Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 310751
Area Forecast Discussion
National Weather Service Columbia SC
351 AM EDT WED AUG 31 2016
Daytime heating and an onshore low-level flow expected to result
in scattered showers and a few thunderstorms today, favoring
areas closer to the coast. A tropical cyclone is forecast to
develop in the Gulf of Mexico and move NE across North Florida and
offshore the Carolina coast mid to late week. Behind the cyclone,
drier and cooler high pressure will build into the region for the
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Early this morning...Any precipitation should remain near the
coast. Low confidence in stratus development despite plenty of
low level moisture in place with persistent easterly flow off the
Atlantic. Overnight lows will be mainly in the lower to mid 70s.
Today...Upper level low near the forecast area will continue to
weaken today as it pushes northeastward. An area of weak surface
low pressure along the Georgia coast will weaken as it moves
northeastward along the South Carolina coast. Models show deeper
moisture in the central and eastern parts of the forecast area
with peak precipitable water values near 2.1 inches. Kept the
highest pops east. Instability appears weak with model LI values
during the afternoon and evening around -2. Near normal high
temperatures are expected, in the upper 80s to lower 90s.
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
Weakening upper low will be tracking off to the northeast of the
area tonight, ahead of a digging trough moving into the Ohio
Valley. TD9 will still be in the northern Gulf of Mexico, but will
be tracking more to the northeast towards the Big Bend of Florida
through Thursday. TD9 then tracks across northern Florida during
Thursday night. Please see the official TPC forecast track for
Ahead of TD9, the main upper level trough digging through the Ohio
Valley will be amplifying, and this will push a cold front closer
to South Carolina through Thursday night. This front will remain
north of the CWA through the period though. The big thing with the
approaching trough is that it should help to steer TD9 east of the
Expect an rain activity this evening to diminish by sunset.
Additional rainfall will be possible through Thursday night with
onshore flow ahead of the approaching tropical system. Best chance
for activity should remain across the east. Highs on Thursday
should still be able to climb to around 90. Lows tonight and
Thursday night in the lower to middle 70s.
.LONG TERM /FRIDAY THROUGH TUESDAY/...
The expected tropical will be pushing off the northeastern Florida
or southeastern Georgia coast Friday morning. The storm is
forecast to track off to the northeast, with the center of
circulation remaining just offshore. Expect scattered to numerous
showers through the day Friday as this system tracks along the
coast, with the best chance for rainfall east. Temperatures on
Friday should be quite a bit cooler, depending on amount of clouds
associated with the tropical storm, and with the cold front
pushing in from the north. Afternoon highs in the lower to middle
Once the low tracks northeast of the area, the drying should
develop as the cold front pushes through the area. Much drier
airmass will settle across the area for the weekend. Behind the
front, high pressure centered well north of the region will nose
down the Appalachians and into the area through Monday. Dry and
somewhat cooler conditions will prevail through the weekend and
into Monday. Temperatures begin warming back up for Tuesday and
Wednesday as upper level ridge builds back over the area,
although conditions will remain dry.
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
Low pressure along the coast will keep the deepest moisture in the
eastern portion of the area today. The pattern supports scattered
showers and thunderstorms with greater coverage associated with
diurnal heating. Thunderstorms were not included in the terminal
forecasts at TAF issuance because of the scattered coverage and
timing uncertainty. High low-level moisture and nocturnal cooling
may result in stratus and fog during the early morning hours. Heating
and mixing should dissipate any fog around 14z.
EXTENDED AVIATION OUTLOOK...Widespread IFR or MVFR conditions may
occur Thursday and Friday associated with a cold front moving
into the area from the northwest. There may also be added
moisture associated with a tropical system forecast to move
northeastward off the southeast coast during this period.