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 Jul 24, 5:42 PM EST, 3 hours 18 minutes earlier.
Area forecast discussion, Jul 24, 5:42 PM EST, 3 hours 18 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
642 PM EDT Sat Jul 24 2021
.SYNOPSIS...
Air quality should improve somewhat over the weekend while afternoon
showers and thunderstorms increase in coverage and intensity through
Monday. A backdoor cold front builds into the forecast area early
next week, bringing more active weather at least through Tuesday.
Late week, additional rainfall is possible, though significant
uncertainty remains at that point.
&&
.NEAR TERM /THROUGH SUNDAY/...
As of 630 PM: Scattered showers and storms continue to track off the
higher terrain and slowly migrate across the foothills and piedmont.
The isolated coverage in areas south of I-85 has mostly come to an
end, but the storms along and north of I-85 still have a chance to
track towards the southeastern zones before all is said and done.
Most of the clouds coverage consists of cu or convective debris from
the storms that have developed. Expect this trend to continue
through sunset before the activity slowly starts to wane off.
Meso analysis shows better than expected effective shear across the
area, with moderate to very unstable CAPE values. DCAPE values are
generally modest but could increase to 800 J/kg ore higher with
heating. Therefore, a few severe storms will be possible. Storm
motion looks to be faster than previous days, but PW values remain
high. Isolated areas of excessive rainfall and flooding will be
possible, especially locations where multiple storms traverse.
Showers will linger into the early overnight but should diminish as
the low level flow turns more southwesterly. That said, can't rule
out an isolated shower in any location overnight. Expect mountain
valley fog and stratus once again, but confidence lower for
locations outside of the mountains. Lows should be near or slightly
above normal.
Northwest flow remains over the area Sunday with moderate
instability developing. Again, no strong trigger mechanism, but
differential heating and a lee trough should be enough for scattered
diurnal convection. An isolated strong to severe storm or area of
heavy rainfall will also be possible. Highs will be near normal.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 150 PM EDT Saturday: Broad ridging over the western two-thirds
of the country will entrench the eastern CONUS in a subdued weather
pattern at the start of the short term forecast period on Monday.
A deep shortwave digs into the Mid-Atlantic throughout the day,
but guidance still keeps the most potent QG forcing associated
with this trough well north of our forecast area. Instead,
our active weather will be driven primarily by low-level forcing
associated with a cold front impinging on the region from the north
by Monday evening. With the Bermuda High enhancing southerly
flow throughout the weekend and Monday, the front will find a
moisture-rich environment in the Carolinas - models agree that
PWATs across the foothills and Piedmont will have risen into the
1.9-2.3" range, and will be pushing at least 1.75" in the mountains.
Prefrontal precipitation should begin by Sunday night or early
Monday morning for the NC mountains, and over the course of the
day, this activity will gradually spread south and east over
the CWA, eventually encompassing the entire forecast area.
Coverage and intensity of showers should increase throughout
the day, before convective potential begins to rise late morning
and early afternoon. The ECMWF, CMC, and NAM all suggest SBCAPE
values of 1500+ J/kg, with the outlier GFS carrying a more modest
500-1000 J/kg. Given that we'll be overcast much/all of the day,
and that rain will likely be underway for most areas by midmorning,
the current thinking is that those higher instability values are
overdone. So, expect this front to feature widespread showers
with some embedded non-severe thunderstorms. The big concern will
be excessive rainfall: with PWATs at/near 2", a deep warm cloud
layer in excess of 12 kft, and weak MBE vectors less than 5kts
all afternoon, backbuilding should be a concern for some cells.
Furthermore, with the front likely stalling somewhere near our
forecast area, some spots are likely to see long durations of
heavy rainfall Monday night into Tuesday.
Temps are still on track to be above-normal both Monday and Tuesday,
though guidance continues to trend toward lower highs in light of
widespread clouds, continued rainfall persisting through the
forecast period, and weakened southerly flow/WAA as the front stalls.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 200 PM EDT Saturday: The details of the medium-range forecast
remain in question. Global models continue to suggest that a strong
Bermuda High will limit the cold front's ability to fully exit our
region on by Tuesday night, so even into Wednesday we'll likely
continue to see frontally-forced rainfall as the boundary stalls
over our CWA or just to the south. The GFS, ECMWF, and CMC all keep
us locked in a wet pattern through Wednesday, before the weakening
boundary finally sags out of our area, carrying low-level forcing
with it and allowing weak high pressure to filter into the area.
