Alert archive / North Carolina / Flash Flood Warnings in 2020

Flash Flood Warning 47, NWS Greenville-Spartanburg, SC

August 15, 20204 counties in North Carolina

NWS Greenville-Spartanburg, SC issued this flash flood warning at Aug 15, 2020, 2:19 AM EDT for 4 counties in North Carolina. It was in force for 4 hr. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 15, 2020, 2:19 AM EDT (06:19 UTC)
Expired
Aug 15, 2020, 6:15 AM EDT
In force
4 hr
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Emergency
Flash flood emergency
Flood severity
None

Counties Alexander County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC

The radar

The Greer radar (KGSP), 123 km from the middle of the area, began a volume at 06:21 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.

What was reported inside it

TimeReportWhereRemark
Aug 15, 2:48 AM EDTFLASH FLOOD4 Ene Hickory, NCFLOODING OVER SPRINGS RD NE
Aug 15, 3:08 AM EDTFLASH FLOOD3 N Hickory, NCREPORTS OF MULTIPLE SWIFT WATER RESCUES IN AREAS NEAR FALLING CREEK AND SNOW CREEK.
Aug 15, 3:15 AM EDTFLASH FLOOD4 Ne Hickory, NCSNOW CREEK FLOODING FORCED THE CLOSURE OF SNOW CREEK ROAD AND KOOL PARK ROAD NE. FLOODING ALSO OCCURRED ON 12TH AVENUE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 3 storm reports to this flash flood warning; the first came 29 minutes after it went out.

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 00:00Z, 6.3 hours before the alert went out and 133 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 00:00Z on 2020-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 754 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2020-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
754 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
787 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

285 
WGUS52 KGSP 150619
FFWGSP
NCC003-023-027-035-151015-
/O.NEW.KGSP.FF.W.0047.200815T0619Z-200815T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Greenville-Spartanburg SC
219 AM EDT Sat Aug 15 2020

The National Weather Service in Greenville-Spartanburg has issued a

* Flash Flood Warning for...
  Southwestern Alexander County in the piedmont of North Carolina...
  Catawba County in the piedmont of North Carolina...
  Southeastern Burke County in western North Carolina...
  Southeastern Caldwell County in western North Carolina...

* Until 615 AM EDT.

* At 219 AM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 3 inches of rain have fallen, especially across the city of 
  Hickory. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar and automated gauges.

  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...
  Hickory, Newton, St. Stephens, Conover, Longview, Granite Falls, 
  Bethlehem, Maiden, Icard, Hildebran, Claremont, Rhodhiss, Catawba, 
  Mountain View, Hickory Regional Airport, Lake Hickory, Lake 
  Rhodhiss, South Mountains State Park, Startown and Propst.

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.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 3557 8163 3583 8139 3584 8113 3574 8131
      3571 8126 3570 8120 3572 8109 3555 8106

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

RWH
2 follow-up statements
206 
WGUS72 KGSP 150726
FFSGSP

Flash Flood Statement
National Weather Service Greenville-Spartanburg SC
326 AM EDT Sat Aug 15 2020

NCC003-023-027-035-151015-
/O.CON.KGSP.FF.W.0047.000000T0000Z-200815T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Alexander NC-Burke NC-Caldwell NC-Catawba NC-
326 AM EDT Sat Aug 15 2020

...FLASH FLOOD EMERGENCY FOR FALLING CREEK AND SNOW CREEK IN 
HICKORY...

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 AM EDT THIS 
MORNING FOR SOUTHWESTERN ALEXANDER, CATAWBA, SOUTHEASTERN BURKE AND 
SOUTHEASTERN CALDWELL COUNTIES...

At 326 AM EDT, emergency management reported thunderstorms producing 
heavy rain across the warned area. Flash flooding is ongoing with 
swift water rescues occurring.

This is a FLASH FLOOD EMERGENCY for Falling Creek and Snow Creek in 
Hickory. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER 
GROUND NOW!

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Emergency management.

IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER
         GROUND NOW! Life threatening flash flooding of low water
         crossings, small creeks and streams, urban areas,
         highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Hickory, Newton, St. Stephens, Conover, Longview, Granite Falls, 
  Bethlehem, Maiden, Icard, Hildebran, Claremont, Rhodhiss, Catawba, 
  Mountain View, Hickory Regional Airport, Lake Hickory, Lake 
  Rhodhiss, South Mountains State Park, Startown and Propst.

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.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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.

Move to higher ground now! This is an extremely dangerous and 
life-threatening situation. Do not attempt to travel unless you are 
fleeing an area subject to flooding or under an evacuation order.

