Alert archive / North Carolina / Flash Flood Warnings in 2020

Flash Flood Warning 54, NWS Greenville-Spartanburg, SC

August 24, 2020McDowell County, North Carolina

NWS Greenville-Spartanburg, SC issued this flash flood warning at Aug 24, 2020, 8:34 PM EDT for McDowell County, North Carolina. It was in force for 3 hr. 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 24, 2020, 8:34 PM EDT (00:34 UTC)
Expired
Aug 24, 2020, 11:30 PM EDT
In force
3 hr
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Flood severity
None

County McDowell County, NC

The radar

The Greer radar (KGSP), 90 km from the middle of the area, began a volume at 00:35 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, 0.6 hours before the alert went out and 341 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 2020-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1026 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 2020-08-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
1026 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
652 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
31 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 flash flood 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 flash flood warning went out at Aug 24, 8:29 PM EDT, 5 minutes earlier.

Area forecast discussion, Aug 24, 8:29 PM EDT, 5 minutes before
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Hazardous weather outlook, Aug 24, 5:27 AM EDT, 15 hours 7 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
527 AM EDT Mon Aug 24 2020

NCZ033-048>053-058-059-062>065-501-503-505-507-509-250930-
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
Rutherford Mountains-Polk Mountains-
527 AM EDT Mon Aug 24 2020

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...Today and tonight.

Scattered thunderstorms will develop across the mountains of North
Carolina this afternoon. The main threats will be gusty winds, small
hail, and cloud to ground lightning. Additionally, heavy rainfall
combined with slow moving storms may produce localized minor flooding.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-
506-508-510-SCZ001>014-019-250930-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-
Union NC-Greater Caldwell-Greater Burke-Eastern McDowell-
Greater Rutherford-Eastern Polk-Oconee Mountains-Pickens Mountains-
Greenville Mountains-Greater Oconee-Greater Pickens-
Greater Greenville-Spartanburg-Cherokee-York-Anderson-Abbeville-
Laurens-Union SC-Chester-Greenwood-
527 AM EDT Mon Aug 24 2020

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...Today and tonight.

Scattered thunderstorms will develop across the western Carolinas and
northeast Georgia this afternoon. The main threats will be gusty winds,
small hail, and cloud to ground lightning.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

Krentz

In the hours before

Special weather statement, Aug 24, 7:36 PM EDT, 58 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
736 PM EDT Mon Aug 24 2020

NCZ035-056-502-250015-
Greater Caldwell NC-Alexander NC-Catawba NC-
736 PM EDT Mon Aug 24 2020

...A HEAVY RAIN SHOWER WILL IMPACT NORTH CENTRAL CATAWBA...WESTERN
ALEXANDER AND EASTERN CALDWELL COUNTIES UNTIL 815 PM EDT...

At 736 PM EDT, Doppler radar was tracking a heavy rain shower 6 miles
northeast of Lenoir, or near Cedar Rock, moving southeast at 10 mph.

Locations to be impacted include...
Lenoir, Taylorsville, Hickory, St. Stephens, Bethlehem, Cedar Rock,
Lake Hickory, Hudson, Granite Falls and Northlakes.

Very heavy rainfall rates up to 2 inches per hour will be possible in
these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall may flood areas with poor drainage, such as
ditches and underpasses. Avoid these areas and do not cross flooded
roads. Water levels of small streams may also rise rapidly. Seek
higher ground if threatened by flood waters.

&&

LAT...LON 3602 8134 3600 8133 3601 8131 3594 8110
      3571 8127 3590 8156 3604 8145 3605 8145
TIME...MOT...LOC 2336Z 300DEG 10KT 3594 8143

RM
Local storm report, Aug 24, 8:33 PM EDT, 1 minute before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 25, 3:24 PM EDTAreal Flood AdvisoryGSPBuncombe, McDowell115 min

Nearby

Flash Flood Warnings in North Carolina, 2020Every flash flood warning in 2020

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.