With broad high pressure persisting over the Atlantic, however,
the prevailing surface flow will still be primarily southerly,
albeit with an increasing westerly component. This slight shift
in overall wind direction should limit PWATs - comparatively,
at least, as they still keep near 1" into Thursday and Friday.
By Friday, we may see the arrival of a shortwave as the upper
pattern slightly amplifies - which would result in another wave
of precipitation late in the week. Once this passes, we may be
in store for some dry weather next weekend.
In any case, temperatures will generally be near- or slightly
above-normal throughout the period.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Convection continues to spread across the
CFWA and staying out with a mix of VCSH/VCTS and TEMPO TSRA based on
current coverage and guidance showing TSRA will be over or near all
TAF sites sometime this evening. Showers may linger into the early
overnight, so have VCSH for those. Guidance agrees on mountain
valley fog/stratus again by morning but disagree on restrictions
outside of the mountains. Have restrictions at KAVL and KHKY where
chances are highest, but left out elsewhere given the low
confidence. Convection will develop again Sunday afternoon, but have
PROB30 at all terminals with the best chances developing after 18Z.
S to SW wind this evening becomes light S or light and variable
overnight. Light SW wind for Sunday.
Outlook: Diurnal thunderstorm chances will steadily increase through
early next week, with some drying expected during mid-week. Early
morning fog or low stratus will be possible each day, primarily in
the mountain valleys.
Confidence Table...
22-04Z 04-10Z 10-16Z 16-18Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 97%
KAVL High 100% High 85% Med 60% High 100%
KHKY High 100% High 95% Med 67% High 100%
KGMU High 100% High 85% High 82% High 97%
KAND High 100% High 100% 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 are available at
the following link:
www.weather.gov/gsp/aviation
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
SYNOPSIS...MPR
NEAR TERM...CAC/RWH
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...CAC/RWHHazardous weather outlook, Jul 24, 7:07 PM EST, 1 hour 53 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
807 PM EDT Sat Jul 24 2021
GAZ010-017-018-026-028-029-NCZ035-036-056-062>065-068>070-501>510-
SCZ001>008-010-260015-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Alexander-Iredell-
Catawba-Macon-Southern Jackson-Transylvania-Henderson-Cleveland-
Lincoln-Gaston-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-Anderson-
807 PM EDT Sat Jul 24 2021
This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.
.DAY ONE...Tonight.
Isolated to scattered thunderstorms will continue over parts of the
Foothills and upper Piedmont. Cloud-to-ground lightning and gusty
winds, and periods of heavy rainfall can be expected with any of
these storms. Localized flash flooding cannot be ruled out,
especially where heavy rain fell earlier today or last night.
Coverage of the storms will gradually diminish into the early
morning hours.
.DAYS TWO THROUGH SEVEN...Sunday through Friday.
No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
None.
NCZ033-037-048>053-057>059-071-072-082-SCZ009-011>014-019-260015-
Avery-Davie-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Rowan-
Graham-Northern Jackson-Mecklenburg-Cabarrus-Union NC-York-Abbeville-
Laurens-Union SC-Chester-Greenwood-
807 PM EDT Sat Jul 24 2021
This Hazardous Weather Outlook is for portions of the North
Carolina mountains as well as the lower Piedmont of the Carolinas.
.DAY ONE...Tonight.
No hazardous weather is expected at this time.
.DAYS TWO THROUGH SEVEN...Sunday through Friday.
No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
None.
Wimberley
In the hours before
Special weather statement, Jul 24, 4:49 PM EST, 4 hours 11 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
549 PM EDT Sat Jul 24 2021
NCZ056-068-069-504-242215-
Cleveland NC-Lincoln NC-Greater Burke NC-Catawba NC-
549 PM EDT Sat Jul 24 2021
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN CATAWBA...
NORTHWESTERN LINCOLN...NORTHWESTERN CLEVELAND AND SOUTH CENTRAL BURKE
COUNTIES UNTIL 615 PM EDT...
