Flash Flood and Flood in Georgia, May 30 to 31, 2018

Name: Flash Flood and Flood in Georgia, May 30 to 31, 2018
Start: 2018-05-30T01:30
End: 2018-05-31T23:00
Location: Georgia

May 30 to 31, 2018 · NWS GSP · 2 events in 1 county or zone

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $3,000
Crop damage: None recorded
Events: 2

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS GSP wrote it up.

A very moist southeast flow developed northeast of subtropical cyclone Alberto, which made landfall across the western Florida Peninsula on the 28th and moved north across Alabama throughout the 29th. Resultant upslope flow into the southern Appalachians resulted in development of widespread heavy rain showers across northeast Georgia throughout the 29th. By the time the showers tapered off during the 30th, total rainfall of 2-5 inches occurred across Rabun County, resulted in some flash flooding followed by an extended period of high stream flow.

What forecasters said that day

The local office's own words before the first event, 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 the first event at May 30, 1:13 AM EST, 17 minutes earlier.

Area forecast discussion, May 30, 1:13 AM EST, 17 minutes before

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
213 AM EDT Wed May 30 2018

.SYNOPSIS...
Deep tropical moisture will persist over the area through Wednesday
as the remnants of Alberto move northward from Alabama to Kentucky
and eventually to the Great Lakes. A moist airmass will persist into
Friday before southerly flow shifts more to the west. Slightly drier
air will mix in from the west over the weekend.

&&

.NEAR TERM /THROUGH TODAY/...
As of 210 AM EDT Wednesday: Main update for 06Z TAF issuance
along with minor tweaks to temperatures to coincide with latest
trends as the rest of the near term forecast remains on track. A
Flash Flood Watch remains in effect across the FA as several
flooding issues persist across portions of western NC and
northeast GA.

Latest radar imagery depicts the continuation of showers moving
northward, all west of the I-77 corridor. Intensity of showers have
decreased within the past few hours, but nonetheless, they continue
to develop, especially across the upslope areas. Anticipate this
activity to persist well through the early morning hours. Localized
flooding and landslides across the higher terrain continue to be the
primary concerns this morning. With the already saturated ground,
even marginal wind gusts could easily bring down a few trees as well.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
As of 200 PM EDT Tuesday: By the start of the short term period
(Wednesday night), the remnant circulation of Alberto will be over
the midwest getting absorbed by a negatively-tilted shortwave trough
lifting out of the Northern Plains. Upper high in the western
Atlantic combined with the slowly merging Alberto/shortwave will
continue to keep a moist fetch from the Gulf across the Southeast
and toward the Southern Appalachians. The trough will slowly lift
through the period as the upper ridge works down over the Bahamas,
with the deep moisture lifting to the northeast as well. A lingering
shortwave embedded in the pattern will push up the OH/TN Valleys
Thursday night into Friday, bringing another push of precip to area.
At least at the start of the period, PW values remain anomalously
high with deep warm cloud processes. Keeping the Flash Flood Watch
in effect through 12z Thursday looks good for now, though the
additional round of convection Thursday afternoon across the
mountains might be enough to warrant another extension...confidence
just not high enough at this time with QPF in the 6-hr period from
18zThu-00zFri less than 1/2 inch (though with the antecedent
conditions, that might be all it takes). Problem is that instability
will increase, Thu afternoon, both the NAM and GFS are creeping
SBCAPEs upwards of 3000J/kg across the escarpment/foothills/adjacent
Piedmont which could seriously intensify convective rates.

That secondary wave of moisture gets caught up over the mountains
Thursday night into Friday morning and might have a slow start with
convective initiation initially across the Piedmont, but still
enough to increase afternoon Piedmont pops to high chance. Keep pops
going overnight across the mountains with likelies again by Friday
afternoon.

