTRAL SC. THIS APPEARS TO HAVE AIDED
IN RAPID INCREASE IN THUNDERSTORM COVERAGE ACROSS THE DISCUSSION
AREA...LEADING TO AN ORGANIZED OUTFLOW BOUNDARY FROM AGS TO CRE.
HIGH THETA-E ENVIRONMENT...WITH 12Z PW VALUE IN EXCESS OF 2 AT
CHS...SUGGESTS PROPAGATION OF COLD POOL SHOULD BE RELATIVELY SLOW.
THIS SHOULD ALLOW FOR TRAINING OF INDIVIDUAL STORMS ALONG THE
BOUNDARY ACROSS CENTRAL/E-CENTRAL SC...WITH SLOW ENEWD MOTION OF
STORMS /AROUND 5 KT/. MLCAPE VALUES AROUND 2000 J/KG...MAY ALLOW FOR
LOCALIZED WET MICROBURSTS OR AN ISOLATED/BRIEF TORNADO ALONG THE SEA
BREEZE BOUNDARY... HOWEVER...PRIMARY THREAT THIS AFTERNOON APPEARS
TO BE HEAVY RAINFALL ACROSS THE MAJORITY OF THE REGION.

..BANACOS.. 06/30/2004

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

ATTN...WFO...ILM...CHS...CAE...

32758010 32798091 33098187 33378221 33658140 33748083
33868055 33907996 34007951 33937905 33867891 33557890
33237904 32977930 32778008

Nearby

Mesoscale Discussions in South Carolina, 2004 Mesoscale Discussions in Georgia, 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.