Area Forecast Discussion
Issued by NWS Columbia, SC

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FXUS62 KCAE 031528

Area Forecast Discussion
National Weather Service Columbia SC
1028 AM EST Sat Dec 3 2016

Dry conditions will persist through this evening with surface
ridging across the region. A low pressure system in the western
Gulf Coast Region Sunday will move northeastward and into the Ohio
River Valley Tuesday. The associated warm front will likely remain
south of the forecast area through Monday then lift north near or
into the forecast area Tuesday ahead of a cold front. The cold
front will likely be off the coast Tuesday night. Another cold front
will bring unseasonably cold conditions for next weekend.


Surface high pressure will continue to ridge into the forecast
area through tonight. Satellite trends indicate high cloudiness
streaming into the forecast area well ahead of the southern stream
system over the southwest part of the nation. The moisture will
continue to increase tonight. The models depict isentropic lift
late especially in the west part of the forecast area. The ARW
displays areas of rain developing in the west section late. The
NAM, GFS, and ECMWF MOS support slight chance or chance pops late.
Cloudiness will help hold up temperatures tonight. The temperature
guidance was consistent.


The models indicate a wedge pattern and isentropic lift developing
Sunday and continuing into Monday night. Surface high pressure
will reside along the mid Atlantic coast providing northeast low-
level winds across the forecast area with a moist southwest flow
aloft. An initial shortwave trough will move east across the
country on Sunday tapping Gulf of Mexico moisture as it tracks
eastward and bring rain to the region by late Sunday. A more
significant closed upper low over northwest Mexico will eject
eastward into the southern plains and western Gulf Coast region by
late Monday and cross the region on Tuesday keeping rain chances
high over the area.

Have indicted likely to categorical pops Sunday afternoon into
Tuesday morning. We kept maximum temperatures below the guidance
Sunday and the upper 40s to mid 50s...because of wedge
conditions. Should see little diurnal cooling...with lows in the
lower 40s to lower 50s.

The GFS...NAM and ECMWF hold the warm front south of the forecast
area through Monday. The warm front may move into the forecast
area Tuesday but this is questionable because the cool wedge may
linger. Isolated storms are possible Tuesday as the upper trough
and surface cold front crosses the region. Severe thunderstorms
could possibly occur if the warm front gets into the forecast area
and surface-based instability develops.


The medium-range models show the cold front off the coast Tuesday
night with dry weather through Wednesday night. Another cold front
looks to cross the region in the Thursday/Friday time frame. The
GFS sweeps the front through on Thursday with little in the way of
precipitation while the ECMWF continues to be slower and wetter.

Seasonable temperatures Wednesday and Thursday are forecast to
cool dramatically for the end of next week as much colder air
pours into the eastern conus.


Surface high pressure will continue to ridge into the forecast
area from the north through the TAF period. A warm front will
develop south of the forecast area well ahead of low pressure in
the western Gulf of Mexico. Cloudiness will be on the increase
during the TAF period but the initial dryness associated with the
surface ridging should help hold up ceilings. The GFS and NAM MOS
and SREF guidance were consistent will IFR or MVFR ceilings
holding off until after the 12z. The MOS indicated light northeast

EXTENDED AVIATION OUTLOOK...Expect widespread IFR conditions
associated with a warm front through Tuesday.




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