Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 272350
Area Forecast Discussion
National Weather Service Columbia SC
750 PM EDT FRI MAY 27 2016
High pressure will remain over the forecast area through tonight.
Newly formed tropical depression two is forecast to become
tropical storm Bonnie on Saturday and push into the coastal plain
early Sunday. Chances of rain will increase over the weekend with
potential for locally heavy rainfall.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Afternoon diurnal cumulus clouds are dissipating with the approach
of sunset and a band of much drier air moves westward over the
region with precipitable water values falling to around a half
inch overnight. Moisture will begin rapidly moving onshore during
the predawn hours Saturday in advance of the approaching tropical
depression two which may become TS Bonnie Saturday morning.
Skies will be mostly clear through much of the night allowing for
strong radiational cooling and overnight lows slightly cooler than
last night in the lower 60s. Higher clouds will approach during
the predawn hours but should not have a significant impact on the
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
Tropical depression two will be steady moving northwestward
approaching the coast on Saturday while a plume of deep tropical
moisture moves inland over the forecast area with precipitable
water values pushing well over 1.5 inches. Expecting Saturday
morning to remain mainly dry across the cwa, then increasing
shower and thunderstorm chances across the east during the
afternoon. Rain/thunderstorm chances continue Sunday into Monday
as the low slowly moves through the region. Highest chances for
precip will remain greatest across the eastern counties, with pops
trending lower the further west you go. Trended towards the WPC
qpf amounts through the period due to wide spread in the forecast
qpf guidance. With the potential slow movement to the low, can
not rule out periods of heavy rainfall which could produce
Used the guidance consensus for the temperature forecast.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Much uncertainty in the longer term forecast period. Models
differ on the upper air solutions through the middle of the week,
with the gfs showing a weak ridge north of the cwa and a weak low
just east. The ecmwf shows a trough east of the area, and high
pressure over the region. All in all, can not rule out any
isolated or scattered afternoon showers and thunderstorms any day
next week. Temperature forecast was a general blend of guidance,
which is generally at or above normal through the period.
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
Early morning mvfr fog possible at AGS/OGB...otherwise VFR through
at least 18z. Ceilings may be lowering in the afternoon with some
potential for restrictions late in the period although confidence
Cumulus dissipating across the area early this evening. Air mass
should remain dry overnight although shallow low-level moisture
and light winds may result in some patchy MVFR fog at
AGS/OGB...suggested by Lamp guidance. Tropical Depression offshore
of South Carolina will be moving Northwest toward the coast
tonight and Saturday. Mid level clouds may increase during the
morning with lower ceilings in the afternoon...possibly resulting
in MVFR conditions late in the period. Greatest threat for
restrictions appears to be near the OGB terminal after 20z as a
few showers move inland. Winds will be light and variable
overnight then become northeast/east 10 knots or less Saturday
EXTENDED AVIATION OUTLOOK...Restrictions probable in showers and
thunderstorms Saturday night through Monday as a tropical system
moves into the area from the Atlantic Basin.