Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
1249 PM EST Tuesday Jan 27 2015
low pressure off the coast of southern New England will continue
to move northeast. High pressure over the Mississippi Valley will
build into the Carolinas through Wednesday. A cold front will move
across the region Thursday night. A few showers are expected ahead
of the front. Temperatures will be below normal through middle week.
Near term /through tonight/...
long wave upper level trough continues over the eastern Continental U.S.
With its deep surface and upper low center moving northward from
coastal southern New England. Northwest flow aloft across the area
and resulting cold air advection. A short wave moving through the
area this afternoon on back side of upper trough will keep some
clouds across the area. Local guidance and met MOS cool bias
suggest maximum temperatures in the middle 40s to lower 50s.
The upper trough will move to the east tonight as ridge builds in
from the Mississippi Valley. As dryer air filters into the region
skies will clear this evening. Overnight lows should range through
the 20s given cold advection.
Short term /Wednesday through Wednesday night/...
high pressure will reside over the area Wednesday and Wednesday
night. Very dry and cool air mass will overspread the region with
dew points likely in the teens. Potential for radiational cooling
conditions Wednesday night with ridge over area. However high
level clouds ahead of short wave trough moving toward Middle Atlantic
States from Midwest possibly spreading into the area late. Kept
highs temperatures for Wednesday in the middle 40s to lower 50s.
Minimum temperatures Wednesday night should range through the 20s.
Long term /Thursday through Tuesday/...
upper trough will deepen over the east Continental U.S. Thu/Fri. Upper energy
and dry cold front will move through our region Thursday nt. Limited
moisture for this system to work with in a general northwest flow aloft.
Latest model consensus indicates slight chance of light rain or
sprinkles possible. Behind the front...dry cold Canadian high
pressure will build in Fri/Sat. Upper energy approaching from the
west will bring surface low pressure...cold front and associated
isentropic lift/moisture into our region late Sat nt/sun/sun
nt...with appearance of weak wedge over our region. At this
time...precipitation type appears will be all liquid for our forecast
area. Generally accepted blend of HPC and MOS guidance. Cold front
will move through early Monday. Some uncertainties early next week
as front may stall just to our south with another wave riding
along it...but that is just beyond our forecast period.
Aviation /18z Tuesday through Sunday/...
VFR conditions expected through the taf period.
Middle level clouds across the taf sites at 18z will clear this
evening as drier air filers into the region. Northwest winds
should average 10 knots...with a few gusts 15 to 20 knots through
22z. Winds will diminish with sunset. Drier air will move into
the region and light winds to fog is not expected overnight.
Extended aviation outlook...restrictions possible Thursday night
as a cold front crosses the region.