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 19, 1:45 PM EST, 42 minutes earlier.
Area forecast discussion, Aug 19, 1:45 PM EST, 42 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
245 PM EDT Wed Aug 19 2020
.SYNOPSIS...
An upper level trough across the Lower Mississippi River
Valley will persist through the end of the work week. This
will result in highs a little below normal and elevated rain chances
across the region. The upper trough will weaken over the weekend,
allowing temperatures and rain chances to return to near normal
as we head into next week.
&&
.NEAR TERM /THROUGH THURSDAY/...
As of 230 PM EDT Wednesday: Coverage of showers and thunderstorms
has steadily expanded over the past few hours with sct coverage
over much of the higher terrain and foothills. This trend will
continue thru the rest of the aftn and into the evening, with
coverage still expected to dwindle thru the evening hours. We
could see a few storms become severe (with damaging downbursts)
over the next few hours, however dCAPE and sfc delta Theta-e values
appear moderate at best. Therefore, most cells should be garden
variety summer-time thunderstorms, with isolated flash flooding
being the main concern given the low FFG values across much of
the fcst area. Otherwise, a series of upper shortwaves will cross
the area as the main trof digs south from the western Ohio Valley
and into the TN Valley. The weak front stalled to our south will
lift north toward the fcst area, and an area of weak low pressure
will move east along the front toward the CWFA as well. We can
expect another round of sct to widespread convection tomorrow aftn/
evening. With increased upper-level forcing and greater low-level
convergence, the potential for severe thunderstorms will be higher,
especially along and south of I-40. High temps are trending cooler,
with values in the low 80s across the lower terrain.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
As of 210 pm Wednesday: Very active convective weather will persist
through at least the first half of the short term, as upper trough
axis will remain west of the forecast area, supporting a
quasi-tropical air mass...with precipitable water values pushing 2
inches across much of the area. Meanwhile, weak cold air damming and
associated boundary will persist providing a low-level focus for
shower and thunderstorms development in addition to the usual
terrain effects. These factors will support another day of numerous
to perhaps widespread coverage Fri afternoon, with the primary
concern continuing to be localized excessive rainfall owing to the
number of storms, continued potential for training/backbuilding of
cells and efficient rainfall rates.
Having said that, Saturday may signal the beginning of the end to
this wet pattern, as short term guidance is converging toward a
consensus of beginning to lift the upper trough/closed low into the
Ohio Valley, allowing the surface boundary and deeper moisture to
shunt north and east of the forecast area. The pattern will still
favor diurnal+ convective activity...good enough for likely pops in
most areas, but overall coverage should be diminished from prior
days. Nevertheless, a locally excessive rainfall threat will likely
persist into Saturday, as some areas will likely be experiencing
poor antecedent conditions by that point. Max temps will remain
below normal and mins right around climo through the period.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 225 pm Wednesday: A bit of a pattern shift is expected during
the medium range, as Bermuda high pressure is forecast to build west
into the Southeast, as the upper trough bringing the unsettled
weather of the near/short term periods lifts into the northeast
quadrant of the country. This is expected to result in an onset of
typical late August weather by the end of the weekend, likely
lasting through the end of this forecast cycle. This equates to
some, but not a great deal of diurnal convective activity (generally
widely scattered coverage across the mtns/isolated elsewhere), max
temps around 90, and mins near 70. Of course, the potential fly in
the ointment is the tropics, and there is very poor agreement among
the global models regarding the details of the evolution of INVEST
98 beyond about Day 3. Thus, while some impacts...mainly in the form
of tropical moisture advection a la the latest GFS...cannot be
completely ruled out as early as the middle of next week,
uncertainty is very high a this time.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
At KCLT and Elsewhere: We're already seeing sct convection develop
over the mountains and escarpment over the last hour or so, and it
is expected to increase in coverage across the rest of the fcst area
as we move into the mid-aftn. I still expect coverage to diminish
thru the evening hours, however the latest CAM runs continue to keep
some activity going after 00z. Otherwise, MVFR cigs and visby return
overnight, with IFR conditions more likely at KAVL and KHKY. I have
all taf sites returning to VFR by 14z or so (except for KAVL, who
maintains an MVFR cig for the rest of the taf period.) Winds will
be light and favor a SELY direction thru the afternoon, then back
to NELY for the evening and overnight. They should gradually become
more ELY by late tomorrow morning/early aftn. KAVL will be an exception
with winds favoring a more NWLY direction this aftn/evening before
becoming light and vrb during the overnight.
