Flash Flood Warning 67, NWS Greenville-Spartanburg, SC

538 
WGUS72 KGSP 121004
FFSGSP

Flash Flood Statement
National Weather Service Greenville-Spartanburg SC
504 AM EST Thu Nov 12 2020

NCC027-121014-
/O.CAN.KGSP.FF.W.0067.000000T0000Z-201112T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Caldwell NC-
504 AM EST Thu Nov 12 2020

...FLASH FLOOD WARNING FOR CALDWELL COUNTY HAS BEEN REPLACED WITH A 
FLOOD WARNING...

LAT...LON 3604 8137 3581 8153 3594 8177 3611 8168
      3611 8155 3610 8152 3610 8148 3609 8147
      3609 8145 3607 8144 3608 8143 3607 8141
      3604 8139 3604 8140 3604 8138

$$

Krentz

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
109 AM EST Thu Nov 12 2020

.SYNOPSIS...
A plume of deep tropical moisture ahead of a slow moving cold front
will affect the region today and tonight, allowing for widespread
rain. The front is expected to move into the mountains tonight and
then slowly east across the Piedmont of the Carolinas Thursday and
Thursday night. Dry air may move into the region for Friday and into
Saturday, with Tropical Storm Eta remaining well to our southeast.

&&

.NEAR TERM /THROUGH TODAY/...
As of 1250 AM Thursday: Heavier rain showers have been blossoming
across the forecast area, as advertised by the CAMs and op models,
as low-level convergence coupled with increasing upper divergence
intensifies along a slow-moving cold front. Expect increasing hydro
concerns over the next several hours, expanding west to east thru
daybreak. Any severe threat we had, looks lower now, as MUCAPE is
not as high as earlier. But with increasing mid and upper support
and still 30-35 kt of 0-3km shear in the eastern zones, cannot
rule out something getting organized enough for some gusty winds.

Otherwise tonight, convergence along/ahead of the front will
lead to redevelopment of showers. PWATs should manage to increase
slightly ahead of it, even as LLJ remains relatively modest and
veered. During the evening the best convergence will be near the
Escarpment, shifting SE into the early morning hours. A small amount
of remaining CAPE should be present on the warm side of the front
as well; though heights will fall slightly that does not appear
to have much of an impact. Nevertheless, the overall setup for
torrential rainfall will remain in place, but with better low-level
forcing than we are seeing this afternoon. Categorical PoPs return
and the Flood Watch still looks appropriate as-is. NAM and GFS,
along with some of the CAMs, all show an axis of especially high
rainfall rates developing in the morning. The NAM for one shows a
mesolow developing in this area. Though they vary on the specific
timing and location of the resulting band, sometime between 2 AM
and noon it looks likely a portion of our eastern watch area would
experience a more pronounced flash flood risk. The NAM also shows
much stronger 0-1km and 0-3km shear developing in the vicinity of
that mesolow; the mesolow scenario could also result in a brief
HSLC tornado threat in the event some SBCAPE lingers that long.

Precip generally will taper off once the front clears the area,
likely by late morning to midday. We can't completely rule
out redevelopment of isolated to scattered showers in its wake,
but subsidence associated with the incoming sfc high should limit
such. Max temps Thursday will remain well above normal, particularly
in the Piedmont, although several degrees cooler than today. Still,
we have favored the warm end of guidance seeing how we made the
most of the warm airmass today.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
As of 230 PM EST Wednesday: Per latest guidance, anticipate
precipitation to be in the process of tapering off from west to east
at the beginning of the forecast period as the recently passed cold
front nears the Carolina coast and Eta rides northeastward across FL
and up along the Carolina coastline. Additional QPF Thursday night
through Friday afternoon looks to range from a trace to maybe a few
hundredths at most. Otherwise, expect dry and quiet conditions for
the end of the week and into the weekend with clearing skies as sfc
high moves into the OH Valley with flattening upper ridge/nearly
zonal flow aloft Friday night into Saturday. Max temps on Friday
will remain above normal, dropping to normal on Saturday with nearly
a 10 degree difference possible between the two days. Min temps will
remain above normal, though a similar downward trend is expected as
well.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 215 PM EST Wednesday: Dry and quiet conditions are expected
Saturday night into early Sunday with sfc high pressure over the Mid-
Atlantic and upper ridging over the Southeast. Throughout the day on
Sunday, clouds will increase in coverage with the return of SW flow
as an upper trough swinging eastward across the central CONUS
quickly brings a cold front to the western Carolinas and northeast
GA Sunday night, progged to be well east of the area by Monday
morning. Moisture is limited with this system, thus aside from some
light showers across the mountains and potentially across the
southeastern fringes of the FA, do not anticipate much in the way of
QPF per latest guidance. With NW flow ushering in dry air, expect
clouds to scatter out by Monday afternoon, with dry and quiet
conditions for the remainder of the fcst period as sfc high pressure
builds in from the west. Temps will remain above normal through
Monday, dropping below normal Monday night and Tuesday.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: A slow-moving cold front is interacting
with a very moist, tropical air mass across the area to start
the 06z TAFs. Periods of heavy rain showers and isolated tstms
possible at all sites thru 12z, then a gradual shift from west to
east from 12-18z time frame. Drying takes over after 18z, but not
enough to scour out the low cigs, which look to remain generally
IFR to MVFR. The low cigs will likely persist tonight as well, with
guidance showing LIFR possible east of the mountains overnight. The
frontal passage will bring winds around from a light S/SW to N/NE,
clearing KCLT around 17z. There is some hint in the guidance that
winds may become light enough to allow fog to form, but overall,
it looks mostly like a stratus event tonight.

