Alert archive / North Carolina / Flash Flood Warnings in 2020

Flash Flood Warning 44, NWS Greenville-Spartanburg, SC

August 13, 2020Iredell County, Rowan County, North Carolina

NWS Greenville-Spartanburg, SC issued this flash flood warning at Aug 13, 2020, 5:32 PM EDT for Iredell County, Rowan 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 outline as issued.

The facts

Issued
Aug 13, 2020, 5:32 PM EDT (21:32 UTC)
Expired
Aug 13, 2020, 8:45 PM EDT
In force
3 hr
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Flood severity
None

Counties Iredell County, NC, Rowan County, NC

The radar

The Roanoke radar (KFCX), 146 km from the middle of the area, began a volume at 21:35 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 9.5 hours before the alert went out and 83 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 2020-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 804 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 2020-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
804 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
678 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

910 
WGUS52 KGSP 132132
FFWGSP
NCC097-159-140045-
/O.NEW.KGSP.FF.W.0044.200813T2132Z-200814T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Greenville-Spartanburg SC
532 PM EDT Thu Aug 13 2020

The National Weather Service in Greenville-Spartanburg has issued a

* Flash Flood Warning for...
  East Central Iredell County in the piedmont of North Carolina...
  Northwestern Rowan County in the piedmont of North Carolina...

* Until 845 PM EDT.

* At 532 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Statesville, Troutman, Cooleemee, Cleveland, Piedmont Research 
  Station and Woodleaf.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3581 8091 3581 8056 3580 8056 3570 8057
      3568 8091

FLASH FLOOD...RADAR INDICATED

$$

Krentz

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 13, 5:09 PM EDT, 23 minutes earlier.

Area forecast discussion, Aug 13, 5:09 PM EDT, 23 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
509 PM EDT Thu Aug 13 2020

.SYNOPSIS...
Scattered to numerous showers and thunderstorms are expected over
the next few days. High temperatures will be slightly below normal
through the weekend due to ample moisture and increased cloud cover.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 5 pm EDT Thursday: Thunderstorm coverage has focused most
strongly over the NC foothills and Piedmont late this afternoon, but
outflows moving southward should permit another round of numerous
storms to develop along the southern foothills, Upstate SC, and
northeast GA through the evening hours. Although sbCAPE values
remain near 3000 J/kg late this afternoon, warm temperatures aloft
and modest lapse rates are keeping most thunderstorms from becoming
severe. Heavy rainfall will remain the primary threat given the weak
steering flow. With the residual boundaries and SELY upslope flow,
expect activity to linger well into the overnight hours.

Another similar day is expected on Friday, with comparable
instability to the past few days and a continued threat of isolated
severe thunderstorms. The bigger threat will once again be localized
flash flooding from slowly moving cells. Otherwise, high temps will
be near normal for mid-August.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 200 PM EDT Thursday: A mid level trof will traverse the area
this weekend. Friday night, Saturday and Saturday night will feature
scattered to numerous showers and thunderstorms. With precipitable
water values near 2 inches and slow storm motion, some areas could
receive heavy rain and localized flooding is possible. The trof axis
will move through the area by Sunday leading to west to northwest
flow and drying across the area. Pops will be much lower on Sunday.

Due to the increased cloud cover on Saturday, highs will be limited
to the mid 80s in the Piedmont and to around 80 in the mountain
valleys. Highs will climb back into the upper 80s in the Piedmont
and lower 80s in the valleys on Sunday.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 200 PM EDT Thursday: Another mid level trof will develop
across the Ohio and Tennessee Valley for the early to middle part of
next week. The atmosphere will start out drier on Monday but then
moisture quickly for Tuesday and Wednesday. Thus, pops will be on
the increase through the period with locally heavy rainfall possible.

