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 17, 7:00 PM EST, 1 hour earlier.
Area forecast discussion, May 17, 7:00 PM EST, 1 hour before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
800 PM EDT Thu May 17 2018
.SYNOPSIS...
The threat for numerous showers and a few thunderstorms will linger
for the rest of the week as a slow moving low pressure system
impacts our region. Locally heavy rainfall remains possible each
day. High temperatures will be near normal and low temperatures
about ten degrees above normal.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 800 PM EDT: Main update for 00Z TAF issuance as the rest of
the near term forecast remains on track.
Showers and isolated thunderstorms continue to blossom along the
escarpment and back into northeastern GA this evening while areas
along the I-77 corridor and along and south of the I-85 corridor
remain fairly dry attm. Isolated thunderstorms producing torrential
rainfall in addition to the recent heavy rainfall is leading to some
minor flooding concerns across western NC - these areas lining up
fairly well in conjunction with the Flash Flood Watch currently in
effect. Do anticipate activity will gradually wane into tonight,
however, latest guidance continues to suggest another uptick in
coverage overnight. Will note guidance also has not had the best
handle on activity the past few days, making for a tricky forecast.
Current temperatures in the low to mid 70s will continue to slowly
decrease, with another mild night on tap as overnight low
temperatures will remain above normal, in the mid to upper 60s
across the Upstate and NW Piedmont, cooler across the mountains.
Friday will have the best forcing of any day this period, with an
upper low beginning to swing towards the northeast up the spine of
the Appalachians. This will place the CWFA in an area of favorable
QG ascent tomorrow afternoon, along with the ever-present southerly
upslope flow induced by the surface Bermuda high. Moderate
destabilization (currently progged at 1500-2000 J/kg) is likely
again tomorrow afternoon, and convection will likely again be
widespread, perhaps even more widespread than today. 850mb flow will
also be slightly more stout tomorrow inducing marginally better
shear, and despite the continued very wet profiles, isolated strong
storms with gusty winds and small hail appear more likely tomorrow
than they have any day this week. Max temperatures will be near
climo, with min temps still about 10 degrees above average due to
the persistent moisture across the CWFA.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 230 PM Thursday: Deep southerly flow remains over the area at
the start of the period with an upper low over the midwest, and its
associated trough over the OH and TN valleys, and a subtropical
anticyclone to our east. However, this flow weakens and turns more
southwesterly Saturday as the low opens up and the trough lifts and
begins moving east to the north of the area. The trough moves east
of the area Sunday with weak short wave ridging moving into the OH
valley, but the center of the anticyclone remains in place, although
maybe suppressed slightly to the south. This keeps the deep
southwesterly flow in place. At the surface, the southerly flow is
also replaced with southwesterly flow as ridging associated with the
Bermuda high builds west across the area. This results in somewhat
of a pattern change. There will still be quite a bit of low level
moisture across the area, but the deep tropical fetch will diminish.
Instability will increase each day with steepening lapse rates, but
PW values fall with drier mid level air. This brings an end to the
widespread heavy rainfall threat, but isolated heavy rainfall
remains possible. The increased instability and drier mid levels
leads to an uptick in surface delta theta-e values, increasing the
potential for strong or isolated severe storms, but DCAPE values
remain modest keeping the threat low. Despite these trends, likely
PoP is still needed for Saturday but only for the mountains on
Sunday. The PoP also takes on more of a diurnal trend with these
changes as well. Highs will be around normal Saturday rising to
around 5 degrees above normal for Sunday. Lows will be 5 to 10
degrees above normal each morning.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 245 pm Thursday: The upper pattern for the early part of next
week looks somewhat non-descript as we are stuck in-between an
Atlantic sub-tropical ridge, a weak upper low over the northeast
Gulf of Mexico, and upper ridging over the OH Valley region. Weak
sfc high pressure will be trapped over the region for Monday
and Tuesday, resulting in slightly above normal temps and mainly
diurnal convection. The pattern slowly evolves toward the middle of
the week as a nrn stream short wave moves across the Gt Lakes/OH
Valley/Mid-Atlantic, which may push a sfc boundary down from the
north toward our region. The WPC guidance suggests the boundary
will remain to our north, and going with that scenario would
mean a continuation of mainly diurnal convection given adequate
moisture. The op GFS would drive the boundary down into/across the
western Carolinas during mid-week, which would mean a higher precip
prob and less diurnal variation. The fcst generally goes for the
middle ground, which ends up looking an awful lot like every other
day recently. However, the fcst looks much more interesting out
beyond the end of the medium range. By now some of you are aware of
what the operational GFS and the 00Z ECMWF have cooked up late next
week over the ern Gulf/FL. For the time being, readers are cautioned
to manage their expectations in spite of the general model agreement
on an early-season low pressure system of tropical origin, as a
great deal can and will happen between now and a week from Saturday.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Mainly VFR with areas of MVFR/IFR prevails
this evening as scattered showers and thunderstorms move across
portions of the area. Expect an unsettled weather pattern to persist
through the valid TAF period.
