Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
1223 am EDT Tue Oct 25 2016
a cold front will move through the forecast area tonight with a
reinforcing shot of cool air through midweek. There is a slight
chance of showers late in the week associated with a fast moving
system forecast to move through the area.
Near term /until 8 am this morning/...
a dry air mass remains across the forecast area with just some
high thin clouds ahead of the shortwave trough in the southern
stream over East Texas. The cold front was pushing into the
central midlands at midnight and will move south of the csra
around 200 am. The front will move through the region dry.
Increased mixing over the relatively warm lakes will result in
breezy conditions. The hrrr suggested wind close but just below
lake Wind Advisory criteria especially on Lake Marion. Mixing in
the boundary layer again tonight will limit net radiational
cooling. Expect overnight lows similar to last night.
Short term /8 am this morning through Wednesday night/...
a broad upper ridge will build over the southeast. High pressure
will ridge into the forecast area from the north at the surface. A
cool and dry air mass will build into the region. Slightly below
normal high temperatures are forecast, in the lower to middle 70s.
Overnight lows in the 40s.
Long term /Thursday through Tuesday/...
an upper-ridge over the center of the country will promote
northwesterly flow aloft over the southeastern states through
midweek. Surface high pressure will ridge into the area from the
north Wednesday before shifting offshore Thursday. A surface low
over the Great Lakes region early Thursday morning will shift
northeastward toward New England. This system will bring a weak
cold front across the area Thursday night/early Friday. Moisture
will be limited throughout the period, so continued with a dry
forecast except during the Thursday/Friday time frame maintained a
slight chance. More dry high pressure will build in from the west
late Friday into Saturday, with another dry cold front moving into
the area Saturday night/Sunday. More high pressure will build in
from the north Monday. Seasonable or above normal temperatures are
forecast for much of the period.
Aviation /04z Tuesday through Saturday/...
a dry cold front will cross the taf sites through 07z.
Intermittent IFR vsbys in fog is possible at ags/ogb until the
cold front moves through around 06z. Behind the front winds will
become north/NE around 5 kts. Models indicate 30-35 knot NE winds
above the surface, around 1000 to 2000 ft. Low level wind shear is possible
06z-12z...although confidence is low at this time. Low level wind shear may need
to be added to the tafs if surface winds go calm later tonight.
Dry weather and mostly clear skies will continue through the taf
period. Expect NE winds from 5 to 10 kts throughout the day
Extended aviation outlook...restrictions possible Thursday and
Thursday night as a weak cold front crosses the region.