Outlook: Chances for more widespread diurnal convection increase late
this week and into the weekend. Fog and low stratus restrictions will
be possible each morning, especially over the usual mountain valleys.
Otherwise expect VFR conditions.
Confidence Table...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT High 100% High 100% High 90% High 83%
KGSP High 100% High 100% High 93% High 86%
KAVL High 100% High 95% Low 55% Med 74%
KHKY High 100% High 95% Low 54% Med 75%
KGMU High 100% High 100% High 94% High 82%
KAND High 100% High 100% High 91% Med 62%
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...JPT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JPTHazardous weather outlook, Aug 19, 4:53 AM EST, 9 hours 34 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
553 AM EDT Wed Aug 19 2020
GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-201000-
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-
553 AM EDT Wed Aug 19 2020
This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.
.DAY ONE...Today and tonight.
Scattered to numerous showers and thunderstorms are expected to
develop across the area this afternoon and into this evening. The
primary threats will be locally heavy rain, gusty winds, and cloud-
to-ground lightning. However, a storm or two may become strong enough
to producing damaging wind gusts. Slow-moving storms may cause
isolated flooding.
.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.
No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
None.
ARK
In the hours before
Special weather statement, Aug 19, 1:00 PM EST, 1 hour 27 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
200 PM EDT Wed Aug 19 2020
SCZ001-004-005-191830-
Greater Pickens SC-Greater Oconee SC-Oconee Mountains SC-
200 PM EDT Wed Aug 19 2020
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN PICKENS AND
SOUTHEASTERN OCONEE COUNTIES UNTIL 230 PM EDT...
At 200 PM EDT, Doppler radar was tracking a strong thunderstorm near
Seneca, moving southeast at 25 mph.
Locations to be impacted include...
Clemson, Seneca, Walhalla, Central, Lake Keowee and Townville.
Wind gusts up to 45 mph and pea size hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Lakes Keowee and Hartwell are in the path of this storm. Cloud to ground
lightning and gusty winds will create dangerous boating conditions.
Move to shore immediately.
&&
LAT...LON 3474 8310 3482 8302 3473 8269 3470 8272
3467 8279 3453 8293
TIME...MOT...LOC 1800Z 298DEG 21KT 3473 8293
LANESpecial weather statement, Aug 19, 1:32 PM EST, 55 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
232 PM EDT Wed Aug 19 2020
NCZ065-507-509-510-191900-
Henderson NC-Polk Mountains NC-Rutherford Mountains NC-
Eastern Polk NC-
232 PM EDT Wed Aug 19 2020
...A STRONG THUNDERSTORM WILL IMPACT WESTERN RUTHERFORD...
NORTHEASTERN HENDERSON AND NORTHWESTERN POLK COUNTIES UNTIL 300 PM
EDT...
At 232 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles northeast of Hendersonville, or near Bat Cave, moving southeast
at 10 mph.
Locations to be impacted include...
Lake Lure, Chimney Rock Village, Chimney Rock State Park, Bat Cave,
Mill Spring, Gerton, Edneyville, Lake Adger and Dana.
Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 3546 8225 3549 8223 3541 8217 3540 8219
3540 8217 3531 8210 3525 8236 3546 8239
3547 8238 3546 8237 3548 8237 3550 8233
TIME...MOT...LOC 1832Z 329DEG 7KT 3541 8232
MOORESpecial weather statement, Aug 19, 1:45 PM EST, 42 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
245 PM EDT Wed Aug 19 2020
SCZ002-005-010-191915-
Pickens Mountains SC-Greater Pickens SC-Anderson SC-
245 PM EDT Wed Aug 19 2020
...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL ANDERSON AND
CENTRAL PICKENS COUNTIES UNTIL 315 PM EDT...
