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 Aug 4, 5:17 PM EST, 18 minutes earlier.
Area forecast discussion, Aug 4, 5:17 PM EST, 18 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
617 PM EDT Fri Aug 4 2017
.SYNOPSIS...
A cold front will cross our area tonight and become stationary from
central Georgia to eastern North Carolina Saturday night. This front
moves north as a warm front Sunday and Sunday night as low pressure
passes from Texas to across the Ohio Valley. The front will become
stationary again across our region for much of the week with deep
moisture and periods of heavy rain.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 615 pm: Recent runs of the HRRR depict convective coverage
filling in across the NC foothills early this evening and surviving
across the NC piedmont through midnight as the surface cold front
finally arrives in the mountains. PoPs have been adjusted up through
04Z in these areas. The meso analysis and recent mesoscale model
runs are now depicting about 30+ kt of sfc to 6 km shear over the
mountains, with lesser amounts over the foothills, but the
instability remains the limiting factor for severe convection with
most areas around 1000 J/kg of sbCAPE. Any severe tstms should be
rather isolated in nature. We will also need to keep an eye on the
expanding area of showers from the GA piedmont for a possible PoP
increase across the southern tier through late evening and early
overnight as well. PoPs should dwindle from the northwest overnight
and mins will be near to just above climo.
The consensus in model guidance is that the front will generally
settle south of our area (or perhaps over our southern zones)
through the day on Saturday, with drier air filtering through much
of the area on NW flow. However, the moisture gradient across the
boundary will be sufficiently broad such that positive buoyancy is
progged to develop from roughly the NC/SC border south. Diurnal
frontal convection should primarily be focused south of our area,
but a slight chance is nevertheless warranted east of I-85.
Meanwhile, instability should be sufficient to fire some isolated
cells across the southern Blue Ridge, and slight chances will be
carried across the southern mtns as well as the southern NC and SC
foothills. Max temps should again fall just shy of climo.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 215 PM Friday: An upper wave will cross the Central Plains and
into the Mid-MS Valley Saturday night thru Sunday, possibly being
enhanced by an MCS. This wave will then shear out within confluent
quasi-zonal flow over the OH Valley to the Mid-Atlantic Sunday night
thru Monday. At the sfc, a stalled front will lift back north as a
warm front, but will be fairly weak. Guidance has slowed down the
return of moisture atop the front thru the day on Sunday, so PoPs
were tweaked downward, especially across the northern half of the
CWFA. As for severe threat, guidance shows limited overlap of CAPE
and bulk shear. So threat should be low. A wavy front roughly
parallel to the upper level flow will set up across the Mid-South to
the OH Valley. Persistent SWLY flow atop the CWFA on the south side
of this boundary will provide plenty of moisture for convection on
Monday. So will have PoPs ramp up to high-end CHC to likely along
the west-facing slopes. Max temps will be near to slightly below
normal and mins near normal both days.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 155 PM Fri: Beginning Monday evening, the cold front drifts
south into our area from Tennessee then becomes nearly stationary
roughly from west to east across the deep south to the Carolinas.
The front remains this way through the remainder of the forecast.
Precipitable water values will be around 2 inches and at times above
that, especially from Wednesday through Friday. This prolonged
period of high Pwats with a stationary front to focus convection
will result in concerns for potential flooding which will increase
as the ground becomes saturated. A broad 500mb trough remains over
the East with shortwaves rotating SE from the upper Plains states to
our region then NE off the New England coast. This will periodically
enhance rainfall as surface low pressures move along the front over
our area. As a result of the thick cloud cover and periods of rain,
max temperatures are trending downward. Looks like Wednesday may be
the coolest as forecast highs from northeast Georgia to Charlotte
are in the lower 80s and this may be too high given the saturation
of the atmosphere. Overall max temperatures several degrees below
normal and Min temperatures near normal or even slightly above given
the thick clouds. There may also be periods of late night and early
morning fog to deal with as dew points and temperatures match
yielding 100% RH.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: An organized area of convection ahead of a
cold front across East TN will move across the mountains of western
NC through late afternoon, while additional development occurs east
over the foothills. The best chances for convection will be at the
western NC sites, where tempos are warranted beginning as early as
20Z at KAVL, and as late as 23Z at KCLT. These sites may actually
see a couple of distinct periods of convection, and tempos may need
adjustment to account for that at some point. Coverage is expected
to be less across Upstate SC. However, developing activity on the
south side of ATL metro moving northeast could impact these sites by
late afternoon (activity could also roll off the Blue Ridge near
KGMU/KGSP by this time). This warrants inclusion of a VCTS at the
Upstate terminals from late afternoon through early evening.
Convection should gradually diminish this evening, but with the cold
front moving into the area late, cannot completely rule out a few
showers through Saturday morning. Low levels will remain moist
overnight, while mid/upper levels dry out. This will create the
potential for fog and/or low stratus, although much may depend upon
what sites receive rainfall later today. Opted to limit early
Saturday restrictions to KAVL/KHKY for the time being.
