271
FXUS62 KGSP 080144
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
944 PM EDT Sun Jul 7 2024

.SYNOPSIS...
A weak surface front will increase the chance for thunderstorm
activity across the area this afternoon and evening. An active
pattern of afternoon and evening showers and storms is expected to
continue for the first half of this week. More typical mid-July
weather is expected toward the end of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 945 PM Sunday: Stratiform rain continues to develop and fall
across most of the Upstate and NC Piedmont. Radar indicates most of
the convective activity is on the fringe of the CWA, moving out
toward the SE. Given he widespread rain, patchy fog and low level
stratus will be likely overnight, especially with winds becoming
calm. Minor adjustments to PoPs, but temps cooled well below
forecast due to the showers and storms.

Otherwise, a widespread deck of low stratus clouds is expected to
build in given a rather moist boundary layer with areas of fog also
possible. Heading into tomorrow, extensive morning clouds will
likely delay daytime heating and the atmosphere will also remain
worked over from today`s storms. Thus, the CAMs are not overly
enthused with the coverage of storms, especially outside of the
mountains. Several storms appear likely over the southern
mountains/escarpment with only isolated to scattered showers and
storms elsewhere. Temperatures will be in the upper 80s to low 90s
tomorrow, but could end up a degree or so cooler if morning clouds
take longer to lift and scatter.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 155 pm Sunday: A deep/weak SW flow will remain over the
southern Appalachians and vicinity through the short term...between
an anomalous trough across the central Conus...and a subtropical
ridge nosing into the Southeast from the western Atlantic. Resultant
quiescent, but very moist atmosphere will continue to support
higher-than-normal coverage of diurnal convection...PoPs mainly
60-70% across the mtns and 50-60% across the Piedmont...through the
period. Diurnal instability is forecast to be adequate for isolated
pulse severe storms...perhaps more than adequate on Wed, when a
consensus of short term guidance indicates sbCAPE will peak at
around 3000 J/kg. One change that is expected is that storm motions
should become a bit swifter, especially on Wed afternoon. This will
be a consequence of the acceleration of the mid-level flow as the
upper trough draws a bit closer...as the circulation associated with
the remnants of T.C. Beryl is expected to become absorbed into the
westerlies...and progresses the central Conus trough to the east.
Nevertheless, the very moist conditions, locally poor antecedent
conditions, and the potential for SW=>NE training cells will result
in a continued low-end threat for excessive rainfall. Temps are
forecast to be a couple of degrees above normal through the period.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 210 pm Sunday: The global models continue to trend
(unfortunately) toward a drier extended period, as upper trough is
expected to progress into the eastern states...albeit weakening and
lifting north of our area over the subtropical ridge. It`s looking
increasingly likely that the proximity of the trough will allow the
deeper/subtropical moisture to shunt east of the CWA during the
latter half of this week, resulting in dwindling chances for
convection. Daily instability and moisture should still be adequate
for diurnal showers and storms, but with coverage more typical for
the time of year. Daily PoPs therefore trend closer to climatology
for much of the period, with standard mid-July threats of a pulse
severe storm or three and locally excessive rainfall. Temps are
forecast at near-to-slightly-above normal through much of the
period.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Ongoing TSRA will start to taper off are all
terminals through midnight, with lingering VCSH afterwards. All
terminals had rain this evening and this will pose a higher
confidence in VSBY/CIG restrictions during the overnight hours.
Patchy BR is expected at all sites east of the mountains with FG
possible at KAVL, with a TEMPO for 1sm VSBY from 09z-13z. Most other
sites also have a TEMPO for a VSBY of 4sm and IFR CIGS during this
time. Conditions should improve after daybreak, but will be slow
given the deep amount of moisture in the area. Once VCSH/TSRA taper
off, winds will become VRB or calm through the overnight hours,
enhancing FG/BR potential. Winds should prevail more southerly once
speeds start to pick up outside the mountain zones. There is a
chance for another round of convection Monday evening, but coverage
is not expected to be as widespread. PROB30 for this at all sites
except KHKY, where confidence is the lowest.

Outlook: An active summertime pattern continues for most of the
upcoming week, leading to showers/thunderstorms and possible
restrictions each afternoon/evening. Fog or low stratus may develop
each morning, especially over areas that received rain the previous
day.

&&

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

&&

$$

SYNOPSIS...JDL
NEAR TERM...CP/TW
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CP