399
FXUS62 KGSP 241447
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1047 AM EDT Fri May 24 2024

.SYNOPSIS...
Temperatures will remain several degrees above normal each day
through the holiday weekend. Daily chances for showers and
thunderstorms. A cold front on Monday brings cooler and drier
conditions for the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1020 AM EDT Friday: No major changes this morning.  No radar
returns to suggest lingering activity at this point, although
isolatd upslope sprinkles remain possible along the NC/TN border.
Upstream convection is now over the AL/MS/TN triple point, and
continuing to migrate east.

The main problem for the next 24 hours or so revolves around
deep convection, and there aren`t any easy answers, because the
CAMs don`t show much agreement in terms of coverage, timing, and
intensity. In reality, new development of showers and storms will
probably be tied to the approach and passage of remnant MCVs and
outflows from storms out west. These may come in a few waves in
the otherwise quasi-zonal flow, but when they pass through, will
help to trigger or bring an uptick in coverage of storms. With
that, also perhaps an increase in potential for severe storms. The
environment will remain somewhat favorable with sufficient buoyancy
on the order of 1500-2500 J/kg of sfc-based CAPE depending on the
model, and enough deep layer shear through the early evening on the
order of 20-30 kt, which could make storms more interesting. No
issues with the Marginal Risk on the Day 1 outlook and it seems
reasonable to expect a few warnings to be issued mainly in the
afternoon/evening. Similar to this past evening, expect some
of this activity to persist into the early morning hours as the
buoyancy is slowly used up. Won`t rule out locally heavy rain,
either. High/low temps will be about five degrees above normal.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
As of 215 AM Friday: Picking up Saturday with gradual strengthening
of an area of high pressure over the Gulf and a weak ridge extending
northward over the CWA. As the ridge progresses eastward, shortwaves
traverse the Carolinas and up the chances for additional showers and
thunderstorms. Guidance keeps a steady stream of moisture in the
area through the forecast period and beyond, with instability
remaining prevalent. Latest guidance does bring some questions as
far as coverage on Saturday, especially outside the mountains. EURO
is trending for a few more areas outside the mountains, but the GFS
trends drier. Cannot rule out a few thunderstorms at this time.
Sunday looks to dry out a bit as the upper ridge axis crosses over
the CWA and suppresses rain chances. However, height rises does make
Sunday the warmest day with low 90s popping up in most places east
of the mtns. Meanwhile, an upper low forms over the southern plains
and lifts NE, bringing a chance for a FROPA across the mountains
Monday, increasing rain and TS chances once again. At this time,
guidance has decent upper flow of 30-40kts and sufficient
instability. Modeled soundings show steep sfc-3km lapse rates, but
with a strong T/Td spread and inverted-V. Will continue to monitor,
though it appears to be more typical TS with a frontal passage.
Overall, hotter temps returning for most of the holiday weekend and
TS chances each day.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 220 AM Friday: Continuing with Monday night onward, the
pattern becomes generally more dry as far as the synoptic pattern
goes. Any remaining FROPA should be weakened closer to Monday night
and pinch off rain and thunderstorms chances by Tuesday. As the
strong upper low lifts towards the Great Lakes, a strong ridge
builds over the central CONUS, taking on an omega pattern toward the
north. Meanwhile, high pressure amplifies zonally to the south and
balances height rise/falls through at least Wednesday. Long range
models show an upper trough dipping southward from the Great Lakes.
Given how far out the model runs are, there is still much
uncertainty as to how far south and if the trough reaches the CWA.
GFS suggests a stronger pressure gradient and possible rain chances,
while the EURO remains less enthusiastic and keeps the area dry.
After Wednesday, the ridge axis from the central CONUS propagates
eastward toward the CWA and shunts rain chances with strong
subsidence aloft. Temperatures should remain close to climo through
the period as well.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: A low confidence forecast this morning
because of much uncertainty with the timing, coverage, and location
of convection over the next 24 hours. Most of the convection will
probably be organized around outflow boundaries and waves aloft,
and some of the guidance indicates that the next wave will not
reach our area until late this afternoon. We will handle this with
amends and TEMPO groups as appropriate, to handle the restrictions
around the precip. Wind will be variable and light. For Friday,
will go VFR prevailing, with a PROB30 for afternoon/evening
thunderstorms and associated restrictions. Wind should be W to
NW. After the loss of daytime heating, we should have only debris
cloudiness. Fog may become a problem early Saturday morning in
places where it rains today.

Outlook: A unsettled pattern will linger thru the weekend and
into early next week, allowing for diurnal shower and thunderstorm
chances each day and fog development each night/morning.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...MPR/PM
SHORT TERM...CP
LONG TERM...CP
AVIATION...PM