Scientific Forecaster Discussion
fxus62 kcae 172346
Area forecast discussion
National Weather Service Columbia SC
746 PM EDT Tue Sep 17 2019
a cold front will sink southward and move through the area
tonight and Wednesday morning. A few showers or thunderstorms
may occur near the front. Behind the front, temperatures and
humidities become more seasonal for the remainder of the
workweek. Above normal temperatures through for the weekend and
early next week as high pressure and upper-level ridging move
over the forecast area.
Near term /until 6 am Wednesday morning/...
tonight a weak front will move into the area from the north
however moisture with the front will be limited. Dynamic lift
with the front will be limited and the nocturnal nature of the
front will also limit instability. As such expect coverage to be
limited with mainly rain showers...and possibly a few rumbles
of thunder. Rainfall amounts will generally be light with most
locations receiving less than one tenth of an inch. Overnight
lows will range from the upper 60s in the northern midlands and
Pee Dee to around 70 in the csra.
Short term /6 am Wednesday morning through Thursday night/...
on Wednesday morning, models indicate that a cold front will
still be pushing through portions of the forecast area from the
north. Weak convergence along the front and minor 500 mb height
falls suggest a slight chance of showers in the morning. By
afternoon drier air will spread into the forecast area. Precipitable water values
drop significantly through the day from above 1.5 inches in the
morning to around 1 inch by the evening. It will also be much cooler
behind the front, with highs in the 80s, which is near normal for
the time of year. Lows Wednesday night will be around 60 degrees.
Thursday, breezy NE winds will continue to feed low Theta-east air
into the forecast area. Precipitable water values continue to decrease to values
well below 1.0 inches. Dry weather and mainly clear skies are
expected. High temperatures will range from the upper 70s to lower
80s. Lows Thursday night will be in the 50s.
Long term /Friday through Tuesday/...
surface high pressure as well as an upper level ridge will remain
over the region through the weekend. GFS and European model (ecmwf) ensembles show
precipitable water values remaining near or below 1.0 inches. Models also indicate
a stable atmosphere. This will result in dry conditions. High
pressure will shift off the coast early next week in advance of an
approaching cold front.
With upper level ridging over the region and a moderating airmass,
temperatures will warm through the long term. Expect a return to
above normal temperatures for the weekend and early next week.
Aviation /00z Wednesday through Sunday/...
VFR conditions expected through the 24-hour taf period.
A frontal boundary extending along the northeastern fringe of
the forecast area will sink southward overnight. Regional radar
showing isolated showers across the area, but no impacts to the
terminals are expected based on current trends, so have not
included mention. Drier air will return to the area by Wednesday
afternoon with the front shifting south of the forecast area.
Fog not expected late tonight and early Wednesday due to mixing
with the front in the area.
Extended aviation outlook...no significant impacts to aviation
expected through Sunday.