Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
625 PM EDT Thursday Sep 3 2015
an upper-level ridge will remain to our south and west...while an
upper-level trough sets up along the East Coast. A cold front
and increasing moisture will bring increasing chances for showers
this weekend into early next week...along with a trend towards
Near term /until 6 am Friday morning/...
a weak surface trough and lift ahead of a middle-level shortwave
trough has helped support scattered showers and thunderstorms.
Weak low-level convergence and somewhat shallow moisture has
limited coverage. Believe showers will dissipate this evening with
the loss of heating and main lift ahead of the middle-level feature
shifting eastward. The temperature guidance was close with lows in
the lower 70s.
Short term /6 am Friday morning through Saturday night/...
surface high pressure building over New England will push a back
door cold front through the forecast area late Friday into
Saturday. Guidance generally suggests sufficient atmospheric
moisture to remain over the region...coupled with diurnal heating
to provide mainly slight chance to low end chance probability of precipitation Friday. Upper
energy to shift SW towards our region Saturday...with surface high
building down into the middle Atlantic with low pressure
offshore...bringing a back door boundary SW into our region late
Friday night into Saturday. This is expected to lead to a trend
towards increasing probability of precipitation and lowering temperatures.
Long term /Sunday through Thursday/...
upper low to cut off over our region through midweek...with
upper flow becoming more zonal by Thursday. Low level moisture
flux off the Atlantic appears to result in continued chance
probability of precipitation...along with below climatology maximum temperatures Sunday into early week.
Gulf moisture will become more prevalent across the area by
Thursday. Overall will keep chance probability of precipitation through the extended
period. Generally accepted guidance blend...trending back towards
climatology by middle week due to uncertainties.
Aviation /22z Thursday through Tuesday/...
regional radar late this afternoon shows isolated thunderstorm
activity across the area. Relatively dry air in place has helped
limit the convective potential. Currently all terminals are VFR
although a passing storm could result in temporary restrictions.
Generally broken high level cloudiness through the evening...before
becoming scattered later tonight. Cannot rule out brief MVFR br
at ags/ogb towards sunrise Friday...with all sites becoming VFR
during the day Friday. Winds will generally remain light out of
Extended aviation outlook...restrictions possible in mainly early
morning fog. By late in the extended period...afternoon and
evening scattered showers or thunderstorms will be possible.