Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 271047
Area Forecast Discussion
National Weather Service Columbia SC
647 AM EDT FRI MAY 27 2016
High pressure will remain over the forecast area through tonight.
Moisture will increase Saturday through Sunday associated with
low pressure nearing the Southeast coast.
.NEAR TERM /THROUGH TONIGHT/...
Water vapor imagery trends and the models depict the mid-level
shortwave trough weakening or the ridge building westward slightly
from the Atlantic while an upper low remains over the vicinity of
the Bahamas. The models display continued surface ridging along
the southeast coast limiting moisture here. Model forecast
soundings indicate a mid-level subsidence inversion or cap which
should help diminish the thunderstorm chance. All the GFS, NAM and
ECMWF MOS have pops less than 20 percent. The high-resolution
models display just isolated coverage at most. Believe the
thunderstorm chance is too low to include in the forecast. Used
the guidance consensus for the temperature forecast.
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
The models display moisture increasing in the forecast area in a
developing easterly flow between ridging shifting north and low
pressure approaching from off the Southeast coast. The shower and
thunderstorm chance should be on the increase, especially in the
east section of the forecast area. Followed the guidance consensus
for the pop forecast. The NAM and ECMWF indicated general rainfall
totals Saturday and Saturday night up to around 0.25 of an inch.
The GFS had more rain will totals 0.25 to 0.50 of an inch in the
east section. Followed the more consistent guidance. Used the
guidance consensus for the temperature forecast.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Uncertainty remains high in the medium-range period. The GFS
displayed low pressure from off the Southeast coast moving inland
and remaining near or in the forecast area through much of the
period. The ECMWF stalled the low near the coast and then
indicated a general northeast movement along the coast. The low
may gain sub-tropical characteristics. The slower GFS solution
indicates more of a flood threat in the forecast area. There may
also be a tornado threat as well because of tropical moisture and
possible high shear. The GFS, ECMWF, and EKD MOS support the
highest pops Sunday and Monday.
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR conditions expected. High pressure and drier air will build
over the Forecast Area today, ensuring fair weather. MVFR
fog/stratus possible at ags and ogb late Friday night/early
Saturday morning, but confidence a little too low to include in
the TAFS at this time.
EXTENDED AVIATION OUTLOOK...Showers and possible thunderstorms
and associated restrictions, with breezy conditions possible at
times, late Saturday afternoon through at least early next week,
as a low pressure system, which may possibly become tropical,
approaches from the SE and then may stall or move slowly near the