Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 270118 AAA
Area Forecast Discussion...UPDATED
National Weather Service Columbia SC
918 PM EDT Sun Mar 26 2017
A series of troughs will move through the area through early
Tuesday and possibly trigger some showers and a few
thunderstorms. A cold front will move through the area Tuesday
night. High pressure will build into the region Thursday from
the north while moisture increases across the area. This may
set up unsettled conditions for the later half of the week with
below normal temperatures possible Thursday but warmer than
normal over the Weekend.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Scattered afternoon convection continues to wane with only
isolated weak showers remaining, mainly across the Upstate and
around the CSRA. Mesoanalysis indicates an axis of higher
precipitable water around 1 to 1.1 inches across the forecast
area, although much of the moisture is confined in the lower
Moist southwesterly flow will continue overnight allowing for
the potential for isolated showers to remain in the forecast
mainly across the upper CSRA and western Midlands. Bufkit data
indicates a 25 knot low level jet tonight which will favor
stratus over fog, though some patchy fog is also possible given
expected low dewpoint depressions. Overnight lows will again be
mild in the mid to upper 50s with mixing and expected cloud
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Surface ridge offshore weakens on Monday. Another upper trough
moves through the region Monday and early Tuesday. Short wave
appears to weaken or lift north during the overnight. Airmass
appears weakly to possibly moderately unstable Monday afternoon
through the early evening. Models do suggest a mid level cap
may limit convection. Mos guidance pops suggest scattered
coverage at times...especially to the northwest where cap may
be weaker and upper level divergence stronger. A weak cold front
appears to move through the region late Tuesday but moisture
will be limited so expect clearing by afternoon behind upper
level trough. Rainfall amounts during the period appear light
with limited precipitable water. Temperatures both days are
forecast above normal with highs in the lower 80s and lows in
the middle to upper 50s.
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Models are in good agreement showing upper ridging over the
Southeastern states on Wednesday as a closed upper low moves
into the southern Plains. Warm advection Wednesday so air mass
modifies quickly although slightly drier with front just south
of the area. So continued above normal temperatures for
Wednesday. Increasing threat for Cold air damming wedge
Thursday...especially in the north Midlands as ridge builds
south across the Carolinas from the New England States. Guidance
temperatures appear too warm...but with several days out
incorporated local wedge guidance/cut temps about 1 category to
near the gfs ensemble mean. The front would presumably
eventually lift back north as a warm front ahead of the next
system that GFS and EC generally bring into our region Thu
nt/Fri time frame. Strong thunderstorms may be possible
associated with approaching upper trough and warm frontal
boundary. However, confidence of model timing and position of
closed upper systems can be limited late in the forecast period.
So, some limited confidence on specifics mid to late week.
Drying out over the weekend with temperatures above normal.
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR conditions for much of the period...with MVFR/IFR conditions
during the early morning and sunrise hours.
Isolated showers continue across the area with a few to the
northwest and northeast of AGS/DNL. Expect the remaining showers
to dissipate by 02z. Main concern for the period will be early
morning fog and stratus at all terminals. With moist southerly
flow over the region...low level moisture from afternoon showers
and a developing inversion expect MVFR to IFR fog and stratus
to develop around 09z. Fog and stratus will erode by 14z...with
afternoon showers and isolated thunder again possible from 18z
through the end of the period. Confidence in timing and coverage
remain low so have included VCSH attm and will adjust as
confidence increases. Winds through the period will be southerly
at 8 knots or less.
EXTENDED AVIATION OUTLOOK...Late night/EARLY morning MVFR to
IFR conditions possible each morning. Restrictions possible in
afternoon and evening convection Tuesday...Thursday and Friday