Should see a slow warming trend through the period, pushing 90 for a
high across the Piedmont by Friday afternoon and continued very
muggy (yuck)...heat indices might be pushing the mid-90s with the
dewpoints remaining quite high at around 70 degrees.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 155 PM Tuesday: A southern tier ridge centered over Texas
will try to briefly ridge into our region Friday night into
Saturday but make little progress.  A weak surface frontal boundary
settles southward through the area to provide a very modest airmass
change. However, a digging northern stream trough will approach the
southern and central Appalachians Sunday and then cross the
mountains on Monday. This feature will enhance convection at a time
when CAPE values will be low on Monday. However, looking at Sunday
PM the GFS has 2000 to 3000 CAPE over the western tip of NC and the
upper Savannah Valley at the time when the EC has the axis of trough
crossing our region. Minor vortices crossing our area on Sunday
afternoon could spark strong convection over NE GA and adjacent
areas. Highest POPs Sunday and Monday along with warmer temps than
what we have had recently.  Above climo maxes on Saturday will dip
below climo by Monday, but with mild nighttime mins continuing.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: With the exception of VFR currently at KCLT,
a mixture of MVFR/IFR prevails across a majority of the FA this
morning due to low cigs and lingering light showers which continue
to move northward, especially across the upslope areas. Looking at
latest satellite/ob trends, do anticipate KCLT will deteriorate to
MVFR/IFR within the next hour or two due to low cigs. Similar to the
past few days, expect patchy areas of fog to develop as well towards
morning. Later this morning, do anticipate cigs to improve to MVFR,
and gradually to VFR this afternoon, as daytime heating allows for
the redevelopment of scattered showers and isolated thunderstorms.
Into the evening hours, expect convection to wane, with VCSH
prevailing. Again, a mixture of VFR/MVFR is expected towards the end
of the valid TAf period, with isolated areas of IFR possible. SSE
winds around 5 to 10 kts will prevail.

Outlook: Drier air begins to move into the area towards the end of
the week, with some degree of diurnal convection expected.

Confidence Table...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       High  80%     High  80%     High 100%     High  98%
KGSP       Med   73%     High  83%     High  90%     High  91%
KAVL       High  88%     High  80%     High  96%     High  92%
KHKY       Med   77%     High  82%     High  83%     High  90%
KGMU       High  81%     High  89%     High  91%     High  89%
KAND       Med   72%     High  94%     High  90%     High  90%

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

www.weather.gov/gsp/aviation

&&

.HYDROLOGY...
Heavy rainfall over the past two weeks across much of the forecast
area, particularly the mountains, has set the stage for serious
flooding and landslide issues to possibly develop with any
additional tropical rainfall through mid-week. Numerical model
profiles exhibiting precipitable water values of 1.75 to 2 inches,
and deep warm cloud layers in excess of 12 kft, will make for highly
efficient heavy rainfall processes and further increase the threat
of flash flooding and river flooding. The latest 3/6 hour FFG
guidance values are generally running 2.0 to 3.5 inches and these
will be quite achievable in the expected waves of tropical rain
showers - especially across the higher terrain. Hydro problems will
likely continue through tonight, and possibly through Wednesday
night across the mountains.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Flash Flood Watch through Thursday morning for GAZ010.
     Flash Flood Watch until 8 AM EDT this morning for GAZ017-018-
     026-028-029.
NC...Flash Flood Watch through Thursday morning for NCZ033-048>053-
     058-059-062>065-501>510.
     Flash Flood Watch until 8 AM EDT this morning for NCZ035>037-
     056-057-068>072-082.
SC...Flash Flood Watch through Thursday morning for SCZ001>003.
     Flash Flood Watch until 8 AM EDT this morning for SCZ004>014-
     019.

&&

SYNOPSIS...DEO
NEAR TERM...ARK/SGL
SHORT TERM...JPT
LONG TERM...TDP
AVIATION...SGL
HYDROLOGY...GSP

Hazardous weather outlook, May 29, 11:15 PM EST, 2 hours 15 minutes before

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
1215 AM EDT Wed May 30 2018

GAZ017-018-026-028-029-NCZ035>037-056-057-068>072-082-SCZ004>014-019-
310415-
Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-Davie-
Catawba-Rowan-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-York-Anderson-Abbeville-Laurens-Chester-Greenwood-
1215 AM EDT Wed May 30 2018

...FLASH FLOOD WATCH IN EFFECT UNTIL 8 AM EDT THIS MORNING...

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

..Wednesday...Heavy rain with flooding possible.
..Thursday...Heavy rain with flooding possible.
..Friday...No hazardous weather is expected at this time.
..Saturday...No hazardous weather is expected at this time.
..Sunday...No hazardous weather is expected at this time.
..Monday...No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

GAZ010-NCZ033-048>053-058-059-062>065-501>510-SCZ001>003-310415-
Rabun-Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson-
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-
1215 AM EDT Wed May 30 2018

...FLASH FLOOD WATCH IN EFFECT THROUGH THURSDAY MORNING...