&&

LAT...LON 3557 8163 3583 8139 3584 8113 3574 8131
      3571 8126 3570 8120 3572 8109 3555 8106

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC

$$

RWH
514 
WGUS72 KGSP 151009
FFSGSP

Flash Flood Statement
National Weather Service Greenville-Spartanburg SC
609 AM EDT Sat Aug 15 2020

NCC003-023-027-035-151019-
/O.EXP.KGSP.FF.W.0047.000000T0000Z-200815T1015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Alexander NC-Burke NC-Caldwell NC-Catawba NC-
609 AM EDT Sat Aug 15 2020

...FLASH FLOOD WARNING WILL EXPIRE AT 615 AM EDT THIS MORNING FOR 
SOUTHWESTERN ALEXANDER, CATAWBA, SOUTHEASTERN BURKE AND SOUTHEASTERN 
CALDWELL COUNTIES...

The heavy rain has ended and flood waters are slowly receding. 
Additional flooding is no longer expected to pose a threat. However, 
high water levels remain across portions of the area and some roads 
are still closed. Please continue to heed the remaining road 
closures.

A Flash Flood Watch remains in effect until 1200 AM EDT Sunday for 
portions of piedmont North Carolina and western North Carolina.

LAT...LON 3557 8163 3583 8139 3584 8113 3574 8131
      3571 8126 3570 8120 3572 8109 3555 8106

$$

RWH

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 15, 2:04 AM EDT, 15 minutes earlier.

Area forecast discussion, Aug 15, 2:04 AM EDT, 15 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
204 AM EDT Sat Aug 15 2020

.SYNOPSIS...
Numerous to widespread showers and thunderstorms are expected
through Saturday with highs slightly below normal. Thunderstorm
chances diminish Sunday then slowly increase through the week. Highs
will be around normal through the first part of the week then fall
below normal.

&&

.NEAR TERM /THROUGH TODAY/...
As of 1020 pm EDT Friday: With shower coverage remaining robust late
this evening across the NC foothills, and the showers being rather
efficient rain producers with more expected overnight, have opted to
extend the Flash Flood Watch for the same areas as the existing FFA
right through Saturday evening.

Otherwise, water vapor imagery shows the base of a digging trough
steadily advancing eastward into central Tennessee late this
evening. Several spokes of convection ahead of this wave are evident
on regional radars across eastern AL, central GA, and central TN,
however this more robust coverage should encounter weakening
instability as it reaches the southern Appalachians and points east
overnight. Will keep relatively high PoPs going through the
overnight hours, especially west and north, but the diminishing
instability should generally keep the precip rates from getting out
of hand, so no expansion in area of the Watch appears necessary
yet.

PoPs will ramp up a bit sooner than typical diurnal trends indicate
on Saturday, as upper DPVA and jet energy begins to push east into
the area. The best 2+ inch precipitable water values of the event
will occur on Saturday, and the deep forcing, abundant moisture and
slightly improved lapse rates should yield more coverage, stronger
storms, and a slight uptick in the hydro threat with any training
cells. Expansions to the Flash Flood Watch could be needed at some
point Saturday where antecedent rainfall conditions are the wettest,
especially across western NC. Expect mild and muggy conditions
overnight, and then below climo maxes Saturday afternoon given all
the cloud cover.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
As of 200 PM EDT Friday: The mid level trof will be pulling east of
the area by Saturday night. We should have some showers and storms
in the evening, but they will move east of the area leaving a dry
overnight period.  As the trof moves east, a drier air mass will
move into the area for Sunday and Monday as northwest mid level flow
develops. There will be a small chance of a shower or storm each day
but conditions should be quiet overall.

Highs both days will be near climo. Slightly lower dewpoints will
make conditions relatively comfortable for mid August.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM EDT Friday: Another mid level trof is expected to
develop to our west for the middle to latter part of next week. This
should act to pull deeper moisture back into the area leading to a
more active, mainly diurnal, convective pattern. The increased cloud
cover and rainfall should keep high temperatures in check and a few
degrees below climo through the period.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and Elsewhere: A cluster of tstms continues to impact KHKY
to start the 06z TAF, but should rain out and shift north over the
next couple of hours. However, overall set up is for expanding SHRA
across the area thru the morning hours as an upper disturbance
approaches from the west. A weak wedge-like boundary has set up,
with IFR cigs north of it across the KHKY area. Not confident it
will reach KCLT, but still expect to see some MVFR cigs developing
there and across the Upstate sites thru daybreak. Rain moving into
the French Broad Valley will support MVFR cigs and possibly vsby. A
lull in precip across the Piedmont during the mid-morning thru
midday, but showers continue across the mountains. Then another
round of widespread convection expected late aftn thru the evening.
the aforementioned boundary may set up near KCLT and could result in
a few hours of SHRA/TSRA around. So will go with prevailing TSRA
from 19-02z at KCLT. Expect very slow drying to begin from the west
right around the end of the TAF period, but with low-level moisture
persisting. Light and variable winds will be mainly S to SW with any
mixing tonight through Saturday, except NW at times in the French
Broad Valley tonight. Winds will be briefly gusty near any
thunderstorms.

Outlook: Slightly less thunderstorm coverage is expected Sunday and
Monday compared to recent days, but perhaps still slightly above
normal as low-level moisture continues. An uptick in thunderstorm
coverage is then likely Tuesday through Wednesday. Fog and low
stratus restrictions will be possible each morning, especially over
the usual mountain valleys.

