Flash Flood Watch 5, NWS Greenville-Spartanburg, SC

220 
WGUS62 KGSP 020213
FFAGSP

Flood Watch
National Weather Service Greenville-Spartanburg SC
1013 PM EDT Thu Jul 1 2021

NCZ033-048>052-058-021200-
/O.CON.KGSP.FF.A.0005.000000T0000Z-210702T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Graham-
Including the cities of Banner Elk, Burnsville, Waterville, Walnut, 
Luada, Celo, Allenstand, Cruso, Micaville, Ingalls, Hot Springs, 
Luck, Mars Hill, Wesser, Spruce Pine, Stecoah, Ramseytown, Faust, 
Swiss, Canton, Busick, Cove Creek, Marshall, Almond, Waynesville, 
Newland, Bryson City, Robbinsville, Poplar, and Alarka
1013 PM EDT Thu Jul 1 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 8 AM EDT FRIDAY...

The Flash Flood Watch continues for

* A portion of western North Carolina, including the following 
  areas, Avery, Graham, Haywood, Madison, Mitchell, Swain and Yancey.

* Until 8 AM EDT Friday.

* Several rounds of showers and thunderstorms have already affected 
  the western mountains of North Carolina Thursday evening, and 
  additional heavy showers with embedded thunderstorms are expected 
  overnight as abundant moisture arrives ahead of a cold front. Many 
  locations within the Watch area have already received 1 to 2 
  inches of rainfall in the past 12 hours, with a few locations 
  reporting in excess of 3 inches. Additional rainfall of 1 to 2 
  inches is likely overnight, and any thunderstorms could yield inch 
  per hour rainfall rates in some locations.

* Showers and thunderstorms repeatedly impacting the same locations 
  in the Tennessee border counties of the North Carolina mountains 
  overnight may lead to excessive rainfall and associated flash 
  flooding. Deep ponding of water will develop from the rainfall in 
  low-lying and poor drainage areas. Many streams and creeks will 
  rise to near bankfull due to the runoff from the heavy rainfall, 
  and some stream flooding is likely.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If the rainfall reaches five inches in steeply sloped areas, the 
risk of landslides and rockslides will increase. If you live on a 
mountainside or in a cove at the base of a mountain, especially near 
a stream, be ready to leave as quickly as possible should rising 
water, moving earth, or rocks threaten. Also, be prepared to move to 
higher ground quickly if a Flash Flood Warning is issued for your 
locations, or if flooding is observed.

&&

$$

HG

259 
WGUS62 KGSP 020809
FFAGSP

Flood Watch
National Weather Service Greenville-Spartanburg SC
409 AM EDT Fri Jul 2 2021

NCZ033-048>052-058-021200-
/O.CON.KGSP.FF.A.0005.000000T0000Z-210702T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Graham-
Including the cities of Banner Elk, Burnsville, Waterville, Walnut, 
Luada, Celo, Allenstand, Cruso, Micaville, Ingalls, Hot Springs, 
Luck, Mars Hill, Wesser, Spruce Pine, Stecoah, Ramseytown, Faust, 
Swiss, Canton, Busick, Cove Creek, Marshall, Almond, Waynesville, 
Newland, Bryson City, Robbinsville, Poplar, and Alarka
409 AM EDT Fri Jul 2 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 8 AM EDT THIS MORNING...

The Flash Flood Watch continues for

* A portion of western North Carolina, including the following 
  areas, Avery, Graham, Haywood, Madison, Mitchell, Swain and Yancey.

* Until 8 AM EDT this morning.

* Several rounds of showers and thunderstorms have already affected 
  the western mountains of North Carolina overnight, and additional 
  heavy showers with embedded thunderstorms are expected to continue 
  through daybreak as abundant moisture filters in ahead of a cold 
  front. Many locations within the Watch area have already received 
  1 to 2 inches of rainfall in the past 12 to 18 hours, with a few 
  locations reporting in excess of 3 inches. Additional rainfall of 
  up to an inch is likely through the morning hours, and any 
  thunderstorms could yield inch per hour rainfall rates in some 
  locations.

* Showers and thunderstorms repeatedly impacting the same locations 
  in the Tennessee border counties of the North Carolina mountains 
  during the early morning hours may lead to excessive rainfall and 
  associated flash flooding. Deep ponding of water will develop from 
  the rainfall in low-lying and poor drainage areas. Many streams 
  and creeks will rise to near bankfull due to the runoff from the 
  heavy rainfall, and some stream flooding is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Rainfall of more than five inches in similar storms has been 
associated with an increased risk of landslides and rockslides. If 
you live on a mountainside or in a cove at the base of a mountain, 
especially near a stream, be ready to leave in advance of the storm 
or as quickly as possible should rising water, moving earth, or 
rocks threaten. Consider postponing travel along mountain roads 
during periods of heavy rainfall.

