River Flood Advisory 16, NWS Greenville-Spartanburg, SC

766 
WGUS82 KGSP 170820
FLSGSP

Flood Advisory
National Weather Service Greenville-Spartanburg SC
420 AM EDT Tue Aug 17 2021

...The Flood Advisory is replaced with a River Flood Warning for the 
following rivers in North Carolina...

  French Broad River Near Fletcher affecting Buncombe and Henderson 
  Counties.

NCC021-089-170930-
/O.CAN.KGSP.FL.Y.0016.000000T0000Z-210817T0820Z/
/FLCN7.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.NO/
420 AM EDT Tue Aug 17 2021

...The Flood Advisory for the French Broad River Near Fletcher has 
been replaced...

The Flood Advisory is replaced by a river flood warning for
  the French Broad River Near Fletcher.
* At 2:30 AM EDT Tuesday the stage was 8.3 feet and cresting.  
  Additional rises are expected Tuesday morning.
* Minor Flood Stage is 13.0 feet.
* Forecast...The river is expected to rise above Action/Advisory 
  Stage by Tuesday afternoon and crest Wednesday.  The crest may 
  exceed the Minor Flood Stage of 13.0 feet and may reach as high as 
  15.0 feet. The river will gradually recede later Wednesday into 
  Thursday.


&&

LAT...LON 3538 8257 3541 8257 3550 8262 3550 8254
      3540 8250 3537 8250

$$

JMP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
213 AM EDT Tue Aug 17 2021

.SYNOPSIS...
A surface front will remain nearly stationary across the area for
the next few days. The remnants of Fred is expected to generate
heavy rainfall from the Gulf coast to the Tennessee River Valley
from tonight into mid week as the circulations move up the
Appalchians. Expect cooler than normal temperatures into mid week.
Abundant tropical moisture will continue across the region through
much of the week leading to areas of heavy rainfall and isolated
strong thunderstorms.

&&

.NEAR TERM /THROUGH TODAY/...
As of 205 am EDT: The forecast remains on track with the center
of T.S. Fred moving northward over southeast AL and southwest GA
at this early hour. Seeing plenty of light returns on the radar,
indicating ongoing light rain/sprinkles. Meanwhile, scattered
showers were developing over the Piedmont, which really could
happen at any time at any location in this very moist S/SE upslope
regime. Rain rates remain tame. No changes to the Flash Flood
Watch yet.

The other concern for tomorrow will be the severe threat, especially
tornadoes. The new SPC Day 1 has a slight risk for roughly the
entire area except for all but the TN border counties. As with
any tropical system, instability is not particularly impressive
(500-750 J/kg SBCAPE) but shear will be 35-45 kt, with impressively
curved hodographs. 5% tornado risk (and corresponding 5% wind risk)
both perfectly in line with current thinking, with best time frame
according to SPC HREF really picking up around 18z and lasting
through the evening hours.

With all the clouds around, expect anomalously cool temperatures
tomorrow (though of course quite humid.) Current winds bring the
remnants of Fred into NE GA and western Upstate late Tuesday and
could see some corresponding gustiness during the evening hours.
Will keep any gusts sub-advisory for now, but they are trending
higher - particularly along the mountain peaks, NE GA, and the
northern Upstate of SC.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
As of 200 PM EDT Monday...The remnants of Fred will be passing to
the west of the forecast area Tuesday night and Wednesday. The risk
for severe weather will continue into the evening hours Tuesday
before shifting northeast of the area overnight. The area of
widespread heavy rain will also pull north of the area on Tuesday
night with some banding remaining into early Wednesday.

Wednesday will be a day of improving conditions as Fred moves away.
There will be plenty of lingering moisture which should lead to more
scattered showers and thunderstorms during the afternoon and evening
hours. Pops will remain well above climo on Wednesday and Wednesday
night. A mid level trof will develop across the Tennesse Valley on
Thursday, which will provide the focus for showers and thunderstorms
yet again.

