Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 261832
Area Forecast Discussion
National Weather Service Columbia SC
232 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 /THROUGH TONIGHT/...
Upper trough moving through our forecast area (FA) this afternoon,
with some drier air aloft moving in behind it. Band of
scattered mainly light showers currently stretched across
portions of the FA. Latest SPC mesoanalysis indicating only weak
instability, along with some CIN. Forecast soundings indicating
some mid level capping, becoming a little more pronounced later
this afternoon. So, thunderstorm threat appears minimal, though
isolated brief thunderstorm not totally out of the question.
Radar trends and latest high resolution models suggest mainly
isolated to scattered brief showers for portions of the FA this
afternoon, dissipating late day. A moist generally southerly
low level flow overnight could contribute to some stratus or fog
development late tonight. Limited confidence on dense at this
time due to boundary layer wind staying up a tad, and
uncertainty regarding the extent of any lingering mid level
.SHORT TERM /MONDAY 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 /18Z SUNDAY THROUGH FRIDAY/...
A brief shower possible this afternoon, otherwise VFR expected
through early tonight. Upper trough moving through our forecast
area (FA) this afternoon. Radar trends and latest high
resolution models suggest generally isolated to scattered mainly
light rain showers. Will handle with VCSH for now and amend for
greater inclusion if/when confidence warrants, based on radar
trends. Thunder threat appears minimal due to only weak
instability. Any convective activity expected to dissipate by
late day. A moist generally southerly low level flow overnight
could contribute to some stratus or fog development late
tonight. Limited confidence on dense at this time due to
boundary layer wind staying up a tad, uncertainty regarding the
extent of any lingering mid level cloud cover, and mixed
results in latest guidance. For now, indicated a period of MVFR
EXTENDED AVIATION OUTLOOK...Late night/morning MVFR to IFR CIG/VSBY
restrictions possible through Tuesday. Brief shower possible Monday
afternoon. Showers, and a possible thunderstorm, Tuesday afternoon
and evening. CIG/VSBY restrictions and chance of showers Thursday.
Thunderstorms possible Friday.