Alert archive / North Carolina / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 285, NWS Greenville-Spartanburg, SC

July 20, 2009Avery County, North Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Jul 20, 2009, 6:25 PM EDT for Avery County, North Carolina. It was in force for 36 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
Jul 20, 2009, 6:25 PM EDT (22:25 UTC)
Expired
Jul 20, 2009, 7:01 PM EDT
In force
36 min
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon

County Avery County, NC

The radar

The Knoxville radar (KMRX), 133 km from the middle of the area, began a volume at 22:28 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 10.4 hours before the alert went out and 182 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 2009-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 632 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 2009-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 square meters per square second.1939587897Sfc1 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
632 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
660 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

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 Jul 20, 2:33 PM EDT, 3 hours 52 minutes earlier.

Area forecast discussion, Jul 20, 2:33 PM EDT, 3 hours 52 minutes before
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Hazardous weather outlook, Jul 20, 3:50 PM EDT, 2 hours 35 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
350 PM EDT MON JUL 20 2009

GAZ010-017-018-026-028-029-NCZ048-051>053-058-059-062>065-082-507-
509-510-SCZ001>014-019-212000-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-MADISON-SWAIN-HAYWOOD-
BUNCOMBE-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-UNION NC-RUTHERFORD MOUNTAINS-POLK MOUNTAINS-EASTERN POLK-
OCONEE MOUNTAINS-PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-
GREATER OCONEE-GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-
CHEROKEE-YORK-ANDERSON-ABBEVILLE-LAURENS-UNION SC-CHESTER-GREENWOOD-
350 PM EDT MON JUL 20 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE INTO THIS EVENING.
CLOUD TO GROUND LIGHTNING WILL BE THE MAIN THREAT THAT ACCOMPANIES
ANY STORMS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

NCZ033-035>037-049-050-056-057-068>072-501>506-508-212000-
AVERY-ALEXANDER-IREDELL-DAVIE-YANCEY-MITCHELL-CATAWBA-ROWAN-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-CALDWELL MOUNTAINS-
GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-MCDOWELL MOUNTAINS-
EASTERN MCDOWELL-GREATER RUTHERFORD-
350 PM EDT MON JUL 20 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH CAROLINA AND
WESTERN NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE INTO
THIS EVENING. A FEW THUNDERSTORMS COULD BECOME SEVERE... PRODUCING
HAIL UP TO THE SIZE OF PENNIES. MORE COMMON WILL BE STORMS CAPABLE
OF PRODUCING PEA SIZE HAIL...ALONG WITH FREQUENT CLOUD TO GROUND
LIGHTNING AND BRIEF...HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

In the hours before

Special weather statement, Jul 20, 4:39 PM EDT, 1 hour 46 minutes before
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Local storm report, Jul 20, 5:09 PM EDT, 1 hour 16 minutes before
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Local storm report, Jul 20, 5:23 PM EDT, 1 hour 2 minutes before
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Local storm report, Jul 20, 5:34 PM EDT, 51 minutes before
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Local storm report, Jul 20, 5:43 PM EDT, 42 minutes before
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Local storm report, Jul 20, 6:22 PM EDT, 3 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 5:08 PM EDTSevere Thunderstorm WarningGSPBuncombe, Madison52 min
Jul 20, 5:19 PM EDTSevere Thunderstorm WarningGSPBurke41 min
Jul 20, 5:30 PM EDTSevere Thunderstorm WarningGSPMitchell, Yancey60 min
Jul 20, 5:48 PM EDTSevere Thunderstorm WarningGSPBurke, Caldwell57 min
Jul 20, 5:52 PM EDTSevere Thunderstorm WarningGSPRowan53 min
Jul 20, 5:56 PM EDTSevere Thunderstorm WarningGSPBuncombe, Madison45 min
Jul 20, 6:44 PM EDTSevere Thunderstorm WarningGSPUnion23 min
Jul 20, 6:54 PM EDTSevere Thunderstorm WarningGSPBurke, Catawba, Lincoln43 min
Jul 20, 7:21 PM EDTSevere Thunderstorm WarningGSPCaldwell17 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 2009Every severe thunderstorm warning in 2009

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.