Alert archive / North Carolina / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 164, NWS Greenville-Spartanburg, SC

August 20, 2004Jackson County, North Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Aug 20, 2004, 9:49 PM EDT for Jackson County, North Carolina. It was in force for 56 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 20, 2004, 9:49 PM EDT (01:49 UTC)
Expired
Aug 20, 2004, 10:45 PM EDT
In force
56 min
Issued by
NWS Greenville-Spartanburg, SC
Area
Counties, with a storm outline in the text

County Jackson County, NC

The radar

The Greer radar (KGSP), 95 km from the middle of the area, began a volume at 01:51 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 1.8 hours before the alert went out and 247 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, Peachtre/Fal Fld, GA at 00:00Z on 2004-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 456 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, Peachtre/Fal Fld, GA at 00:00Z on 2004-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 147 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
456 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
1079 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
147 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 20, 9:00 PM EDT, 49 minutes earlier.

Area forecast discussion, Aug 20, 9:00 PM EDT, 49 minutes before
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
900 PM EDT FRI AUG 20 2004

.SHORT TERM (REST OF TONIGHT)...
UPDATING TO INCREASE POPS IN NC MTS AND UPPER SAVANNAH RIVER VALLEY
PER RADAR TRENDS. INCREASED CLOUD COVER PER SATELLITE
IMAGERY. TEMPERATURES AND DEW POINTS GENERALLY APPEAR IN ORDER.

&&

.PREVIOUS DISCUSSION...
THE FOLLOWING WAS ORIGINALLY ISSUED AT 456 PM EDT FRI AUG 20 2004

SHORT TERM (REST OF TONIGHT)...
UPDAINT FOR SEVERE THUNDERSTORMS WATCH IN SWAIN...GRAHAM AND MACON
COUNTIES UNTI 02Z. CONVECTION RACING INTO KCHA AREA OF E TN EXPECTED
TO ARRIVE SW NC WITHIN TWO TO THREE HOURS.

THE FOLLOWING WAS ORIGINALLY ISSUED AT 303 PM EDT FRI AUG 20 2004

SHORT TERM (TONIGHT THROUGH MONDAY)...
CONVECTIVE MASS AHEAD ON THE FRONTAL LOW CURRENTLY SWINGING NE
ACROSS EASTERN TN ATTM. ISO SH HAVE DEVELOPED OVER THE NC MTNS THIS
AFTERNOON. COVERAGE OF SH/TS SHOULD CONTINUE TO INCREASE THIS
AFTERNOON AND EARLY EVENING AS ENVIRONMENT BECOME MORE UNSTABLE.
WILL COVER WITH CHC POPS EAST OF I-85 THROUGH THIS EVENING.

WITH THE LOSS OF HEATING AND LOW MOVING FURTHER NE...CONVECTION
SHOULD BECOME MORE ASSOCIATED WITH THE FRONTAL POSITION TONIGHT. W
TO SW H85 WINDS AHEAD OF THE FRONT INCREASE TO 20 TO 30 KTS AND
SHOULD SUPPORT UPSLOPE PRECIP OVERNIGHT. EARLY PERIODS OF THE GFS
SHOWING THAT THE MODEL HAS INITIALIZED TOO WET. WILL FAVOR THE ETA
SOLUTION OF KEEPING THE PRECIP OVER THE MTNS AND ISO TO SCT
EAST OF THE HIGHER TERRAIN. AFTER COORDINATION WITH THE CLUSTER WILL
ADVERTISE CATE POPS ALONG THE TN BORDER WITH HIGH CHC TO LIKELY OVER
THE REMAINDER OF THE MTNS. EAST OF MTNS...SCT SH AND ISO TS SHOULD
ADVANCE TOWARD THE EAST BY DAYBREAK.

COLD FRONT WILL SLOWLY MOVE ACROSS THE WESTERN CAROLINAS AND NE GA
SAT AFTERNOON AND EVENING. WILL CONTINUE AT LEAST CHC POPS THROUGH
3Z SUN. WITH CAPES APPROACHING 2K J/KG AND HEALTHY WIND
FIELDS...SVR WX POTENTIAL WILL BE A CONCERN SAT AFTERNOON.

GFS AND ETA SOLUTIONS ARE TRENDING TO MORE OF A CAD PATTERN FOR SUN
INTO MON. WILL ADVERTISE STABLE NE BL FLOW FROM SUN AM THROUGH MON
AND WILL KEEP MAX TEMPS SLIGHTLY BELOW NORMAL. EXPECT THAT THE
PATTERN WILL YIELD LITTLE CHC FOR MEASURABLE PRECIP. HOWEVER...WITH
STALLING FRONT WILL GRID SOME SH/TS ACROSS THE SOUTHERN THIRD OF THE
FA SUN AFTERNOON.

LONG TERM (MONDAY NIGHT THROUGH FRIDAY)...
FRONT WILL BE STALLED JUST SOUTH OF THE REGION BY EARLY TUESDAY AS
WEAK SHORT WAVES RIDE NORTHEAST THROUGH THE MS RIVER VALLEY. WEAK
SRLY RETURN FLOW ALLOWS FAIRLY ABUNDANT SFC TO 850 MB MOISTURE TO
PERSIST THROUGH MID WEEK...WITH THE BEST MOISTURE CONVERGENCE IN THE
MOUNTAINS. THE ATLANTIC RIDGE GRADUALLY BUILDS WESTWARD TO INCREASE
HEIGHTS ACROSS THE REGION...BUT MOISTURE UNDER THE RIDGE PERSISTS TO
REQUIRE CHANCE POPS WEST AND SLIGHT CHANCE POPS EAST THROUGH THE
PERIOD.