&&

$$

CAC

051 
WGUS62 KGSP 020959
FFAGSP

Flood Watch
National Weather Service Greenville-Spartanburg SC
559 AM EDT Fri Jul 2 2021

NCZ033-048>052-058-021100-
/O.CAN.KGSP.FF.A.0005.000000T0000Z-210702T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Avery-Madison-Yancey-Mitchell-Swain-Haywood-Graham-
Including the cities of Banner Elk, Burnsville, Waterville, Walnut, 
Luada, Celo, Allenstand, Cruso, Micaville, Ingalls, Hot Springs, 
Luck, Mars Hill, Wesser, Spruce Pine, Stecoah, Ramseytown, Faust, 
Swiss, Canton, Busick, Cove Creek, Marshall, Almond, Waynesville, 
Newland, Bryson City, Robbinsville, Poplar, and Alarka
559 AM EDT Fri Jul 2 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of western North Carolina, 
including the following areas, Avery, Graham, Haywood, Madison, 
Mitchell, Swain and Yancey has been cancelled.

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

$$

CAC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
253 PM EDT Thu Jul 1 2021

.SYNOPSIS...
High pressure off the Atlantic coast weakens as a cold front drops
into the area from the Ohio River Valley on Friday. Increasing
moisture will lead to increasing coverage of showers and
thunderstorms on Friday. The front moves east and south of the area
by Saturday and Independence Day. Near seasonal conditions expected
early next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 210 pm: Widely scattered convection initiated across the high
terrain earlier this afternoon, when a couple of stronger updrafts
were noted, but the more robust activity has fizzled and or moved
north of the forecast area. The latest SPC Mesoanalysis depicts
relatively tame sbCAPE (generally 1500-2000 J/kg) across the area,
owing to very unimpressive mid-level lapse rates and dewpoints that
have again mixed out to the mid-60s across a good chuck of the area.
Nevertheless, scattered cells should continue to bubble across the
mountains over the next couple of hours, and resultant outflows
should instigate isolated/widely scattered activity in the Piedmont
as early as late afternoon.

Most of our attention in the near term is focused on the rather
impressive height falls currently overspreading the Ohio Valley and
vicinity and attendant frontal zone that will begin impacting the
area later this evening into the overnight. The well-forced and very
moist (PWATs 1.75-2" during that time) environment will support
maintenance of widespread showers and at least scattered
thunderstorms across the area. High moisture content/warm cloud
depth will support efficient rainfall production while
unidirectional flow oriented roughly parallel to the slow-moving
front will support a favorable scenario for training cells. Having
said that, with overnight instability remaining somewhat meager, we
can't say that any one area will be more prone to excessive rainfall
over another...while the general storm total amounts of 1 to 2
inches don't support Flash Flood Watch issuance. Nevertheless,
locally higher amounts as much as two times those totals appear
likely and a localized flash flood event or two seems virtually
inevitable.

In terms of the severe threat, such as it is, it should mainly occur
this afternoon/evening with the more discrete/scattered cells, and
be very much of the pulse mode. Waning instability overnight...
along with even weaker upstream instability indicates very little
chance of convection organizing to any great extent...despite wind
shear becoming marginally favorable for such.

Convective chances will steadily taper off from NW to SE across the
area through the morning hours as the better forcing/deeper moisture
shift east. However, with the frontal boundary expected to lag
behind over the forecast area, scattered redevelopment is likely
during the afternoon, mainly across the southeast half. Max temps
will be around 5 degrees below normal, owing largely to extensive
cloud cover that will be stubborn to relent.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH MONDAY/...
As of 300 PM EDT Thursday: At the beginning of the period Friday
night, the cold front is expected to be moving through the
Piedmont such that by Saturday morning, dramatic changes to the
sensible weather will be well underway.  With a sprawling 1020mb
high pressure over the central Mississippi River Valley, a dry
continental airmass will overtake the region, setting us up for a
picture-perfect Independence Day long weekend.  Saturday will be
the blue-ribbon winner of the weekend with the lowest July 3rd high
temperatures since 2015, topping out about 5 degrees below-normal.
With dewpoints plunging into the lower to middle 50s by Saturday
afternoon, humidity values will be very comfortable across the
entire region.