At 549 PM EDT, Doppler radar was tracking a strong thunderstorm 16
miles southeast of Morganton, or near Casar, moving southeast at 5
mph.
Locations to be impacted include...
Belwood, Lawndale, Fallston, Casar, Cooksville, Vale and Pleasant
Grove.
Wind gusts up to 40 mph and pea size hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.
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 3550 8168 3564 8157 3557 8136 3538 8153
TIME...MOT...LOC 2149Z 304DEG 6KT 3553 8156
ARK
Special weather statement, Jul 24, 5:14 PM EST, 3 hours 46 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
614 PM EDT Sat Jul 24 2021
NCZ068>070-242245-
Gaston NC-Cleveland NC-Lincoln NC-
614 PM EDT Sat Jul 24 2021
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN LINCOLN...CENTRAL
CLEVELAND AND NORTHWESTERN GASTON COUNTIES UNTIL 645 PM EDT...
At 614 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles north of Shelby, or near Fallston, moving southeast at 10 mph.
Locations to be impacted include...
Shelby, Belwood, Lawndale, Fallston, Waco, Cherryville and Polkville.
Wind gusts up to 40 mph and pea size hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.
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 3546 8164 3555 8150 3541 8134 3529 8154
TIME...MOT...LOC 2214Z 327DEG 8KT 3545 8154
ARK
Special weather statement, Jul 24, 6:20 PM EST, 2 hours 40 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
720 PM EDT Sat Jul 24 2021
NCZ068-242345-
Cleveland NC-
720 PM EDT Sat Jul 24 2021
...A STRONG THUNDERSTORM WILL IMPACT SOUTHERN CLEVELAND COUNTY UNTIL
745 PM EDT...
At 718 PM EDT, Doppler radar was tracking a strong thunderstorm over
Shelby, moving southeast at 10 mph.
Locations to be impacted include...
Shelby, Patterson Springs, Lattimore, Earl, Waco and Boiling Springs
NC.
Wind gusts up to 45 mph and half inch hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.
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 3528 8135 3528 8136 3527 8134 3527 8135
3517 8158 3517 8159 3531 8168 3541 8149
TIME...MOT...LOC 2318Z 327DEG 8KT 3530 8154
ARKSpecial weather statement, Jul 24, 6:43 PM EST, 2 hours 17 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
743 PM EDT Sat Jul 24 2021
NCZ068-SCZ008-250015-
Cleveland NC-Cherokee SC-
743 PM EDT Sat Jul 24 2021
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN CLEVELAND AND NORTH
CENTRAL CHEROKEE COUNTIES UNTIL 815 PM EDT...
At 742 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles southwest of Shelby, or near Boiling Springs NC, moving south
at 10 mph.
Locations to be impacted include...
Shelby, Boiling Springs NC, Patterson Springs, Earl, Blacksburg,
Mooresboro and Lattimore.
Wind gusts up to 40 mph and pea size hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Gusty winds can blow down trees that are dead, or that have weakened
root systems. Outdoor furniture and similar items can be tossed
around if not anchored. Seek shelter indoors.
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 3532 8169 3528 8149 3512 8149 3514 8176
TIME...MOT...LOC 2342Z 010DEG 8KT 3523 8161
ARK
Special weather statement, Jul 24, 7:13 PM EST, 1 hour 47 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
813 PM EDT Sat Jul 24 2021
NCZ068-508-250045-
Greater Rutherford NC-Cleveland NC-
813 PM EDT Sat Jul 24 2021
...STRONG THUNDERSTORMS WILL IMPACT EAST CENTRAL RUTHERFORD AND
SOUTHWESTERN CLEVELAND COUNTIES UNTIL 845 PM EDT...
At 813 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 7 miles northeast of Forest City to 4 miles
southwest of Shelby. These storms were nearly stationary.
Locations to be impacted include...
Shelby, Forest City, Boiling Springs NC, Ellenboro, Lattimore,
Mooresboro, Bostic, Kingstown, Patterson Springs and Spindale.
Wind gusts up to 35 mph 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 3525 8150 3517 8161 3517 8163 3539 8195
3552 8179
TIME...MOT...LOC 0013Z 034DEG 4KT 3543 8181 3525 8161
ARK