332
FXUS62 KGSP 172313
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
713 PM EDT Mon Jun 17 2024

.SYNOPSIS...
High pressure atop the region from Tuesday through Thursday will
suppress any storms from developing until moisture returns on Friday
and into the weekend.  Expect the weekend to be quite hot.  A cold
front approaches from the north early next week.

&&

.NEAR TERM /THROUGH TUESDAY/...
Key Messages:

1) Scattered Showers and Thunderstorms Will Continue Across the
Mountains through this Evening

2) Mountain Valley Fog May Develop Again Overnight into Daybreak
Tuesday

3) Drier and Slightly Less Humid on Tuesday

As of 522 PM EDT Monday...No major changes to the forecast
this evening.  Pretty much everything was on track...so blended
the latest RTMA verification into the impending forecast and
modified PoPs a little based on current convection trends over
the NC mountains.

A large anticyclone will remain over the Carolinas through the
period keeping summer-like conditions around. Scattered showers and
thunderstorms have developed across portions of the North Carolina
mountains this afternoon, with daytime cumulus (and some upper
cirrus) across the entire forecast area. Convection is expected
to continue through at least the early evening hours across the
mountains, with mostly dry conditions persisting along and east of
I-85. Have the highest PoPs (likely, 55%-72%) confined to the NC/TN
border through late this afternoon, with chance PoPs (25%-54%)
across the rest of the mountain zones and the NC Foothills. Did
lower high temps a degree or two area-wide as widespread cumulus
have limited daytime heating somewhat. However, highs are still
expected to climb into the mid to upper 80s in the mountain
valleys and east of the mountains. Cumulus will dissipate around
sunset but upper cirrus will increase in coverage this evening
into tonight. Upper clouds combined with continued S/SE`ly flow
will allow lows to end up around 5-8 degrees above climo. Winds
will turn more E`ly on Tuesday leading to drier conditions. Highs
will be similar on Tuesday compared to today, remaining around
2-4 degrees above climo.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 145 PM EDT Monday: Large elongated upper ridge will be in
place across the Eastern Seaboard, from the Carolinas to New
England, as we start the short term. Surface high in place over the
North Atlantic will provide an easterly to northeasterly fetch for
the surface flow which will counter the subsidence from the upper
ridge, leading to near normal temperatures on Wednesday. The past
couple of days guidance has been waffling back and forth with
temperatures and am generally inclined to lean warmer than cooler
(except for wishful thinking that is) but Wednesday should be the
most pleasant day through the end of the period. Gradual warming on
Thursday as the surface high begins to slip south and the upper
ridge strengthens further. Continued trend of no pops expected
through the near term with the subsident flow aloft.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 200 PM EDT Monday: Upper ridge will remain stretched just to
our north while an inverted trough pushes across to our south as we
move into the extended. Evolution of the tropical wave in the
western Atlantic still remains very uncertain but latest guidance
seems to agree more on it getting picked up around the western
periphery of the Atlantic high and lifted up the East Coast late in
the week. Meanwhile the upper ridge breaks down somewhat as a result
and splits, but there is very little structure to the overall upper
pattern this weekend. Upper subsidence, increasing thicknesses, and
weak southerly flow will allow temperatures to climb toward the end
of the period, reaching the mid 90s across the Piedmont this
weekend. Not enough moisture for excessive heat concerns, just
typically miserable. With the new guidance coming in keeping the
tropical wave to the east, diurnal convection looks a little more
suppressed than previous forecasts due to increased subsidence with
the midlevel inversion. Have backed off on previous pops on
Saturday, but may see a weak upper trough approach for Sunday so
even with the heat could diurnal pops return.

&&

.AVIATION /23Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: VFR at all terminals as of ~2315 Zulu.
Expect diminishing cu field the next couple hours as the sun
sets and daytime mixing breaks down; overnight, expect SCT to
BKN cirrus everywhere.  The mountain valleys are once again at
risk of developing low stratus and vis issues.  Now advertising
IFR restrictions for a couple hours at KAVL around daybreak;
all the other TAF sites to remain VFR through the period.
Tomorrow afternoon, expect another round of highly isolated ridgetop
convection, but coverage is expected to be even lower than today`s,
and thus too low to warrant a mention even at KAVL.  Winds will
remain out of the SE through the period (notwithstanding some VRB
winds overnight) but where today`s winds have been more S than E,
tomorrow`s winds will be more E than S.  May see some afternoon
gusts, with blended guidance suggesting an occasional ~15kt gust
during peak afternoon heating is reasonable.

Outlook: An upper ridge will result in mostly dry and VFR conditions
through Friday. Mountain valley fog and/or low stratus may develop
each morning.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...AR/MPR
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...MPR