Heading into July 4th, the high pressure will weaken and propagate
slowly east into the Ohio River Valley, keeping our winds light
and variable.  Dewpoints will creep back into the upper 50s
for Sunday and, as the high continues to weaken into Monday,
subtropical high pressure over the Atlantic will dominate our wind
field and weak southerly flow returns.  Therefore, expect another
incremental increase in dewpoints for Monday into the lower 60s,
but still fairly pleasant humidities for July.  Regardless, skies
will remain mostly sunny through the Monday holiday and though
high temperatures warm a couple of degrees each day, by Monday
they are just about normal for this time of year.  All-in-all,
it will be a perfect weekend for festivals and fireworks.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
As of 300 PM EDT Thursday: Of course, all eyes are on tropical
cyclone Elsa for the extended period and her possible path
towards the southeast US, but tremendous uncertainty remains.
At the beginning of the extended on Tuesday, the upper-level
pattern is a bit complex with the Southeast coast underneath a
weakness aloft, a retreating subtropical ridge to the east, and a
shortwave ridge over the Ohio and Tennessee Valleys to the west.
Meanwhile, a strong shortwave trough is digging into the central
Great Plains and the Midwest while Elsa gets drawn into the
weakness between the approaching trough and the retreating ridge.
As is often the case in the midlatitudes, the exact track will be
determined by the speed and amplitude of the incoming trough and
the strength and westward expansion of the subtropical ridge.
Ensemble track guidance from overnight had extreme spread and
the official NHC forecast generally reflects the mean of the
broadly distributed track guidance.  The deterministic 12Z GFS and
Canadian solutions bring Elsa up into the Carolina coastal plain
or coastline Wednesday night through Thursday night, with a ~150
mile spread of the low-pressure center between the two, whereas the
12Z ECMWF continues the solution of previous runs and dissipates
the cyclone over the rugged terrain of Hispaniola.  What is left
of Elsa is absorbed into the offshore stationary front as an open
tropical wave.  Clearly, there is no justification for focusing
on one solution or another this far out and our best advice is to
enjoy your long weekend and keep an eye on the forecast heading
into early next week.

At a broad level, our forecast will gradually become more unsettled
Tuesday through Thursday next week as moisture returns to the
region in advance of the shortwave trough to our west and the
subtropical ridge to our east.  Expect slight chance pops for
Tuesday afternoon increasing to solid chance pops Wednesday
and Thursday.  Generally unsettled conditions may persist into
Friday even if Elsa lifts well to the NE of our region, as the
upper-level trough that settles into our area late next week may be
slow to depart the area.  High temperatures through the extended
are currently forecasted to remain near to slightly above-normal
with humidity values more typical of a subtropical airmass.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Scattered convection developed early this
afternoon across the mountains, but has since fizzled a bit.
Nevertheless, moderate instability should yield steadily increasing
coverage through the afternoon...initially in the favored high
terrain areas, with scattered activity likely developing into the
foothills and Piedmont from late afternoon into the evening. Most
sites receive a VCSH/VCTS to account for this possibility, with KAVL
and KCLT receiving tempos for TSRA during that time (although the
KCLT tempo is an "on-the-fence" situation).

A relatively strong cold front will approach the area from the
northwest tonight, with widespread showers and scattered/numerous
thunderstorms expected to accompany the front...as early as this
evening at KAVL...and mainly overnight at the other terminals.
Categorical -SHRA/VCTS w/ Prob30s for TSRA warranted at all sites.
Cigs will also lower steadily late tonight, with IFR likely at most
sites by sunrise. Occl MVFR/IFR visby can also be expected during
periods of heavier rainfall. Showers/storms will steadily taper off
throughout Fri morning, although scattered redevelopment may occur
during the afternoon, as the front is not expected to completely
clear the area until late in the day. Cigs are expected to remain
restricted at most sites until afternoon.

Outlook: Drying is expected from Saturday into early next week.
Diurnal showers and thunderstorm chances, along with the potential
for mainly mountain valley morning fog/low stratus will return by the
middle of the week.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High 100%     High  95%     High  88%     High  81%
KGSP       High 100%     High  97%     Med   65%     Med   62%
KAVL       High  95%     Med   71%     High  83%     High  83%
KHKY       High 100%     Med   66%     Med   74%     Med   76%
KGMU       High 100%     High  97%     Med   60%     Med   66%
KAND       High 100%     High 100%     Med   72%     Med   63%

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...None.
NC...None.
SC...None.

&&

SYNOPSIS...DEO
NEAR TERM...JDL
SHORT TERM...JMP
LONG TERM...JMP
AVIATION...JDL

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
425 AM EDT Thu Jul 1 2021

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-020830-
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 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 Oconee-
Greater Pickens-Greater Greenville-Spartanburg-Cherokee-York-
Anderson-Abbeville-Laurens-Union SC-Chester-Greenwood-
425 AM EDT Thu Jul 1 2021

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...Today and tonight.

Showers and thunderstorms are expected to increase in coverage ahead
of a cold front this afternoon and continue overnight. Cloud-to-
ground lightning and very gusty winds can occur with any of the
storms. Areas of heavy rainfall will be possible, potentially leading
to isolated flash flooding, especially across the mountains.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Showers and thunderstorms will cross the area Friday as the cold
front moves southeast across the area. Cloud-to-ground lightning and
very gusty winds can occur with any of the storms. Areas of heavy
rainfall will be possible, potentially leading to isolated flash
flooding. Rainfall will quickly move east of the area Friday evening.

.SPOTTER INFORMATION STATEMENT...

None.