030
FXUS62 KGSP 300612
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
212 AM EDT Tue Apr 30 2024

.SYNOPSIS...
A cold front will push through the forecast area today bringing
scattered showers and thunderstorms. Dry and warm high pressure
builds in Wednesday through Thursday, before another active frontal
system moves in Friday and lingers through the weekend.

&&

.NEAR TERM /THROUGH TODAY/...
As of 945 PM EDT Monday: Cirrus continue to creep in from the west
this evening, with the thicker cirrus noted across the western third
of the forecast area. No major changes were needed as the forecast
remains on track.

Otherwise, an upper ridge will break down as it progresses off the
East Coast tonight, downstream of large scale height falls
associated with a series of short wave troughs moving east of the
Miss Valley. One of these waves is expected to evolve into a small
upper low just west of our area tomorrow morning as it catches up to
the weakening ridge. A weak cold front will accompany height falls
into our forecast area during the daylight hours Tuesday. Pre-
frontal convection could make a run toward far western NC by
sunrise, warranting chance PoPs for SHRA across those areas prior to
12Z. PoPs ramp up from the west Tuesday as the frontal zone crosses
the area, mainly during the afternoon. A consensus of model guidance
indicates modest instability...sbCAPE of around 1000 J/kg to
interact with a rather weak frontal circulation. Nevertheless, with
the upper low poised to pass over the CWA during the afternoon...at
least solid chances PoPs appear warranted throughout the CWA, with
likelies advertised across much of the western 1/3 or so of the
area. Shear parameters are forecast to be unimpressive...around 30
kts of 0-6km bulk shear. Given the expected instability, the
potential for severe storms will be very low. Temps are expected to
be around 5 degrees above normal through the period.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...
As of 105 AM Tuesday...A mid-level trof axis continues to shift east
of the area to begin the short range period. This will give way to a
building upper ridge across the east coast, which will control the
weather across the FA thru Thu night. Profiles remain quite dry with
PWATS remaining below 1.0 inches each day, so along with neg
forcing, rain chances are nil with mainly fair-wx Cu each day. Winds
will be weakly cold advective as sfc high pressure builds in from
the north, yet high temps will reach the low to mid 80s each day in
a modifying airmass. With the n/ly to ne/ly flow, sfc dewps and RH
values wont increase much, so expect rather nice feeling weather for
late April.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 150 AM Tuesday...The ext range forecast remains unsettled as
upper ridging finally breaks down in advance of mlvl srn stream
energy. The latest op models generally agree on a modest h5 s/w
approaching the FA Fri pushing an active sfc bndry in from the west,
while sfc ridging breaks down across the nrn GOM supplying very good
moisture flux to the system. This wont be a very dynamic system as
deep layered shear remains less than 30 kts with only a 60 kt upper
jet core arriving by Sun evening. Thermo profiles indicate a
saturated column likely with skinny CAPE on the order of 700-1000
J/kg. So, expect some strong thunderstorms each day with high
rainfall rates possible. An organized severe threat looks low-end as
aforementioned dyno remains low and mlvl LRs area held less than
optimal while a highly moist sfc bndry settles across the area thru
Sun, possibly into Mon. Low level winds remain s/ly to se/ly each
day and temps will remain abv normal, with a drop off to near normal
levels Sat due to a better chance of widespread cloudiness and
precip.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Expect VFR conditions to persist thru day-
break as the western edge of a sfc high lingers over our area. A
cold front will approach from the west this morning and move thru
the western Carolinas this afternoon and evening. Rain chances
increase across the western terminals (KAVL and the SC Upstate
terminals) by late morning with VCSH beginning just before noon.
Being further east, KHKY and KCLT should remain dry a bit longer
with any showers reaching them a few hrs later. Sct thunderstorms
will be possible during the afternoon and evening across the fcst
area. Thus, I have PROB30s for TSRA at all terminals beginning in
the afternoon and going into the evening with lingering VCSH. Winds
will remain light to calm overnight and into the morning. They will
pick back up by late morning and continue to favor a S to SW direc-
tion thru the period. Low-end gusts are possible this afternoon,
especially at KCLT and KHKY, where I included them in the taf.
Otherwise, cigs should generally remain VFR outside of any TSRA.

Outlook: Scattered showers and thunderstorms will remain possible
thru late tonight. More numerous showers and storms are expected
on Saturday ahead of a cold front.

&&

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

&&

$$

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