Outlook: Dry high pressure will finally build in Friday, scouring
out the low clouds and any fog that's around Friday morning,
bringing back mostly VFR conditions thru the weekend.

Confidence Table...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       Med   72%     Med   78%     Med   73%     Med   74%
KGSP       Med   72%     Med   71%     High  88%     Med   67%
KAVL       Med   74%     Med   71%     Med   75%     High  93%
KHKY       Med   72%     Med   67%     Med   65%     Med   66%
KGMU       Med   70%     Med   65%     High  82%     Med   64%
KAND       Med   75%     Med   70%     High  88%     Med   69%

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

&&

.CLIMATE...
RECORDS FOR 11-12

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      77 1890     35 1968     56 1929     16 1894
                            1934
   KCLT      81 1989     43 1894     61 1915     24 1894
   KGSP      81 1989     43 1968     58 1935     19 1913

RECORDS FOR 11-13

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      75 1964     32 1906     58 1929     13 1911
                1958
                1938
   KCLT      81 1931     40 1920     63 1879     21 2013
   KGSP      81 1909     40 1920     61 1929     20 1906

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Flood Watch through this evening for GAZ010.
NC...Flood Watch through this evening for NCZ033-035>037-048>053-
     056>059-062>065-068>072-082-501>510.
SC...Flood Watch through this evening for SCZ001>003-005>009-
     012>014.

&&

SYNOPSIS...PM
NEAR TERM...ARK/Wimberley
SHORT TERM...SGL
LONG TERM...SGL
AVIATION...ARK
CLIMATE...

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
657 PM EST Wed Nov 11 2020

GAZ010-NCZ033-035>037-048>053-056>059-062>065-068>072-082-501>510-
SCZ001>003-005>009-012>014-130000-
Rabun-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 NC-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 Pickens-Greater Greenville-Spartanburg-Cherokee-York-Laurens-
Union SC-Chester-
657 PM EST Wed Nov 11 2020

...FLOOD WATCH IN EFFECT THROUGH THURSDAY EVENING...

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, 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.

   Flood Watch.

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

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

   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.

GAZ017-018-026-028-029-SCZ004-010-011-019-130000-
Habersham-Stephens-Franklin-Hart-Elbert-Greater Oconee-Anderson-
Abbeville-Greenwood-
657 PM EST Wed Nov 11 2020

This Hazardous Weather Outlook is for northeast Georgia and upstate
South Carolina.

.DAY ONE...Tonight.

Widespread heavy rainfall with a few embedded thunderstorms are
expected tonight, which may result in localized flash flooding and a
few cloud- to- ground lightning strikes.

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

Through Thursday, a pool of tropical moisture along a cold front may
support heavy rainfall with isolated flash flooding of low lying
areas including near streams and urban areas.

.SPOTTER INFORMATION STATEMENT...

None.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1201 AM EST Thu Nov 12 2020

GAZ010-017-NCZ062-120545-
Rabun GA-Habersham GA-Macon NC-
1201 AM EST Thu Nov 12 2020

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT NORTH CENTRAL
HABERSHAM...RABUN AND SOUTHEASTERN MACON COUNTIES UNTIL 1245 AM
EST...

At 1200 AM EST, Doppler radar was tracking a thunderstorm with
torrential rainfall 6 miles northwest of Clayton, or 4 miles
northwest of Black Rock Mountain State Park, moving northeast at 30
mph.

Locations to be impacted include...
Clayton, Franklin, Highlands, Mountain City, Tiger, Dillard, Sky
Valley, Lake Burton, Black Rock Mountain State Park and Scaly
Mountain.

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 3488 8366 3490 8363 3491 8363 3492 8360
      3494 8360 3495 8355 3499 8355 3500 8348
      3500 8352 3502 8352 3504 8355 3518 8342
      3508 8316 3506 8317 3504 8313 3502 8313
      3473 8357 3481 8366
TIME...MOT...LOC 0500Z 227DEG 27KT 3494 8348

KRENTZ