Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston SC
649 PM EDT Sat Oct 25 2014
high pressure will prevail through the middle of next week. A cold
front will move into the area Thursday and off the coast by
Near term /until 6 am Sunday morning/...
clear skies and light-calm winds will promote solid radiational
conditions again tonight. Fast northwest flow atop the southern
Appalachians will likely induce weak Lee-side toughing across the
foothills late...but the nocturnal inversion looks too strong to
support a significant recouping of the boundary layer despite a
slight increase in the surface pressure gradient.
The low temperature forecast was updated to show some slightly
colder temperatures in some of the normally chillier areas...but
the general flavor of the previous forecast was maintained. Lows
will range from the middle-upper 40s to the Lower-Middle 50s at the
coast with upper 50s-around 60 along the beaches...downtown
Charleston and around the Santee lakes...including Pinopolis.
Its interesting to see that Monks Corner dropped to 46 this
morning while Pinopolis just a few miles away only dropped to
59--a testament to the influence of the warmer lake waters of
Short term /6 am Sunday morning through Tuesday/...
deep layered high pressure will dominate the weather during the
short term period with above normal normal temperatures in the 80s expected
away from the immediate coast under plentiful sunshine. Winds will
be generally light...with an afternoon sea breeze cooling
temperatures down at the beaches by several degrees. Precipitable
water values will be below 1 inch...keeping clouds and showers at
Bay. Only potential weather problem will be morning fog...which
could become dense in spots Tuesday morning as low level dew points
increase to the climatologically favored values of middle 50s inland to
near 60 at the coast. Clear skies and nearly calm winds will allow
for a nice surface inversion to set up.
Long term /Tuesday night through Saturday/...
the upper ridge finally breaks down during the middle of next week
with a long wave trough gradually developing across the central and
eastern United States. The GFS and European model (ecmwf) are now in better agreement
on a weak cold front dropping through the area on Thursday. Due to
the relatively flat upper trough...moisture return ahead of the
front will be marginal so we do not anticipate more than isolated
showers along the front Thursday and Thursday night. The models
diverge Friday into Saturday...though the trend is toward a
significantly colder airmass moving in late week or next weekend.
Aviation /00z Sunday through Thursday/...
Extended outlook...low probabilities for shallow ground fog...
mainly Tuesday and Wednesday mornings.
tonight...variable winds early this evening will become west/northwest after
midnight as the pressure gradient tightens slightly across the
area. Winds look to go no higher than 10 knots with seas 1-2 feet.
Sunday through Tuesday...a broad high pressure system
will dominate the marine weather Sunday through Thursday with
winds generally 15 knots or less and seas no higher than 3 feet.