Outlook: The cold front is expected to settle south of the terminals
on Saturday, with coverage of diurnal convection expected to be
isolated at best. Moisture returning over the front may permit
convection to return through the late weekend, with conditions
becoming unsettled through the middle of next week. Restrictions
will be possible with any showers or thunderstorms and fog and low
clouds will be possible each morning around daybreak, mainly in the
mtn valleys, but also in areas that receive heavy rainfall the day
before.
Confidence Table...
22-04Z 04-10Z 10-16Z 16-18Z
KCLT High 100% High 100% High 94% High 100%
KGSP High 100% High 100% High 86% High 100%
KAVL High 100% High 91% High 83% High 100%
KHKY High 97% High 100% Med 75% High 100%
KGMU High 100% High 100% High 97% High 100%
KAND High 100% High 100% High 83% 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...DEO
NEAR TERM...HG/JDL
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...HG/JDLHazardous weather outlook, Aug 4, 3:29 PM EST, 2 hours 6 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
429 PM EDT Fri Aug 4 2017
GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-052030-
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-
429 PM EDT Fri Aug 4 2017
This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.
.DAY ONE...Tonight.
Scattered thunderstorms are expected to develop across the area
through this evening. Any of these thunderstorms may produce cloud-
to-ground lightning and heavy rainfall. A few isolated thunderstorms
may become severe, producing damaging wind gusts and hail up to
around one inch in diameter.
.DAYS TWO THROUGH SEVEN...Saturday through Thursday.
..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.
..Thursday...No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
Skywarn spotters are requested to forward any reports of large hail,
damaging winds, tornadoes, or flash flooding to our office.
ARK
In the hours before
Special weather statement, Aug 4, 3:24 PM EST, 2 hours 11 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
424 PM EDT FRI AUG 4 2017
NCZ048-052-042115-
Haywood NC-Madison NC-
424 PM EDT FRI AUG 4 2017
...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT MADISON
AND NORTH CENTRAL HAYWOOD COUNTIES UNTIL 515 PM EDT...
At 423 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning 15 miles west of Marshall, or 8 miles east of Smoky
Mountains-Big Creek, moving east at 30 mph.
Locations to be impacted include...
Marshall, Hot Springs, Allenstand, Walnut, Luck, Fines Creek, Spring
Creek, Max Patch and Canto.
In addition to intense lightning, wind gusts up to 40 mph and pea
size hail 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.
Frequent lightning is occurring with this storm. If outdoors, try to
get indoors or into a hard topped vehicle. Otherwise, stay away from
open areas and isolated high objects such as trees. When indoors,
stay away from windows and doors and avoid using wired electronic
devices. Do not take a shower or bath. Try to unplug unnecessary
appliances before the storm approaches.
&&
LAT...LON 3576 8262 3573 8267 3573 8271 3572 8271
3569 8281 3570 8285 3568 8288 3568 8302
3579 8306 3577 8299 3584 8292 3587 8292
3588 8290 3593 8292 3595 8287 3593 8281
3597 8278 3600 8278 3603 8271
TIME...MOT...LOC 2023Z 255DEG 24KT 3579 8297
CDGSpecial weather statement, Aug 4, 4:42 PM EST, 53 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
542 PM EDT FRI AUG 4 2017
NCZ053-042215-
Buncombe NC-
542 PM EDT FRI AUG 4 2017
...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN BUNCOMBE COUNTY
UNTIL 615 PM EDT...
At 541 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Downtown Asheville, or near Fairview In Buncombe
County, moving east at 25 mph.
Locations to be impacted include...
Black Mountain, Swannanoa, Fairview In Buncombe County, B.R.
Parkway-Nc Arboretum To East Asheville, Warren Wilson College, East
Asheville and Montreat.
Wind gusts up to 40 mph and pea size hail 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 3565 8229 3562 8227 3561 8228 3559 8229
3556 8225 3555 8222 3553 8217 3552 8223
3550 8223 3549 8231 3550 8233 3548 8237
3546 8248 3558 8251 3567 8228
TIME...MOT...LOC 2141Z 249DEG 22KT 3555 8242
CDGSpecial weather statement, Aug 4, 4:59 PM EST, 36 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
559 PM EDT FRI AUG 4 2017
NCZ505-506-042245-
McDowell Mountains NC-Eastern McDowell NC-
559 PM EDT FRI AUG 4 2017
...A STRONG THUNDERSTORM WILL IMPACT MCDOWELL COUNTY UNTIL 645 PM
EDT...
At 559 PM EDT, Doppler radar was tracking a strong thunderstorm 13
miles west of Marion, or 4 miles west of Old Fort, moving east at 30
mph.
Locations to be impacted include...
Marion, Old Fort, Lake James, Sugar Hill, Pleasant Gardens, Glenwood,
Fero, Woodlawn, Montreat and Busick.
Wind gusts up to 40 mph and pea size hail 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 3558 8190 3554 8220 3556 8226 3559 8229
3562 8227 3565 8229 3567 8228 3568 8229
3570 8229 3570 8226 3573 8219 3577 8217
3583 8200
TIME...MOT...LOC 2159Z 253DEG 24KT 3564 8225
CDG