887
FXUS62 KGSP 182201
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
601 PM EDT Thu Jul 18 2024

.SYNOPSIS...
A nearly stationary front will meander across our region through
early next week providing a focus for above normal chances of mainly
afternoon and evening showers and thunderstorms. Another cold front
will approach from the north later next week. Temperatures will be
near normal or just a bit cooler than normal.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 556 PM Thursday: Plenty of convection ongoing, but most of the
good stuff was pushing east across the Piedmont of the Carolinas
and will move out of the fcst area over the next hour or two. No
changes to the Severe Tstm Watch yet as we prefer to cancel all of
our area at once, and we will have lingering thunderstorm activity
over the eastern side of metro Charlotte in the mean time. Look
for another update in about one hour for cancellation. The greater
threat at this point might be heavy rain. Otherwise, temps have
been cooled off behind the ongoing storms, so expect things to
wind down a bit early this evening.

Otherwise, broad upper troffing will linger to our north over the
Great Lakes while broad upper ridging persists to our west and to
our east. At the sfc, Canadian high pressure will linger to our
NW while the Bermuda High keeps moist, southerly low-lvl flow
to our south. Between these two highs, a weak frontal boundary
that is currently draped across our area will slowly move south
and east of our CWA this evening. Nonetheless, the deeper moisture
associated with the broad region of low-lvl convergence will persist
over the Southeast well beyond the near-term period. The drier air
to our north, associated with the Canadian high, will make little
progress southward over the next few days. For Friday, we can expect
another round of sct to widespread convection across our area as
we remain under the moist airmass. The model profiles, however,
appear less supportive of strong to severe thunderstorms. Thus,
our primary threat will likely be localized heavy rainfall and
the potential for isolated flooding. As for temperatures, they
will trend cooler with highs on Friday expected to remain in the
80s over the lower terrain and 70s over the mtns.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 100 PM Thursday...A rather stationary pattern will persist
over the short range as a strong Canadian high builds south and
traps a frontal zone against the Bermuda High. The flow around the
subTrop ridge will will allow for very good moist advect each day
and cross sections indicate high saturation thru the mid levels. Fri
night into Sat may see the best chance for widespread showers and an
increased hydro threat as s/w forcing crosses the area. High cloud
cover and rather warm mid-levels will limit sbCAPE potential each
day as sfc heating and max temps are curtailed a cat or so below
normal, yet diff heating will likely allow for more robust and
longer lived tstms, possibly leading to a multi-cell mode. The
various guidance continues to disagree sigfnt/ly on the location of
the sfc convg zone which will be key in the generation and amts of
precip each day. Models aren`t too excited about over all precip
totals either, but localized areas could see arnd an inch in a short
amt of time potentially leading to flood issues depending on where
the sfc front interacts more with the stronger updrafts. Training
cells with high rainfall rates will also be possible as the mean
steering flow aloft aligns parallel with the stationary front thru
the period. Pops were maintained quite a bit abv climo each day with
lower noctural precip likely continuing each night.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 140 PM Thursday...The ext range fcst remains quite active as
the latest guidance continues to show an activated stationary front
draped across the area each day. A strong subTrop ridge will hold
it/s own against upper energy diving out of Canada and possibly
strengthen and shift west by Tue. Decent agreement is seen in the
llvl mass fields Mon thru Wed with the GOM wide open for efficient
moisture flux each day. This could be a period of increased hydro
issues as antecedent water level conds by that time may be quite
elevated. A lot will depend on the areas where the front situates as
it wafts north and south thru the period, but the latest trends
begin to shift the heavy rain focus across the srn BR as the Bermuda
High becomes more dominant across the SE region. The going high-end
PoPs have been maintained thru the period including abv normal PoPs
during the overnight periods. Max temps will likely be held below
normal each day by a few degrees while mins remain abv normal.

&&

.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere: A weak cold front will move thru the fcst
area this afternoon/evening helping to kick-off sct to numerous
showers and thunderstorms. I kept TEMPOs for TSRA at all taf sites
from roughly 19 to 23z with KAVL starting at 18z and KCLT starting
at 21z. Most of the convective activity should dissipate after 00z
with some lingering showers possibly hanging around into the over-
night. Still expect cigs/visby to deteriorate overnight as the front
lingers over the area. I have prevailing MVFR cigs/vsby with TEMPOs
for IFR cigs/visby at each taf site. KAVL should have the best chance
of seeing sub-IFR conditions, so I have their visby lowering to LIFR
between 09 and 13z. Otherwise, VFR conditions should return by 14z
or so tomorrow morning once daytime heating kicks in. Winds will
veer from south of west to north of west later this aftn/evening
as the front slides further SE. Winds will go light to calm over-
night and begin to pick up from the NE later tomorrow morning.
By the end of the taf period tomorrow aftn, they should be more
ELY across the area.

Outlook: Expect sct to numerous showers and thunderstorms each aftn/
evening thru the weekend. Morning fog/low stratus will be possible
each day, especially in the mtn valleys and over areas that received
rainfall from the previous day.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$

SYNOPSIS...DEO
NEAR TERM...JPT/PM
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...JPT