Highs will be near climo on Monday and then a few degrees below
climo for the middle part of the week due to increased clouds and
rain.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
At KCLT and Elsewhere: Another round of thunderstorms this evening
has a good chance of affecting any of the TAF sites with temporary
IFR conditions. Timing is similar to recent days, with thunderstorms
from now until after sunset.  Outside of gusts from storm outflows,
winds are light and variable as a weak upper pattern is in place.
Upper pattern becomes less weak Friday afternoon as a mid-level
shortwave organizes west of the region. This is expected to increase
coverage and duration of storms for Friday afternoon, and give a
more general southwesterly wind direction in areas south of I85.
Some fog and low CIGs are also possible Friday morning, similar to
the pattern seen this morning, especially in mountain valleys
affected by recent rains.

Outlook: Above normal coverage of diurnal convection is expected thru
the upcoming weekend and into early next week. Fog and low stratus
restrictions will be possible each morning, especially over the usual
mountain valleys.

Confidence Table...

            21-03z        03-09Z        09-15Z        15-18Z
KCLT       High 100%     High 100%     Med   73%     High  86%
KGSP       High 100%     High 100%     Med   69%     High  81%
KAVL       High 100%     High  80%     Med   68%     High  86%
KHKY       High 100%     High  97%     Low   36%     High  94%
KGMU       High 100%     High  94%     High  81%     Med   79%
KAND       High 100%     High 100%     High  83%     High  86%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

SYNOPSIS...SW
NEAR TERM...HG/WJM
SHORT TERM...SW
LONG TERM...SW
AVIATION...HG/WJM
Hazardous weather outlook, Aug 13, 4:59 PM EDT, 33 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
459 PM EDT Thu Aug 13 2020

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-142100-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Avery-Alexander-
Iredell-Davie-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Catawba-
Rowan-Graham-Northern Jackson-Macon-Southern Jackson-Transylvania-
Henderson-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union NC-
Caldwell Mountains-Greater Caldwell-Burke Mountains-Greater Burke-
McDowell Mountains-Eastern McDowell-Rutherford Mountains-
Greater Rutherford-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-
459 PM EDT Thu Aug 13 2020

This Hazardous Weather Outlook is for northeast Georgia, Piedmont
North Carolina, western North Carolina, and Upstate South Carolina.

.DAY ONE...Tonight.

Scattered to numerous showers and thunderstorms will continue to
develop across the region through the evening hours, with coverage
slowly diminishing through the early morning hours. The primary
threats with these storms will be frequent cloud to ground lightning,
locally heavy rainfall, and gusty winds. Storms and heavy rain
showers will occasionally become stationary, posing a threat of
excessive rainfall and flash flooding, especially in locations that
have received heavy rainfall over the past few days.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

HG

In the hours before

Special weather statement, Aug 13, 4:06 PM EDT, 1 hour 26 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
406 PM EDT Thu Aug 13 2020

NCZ505>508-132030-
Greater Rutherford NC-McDowell Mountains NC-Rutherford Mountains NC-
Eastern McDowell NC-
406 PM EDT Thu Aug 13 2020

...A STRONG THUNDERSTORM WILL IMPACT SOUTHERN MCDOWELL AND
NORTHWESTERN RUTHERFORD COUNTIES UNTIL 430 PM EDT...

At 406 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles southwest of Marion, or near Old Fort, moving southeast at 10
mph.

Locations to be impacted include...
Marion, Old Fort, Shingle Hollow, Sugar Hill, Pleasant Gardens,
Glenwood, Fero, Dysartsville and Thermal City.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

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 3574 8209 3560 8186 3543 8212 3552 8219
      3553 8218 3553 8217 3555 8221 3561 8226
TIME...MOT...LOC 2006Z 319DEG 7KT 3563 8212

KRENTZ
Special weather statement, Aug 13, 4:28 PM EDT, 1 hour 4 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
428 PM EDT Thu Aug 13 2020

NCZ035>037-056-057-502-504-132115-
Rowan NC-Davie NC-Iredell NC-Greater Burke NC-Greater Caldwell NC-
Alexander NC-Catawba NC-
428 PM EDT Thu Aug 13 2020

...A CLUSTER OF THUNDERSTORMS WILL IMPACT NORTH CENTRAL CATAWBA...
SOUTHWESTERN DAVIE...SOUTHERN ALEXANDER...CENTRAL IREDELL...
SOUTHEASTERN CALDWELL...NORTHWESTERN ROWAN AND EAST CENTRAL BURKE
COUNTIES UNTIL 515 PM EDT...

