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 18, 1:39 PM EST, 2 hours 6 minutes earlier.
Area forecast discussion, May 18, 1:39 PM EST, 2 hours 6 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
239 PM EDT Fri May 18 2018
.SYNOPSIS...
The threat for numerous showers and a few thunderstorms will linger
into Saturday as a slow moving low pressure system impacts our
region. Locally heavy rainfall will remain possible until the low
departs. High temperatures will be near to just above normal and low
temperatures about ten degrees above normal.
&&
.NEAR TERM /THROUGH SATURDAY/...
A broad upper level trof continues to spin across the South
maintaining deep and moist s/ly flow into the FA. This pattern will
change little during the period...with some n/ly lift expected by
Sat afternoon. Very little change is fcst/d in pwat values which are
running abv seasonal levels. With decent diff heating and tall
skinny CAPE...low-top convection has spawned a few short-lived
general tstms. These cells are generally moving to the north arnd 20
mph...however some anchoring is noted across the srn BR where there
could be isol new hydro issues over the next couple hrs. The FF.A
still looks good as the best precip amts will generally fall across
the higher terrain this afternoon and into the evening. The hi-res
guidance shows a decreasing chance of activity across the piedmont
this afternoon and this makes sense with convg zones noted upstream
over cent GA and the Midlands.
Hydro-wise...the advisories and warnings look to be in good shape as
runoff from earlier precip continues in an expected fashion. Will
expect less thunder chances overnight...yet still a high PoP -shra
thru the morning with a continued hydro threat across the srn BR.
Thunderstorms will once again be possible by mid-day Sat within a
persistent and high confidence synoptic pattern. Mins overnight will
be held abt 10 degrees F abv normal with widespread low cloud cover.
Maxes Sat will be right arnd normal and with high sfc td/s it will
feel rather muggy once again.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 225 PM EDT Friday: Subtropical anticyclone remains anchored
off the Southeast Atlantic coast throughout the period. Another
upper low, although weaker and not well defined, will move out of
the Gulf of Mexico into the Gulf coast states by Monday. These
features keep a moist south to southwest low level flow across the
area each day. The good news is the deep tropical moisture fetch
will not return during this period. However, instability will
increase each day, along with decent upper divergence, keeping the
threat of mainly diurnal convection in place. Greatest coverage
continues to be across the mountains both days with high end
scattered coverage elsewhere. Shear is relatively weak both days,
but surface delta theta-e values increase with steadily drying mid
levels. This leads to an increasing threat of severe thunderstorms
each day, but these should remain isolated as overall DCAPE values
remain on the low side. Heavy rain is possible but the threat is not
as widespread as in previous days. Still, the wet antecedent
conditions could make flooding possible with lower rainfall amounts.
Highs will be nearly steady around 5 degrees above normal. Lows will
be nearly steady as well but around 10 degrees above normal.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 200 PM EDT Friday: Still little airmass change expected as the
medium range begins Monday night. Models are generally plagued by
disagreement in the finer details of the forecast, which
unfortunately make all the difference in a nebulous pattern like the
present one. A Bermuda high will remain off the east coast in the
Atlantic (welcome to summertime), with the southeast on the northern
periphery of an upper subtropical high. Some type of surface
stationary boundary will likely be laid over the Carolinas through
much of the next work week with little progression out of the area
expected. The GFS does spin up an upper/surface low over the
northern Gulf and swing it up towards our area Wednesday, but that
is likely an artifact of a known convective feedback problem in the
GFS (the parallel FV3 core has it too while the low is absent on all
other global models, suggesting this is a GFS model physics issue).
I've therefore favored the ECMWF through much of the medium range.
As far as sensible weather, the Bermuda high will induce weak
southerly flow over the area, though it is not as persistent our
stout as it has been over the past week. PWATs will remain elevated,
but in the absence of much large-scale forcing, a mostly diurnal
pattern favoring afternoon showers and thunderstorms will persist
through next week. Shower and thunderstorm coverage should be
decreased from this week, and chances of any flooding or severe
storms do not stand out any particular day next week at the moment.
The pattern we will enter into next week looks distinctly summer-
ish, as a matter of fact, just with a bit more moisture than usual
to work with. Max temperatures will increase a little to just above
average, with lows remaining about 10 degrees above average.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: A highly moist airmass will continue to lift
across the area thru the period. This will create widespread -shra
and perhaps a few short-lived general tstms at times. CIGs will
remain VFR to MVFR this afternoon all sites...then drop overnight
into more widespread MVFR with IFR likely over most terminals arnd
daybreak. Thunder activity shud wane overnight with increasing
chances by late morning.