At 245 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles southwest of Easley, or over Liberty, moving southeast at 20
mph.
Locations to be impacted include...
Easley, Pickens, Powdersville, Central, Liberty, Norris, Six Mile,
Northlake and Piedmont.
Wind gusts up to 45 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 3472 8281 3481 8282 3493 8275 3491 8260
3476 8245 3472 8247 3457 8268
TIME...MOT...LOC 1845Z 320DEG 18KT 3479 8268
MOORESpecial weather statement, Aug 19, 1:52 PM EST, 35 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
252 PM EDT Wed Aug 19 2020
SCZ005-006-010-191915-
Greater Pickens SC-Anderson SC-Greater Greenville SC-
252 PM EDT Wed Aug 19 2020
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL GREENVILLE...
NORTHEASTERN ANDERSON AND EAST CENTRAL PICKENS COUNTIES UNTIL 315 PM
EDT...
At 251 PM EDT, Doppler radar was tracking a strong thunderstorm 4
miles northeast of Easley, or 4 miles west of Berea, moving southeast
at 20 mph.
Locations to be impacted include...
West Greenville, Berea, Welcome,
Powdersville, Piedmont and Dacusville.
Wind gusts up to 40 mph and pea size hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 3490 8260 3495 8258 3496 8249 3478 8237
3470 8247
TIME...MOT...LOC 1851Z 322DEG 17KT 3488 8254
MOORESpecial weather statement, Aug 19, 2:03 PM EST, 24 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
303 PM EDT Wed Aug 19 2020
NCZ053-503>507-191930-
Buncombe NC-McDowell Mountains NC-Burke Mountains NC-
Greater Burke NC-Rutherford Mountains NC-Eastern McDowell NC-
303 PM EDT Wed Aug 19 2020
...STRONG THUNDERSTORMS WILL IMPACT MCDOWELL...SOUTHEASTERN BUNCOMBE
AND WEST CENTRAL BURKE COUNTIES UNTIL 330 PM EDT...
At 303 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 7 miles north of Marion to 11 miles east of
Downtown Asheville, and moving south at 5 mph.
Locations to be impacted include...
Marion, Black Mountain, Swannanoa, Old Fort, Lake James State Park,
Lake James, B.R. Parkway-Little Switzerland To Linville, Chimney Rock
Village, Bat Cave and B.R. Parkway-Craggy To Little Switzerland.
Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These storms may intensify, so be certain to monitor local radio and
tv stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 3589 8198 3575 8177 3544 8228 3547 8227
3550 8233 3560 8242 3570 8227 3570 8226
3573 8219 3577 8217
TIME...MOT...LOC 1903Z 337DEG 5KT 3579 8200 3558 8235
MOORESpecial weather statement, Aug 19, 2:18 PM EST, 9 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
318 PM EDT Wed Aug 19 2020
SCZ005-006-010-191945-
Greater Pickens SC-Anderson SC-Greater Greenville SC-
318 PM EDT Wed Aug 19 2020
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL GREENVILLE...
NORTHEASTERN ANDERSON AND EAST CENTRAL PICKENS COUNTIES UNTIL 345 PM
EDT...
At 318 PM EDT, Doppler radar was tracking a strong thunderstorm near
Greenville Downtown, or near West Greenville, moving southeast at 15
mph.
Locations to be impacted include...
Greenville Downtown, Easley, Greenville Eastside, West Greenville,
Mauldin, Berea, Welcome, Powdersville, Piedmont and Williamston.
Wind gusts up to 40 mph, pea size hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 3461 8248 3481 8261 3490 8257 3494 8246
3487 8223 3485 8223 3485 8222 3483 8222
TIME...MOT...LOC 1918Z 311DEG 12KT 3481 8242
MOORE