Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 272257
Area Forecast Discussion
National Weather Service Columbia SC
657 PM EDT TUE SEP 27 2016
A cold front will slowly push into the area through Wednesday
night. Cooler and drier more seasonable temperatures expected late
in the week and over the weekend with little rain chances.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Cold front continues to move into the upstate with showers and
thunderstorms moving into the western Midlands and northern CSRA.
With sunset and loss of heating expect convective activity to
diminish over the next several hours...however have increased pops
over the much of the forecast area as current convection will move
into the area before dissipating later tonight. Instability
remains moderate with cape between 1000 and 2500 j/Kg and LIs -3
to -4 and with dry air aloft some potential exists for damaging
wind gusts. With current situation and expected weakening of cells
believe threat of damaging winds gusts is low. Debris clouds and
abundant boundary layer moisture will keep overnight lows in the
upper 60s to lower 70s.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
Models are a fairly good agreement on the movement of the Great
Lakes upper low the next few days. The center of the low will
slowly push southward towards Kentucky through Friday. This will
help to finally drive a cold front through the cwa Wednesday night
into Thursday. Some instability will exist on Wednesday ahead of
the front, and can not rule out some stronger winds in the
convection. SPC does have the northeastern portions of the cwa in
a marginal risk for Wednesday. Expecting chance pops through the
day Wednesday, lingering into the early portions of Wednesday
evening. Activity should be east of the cwa by Thursday morning,
with drier air pushing into the area. Dry forecast for Thursday
through Friday night. As for temperatures, with the region in the
warm sector for Wednesday, expect readings slightly above normal
in the mid to upper 80s. Temperatures drop for Thursday and
Friday, with readings around 80 on Thursday, and then highs in the
mid to upper 70s for Friday. Overnight lows will range from the
upper 50s west to mid 60s east Wednesday night, then cooler
overnight readings in the 50s the remainder of the short term.
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Dry and fair conditions will prevail through the weekend and into
the early portions of next week. The closed upper low will lift
back north by Monday, bringing a more zonal pattern to the region
to start off the work week. As previously mentioned, the models
indicate a tropical low in the Caribbean Monday and Tuesday.
Models diverge Monday evening into Tuesday though, with the GFS
bringing the system due north but keeping it in the western
Atlantic. The ECMWF takes the low more towards Cuba. This low is
currently over the Atlantic, well east of Barbados, and is being
monitored by the National Hurricane Center. Temperatures will be
near normal with highs around 80 to the lower 80s and lows in the
50s and 60s.
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A slow moving cold front will approach from the northwest through
the TAF period. Convergence ahead of front should help cause
showers and thunderstorms but expect limited coverage because
deepest moisture will remain east of the forecast area. The high-
resolution models support scattered coverage. The thunderstorm chance
was too low to include in the terminal forecast at this time.
Nocturnal cooling and low-level moisture that has pooled ahead of
the front should help support stratus and fog during the early
morning hours. The GFS and NAM MOS were close with MVFR or IFR
conditions with the greater restriction at the river valley
terminal of AGS. Heating and mixing should dissipate fog by 14z.
EXTENDED AVIATION OUTLOOK...A slow moving cold front will help
support scattered showers and thunderstorms and associated
restrictions through Wednesday.