Outlook: Unsettled weather will continue into the weekend with
isolated to scattered SHRA/TSRA throughout the day/night periods and
deteriorating restrictions at times.
Confidence Table...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT High 87% Med 77% High 86% High 91%
KGSP High 90% High 83% High 80% High 93%
KAVL High 88% High 84% High 81% High 92%
KHKY High 83% High 82% High 90% High 90%
KGMU High 92% High 88% High 88% High 92%
KAND High 95% High 86% Med 71% 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
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Flash Flood Watch until 8 PM EDT this evening for GAZ010.
NC...Flash Flood Watch until 8 PM EDT this evening for NCZ033-049-
050-053-062>065-501-503-505-507-509.
SC...Flash Flood Watch until 8 PM EDT this evening for SCZ001>003.
&&
SYNOPSIS...Carroll
NEAR TERM...SBK
SHORT TERM...RWH
LONG TERM...Carroll
AVIATION...SBKHazardous weather outlook, May 18, 9:09 AM EST, 6 hours 36 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
1009 AM EDT Fri May 18 2018
GAZ017-018-026-028-029-NCZ035>037-048-051-052-056>059-068>072-082-
502-504-506-508-510-SCZ004>014-019-191415-
Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-Davie-
Madison-Swain-Haywood-Catawba-Rowan-Graham-Northern Jackson-
Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union-Greater Caldwell-
Greater Burke-Eastern McDowell-Greater Rutherford-Eastern Polk-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Cherokee-York-Anderson-Abbeville-Laurens-Chester-Greenwood-
1009 AM EDT Fri May 18 2018
This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.
.DAY ONE...Today and Tonight.
Numerous showers and thunderstorms will continue across the area
today. Slow-moving and training storms may produce torrential
downpours over a short period of time, resulting in localized flash
flooding. In addition to the heavy rain potential, cloud-to-ground
lightning and gusty winds will be possible with stronger storms.
Gusty winds could blow down a few trees due to very wet or saturated
soils.
.DAYS TWO THROUGH SEVEN...Saturday through Thursday.
..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.
..Tuesday...No hazardous weather is expected at this time.
..Wednesday...No hazardous weather is expected at this time.
..Thursday...No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
Skywarn spotters are requested to forward any reports of flash
flooding to our office.
GAZ010-NCZ033-049-050-053-062>065-501-503-505-507-509-SCZ001>003-
191415-
Rabun-Avery-Yancey-Mitchell-Buncombe-Macon-Southern Jackson-
Transylvania-Henderson-Caldwell Mountains-Burke Mountains-
McDowell Mountains-Rutherford Mountains-Polk Mountains-
Oconee Mountains-Pickens Mountains-Greenville Mountains-
1009 AM EDT Fri May 18 2018
...FLASH FLOOD WATCH IN EFFECT UNTIL 8 PM EDT THIS EVENING...
This Hazardous Weather Outlook is for northeast Georgia, western
North Carolina and upstate South Carolina.
.DAY ONE...Today and 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.
In addition to the flooding potential, isolated to scattered
thunderstorms will be possible. These storms could produce cloud to
ground lightning, gusty winds, and an enhanced threat of heavy or
excessive rainfall. Gusty winds could blow down a few trees due to
very wet or saturated soils.
.DAYS TWO THROUGH SEVEN...Saturday through Thursday.
..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.
..Tuesday...No hazardous weather is expected at this time.
..Wednesday...No hazardous weather is expected at this time.
..Thursday...No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
Skywarn spotters are requested to forward any reports of flash
flooding to our office.
In the hours before
Special weather statement, May 18, 10:07 AM EST, 5 hours 38 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1107 AM EDT FRI MAY 18 2018
NCZ035-056-069-070-181600-
Gaston NC-Lincoln NC-Alexander NC-Catawba NC-
1107 AM EDT FRI MAY 18 2018
...A CLUSTER OF HEAVY SHOWERS AND SOME THUNDERSTORMS WILL IMPACT
CENTRAL CATAWBA...ALEXANDER...CENTRAL LINCOLN AND NORTHWESTERN GASTON
COUNTIES UNTIL NOON EDT...
At 1103 AM EDT, Doppler radar was tracking a cluster of heavy showers
and some thunderstorms with cloud-to-ground lightning
along a line from Cherryville, to Lincolnton, to Newton, to Conover
to Lake Hickory, to Bethlehem, Taylorsville, and Ellendale,
moving north at 20 mph.