At 428 PM EDT, Doppler radar indicated the leading edge of a cluster
of thunderstorms along a line extending from 4 miles west of
Mocksville to near Lenoir, and moving south at 10 mph.

Locations to be impacted include...
Statesville, Lenoir, Mocksville, Taylorsville, Hickory, St. Stephens,
Sawmills, Granite Falls, Bethlehem and Hudson.

Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

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 3575 8046 3575 8159 3593 8159 3593 8056
TIME...MOT...LOC 2028Z 342DEG 8KT 3588 8063 3588 8154

KRENTZ
Special weather statement, Aug 13, 4:31 PM EDT, 1 hour 1 minute before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
431 PM EDT Thu Aug 13 2020

NCZ503>506-132100-
McDowell Mountains NC-Burke Mountains NC-Greater Burke NC-
Eastern McDowell NC-
431 PM EDT Thu Aug 13 2020

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN MCDOWELL AND
SOUTHWESTERN BURKE COUNTIES UNTIL 500 PM EDT...

At 431 PM EDT, Doppler radar was tracking a strong thunderstorm near
Marion, moving northeast at 5 mph.

Locations to be impacted include...
Marion, Lake James State Park, Lake James, Nebo and Pleasant Gardens.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

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 3561 8204 3573 8211 3584 8190 3566 8180
TIME...MOT...LOC 2031Z 244DEG 5KT 3570 8200

KRENTZ
Special weather statement, Aug 13, 4:33 PM EDT, 59 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
433 PM EDT Thu Aug 13 2020

SCZ001-132100-
Oconee Mountains SC-
433 PM EDT Thu Aug 13 2020

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL OCONEE COUNTY UNTIL 500
PM EDT...

At 432 PM EDT, Doppler radar was tracking a strong thunderstorm 6
miles northwest of Walhalla, or over Oconee State Park. This storm
was nearly stationary.

Locations to be impacted include...
Walhalla, Oconee State Park, Salem, Lake Keowee, Mountain Rest and
Long Creek.

Wind gusts up to 40 mph and pea size hail 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 3488 8323 3489 8322 3488 8321 3492 8317
      3492 8316 3493 8316 3493 8299 3477 8296
      3474 8299 3475 8328
TIME...MOT...LOC 2032Z 002DEG 2KT 3486 8311

KRENTZ
Special weather statement, Aug 13, 4:37 PM EDT, 55 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
437 PM EDT Thu Aug 13 2020

NCZ036-057-071-072-132100-
Rowan NC-Iredell NC-Cabarrus NC-Mecklenburg NC-
437 PM EDT Thu Aug 13 2020

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN CABARRUS...
SOUTHEASTERN IREDELL...NORTH CENTRAL MECKLENBURG AND SOUTHWESTERN
ROWAN COUNTIES UNTIL 500 PM EDT...

At 437 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles northwest of Kannapolis, or near Enochville. This storm was
nearly stationary.

Locations to be impacted include...
Kannapolis, Mooresville, Davidson, China Grove, Landis, Enochville,
Coddle Creek Reservoir, Cornelius and Mount Ulla.

Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

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 3561 8054 3544 8061 3547 8087 3572 8075
TIME...MOT...LOC 2037Z 110DEG 4KT 3556 8066

KRENTZ
Special weather statement, Aug 13, 5:00 PM EDT, 32 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
500 PM EDT Thu Aug 13 2020

NCZ035>037-056-057-502>506-508-132145-
Rowan NC-Greater Rutherford NC-Davie NC-McDowell Mountains NC-
Iredell NC-Burke Mountains NC-Greater Burke NC-Greater Caldwell NC-
Alexander NC-Eastern McDowell NC-Catawba NC-
500 PM EDT Thu Aug 13 2020

...A CLUSTER OF THUNDERSTORMS WILL IMPACT EASTERN MCDOWELL...
CATAWBA...NORTHEASTERN RUTHERFORD...DAVIE...SOUTHERN ALEXANDER...
IREDELL...SOUTHERN CALDWELL...NORTHWESTERN ROWAN AND BURKE COUNTIES
UNTIL 545 PM EDT...

At 458 PM EDT, Doppler radar indicated the leading edge of a cluster
of thunderstorms along a line extending from 7 miles north of
Salisbury to near Marion, and moving south at 5 mph.

Locations to be impacted include...
Hickory, Salisbury, Statesville, Morganton, Newton, Marion,
Mocksville, Taylorsville, Lenoir and St. Stephens.

Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

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 3562 8033 3556 8158 3557 8167 3558 8169
      3556 8169 3555 8209 3586 8195 3593 8112
      3606 8093 3605 8056 3591 8038 3589 8038
      3588 8042 3584 8039 3585 8042 3583 8043
      3584 8048 3583 8049 3573 8045 3572 8035
TIME...MOT...LOC 2058Z 001DEG 6KT 3577 8044 3565 8202

KRENTZ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 8:08 PM EDTSpecial Weather StatementGSPJackson37 min
Aug 13, 12:30 AM EDTSpecial Weather StatementGSPDavie30 min
Aug 13, 2:03 PM EDTSpecial Weather StatementGSPBuncombe27 min
Aug 13, 2:35 PM EDTSpecial Weather StatementGSPHenderson25 min
Aug 13, 2:56 PM EDTSpecial Weather StatementGSPCaldwell34 min
Aug 13, 2:59 PM EDTSpecial Weather StatementGSPHenderson31 min
Aug 13, 3:25 PM EDTSpecial Weather StatementGSPBurke35 min
Aug 13, 3:50 PM EDTSpecial Weather StatementGSPAlexander, Caldwell, Davie40 min
Aug 13, 4:06 PM EDTSpecial Weather StatementGSPMcDowell24 min
Aug 13, 4:28 PM EDTSpecial Weather StatementGSPAlexander, Iredell47 min
Aug 13, 4:31 PM EDTSpecial Weather StatementGSPMcDowell29 min
Aug 13, 4:37 PM EDTSpecial Weather StatementGSPRowan23 min
Aug 13, 5:00 PM EDTSpecial Weather StatementGSPAlexander, Burke, Catawba, Davie, Iredell, Rowan45 min
Aug 13, 5:17 PM EDTAreal Flood AdvisoryGSPCatawba, Iredell, Rowan3 hr
Aug 13, 5:41 PM EDTSevere Thunderstorm WarningGSPCatawba, Iredell, Lincoln49 min
Aug 13, 5:45 PM EDTSpecial Weather StatementGSPCleveland30 min
Aug 13, 5:48 PM EDTSpecial Weather StatementGSPLincoln27 min
Aug 13, 6:03 PM EDTSevere Thunderstorm WarningGSPGaston, Lincoln, Mecklenburg27 min
Aug 13, 6:11 PM EDTSevere Thunderstorm WarningGSPCleveland, Rutherford49 min
Aug 13, 6:30 PM EDTSevere Thunderstorm WarningGSPGaston, Lincoln, Mecklenburg17 min
Aug 13, 6:38 PM EDTSpecial Weather StatementGSPCleveland52 min
Aug 13, 6:54 PM EDTSpecial Weather StatementGSPMcDowell36 min
Aug 13, 6:56 PM EDTSevere Thunderstorm WarningGSPCleveland, Gaston11 min
Aug 13, 7:36 PM EDTSpecial Weather StatementGSPMcDowell24 min
Aug 13, 7:57 PM EDTSpecial Weather StatementGSPBuncombe33 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.