Latest radar imagery depicts showers and isolated thunderstorms
pushing northwestward across the northwestern portions of the FA as
areas along the I-77 corridor and along/south of the I-85 corridor
remain fairly dry. Latest guidance continues to suggested an uptick
in SHRA/TSRA activity overnight, however the forecast remains a
tricky one as the guidance has not had the greatest handle on
SHRA/TSRA activity the past few days. Though confidence remains low
attm, overall, with VCSH/VCTS anticipated through the overnight
period, areas of fog and low cigs along with any heavy downpours
will allow for MVFR/IFR to develop. After daybreak, do anticipate a
brief lull in the activity with a cigs climbing to VFR/marginal MVFR
status, only lowering again in association with any
shower/thunderstorm activity. Southeast winds 5 to 10 mph will
persist, with occasional gusts possible in any convection.
Outlook: Unsettled weather will continue through the end of the work
week, with isolated to scattered SHRA/TSRA throughout the day/night
periods and deteriorating restrictions at times. Over the weekend,
precipitation is expected to return to a more typical
afternoon/evening occurrence.
Confidence Table...
00-06Z 06-12Z 12-18Z 18-00Z
KCLT High 90% High 91% Med 74% Med 79%
KGSP High 89% Med 72% High 86% High 87%
KAVL High 88% High 87% High 81% High 83%
KHKY High 89% High 91% Med 73% Med 69%
KGMU High 92% High 84% High 87% High 92%
KAND High 96% High 89% High 82% High 95%
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 through Friday morning for GAZ010.
NC...Flash Flood Watch through Friday morning for NCZ033-049-050-
053-062>065-501-503-505-507-509.
SC...Flash Flood Watch through Friday morning for SCZ001>003.
&&
SYNOPSIS...JMP
NEAR TERM...Carroll/SGL
SHORT TERM...RWH
LONG TERM...PM
AVIATION...SGLHazardous weather outlook, May 17, 5:29 AM EST, 14 hours 31 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
629 AM EDT Thu May 17 2018
GAZ017-018-026-028-029-NCZ035>037-048-051-052-056>059-068>072-082-
502-504-506-508-510-SCZ004>014-019-181030-
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-
629 AM EDT Thu May 17 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 are expected to redevelop over the
area later 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...Friday through Wednesday.
..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.
..Tuesday...No hazardous weather is expected at this time.
..Wednesday...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-
181030-
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-
629 AM EDT Thu May 17 2018
...FLASH FLOOD WATCH IN EFFECT THROUGH FRIDAY MORNING...
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, mainly this afternoon and evening.
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...Friday through Wednesday.
..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.
..Tuesday...No hazardous weather is expected at this time.
..Wednesday...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.
Lane
In the hours before
Special weather statement, May 17, 3:40 PM EST, 4 hours 20 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
440 PM EDT THU MAY 17 2018
NCZ033-501>505-172115-
McDowell Mountains NC-Caldwell Mountains NC-Burke Mountains NC-
Greater Burke NC-Greater Caldwell NC-Avery NC-
440 PM EDT THU MAY 17 2018
...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT LOCATIONS
ALONG AND EAST OF THE NORTH CAROLINA BLUE RIDGE THROUGH 515 PM
EDT...