Locations to be impacted include...
Hickory, Newton, Lincolnton, Taylorsville, St. Stephens, Conover,
Bethlehem, Maiden, Stony Point and Claremont.
In addition to some cloud-to-ground lightning, extreme rainfall
rates in excess of 3 inches per hour will be possible in these areas.
These rates will produce accumulations of 1-3 inches in 60-90
minutes. Therefore, this area may see localized flooding and
ponding on roadways. Drivers are encouraged to exercise caution.
This product may be upgraded to a Flood Advisory if rainfall
persists.
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.
Lake Hickory is in the path of these storms. Cloud to ground
lightning and gusty winds will create dangerous boating conditions.
Move to shore immediately.
&&
LAT...LON 3599 8100 3596 8100 3586 8104 3580 8108
3578 8111 3573 8106 3533 8118 3534 8137
3569 8132 3574 8138 3580 8133 3592 8134
3600 8133 3603 8127 3604 8119 3603 8117
3604 8113 3603 8107 3605 8103
TIME...MOT...LOC 1505Z 187DEG 16KT 3583 8125
JMPSpecial weather statement, May 18, 10:17 AM EST, 5 hours 28 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1117 AM EDT FRI MAY 18 2018
NCZ501-502-181615-
Caldwell Mountains NC-Greater Caldwell NC-
1117 AM EDT FRI MAY 18 2018
...A LINE OF HEAVY RAIN SHOWERS WILL IMPACT CALDWELL COUNTY
UNTIL 1215 PM EDT...
At 1114 AM EDT, Doppler radar was tracking a line of heavy rain
showers extending from Rhodhiss Lake to Cajah's Mountain,
to Lenoir, to Patterson and Kings Creek. These showers are moving
north at 10-15 mph.
Locations to be impacted include...
Lenoir, Sawmills, Gamewell, Hudson, Cajah's Mountain, Cedar Rock,
Blowing Rock In Caldwell County, Lake Rhodhiss, Granite Falls and
Kings Creek.
Very heavy rainfall rates up to 2 inches per hour will be possible in
these areas. Therefore, this area may see localized flooding and
ponding on roadways. Drivers are encouraged to exercise caution.
This product may be upgraded to a Flood Advisory if the flood threat
increases.
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 3612 8155 3610 8152 3610 8150 3609 8147
3609 8145 3607 8144 3607 8141 3604 8139
3604 8137 3602 8135 3577 8144 3579 8145
3578 8154 3585 8164 3612 8167
TIME...MOT...LOC 1514Z 196DEG 15KT 3604 8151
JMPLocal storm report, May 18, 2:23 PM EST, 1 hour 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
323 PM EDT FRI MAY 18 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0321 PM FLOOD 2 WSW ASHEVILLE 35.57N 82.58W
05/18/2018 BUNCOMBE NC NWS EMPLOYEE
CARRIER PARK IN ASHEVILLE ON THE FRENCH BROAD IS FLOODED.
&&
LVISINLocal storm report, May 18, 2:26 PM EST, 1 hour 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
326 PM EDT FRI MAY 18 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0321 PM FLOOD 1 WSW ASHEVILLE 35.57N 82.57W
05/18/2018 BUNCOMBE NC NWS EMPLOYEE
FRENCH BROAD RIVER PARK IN ASHEVILLE IS FLOODED.
&&
LVISINSpecial weather statement, May 18, 3:13 PM EST, 32 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
413 PM EDT FRI MAY 18 2018
NCZ504-506-508-182045-
Greater Rutherford NC-Greater Burke NC-Eastern McDowell NC-
413 PM EDT FRI MAY 18 2018
...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT SOUTHEASTERN
MCDOWELL...NORTHEASTERN RUTHERFORD AND SOUTHWESTERN BURKE COUNTIES
UNTIL 445 PM EDT...
At 411 PM EDT, Doppler radar was tracking a series of heavy rain
producing showers and thunderstorms developing about miles north of
Rutherfordton, moving northeast at 15 mph.
Locations to be impacted include...
Rutherfordton, Forest City, Lake James State Park, Spindale, Lake
James, South Mountains State Park, Nebo, Green Hill, Thermal City and
Glenwood.
Wind gusts up to 35 mph and very heavy rainfall rates of 1 to 2
inches per hour will be possible in these areas. Expect deep ponding
of water in low-lying 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 3535 8186 3539 8209 3575 8196 3567 8166
TIME...MOT...LOC 2011Z 208DEG 12KT 3550 8192
HG