Flash Flood Warning 47, NWS Greenville-Spartanburg, SC

427 
WGUS72 KGSP 121020
FFSGSP

Flash Flood Statement
National Weather Service Greenville-Spartanburg SC
620 AM EDT WED SEP 12 2018

NCC023-111-121215-
/O.CON.KGSP.FF.W.0047.000000T0000Z-180912T1215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
McDowell NC-Burke NC-
620 AM EDT WED SEP 12 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 AM EDT FOR
NORTHEASTERN MCDOWELL AND NORTHWESTERN BURKE COUNTIES...

At 616 AM EDT, Doppler radar indicated continued showers over the 
warned area, but rainfall rates have begun to diminish. Rain gages 
report 2 to 3 inch rainfall maxes within the warned area over the 
past 3 hours. Rainfall rates should be one-half inch per hour or 
less through 8 AM, but flooding may still develop given the recent 
heavy rainfall. 

Some locations that will experience flooding include...  
North Cove, Ashford, Woodlawn, Jonas Ridge, Linville Falls, the 
Blue Ridge Parkway-Linville Falls To Grandfather and Blue Ridge 
Parkway-Little Switzerland To Linville. Flooding will also likely 
develop along Upper Creek, Warrior Fork, and tributaries to the 
Linville River through 8 AM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Most flood deaths occur in vehicles. Do not attempt to cross
water-covered roadways, bridges, or low-level crossings. Only a few
inches of rapidly flowing water can carry away your vehicle. It is 
not worth the risk. Please TURN AROUND, DON'T DROWN. Be especially 
cautious at night when it is harder to recognize the dangers of 
flooding.

When it is safe to do so, please report flood waters or landslides
flowing over roads or threatening property to the National Weather
Service by calling toll free, 1, 800, 2 6 7, 8 1 0 1, by posting on
our Facebook page, or via Twitter using hashtag NWSGSP. Your message
should describe the event and the specific location where it
occurred, including roadways, nearby cross streets, stream names and
other landmarks.

&&

LAT...LON 3598 8187 3598 8186 3592 8175 3572 8201
      3579 8212 3585 8205 3586 8203 3589 8202
      3587 8200 3589 8198 3591 8198 3593 8195
      3594 8196 3600 8190

$$

HG

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
337 AM EDT Wed Sep 12 2018

.SYNOPSIS...
A stationary front will remain draped over the Appalachians through
midweek, bringing showers and thunderstorms to our area. Hurricane
Florence may make landfall somewhere along the Carolina coast late
Thursday or early Friday. There will be an increasing threat for
flooding through the weekend and next week as the remnants of
Florence drifts slowly inland.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 AM: KGSP radar is showing showers and a few thunderstorms
continuing to develop in the upslope zone along the northern parts
of the Blue Ridge early this morning. The 00Z NAMNest handled this
activity much better than the recent HRRR runs, and it pushes it
northward along the northern Blue Ridge through daybreak. Forward
progress has slowed a bit, but any lingering flash flood issues
should be confined to the existing Flash Flood Warning for far
northern sections through daybreak. Any other showers around the
region this morning will remain spotty.

Otherwise, a 592 to 594 dm 500 mb ridge will remain draped over the
forecast area today through Thursday as Hurricane Florence
approaches the Carolina coastline well to the east. The main forcing
mechanism for our region will be continued easterly upslope flow at
low levels. Instability will be best in the lower piedmont this
afternoon, but terrain forcing will remain highest along the eastern
escarpment of the mountains, and also along the ridge tops. Will
feature numerous showers and thunderstorms over the mountains, and
high end scattered PoPs east given the moist boundary layer. Diurnal
activity will then wane steadily tonight, with continued mild
minimum temperatures some 10 degrees above climatology.

The subsidence and drying zone on the western fringe of the Florence
circulation will drift west across our forecast area on Thursday.
Instability will be much less, and more of a NE component to the
surface wind will limit PoPs. Despite the northeast winds,
temperatures will rebound slightly given the better insolation and
subsidence.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
As of 130 AM EDT Wednesday: The abbreviated short term picks up 00Z
Friday with strong upper ridging over the eastern CONUS and a strong
upper high centered off the Mid-Atlantic states steering Florence
into the coast of the Carolinas. Confidence in the track of Florence
leading up to landfall has increased, and an initial approach very
close the the Wilmington, NC area Thursday evening appears more and
more likely at this point. Florence will then stall along the NC
coast, so the main driver of our local weather on Friday will be a
very weak remnant frontal boundary draped across the southern
Appalachians and Atlantic moisture transport from Florence's large
circulation. Pops Friday are mainly diurnal in nature and favor the
eastern parts of our forecast area (closer to Florence) and the
higher terrain closer to the surface boundary. Winds could be breezy
on Friday in areas east of I-77 as the far outer circulation of
Florence expands inland, but with the current track forecast
stalling it near the coast, even max gusts should remain about 25
mph of less. Max temps will be 5-10 degrees above average due to the
strong eastern upper ridge. It should be noted that though
confidence in this part of the forecast is increasing, any track
shifts that bring Florence inland sooner could mean more significant
wind and rain impacts in our area on Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 300 AM EDT Wednesday: Heavy rainfall and flooding as a result
of Florence will be the main threats to monitor in the medium range
forecast. While there remains a very large amount of uncertainty in
Florence's exact track once it moves inland, confidence in impacts
to our area is increasing rapidly. Preparations for flooding
rainfall, landslides in mountainous areas, and gusty winds resulting
in power loss should be completed as soon as possible.

