Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston SC
349 am EDT sun Oct 26 2014
high pressure will prevail through the middle of the week. A cold
front will move into the area Thursday and off the coast by Friday.
Then dry high pressure will rebuild for next weekend.
Near term /through tonight/...
pre-dawn...clear skies and calm winds this morning. Inland colder
rural locations may dip into the lower to middle 40s with readings
only in the lower 50s along the U.S. 17 corridor.
Middle level heights on the rise today as an expansive subtropical
ridge builds over the lower Gulf Coast and southeast states. Low level
thickness values support Lower/Middle 80s today under full sunshine.
We bumped maximum temperatures up a degree or two in some zones with the
weak flow in the boundary layer veering more west this afternoon.
While certainly warm for this time of year...high temperatures will likely
fail to reach record readings which are 87 degrees at both Savannah
and Charleston today.
Clear skies prevail tonight with lows most areas 50-55 degrees.
Cannot rule out the development of some shallow ground fog around
dawn on Monday morning but bufr sounding profiles look uneventful
for the potential of any significant fog at this point.
Short term /Monday through Wednesday/...
a deep layered ridge will persist Monday into Tuesday before
shifting off the coast with the approach of a long wave trough on
Wednesday. Warm low-level thicknesses and plenty of sunshine Monday
and Tuesday will allow temperatures to reach the middle to upper 80s. As
the upper trough approaches on Wednesday...low-level flow will
become southwesterly with moisture increasing across the southeast
states. A cold front will be approaching from the northwest late in
the day but any precipitation should hold off until after sunset.
Compression ahead of the front should offset the increase in sky
cover and allow temperatures to climb back into the lower 80s on Wednesday.
Long term /Wednesday night through Saturday/...
an upper shortwave shifting into the region Wednesday night will
push a weak cold front into the area on Thursday...then off the
coast by Friday morning. Moisture return ahead of the front and
upper forcing will be fairly limited so only isolated to scattered
rain showers are anticipated. Cold and dry Canadian high pressure
will overspread the area Friday through Sunday. Although there
continue to be significant differences between the GFS and European model (ecmwf) for
days 5-8...the trend is toward a fairly chilly weekend with highs
struggling to climb out of the low/middle 60s.
Aviation /08z Sunday through Thursday/...
Extended outlook...low probabilities for shallow ground fog...
mainly Tuesday and Wednesday mornings.
broad high pressure will continue to expand over the waters through
tonight. Winds will remain below 15 knots and in most cases below 10 knots
while seas continue in the 1-2 feet range.
High pressure will dominate the marine area Monday through Thursday
night with winds at or below 15 knots and seas no higher than 3 feet.
Friday into the weekend...strengthening north-northeast winds could result in
Small Craft Advisory conditions over parts of the waters due to cold
advection and a tight gradient.