At 438 PM EDT, Doppler radar was tracking a series of showers and
thunderstorms with torrential rainfall from 10 miles northwest of
Morganton, or near Table Rock, moving slowly northward just east of
the Blue Ridge.
Locations to be impacted include...
Blowing Rock In Caldwell County, Table Rock, Glen Alpine, Linville
Falls, Gamewell, B.R. Parkway-Linville Falls To Grandfather,
Edgemont, Collettsville, Ashford and Patterson.
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 to develop 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 3612 8155 3610 8152 3610 8150 3609 8147
3609 8145 3607 8144 3607 8141 3606 8140
3573 8178 3589 8198 3592 8198 3612 8176
TIME...MOT...LOC 2038Z 178DEG 4KT 3588 8178
HGSpecial weather statement, May 17, 5:44 PM EST, 2 hours 16 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
644 PM EDT THU MAY 17 2018
NCZ051-172330-
Swain NC-
644 PM EDT THU MAY 17 2018
...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT NORTHEASTERN
SWAIN COUNTY UNTIL 730 PM EDT...
At 642 PM EDT, Doppler radar was tracking a series of showers and
strong thunderstorms impacting the area around 15 miles northwest of
Waynesville, or 4 miles northwest of Balsam Mountain. These showers
were producing rainfall at rates of 1 to 2 inches per hour and
additional rainfall is likely through 730 pm before the showers
dissipate.
Locations to be impacted include...
Smoky Mountains-Balsam Mountain, B.R. Parkway-Smoky Mountains To
Balsam Gap, Smoky Mountains-Oconaluftee and Smoky Mountains-Newfound
Gap.
Rapid stream rises are expected and flooding of low-lying areas
could occur.
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 3566 8333 3565 8331 3567 8329 3569 8326
3569 8322 3567 8318 3564 8320 3563 8318
3560 8319 3558 8317 3555 8316 3553 8317
3552 8324 3564 8337
TIME...MOT...LOC 2242Z 164DEG 21KT 3561 8323
HGSpecial weather statement, May 17, 6:26 PM EST, 1 hour 34 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
726 PM EDT THU MAY 17 2018
NCZ503>508-180015-
Greater Rutherford NC-McDowell Mountains NC-Burke Mountains NC-
Greater Burke NC-Rutherford Mountains NC-Eastern McDowell NC-
726 PM EDT THU MAY 17 2018
...THUNDERSTORMS WITH TORRENTIAL RAINFALL WILL IMPACT MCDOWELL...
NORTHWESTERN RUTHERFORD AND WESTERN BURKE COUNTIES UNTIL 815 PM
EDT...
At 726 PM EDT, Doppler radar indicated showers and thunderstorms
with torrential rainfall along a line extending from 6 miles east of
Marion to 7 miles northwest of Rutherfordton, and moving northwest
at 5 mph.
Locations to be impacted include...
Marion, Old Fort, Linville Falls, B.R. Parkway-Craggy To Little
Switzerland, Lake James State Park, B.R. Parkway-Little Switzerland
To Linville, Lake James, Chimney Rock State Park, B.R.
Parkway-Linville Falls To Grandfather and Nebo.
Very heavy rainfall at rates of 1 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 3571 8179 3535 8208 3541 8216 3540 8221
3547 8225 3550 8222 3552 8223 3553 8217
3559 8229 3562 8227 3569 8229 3574 8219
3580 8216 3585 8210 3585 8205 3588 8202
3587 8200 3593 8195 3595 8196 3599 8191
TIME...MOT...LOC 2326Z 182DEG 6KT 3568 8188 3541 8209
HGSpecial weather statement, May 17, 6:48 PM EST, 1 hour 12 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
748 PM EDT THU MAY 17 2018
NCZ053-065-509-510-180015-
Buncombe NC-Henderson NC-Polk Mountains NC-Eastern Polk NC-
748 PM EDT THU MAY 17 2018
...THUNDERSTORMS WITH TORRENTIAL RAINFALL WILL IMPACT HENDERSON...