Confidence Table...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       High  83%     Med   75%     High  99%     High  91%
KGSP       High  83%     High  82%     High  97%     High  97%
KAVL       High  81%     High  85%     High  87%     High  86%
KHKY       Med   76%     Med   76%     High  89%     Med   77%
KGMU       High  84%     High  83%     High  96%     High  97%
KAND       High  85%     Med   75%     High  96%     High 100%

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...Flash Flood Watch through this evening for NCZ033-035>037-056-
     057-501>506.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...HG
SHORT TERM...SCW
LONG TERM...SCW
AVIATION...ARK
Hazardous weather outlook, Aug 14, 10:10 PM EDT, 4 hours 9 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
1010 PM EDT Fri Aug 14 2020

GAZ010-017-018-026-028-029-NCZ048>053-058-059-062>065-068>072-082-
507>510-SCZ001>014-019-160215-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Madison-Yancey-
Mitchell-Swain-Haywood-Buncombe-Graham-Northern Jackson-Macon-
Southern Jackson-Transylvania-Henderson-Cleveland-Lincoln-Gaston-
Mecklenburg-Cabarrus-Union NC-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-
1010 PM EDT Fri Aug 14 2020

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

.DAY ONE...Tonight.

Numerous showers and thunderstorms will continue to develop across
the region through the overnight hours. The primary threats with
these storms will be cloud-to- ground lightning and locally heavy
rainfall. The 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...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

NCZ033-035>037-056-057-501>506-160215-
Avery-Alexander-Iredell-Davie-Catawba-Rowan-Caldwell Mountains-
Greater Caldwell-Burke Mountains-Greater Burke-McDowell Mountains-
Eastern McDowell-
1010 PM EDT Fri Aug 14 2020

...FLASH FLOOD WATCH IN EFFECT THROUGH SATURDAY EVENING...

This Hazardous Weather Outlook is for the northwest Piedmont,
northern foothills, and Avery county in western North Carolina.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Please relay any information about
observed severe weather to the NWS while following all local, state,
and CDC guidelines.

HG

In the hours before

Special weather statement, Aug 14, 10:47 PM EDT, 3 hours 32 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1047 PM EDT Fri Aug 14 2020

NCZ035-036-056-150400-
Iredell NC-Alexander NC-Catawba NC-
1047 PM EDT Fri Aug 14 2020

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT NORTHEASTERN
CATAWBA...SOUTHERN ALEXANDER AND NORTHWESTERN IREDELL COUNTIES UNTIL
MIDNIGHT EDT...

At 1046 PM EDT, Doppler radar was tracking a thunderstorm with
torrential rainfall 6 miles northeast of Hickory, or near St.
Stephens, moving east at 5 mph.

Locations to be impacted include...
Newton, Hickory, St. Stephens, Conover, Bethlehem, Stony Point,
Claremont, Catawba, Lookout Shoals Lake and Lake Hickory.

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 3568 8130 3585 8130 3594 8100 3570 8099
TIME...MOT...LOC 0246Z 256DEG 6KT 3579 8122

08
Local storm report, Aug 15, 1:23 AM EDT, 56 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
123 AM EDT SAT AUG 15 2020

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

0116 AM     FLASH FLOOD      3 S GLEN ALPINE         35.68N 81.78W
08/15/2020                   BURKE              NC   BROADCAST MEDIA

            FLOODING ON WOOD GLEN DR AT TRESTLEWOOD LN

&&

RWH

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 14, 10:47 PM EDTSpecial Weather StatementGSPAlexander73 min
Aug 15, 12:19 AM EDTFlash Flood WarningGSPCatawba6 hr
Aug 15, 12:56 AM EDTFlash Flood WarningGSPBurke, Caldwell6 hr
Aug 15, 4:29 AM EDTAreal Flood AdvisoryGSPAlexander, Catawba5 hr
Aug 15, 10:48 AM EDTRiver Flood AdvisoryGSPHenderson, Transylvania8 hr
Aug 15, 3:09 PM EDTSpecial Weather StatementGSPUnion36 min
Aug 15, 4:04 PM EDTSpecial Weather StatementGSPPolk, Rutherford26 min
Aug 15, 4:28 PM EDTFlash Flood WarningGSPAlexander, Burke, Caldwell, Catawba, Iredell2 hr
Aug 15, 4:33 PM EDTSpecial Weather StatementGSPCleveland27 min
Aug 15, 4:50 PM EDTFlash Flood WarningGSPMecklenburg, Union3 hr
Aug 15, 5:57 PM EDTSpecial Weather StatementGSPIredell33 min
Aug 15, 6:10 PM EDTFlash Flood WarningGSPCatawba, Davie, Iredell, Rowan2 hr
Aug 15, 7:43 PM EDTSpecial Weather StatementGSPCabarrus, Mecklenburg32 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.