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

..Wednesday...Heavy rain with flooding possible.
..Thursday...Heavy rain with flooding possible.
..Friday...No hazardous weather is expected at this time.
..Saturday...No hazardous weather is expected at this time.
..Sunday...No hazardous weather is expected at this time.
..Monday...No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

None.

In the hours before

Local storm report, May 29, 11:29 PM EST, 2 hours 1 minute before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1229 AM EDT WED MAY 30 2018

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

1200 AM     FLASH FLOOD      3 E ASHEVILLE           35.58N 82.49W
05/30/2018                   BUNCOMBE           NC   SOCIAL MEDIA

            SWANNANOA RIVER FLOODING IN OTEEN NEAR HIGHWAY 81.

&&

HG

Local storm report, May 29, 11:38 PM EST, 1 hour 52 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1238 AM EDT WED MAY 30 2018

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

1120 PM     FLASH FLOOD      OLD FORT                35.63N 82.18W
05/29/2018                   MCDOWELL           NC   BROADCAST MEDIA

            MOST OF DOWNTOWN OLD FORT UNDER WATER DUE TO EXTREME
            FLOODING WITH NUMEROUS EVACUATIONS AND SWIFT WATER
            RESCUES.

&&

HG

Local storm report, May 30, 1:10 AM EST, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
210 AM EDT WED MAY 30 2018

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

0130 AM     DEBRIS FLOW      1 SSW FAIRVIEW          35.51N 82.42W
05/30/2018                   BUNCOMBE           NC   BROADCAST MEDIA

            DEBRIS FLOW ON CANE CREEK RD. ONE LANE OF THE ROAD
            CLOSED.

&&

LEC

Local storm report, May 30, 1:14 AM EST, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
214 AM EDT WED MAY 30 2018

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

0100 AM     FLASH FLOOD      5 SSE MICAVILLE         35.85N 82.18W
05/30/2018                   YANCEY             NC   BROADCAST MEDIA

            HALLS CHAPEL RD CLOSED DUE TO FLOODING OF THE SOUTH TOE
            RIVER

&&

LEC

Local storm report, May 30, 1:17 AM EST, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
217 AM EDT WED MAY 30 2018

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

0216 AM     FLASH FLOOD      2 WNW MARION            35.70N 82.04W
05/30/2018                   MCDOWELL           NC   BROADCAST MEDIA

            STRUCTURE COLLAPSE DUE TO FLOODING ON ROBY CONLEY RD.

&&

LEC

Local storm report, May 30, 1:24 AM EST, 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
224 AM EDT WED MAY 30 2018

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

0221 AM     FLASH FLOOD      4 ENE NEBO              35.73N 81.86W
05/30/2018                   BURKE              NC   BROADCAST MEDIA

            LAKE JAMES CAMPGROUND BEING EVACUATED DUE TO FLOODING.

&&

LEC

The radar

The Greer radar (KGSP), 121 km away, was scanning. The volume nearest the first event began at 06:29 UTC.

Open the radar archive at this moment

Event by event

1 flash flood, 1 flood. Local standard time, as filed.

Flash Flood, Rabun

When: May 30, 1:30 AM EST to 7:00 AM EST
Where: Rabun County, 6.9 mi W of Wiley to 5.25 mi W of Wiley
Cause: Heavy Rain
Property damage: $2,000
Reported by: Emergency Manager
Coordinates: 34.790, -83.541

EM reported that minor flash flooding developed along the Tallulah River downstream of Lake Burton due to dam releases caused by high water levels after 2 to 5 inches of rain fell across western Rabun County throughout the 29th and ealry part of the 30th. A few roads along the river became flooded, including Shady Lane in the Lakemont area. Flooding was also reported elsewhere in the county.

Flood, Rabun

When: May 30, 7:00 AM EST to May 31, 11:00 PM EST
Where: Rabun County, 6.9 mi W of Wiley to 5.25 mi W of Wiley
Cause: Heavy Rain
Property damage: $1,000
Reported by: Emergency Manager
Coordinates: 34.790, -83.541

EM reported that minor flooding continued along the Tallulah River downstream of Lake Burton well after heavy rain ended during the early morning hours of the 30th. A few roads remained flooded along the river, including Shady Lane in the Lakemont area. Flooding also continued elsewhere in the county.

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Georgia in 2018 Every state in 2018 This day in weather history Warnings in Georgia, May 2018

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 760106, 760107.