Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Columbia SC
1039 am EDT Tuesday Aug 30 2016

Synopsis...
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
this weekend.

&&

Near term /until 6 PM this evening/...
a few showers continue across portions of the midlands and csra
late this morning due to a weak upper level short wave. Latest Storm Prediction Center
hrrr not showing much precipitation at all over the next few
hours, but based on latest radar returns, will keep mention of
mainly slight chance for much of the area into the afternoon. 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 trimmed
back pops a bit across the eastern counties given the latest hi-
res model data. High temperatures are forecast a few degrees
above normal, in the lower 90s.

&&

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 east-northeast 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, dew point 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. Dew point 9 will remain in the Gulf of Mexico through
the short term period, with some strengthening possible. Even so,
dew point 8 will not impact the County Warning Area through the short term.

&&

Long term /Thursday through Monday/...
in the longer term, focus will be on the track of dew point 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. European model (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
to normal.

&&

Aviation /14z Tuesday through Saturday/...
a few light showers across the midlands late this morning but not
affecting any of the terminals at this time. However, will
continue to monitor. 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 mainly widely
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
morning hours.

&&

Cae watches/warnings/advisories...
Georgia...none.
SC...none.

&&

$$

National Weather Service Glossary of Abbreviations