AVIATION...
HAZE CONTINUES TO RESTRICT VSBY TO MVFR RANGE AT MOST TAF LOCATIONS
AND THIS SHOULD ONLY SLOWLY IMPROVE THROUGH EVENING AS MIXING
INCREASES. FAIRLY EXPANSIVE SHIELD OF SHOWERS AND THUNDERSTORMS
SHOULD ADVANCE SLOWLY TOWARD THE MOUNTAINS...BUT BEST AXIS OF
MOISTURE AHEAD OF THE FRONTAL ZONE WILL REMAIN MAINLY WEST OF MOST
TERMINAL LOCATIONS UNTIL VERY LATE IN THE CURRENT FORECAST PERIOD.
TSRA CHANCES WILL BE HIGHEST AT AVL THROUGH PERIOD...BUT NARROWING
THE CHANCES DOWN TO A SMALLER TEMPO WINDOW REMAINS ELUSIVE. MIXING
AND HIGHER CLOUDS SHOULD KEEP CIGS ABOVE THE LOW IFR RANGE OBSERVED
THIS MORNING...HOWEVER.
&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...SEVERE THUNDERSTORM WATCH FOR ZONES NCZ051-058-062 UNTIL 10 PM
     EDT.
SC...NONE.
&&

SHORT TERM (UPDATE)...
Hazardous weather outlook, Aug 20, 5:59 AM EDT, 15 hours 50 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
559 AM EDT FRI AUG 20 2004

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-211000-
ABBEVILLE SC-ALEXANDER NC-ANDERSON SC-AVERY NC-BUNCOMBE NC-BURKE NC-
CABARRUS NC-CALDWELL NC-CATAWBA NC-CHEROKEE SC-CHESTER SC-
CLEVELAND NC-DAVIE NC-ELBERT GA-FRANKLIN GA-GASTON NC-GRAHAM NC-
GREATER GREENVILLE SC-GREATER OCONEE SC-GREATER PICKENS SC-
GREENVILLE MOUNTAINS SC-GREENWOOD SC-HABERSHAM GA-HART GA-HAYWOOD NC-
HENDERSON NC-IREDELL NC-LAURENS SC-LINCOLN NC-MACON NC-MADISON NC-
MCDOWELL NC-MECKLENBURG NC-MITCHELL NC-NORTHERN JACKSON NC-
OCONEE MOUNTAINS SC-PICKENS MOUNTAINS SC-POLK NC-RABUN GA-ROWAN NC-
RUTHERFORD NC-SOUTHERN JACKSON NC-SPARTANBURG SC-STEPHENS GA-
SWAIN NC-TRANSYLVANIA NC-UNION SC-UNION NC-YANCEY NC-YORK SC-
559 AM EDT FRI AUG 20 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA...
UPSTATE SOUTH CAROLINA...AND EXTREME NORTHEAST GEORGIA.

.DAY ONE...
SCATTERED SHOWERS AND THUNDERSTORMS ARE IN THE FORECAST
TODAY...MAINLY FOR LATE AFTERNOON AND EARLY EVENING FOR NON-MOUNTAIN
AREAS. AN ISOLATED SEVERE STORM OR TWO CANNOT BE RULED OUT. SEE
THE LATEST SEVERE WEATHER OUTLOOK FROM GREENVILLE SPARTANBURG...UNDER
THE PRODUCT INVENTORY LIST HEADER CAESPSGSP...FOR DETAILS.

.DAYS TWO THROUGH SEVEN...

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MIGHT BE NEEDED LATER TODAY IF THE ATMOSPHERE
BECOMES UNSTABLE ENOUGH.

BURRUS

In the hours before

Local storm report, Aug 20, 9:34 PM EDT, 15 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
934 PM EDT FRI AUG 20 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0915 PM     TSTM WND DMG     CLARKESVILLE            34.61N 83.52W
08/20/2004                   HABERSHAM          GA   LAW ENFORCEMENT

            DISPATCH CENTER HAS RECEIVED MULTIPLE REPORTS OF TREES
            AND POWER LINES DOWN ACROSS THE COUNTY. CLARKESVILLE AND
            BALDWIN WERE HARDEST HIT BUT OTHER LOCATIONS HAD DAMAGE
            AS WELL.

&&

LAMB
Local storm report, Aug 20, 9:44 PM EDT, 5 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
944 PM EDT FRI AUG 20 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0925 PM     TSTM WND DMG     CLAYTON                 34.88N 83.40W
08/20/2004                   RABUN              GA   LAW ENFORCEMENT

            DISPATCHERS REPORTED MULTIPLE TREES AND POWER LINES DOWN
            ACROSS THE COUNTY...INCLUDING CITY OF CLAYTON. WIND HAS
            SINCE DIED DOWN AT DISPATCH CENTER IN CLAYTON.

&&

LAMB

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 20, 9:30 PM EDTSevere Thunderstorm WarningGSPMacon45 min
Aug 20, 9:22 PM EDTSevere Thunderstorm WarningGSPOconee53 min
Aug 20, 10:07 PM EDTSevere Thunderstorm WarningGSPPickens53 min
Aug 20, 10:29 PM EDTSevere Thunderstorm WarningGSPAnderson46 min
Aug 20, 10:43 PM EDTSevere Thunderstorm WarningGSPGreenville32 min
Aug 20, 8:51 PM EDTSevere Thunderstorm WarningGSPHabersham, Rabun54 min
Aug 20, 10:08 PM EDTSevere Thunderstorm WarningGSPElbert52 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 2004Every severe thunderstorm warning 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.