Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 301201
Area Forecast Discussion
National Weather Service Columbia SC
801 AM EDT TUE AUG 30 2016
Daytime heating and an onshore low level flow expected to result
in scattered showers and a few thunderstorms through Wednesday,
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 cooler high pressure will build in for most areas
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A few showers across portions of the Midlands this morning due to
a weak upper level short wave. Have updated pops to reflect
slight chance of showers over the next couple of hours mainly
across the central and southern Midlands and CSRA. Previous
discussion: Weak upper ridge axis to our north will weaken and
shift west today. Tropical Depression 8 which is currently located
near the Outer Banks of North Carolina is expected to strengthen
into a tropical storm today, although little to no impacts
expected across the Midlands and CSRA. The deepest moisture will
be in the eastern Midlands with precipitable water values near 2
inches. Models show drier air in the western portion of the
forecast area with precipitable water values near 1.5 inches.
Instability appears weak with LI values around -2 during the
afternoon. Have continued to indicate chance pops east. High
temperatures are forecast a few degrees above normal, in the lower
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
Upper low will remain along the Carolina coastline tonight into
Wednesday. A weak surface trough also remains along the coast,
with surface ridging extending across the central and western
Carolinas. Low level ENE flow will promote best low-level
moisture across the eastern portions of the cwa. Would expect best
probability for precip will be across the east and southeastern
counties closer to the areas of low pressure. Temperatures
remain around normal.
As for any tropical activity, TD 8 is still forecast to move
towards the North Carolina outer banks, then curve back to the
northeast and back out to sea. This will have little impact to the
Midlands and CSRA. TD 9 will remain in the Gulf of Mexico through
the short term period, with some strengthening possible. Even so,
TD 8 will not impact the CWA through the short term.
.LONG TERM /THURSDAY THROUGH MONDAY/...
In the longer term, focus will be on the track of TD 9. By
Thursday it should be a Tropical Storm and generally be across the
northern Gulf of Mexico, tracking in a northeasterly direction.
Current forecast track brings the storm across northeastern
Florida, then back into the western Atlantic Thursday night into
Friday morning. A cold front and upper trough will be pushing into
the southeastern States Thursday into Friday, and this should help
keep the Storm far enough away from the forecast area. The storm
should continue tracking northeast, remaining east of the
Carolina coastline through the day Friday as the upper trough
picks up the storm system. Please keep in mind, the track of this
system may change in the next few days, so continue to monitor the
latest official forecasts from the Tropical Prediction Center.
Through much of the period, can not rule out the potential for late
afternoon and evening isolated showers/storms through Friday.
Generally went with a blend of guidance. From Friday night
through the weekend, it appears drier and cooler air will work
into the region behind the exiting tropical system. High pressure
centered over New England will nose down the Appalachians and into
the region through Monday. Uncertainty past Monday. ECMWF shows an
area of low pressure developing off the Carolina coast Monday
night into Tuesday, whereas the GFS keeps ridging across the
region. Would expect to see a return of diurnal precip chances as
we get into the middle of next week. Temperatures remaining close
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
A few light showers across the Midlands this morning but not
affecting any of the terminals at this time. Ridging through the
Mid- Atlantic region and troughing off the Southeast Coast will
continue to promote a deep moist easterly flow today. The pattern
supports scattered showers and thunderstorms today with greater
coverage associated with diurnal heating. The best chance will be
in the eastern portion of the area where moisture is deepest.
EXTENDED AVIATION OUTLOOK...There may be restrictions in scattered
showers and thunderstorms mainly during the afternoons and
evenings. Widespread stratus and fog may occur during the early