Area Forecast Discussion Issued by NWS Greer, SC
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KGSP 080606
AFDGSP
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
206 AM EDT Thu Jun 8 2023
.SYNOPSIS...
-- Changed Discussion --
Cool and dry high pressure will begin to spread into the region
today and linger into Saturday, bringing mild temperatures and
fairly low humidity. Another moist cold front will approach from
the northwest late Sunday and move through our area on Monday.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TODAY/...
-- Changed Discussion --
As of 150 AM: A gradient of dewpoints is seen across the CWA, but
delineating the actual cold front is difficult. Abundant moisture
in the 850-700mb layer is still present over the south half of the
CWA, but resultant clouds are becoming a bit more ragged. A weak
shortwave axis is seen on water vapor imagery over the Upstate,
and it has respawned some high based showers from that cloud layer
(even a few lightning strikes). Thinking these will taper off from
N to S over the next couple of hrs. A compact shortwave is also
seen near Cincinnati and will quickly move over the CWA by around
12z. Preceding it, a few models depict new showers forming a bit
north of where the present ones are. The upshot is an isolated
to scattered shower mention persists over much of the CWA south
of US 74, thru 12-13z; isolated thunder is also mentioned in our
southernmost zones. The front will push south during the morning,
so PoPs drop off and we should see skies to start to clear, from N
to S. Some shallow instability redevelops diurnally this afternoon,
esepcially in the Lakelands of GA/SC, but the convective layer
looks shallow enough that thunder is not expected. Highs will be
several degrees below normal today.
Air Quality Alerts (Code Orange) remain in effect thru midnight
tonight for our North Carolina zones although smoke concentrations
have diminished over much of the area since yesterday.-- End Changed Discussion --
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
As of 215 PM Wednesday: The overall synoptic pattern continues to
churn out a persistent omega block across the CONUS. A wide swath of
upper high pressure extends through the central U.S. and a strong
upper low situated over the NE will keep drier air in the area. A
frontal boundary is expected to pass through earlier on Thursday,
bringing even drier Canadian air into the area through the forecast
period. Thursday night into Saturday night, high pressure will
dominate the region and keep a lid on any precipitation chances. As
the upper low begins to slowly slide off the east coast, the ridge
over the central CONUS is expected to move eastward and assist in
building in the higher pressure. This will also bring temperatures
closer to normal with most of the CWA reaching the mid 80s on
Saturday. Lower humidity from the drier air will allow for somewhat
cooler overnight temps in the 50s outside the mountains for both
Thursday and Friday nights.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 210 PM Wednesday: By Saturday night, the persistent omega
blocking pattern continues to persist. The ridge that built in
across the eastern portion of the CONUS will be replaced with
another upper low descending from Canada. High pressure returns to
the central U.S. and the omega pattern strengthens once again by
Monday. During this transition, a cold front could extend southward
and traverse across the TN/OH valley and into the region by Sunday
night into Monday morning. As the high pressure breaks down ahead of
this FROPA, a deep pool of moisture will advect into the area,
allowing for precipitation chances to increase. For this, likely
PoPs from west to east starting Sunday evening through Monday night.
Behind the boundary, dry Canadian air returns once again and keep
the region mostly dry through the end of the forecast period. Long
range model guidance hints at some precip chances returning by mid
week with a series of shortwaves, but it`s too far out to pinpoint
anything certain at this time. Meanwhile, mostly light SW winds
until Monday night when the cold front pushes through and veers the
wind NW. Daytime temperatures will likely decrease slightly with the
cooler and drier air from the FROPA, but quickly rebound into the
mid and upper 80s for the remainder of the forecast period.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
At KCLT and elsewhere: Midlevel moisture remains plentiful across
the region invof very diffuse cold front, which should continue
to slowly sag southward thru the morning. This is responsible for
widespread cloud cover in the 070-110 range. Where moisture is a
bit deeper in Upstate SC, weak shortwave axis has triggered some
shallow convection and a new round of SHRA. Only KAND appears at
risk of any associated restrictions, reflected in TEMPO. A few
sprinkles are possible near KGSP/KGMU/KCLT with this activity. A
stronger shortwave will dive south closer to daybreak and could
spawn additional -SHRA near those same sites, but chance (and
impacts) small enough to omit other than VCSH at KCLT. Cloud bases
should remain VFR thru the morning, but may lower below 050 near
daybreak. MVFR radiation fog is TEMPO`d at KHKY/KAVL, and an area
of IFR fog may develop in the Piedmont where more appreciable rain
fell in the evening. This probably will stay north of KCLT but bears
watching thru 12-13z. Skies trend clearer from N to S late morning
to midday; should be too dry tonight for any restrictions. Winds
may be southerly at times before dawn in the Upstate, but otherwise
should be NW to N thru the period.
Outlook: Dry high pressure dominates tonight thru Sat. Diurnal
convective chances return for Sunday and Monday.-- End Changed Discussion --
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...Wimberley
NEAR TERM...Wimberley
SHORT TERM...CP
LONG TERM...CP
AVIATION...Wimberley