With the new track shifts rather dramatically southward over the
past 24 hours, it appears likely our area will be on the north/east
side of Florence after it is able to resume motion and move inland
due to a stronger ridge developing over the Midwest. Put simply,
this is not a good place to be in a tropical cyclone that is moving
inland, and implies the potential for more serious impacts in our
forecast area, especially as far as rainfall is concerned.
Florence's now slower motion also increases the risk of serious
hydro concerns as the system drifts southward along the SC coast on
Saturday before swinging inland over western SC/eastern GA on
Sunday. The exact area where highest rainfall totals would set up
remains a question, though a good starting place would assume very
healthy totals (enough to produce flooding and potential landslides)
in the normal upslope zones along the Blue Ridge Escarpment.
Guidance is attempting to create another NW/SE oriented axis of
heavy rainfall across central SC, and though this exact positioning
will likely change, it raises some alarms as far as flooding
potential in Upstate SC and NE GA, on top of the Piedmont and
mountains of western NC. Heavy rainfall associated with Florence and
an approaching frontal boundary may last through next Tuesday, and
potentially past the end of the medium range forecast.

The (maybe only) upside to Florence's slower motion would be
slightly lessened wind impacts. Because it will stall and sit with
much of its circulation inland from Thursday through Saturday,
weakening will likely occur such that only minimal tropical storm
force gusts may be able to make it into our area, perhaps by late
Friday night at the earliest. Of course, with soil expected to be
saturated due to heavy rainfall, it won't necessarily take tropical
storm force winds to knock down some trees and lead to power loss.
Breezy to gusty winds Friday night through Sunday will therefore
remain a concern, especially in the southeastern third of our
forecast area where Florence's outer circulation would arrive first.
Finally, though it is a little early to get into the details,
tropical cyclone tornado potential may now be in play due to the GSP
area's eventual positioning in the NE quadrant of Florence after it
moves inland. Tornado potential will be heavily dependent on the
finer details of the exact track of Florence. Awareness of the
forecast is urged for all areas of the GSP forecast area as
Florence's inland track is further refined and flooding, strong
wind, and tornado threats become clearer.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: With lingering convection moving north along
the Blue Ridge, and away from KAVL, the primary concern the rest of
the morning will be lowering stratus in moist, easterly flow across
the TAF sites. Anticipate clouds filling in at IFR levels early this
morning, with spotty LIFR at times around daybreak. Cloud bases will
improve very slowly today given the continued easterly flow and
deeper moisture up the column to limit instability. Expect MVFR cigs
to linger at least into early afternoon, if not longer. Surface
winds will toggle northeasterly, except remaining southeasterly at
KAVL through the period. Shower and thunderstorm chances ramp up
again mainly during the afternoon and evening. Will add categorical
showers at KAVL and also PROB thunder throughout mainly during the
18Z to 00Z period. Spotty lower stratus will return late in the
period as well.

Outlook: Shower and thunderstorm coverage may come down a bit on
Thursday as a subsidence drying zone west of Florence moves across
the region. Tropical conditions will then approach from the east
late Friday through the weekend with the Florence circulation.
Strong gusty winds, heavy rainfall, and associated restrictions may
develop and worsen through the weekend.

Confidence Table...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       Med   77%     High  82%     High  92%     High 100%
KGSP       High  86%     High  82%     High 100%     High 100%
KAVL       Med   65%     High  81%     High  98%     High  82%
KHKY       Low   44%     Med   76%     High  95%     High  87%
KGMU       High  91%     High  82%     High 100%     High 100%
KAND       High  95%     Med   78%     High 100%     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 and ensemble forecasts
are available at the following link:

www.weather.gov/gsp/aviation

&&

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

&&

SYNOPSIS...Carroll
NEAR TERM...HG
SHORT TERM...Carroll
LONG TERM...Carroll
AVIATION...HG

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
428 AM EDT Wed Sep 12 2018

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-130830-
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-
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-Chester-Greenwood-
428 AM EDT Wed Sep 12 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 storms will develop across the area this
afternoon and evening. Storms will be slow-moving, and heavy rainfall
could lead to isolated flash flooding. Any storm could contain
frequent cloud-to-ground lightning and gusty winds.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Impacts from heavy rainfall due to Tropical Cyclone Florence are
becoming increasingly likely late this week into early next week.
Preapredness measures for flooding rain, landslides in mountainous
areas, and gusty winds that could damage trees and power lines should
be taken. The track of Tropical Cyclone Florence will need to be
closely monitored by interests across the western Carolinas and
northeast Georgia throughout the week. Please continue to follow the
latest forecasts from the National Hurricane Center.

.SPOTTER INFORMATION STATEMENT...

None.

Carroll

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
256 AM EDT WED SEP 12 2018

NCZ033-050-501>506-120815-
McDowell Mountains NC-Caldwell Mountains NC-Burke Mountains NC-
Greater Burke NC-Greater Caldwell NC-Eastern McDowell NC-Mitchell NC-
Avery NC-
256 AM EDT WED SEP 12 2018

...SHOWERS AND THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAINFALL
ACROSS THE NORTHERN BLUE RIDGE MOUNTAINS IN WESTERN NORTH CAROLINA
THIS MORNING...

At 249 AM EDT, Doppler radar was tracking a series of showers and
thunderstorms moving slowly northward across the area from Old Fort
to near Blowing Rock. These showers were producing rainfall at rates
nearing one inch per hour in the heaviest downpours. Additional
heavy rain rates are likely through at least 4 AM this morning .

Locations to be impacted include...
Lenoir, Marion, Spruce Pine, Gamewell, Blowing Rock In Caldwell
County, Cedar Rock, Linville Falls, B.R. Parkway-Linville Falls To
Grandfather, Lake James State Park and Table Rock.

Low spots may see deep standing and running water through daybreak.

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 8134 3601 8134 3561 8199
      3582 8214 3584 8214 3611 8181 3612 8169
TIME...MOT...LOC 0649Z 234DEG 31KT 3594 8182

HG