Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Columbia SC
621 am EDT sun Jul 13 2014
little change today. Fair weather expected over our forecast area
(fa) today with only a slight chance of a shower or isolated
thunderstorm across the southern forecast area. A cold front will move into
the area Tuesday into early Wednesday...increasing shower and
thunderstorm chances. The front will stall to our south Thursday and
lift back north into our region by Friday providing a continued
chance of showers and thunderstorms.
Near term /through tonight/...
little change today. Weak upper trough offshore will lift NE
with flat upper ridge sliding east over our region. Weak surface
boundary near the coast will become diffuse. An axis of
drier air will generally remain over much of our forecast area. A
little better moisture to the south along with a sea breeze may
provide slight chance showers/isolated thunder across the southern
forecast area. Severe convection not anticipated. Both instability and shear are
weak today under the influence of the upper ridge. Warm aloft
with 500mb temperatures around -6c and plenty of dry air in place with high
level of free convection values around 8000 feet and precipitable water values less than 1.5 inches.
Expect most of the convection to be focused along the old boundary
and sea breeze south and east of the forecast area this afternoon.
A stray shower or storm cannot be ruled out in the csra and
southeast midlands but severe convection not expected.
Short term /Monday through Tuesday night/...
some slight upper height falls begin to take shape over our forecast area Monday
as closed upper low dives into the western Great Lakes region. Some
slight atmospheric moisture increase to begin Monday ahead of an
approaching front...and Lee side trough. As Great Lakes upper low
shifts east into east can and deepening upper trough shifts east into
the east Continental U.S....surface front prognosticated to move into our region
Tuesday/Tuesday nt. Likely probability of precipitation expected with the front...with a threat
of severe as well.
Long term /Wednesday through Saturday/...
front to move towards the coast Wednesday. Models suggest some
drier and cooler air behind the front for Wednesday nt into Thursday. Latest
GFS and European model (ecmwf) runs continue to indicate front will lift back north
ahead of an approaching short wave and provide precipitation potential for
US again by Friday into Sat.
Aviation /11z Sunday through Thursday/...
fog development only occurred at ags this morning and is showing
signs of improving at this hour. Generally VFR conditions all
terminals through the period but will carry IFR visibilities and LIFR ceiling
at ags through 13z and possible LIFR ceiling at dnl with some stratus
lifting northwestward. Otherwise VFR conditions all terminals
after 14z. Little chances of convection today due to continued
dry and warm middle levels and surface boundary along the coast.
South winds will develop by 15z 5 to 10 miles per hour.
Extended aviation outlook....a cold front will likely move into the
area Tuesday and stall. Widespread thunderstorms associated with the
front expected for Tuesday and Wednesday.