Highs both Wednesday and Thursday will be near climo.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 200 PM EDT Monday...Mid level ridging will develop across the
southeast Friday into the weekend. This will put the forecast area
into an an west/northwest flow convective pattern, which can be very
active. However, models are lowering the pops for this period while
keeping some chance going. Will go with this for now and make some
adjustments as needed as this pattern develops.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Aviation weather looks grim over the next
18 hours or so as Fred or its remnants approach early this morning
and track over the srn Appalachians later today. We are locked
in to a S/SE upslope flow of deep tropical moisture, which will
allow for ceiling to fall down to IFR/LIFR at all sites through
the morning hours, while more intermittent shower activity spreads
up from the south/southeast ahead of the storm. A shower or storm
could develop at any time at any location in this regime. That
makes TAFs necessarily pessimistic, with prevailing MVFR vis and
IFR ceiling for most of the day, altho there will be some MVFR
or better holes from time to time. As the main system moves past
late in the day, wind should become gusty from the SE. This will
probably lead to a low level wind shear at least at KAVL. Once
the center passes this evening, very slow improvement should begin
with drier air wrapping in from the SW. Guidance keeps prevailing
IFR restrictions at this time, and this was generally accepted.

Outlook: A gradual downward trend in diurnal convection is expected
Wednesday in the wake of Fred's remnant, then continuing during
the latter half of the week. Widespread low stratus and areas of
fog are expected each morning through at least late-week.

Confidence Table...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       High  83%     High  83%     High  87%     Med   75%
KGSP       High  80%     High  80%     Med   77%     Med   77%
KAVL       High  85%     High  92%     High  91%     High  92%
KHKY       Med   72%     High  85%     Med   69%     High  87%
KGMU       Med   79%     High  86%     High  81%     Med   78%
KAND       High  86%     High  83%     High  89%     High  84%

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

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Flash Flood Watch through Wednesday morning for GAZ010-017-018-
     026-028-029.
NC...Flash Flood Watch through Wednesday morning for NCZ033-048>053-
     058-059-062>065-501>510.
SC...Flash Flood Watch through Wednesday morning for SCZ001>007-
     010>012-019.

&&

SYNOPSIS...DEO
NEAR TERM...HG/PM
SHORT TERM...SCW
LONG TERM...SCW
AVIATION...PM

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
857 PM EDT Mon Aug 16 2021

GAZ010-017-018-026-028-029-NCZ033-048>053-058-059-062>065-501>510-
SCZ001>007-010>012-019-180100-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-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-Greater Oconee-Greater Pickens-
Greater Greenville-Spartanburg-Anderson-Abbeville-Laurens-Greenwood-
857 PM EDT Mon Aug 16 2021

...FLASH FLOOD WATCH IN EFFECT FROM MIDNIGHT EDT TONIGHT THROUGH
WEDNESDAY MORNING...

This Hazardous Weather Outlook is for northeast Georgia, western
North Carolina, and most of 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.

Isolated to scattered to thunderstorms may develop through the
nighttime hours. Occasional cloud-to-ground lightning strikes and
heavy rainfall will be the primary threats.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

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

   Flash Flood Watch.

Isolated tornadoes are possible across the western Carolinas and
northeast Georgia Tuesday afternoon and evening.

.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.

NCZ035>037-056-057-068>072-082-SCZ008-009-013-014-180100-
Alexander-Iredell-Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-
Mecklenburg-Cabarrus-Union NC-Cherokee-York-Union SC-Chester-
857 PM EDT Mon Aug 16 2021

This Hazardous Weather Outlook is for piedmont North Carolina and
upstate South Carolina.

.DAY ONE...Tonight.

Isolated to scattered thunderstorms will be possible across the
western Carolinas through the nighttime hours. Cloud-to-ground
lightning strikes and locally heavy rainfall will be the primary
threats. Isolated flooding will be possible in any areas repeatedly
affected by showers and thunderstorms.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Deep tropical moisture associated with the remnants of tropical
storm Fred will interact with an old front and the mountains to
produce periodic heavy rainfall through the middle part of the week.
The flood threat will steadily increase as showers and thunderstorms
wet the soil. At this time, the greatest potential for excessive
rain appears to be Tuesday and Tuesday night as a remnant
circulation from Fred moves northward along the mountains. This
could result in a flash flooding threat, especially in areas that
receive multiple rounds of heavy rainfall.

Isolated tornadoes are possible across the western Carolinas Tuesday
afternoon and Tuesday evening.

.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.

HG