374
FXUS62 KGSP 022340
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
740 PM EDT Sun Jun 2 2024

.SYNOPSIS...
A typical summer pattern is returning during the first half of the
week with daily afternoon thunderstorm chances.  Showers and
thunderstorms will likely increase in coverage for Wednesday and
Thursday as a weak cold front approaches our area.  Drier weather is
expected to return by the end of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 730 PM EDT Sunday: Showers continue to roam across the
Piedmont zones with a few embedded thunderstorms. Clouds beginning
to scour out over the western zones and should continue to breakdown
farther east later this evening as showers will gradually move east
of our area later tonight/overnight with low temps dropping to near-
normal if not slightly above. With winds going light to calm and
ample lingering boundary layer moisture, there`s a good chance that
we`ll see at least patchy dense fog across our area with widespread
fog certainly possible by daybreak.

Otherwise, an upper shortwave trof will translate over our fcst area
and help push a weakening upper ridge off the Atlantic Coast today/
tonight. As we move into Monday, heights begin to rebound as upper
ridging starts to build over the Southeast again. At the sfc, high
pressure will continue to slowly move further off the SE Coast as a
moist frontal boundary gradually moves thru our fcst area today and
tonight and eventually washes out to our east on Monday. This will
result in profiles undergoing some amount of drying on Monday. None
theless, we will remain under warming SLY low-level flow which will
likely produce another round of diurnal, isolated to sct showers and
thunderstorms, yet the severe potential still appears minimal at
best on Monday. In addition, temperatures on Monday will rebound to
near, if not slightly above, normal values under significantly less
cloud cover and increasing thicknesses.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 130 pm Sunday: A weak short wave ridge will meander across the
region through much of the period, before shunting to the Coast by
Wed evening, as an area of large scale height falls overspreads the
Appalachians and vicinity. SW low level flow will provide the heat
and humidity for diurnal deep convection Tue afternoon...although
coverage is expected to be somewhat limited due to weak anticyclonic
flow aloft and relatively low precipitable water values. Moderate
instability should nevertheless allow for isolated to widely
scattered coverage (20-40 PoPs) across much of the area, esp the
high terrain.

A cold front associated with aforementioned height falls will enter
the picture from the west by the end of Wednesday, enhancing diurnal
convective chances during the afternoon/evening, especially over the
mountains, where 60-70 PoPs are warranted. A consensus of short term
guidance suggests destabilization could be quite robust Wed
afternoon, with sbCAPE of 2000+ J/kg likely. Shear parameters are
forecast to be quite meager, but 0-3km shear of 15-20 kts could
support some local cell clustering along outflow boundaries which
would pose a threat of isolated downbursts, while a few pulse severe
storms also appear to be a good bet. With the front expected to
steadily cross the region Wed night, some degree of convective
coverage will likely persist long after the end of the diurnal
heating cycle, albeit with a warning risk of strong-to-severe
convection. Temps are expected to be a category or so above climo
through the period.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 150 pm Sunday: A trough associated with a deep upper low is
expected to develop across the East early in the extended...
gradually shifting off the East Coast through the period. An
associated frontal boundary is expected to be draped over or near
the forecast area at the start of the period, with scattered
convection (generally 30-50 PoPs) expected from late morning through
the afternoon Thursday. Lower theta-E air is expected to begin
filtering in from the west by the end of the day, bringing an end to
substantial convective chances from Friday through next weekend,
although a few showers (PoPs 30% at most) will be possible across
the mountains within deep NW/upslope flow regime Friday through
Sunday. Other than a stretch of near-to-slightly below normal
temperatures expected Fri night through Sat night, temps are
expected to remain a category or so above normal through the
period.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Sct showers with some embedded thunderstorms
are expected to linger over the fcst area through this evening. Have
TEMPOs for thunder at all Upstate SC sites and KCLT until roughly
02z with some lingering vcsh after that for all terminals. After the
rain moves east of the area overnight, expect cigs and visby to
lower. There`s a decent chance that all TAF sites will see a few hrs
of IFR cigs and at least MVFR visby overnight and into the morning,
with the lowest confidence at KCLT. KAVL and KHKY have the best
chance of seeing LIFR or lower around sunrise. Expect visby to
improve and the lower cigs to sct out by roughly 14z late tomorrow
morning with VFR for the rest of the day. We will likely see another
round of diurnal isolated to sct showers and thunderstorms Monday
afternoon/evening, which is represented in a PROB30 for all TAF
sites between 18Z and 24Z. Otherwise, winds will go light and
variable later this evening/overnight and continue to favor a S to
SW direction on Monday.

Outlook: Diurnal shower and thunderstorm chances with associated
restrictions will linger thru the middle of next week.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...CAC/JPT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CAC/JPT