Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 232157
Area Forecast Discussion
National Weather Service Columbia SC
557 PM EDT FRI SEP 23 2016
Upper level trough and surface low pressure will exit the region
overnight. Slightly drier air will filter into the area for
Saturday as an upper level ridge builds over the region. A cold
front will approach from the north Sunday and stall over the
region through much of next week.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Weakening upper level low will eject northeastward from the
region overnight while surface low pressure along the coast
dissipates. Isolated showers mainly over the eastern Midlands
expected to gradually diminish this evening. Clouds will continue
to clear across the western Midlands this evening...with clearing
spreading east tonight as the low opens up and moves offshore
allowing slightly drier air to work into the northern and western
portions of the forecast area. Models indicate potential for
patchy fog given clearing skies and low level moisture. Above
normal overnight lows expected in the mid to upper 60s.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
High amplitude upper level ridge will build over the MS River
Valley with surface high pressure moving into the New England
states this weekend. This will allow a frontal boundary to slide
southward into the mid Atlantic states Saturday and the northern
Midlands on Sunday. This will result in a brief period of dry
weather on Saturday with slight chances of showers returning on
Sunday. With weak dynamics rainfall amounts on Sunday are expected
to be light with less than one tenth of an inch expected.
High temperatures through the short term will be upper 80s to
near 90 with overnight lows in the middle to upper 60s.
.LONG TERM /MONDAY THROUGH FRIDAY/...
Upper ridge will become highly amplified from the Southeast US to
Ontario Monday with a cut-off low/upper trough moving the
Northeast Tuesday into Wednesday. At the surface, a cold front
will slowly push towards the Eastern Seaboard through Wednesday.
Chance pops look reasonable Monday and Tuesday, diminishing
Wednesday as the front moves through the area. GFS and ECMWF
solutions are somewhat similar. Cold front will slide into the
Atlantic Wednesday night with high pressure building into the
region Thursday and Friday along with cooler and drier air.
Temperatures through the long term will be generally near normal.
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
Expect mainly VFR conditions through the evening. Low pressure
near the coast will continue to weaken and move away from the area
through tonight. Scattered showers should dissipate with the loss
of heating this evening. Instability is forecast to remain weak
with a diminished chance of thunderstorms.
Late night fog is possible with low-level moisture in place and
dry air aloft. Given increasing confidence based on better model
agreement, have indicated restrictions at the river valley
terminals of OGB and AGS 06Z-13Z. After 14Z we should see VFR
conditions at all sites because of heating and mixing. expect
northerly winds less than 10 knots.
EXTENDED AVIATION OUTLOOK...No significant impacts to aviation
expected Saturday as drier air moves into the area, though late
night/early morning fog possible at the fog-prone sites.
Convection possible Sunday through Tuesday as a frontal system
stalls in the area.