Area Forecast Discussion
Issued by NWS Columbia, SC
FXUS62 KCAE 202150
Area Forecast Discussion
National Weather Service Columbia SC
550 PM EDT FRI MAY 20 2016
A wedge front will lift north into the area late tonight. A cold
front will cross the area Saturday. Drier high pressure slowly
builds into the region early next week.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A wedge of cool air and cloudy skies will remain entrenched
across the Midlands and CSRA this evening. A low level northeast
flow will continue. Dewpoints ranged from the upper 50s north to
mid 60s across the CSRA and Southern Midlands. Current radar
indicated patches of light rain and drizzle over the Midlands.
The wedge front now south of the CSRA is forecast lift north into
the midlands overnight. Low pressure over Mississippi will travel
along this boundary will cross our area Saturday morning.
Widespread convection along the Gulf coast will not allow
ample moisture to flow northward for widespread precipitation in
The wedge is expected to break down early Saturday as
surface winds finally become southwest/west. Light rain/drizzle to
continue off/on throughout tonight. Have ranged pops from near 40
percent east to around 70 percent west.
Temperatures will only cool a few degrees tonight given clouds/light
precipitation. Also, model time sections show an increase in the
low level jet over the area tonight with a 30 to 35 kt low level
jet towards morning. Any light wind will help keep temps up as
well. Still expect overnight lows ranging from the upper 50s north
to the mid 60s south.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Broad but amplified upper trough over the eastern CONUS shifting
slowly to the eastern seaboard during the period. Several short
waves rotating through the base of the trough with the strongest
moving through SC/GA late Saturday night through Sunday morning.
Cold front moving into the coastal area early Saturday morning.
Drying and downslope developing behind the front...so mostly sunny
conditions developing and warming temperatures despite frontal
passage. A secondary cold front moves through late in the
afternoon or early evening. Moderate instability possible with
shallow moisture...although little in the way of lift. A few
showers or thunderstorms possible mainly across the North Midlands
and Pee Dee...Isolated to scattered. Guidance temps consistent and
warm in the low to mid 80s. Moisture limited behind secondary
front and expect dry conditions Saturday night and Sunday...dew
points dropping possibly into the upper 40s Sunday. Moisture
limited for convection and subsidence expected Sunday. Should be
slightly cooler than Saturday. Gusty winds possible both
afternoon. Mos consistent with Overnight minimum temperatures.
Cool temperatures Sunday night with boundary layer decoupled and
clear skies...in the 50s.
.LONG TERM /MONDAY THROUGH FRIDAY/...
The upper low will lift northeast early next week allowing
ridging and surface high pressure to build into the area. This
pattern supports dry weather and near normal temperatures.
Moisture may increase late in the period as ridge moves off the
coast and air mass becomes weakly to moderately unstable.
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
Wedge pattern remains in place with stalled boundary south of the
CSRA. Approaching upper level trough aiding isolated shower
formation...which may cause fluctuations in ceiling/visibility as
they pass through terminals...but overall overrunning and upglide
will keep moisture and IFR/LIFR ceilings in place through Saturday
Guidance favors decrease overnight to LIFR at all terminals as
instability aloft pushes through...limited confidence in guidance
visibility forecasts as setup favors stratus over dense
fog...although it is possible at primarily at OGB and AGS on the
periphery of the wedge.
As upper level troughing pushes through late tomorrow morning...
wind shift to the west and northwest will allow ceilings to lift
first to MVFR and then VFR as as downsloping winds increase.
EXTENDED AVIATION OUTLOOK...Downslope flow and a drier airmass is
expected as high pressure builds in Sunday through Tuesday...bringing