WESTERN POLK AND SOUTHEASTERN BUNCOMBE COUNTIES UNTIL 815 PM EDT...
At 747 PM EDT, Doppler radar indicated thunderstorms with torrential
rainfall along a line extending from 10 miles north of Columbus to 13
miles south of Hendersonville, and moving northwest at 10 mph.
Locations to be impacted include...
Hendersonville, Arden, Black Mountain, Mills River, Fletcher, Flat
Rock, Etowah, Fairview In Buncombe County, Mountain Home and Laurel
Park.
Very heavy rainfall rates of 1 to 2 inches per hour will be possible
in these areas. This heavy rain may flood 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 3562 8227 3559 8229 3553 8218 3552 8223
3550 8222 3547 8224 3545 8228 3540 8227
3541 8216 3539 8214 3519 8234 3519 8238
3521 8239 3517 8244 3517 8249 3515 8258
3519 8260 3529 8261 3535 8267 3565 8229
TIME...MOT...LOC 2347Z 151DEG 9KT 3539 8223 3512 8249
HGSpecial weather statement, May 17, 6:52 PM EST, 1 hour 8 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
752 PM EDT THU MAY 17 2018
GAZ010-NCZ062-063-180015-
Rabun GA-Southern Jackson NC-Macon NC-
752 PM EDT THU MAY 17 2018
...THUNDERSTORMS WITH VERY HEAVY RAINFALL WILL IMPACT NORTHERN
RABUN...SOUTHERN MACON AND SOUTH CENTRAL JACKSON COUNTIES UNTIL 815
PM EDT...
At 751 PM EDT, Doppler radar indicated showers and thunderstorms
with very heavy rainfall along a line extending from 17 miles north
of Walhalla to near Clayton, and moving northwest at 15 mph. These
showers were producing 1 to 1.5 inch per hour rainfall rates, and
localized flooding of low-lying areas may result.
Locations to be impacted include...
Franklin, Clayton, Highlands, Mountain City, Tiger, Dillard, Sky
Valley, Cashiers, Lake Glenville and Black Rock Mountain State Park.
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 3524 8330 3523 8328 3524 8323 3523 8322
3526 8307 3508 8304 3505 8306 3502 8303
3500 8310 3497 8312 3480 8347 3494 8358
3495 8355 3499 8355 3500 8348 3500 8352
3502 8352 3504 8356 3507 8357 3510 8360
TIME...MOT...LOC 2351Z 159DEG 14KT 3502 8313 3488 8341
HGSpecial weather statement, May 17, 7:21 PM EST, 39 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
821 PM EDT THU MAY 17 2018
NCZ053-063>065-SCZ001>003-180045-
Buncombe NC-Transylvania NC-Henderson NC-Southern Jackson NC-
Pickens Mountains SC-Oconee Mountains SC-Greenville Mountains SC-
821 PM EDT THU MAY 17 2018
...THUNDERSTORMS WITH TORRENTIAL RAINFALL WILL IMPACT
TRANSYLVANIA...HENDERSON...JACKSON...BUNCOMBE...NORTHWESTERN
GREENVILLE...NORTHWESTERN PICKENS AND NORTHEASTERN OCONEE COUNTIES
UNTIL 845 PM EDT...
At 819 PM EDT, Doppler radar indicated thunderstorms with torrential
rainfall along a line extending from 15 miles north of Columbus to 11
miles northwest of Pickens, and moving west at 10 mph.
Locations to be impacted include...
Hendersonville, Brevard, Downtown Asheville, Arden, Black Mountain,
Mills River, Fletcher, Swannanoa, Flat Rock and Etowah.
Wind gusts up to 35 mph and very heavy rainfall rates of 1 to 2
inchesup 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 3563 8227 3559 8229 3553 8218 3552 8223
3547 8224 3545 8228 3540 8227 3491 8288
3516 8322 3523 8322 3532 8283 3541 8275
3545 8278 3569 8232
TIME...MOT...LOC 0019Z 075DEG 9KT 3547 8224 3495 8289
HG