Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
643 am EDT Friday Sep 19 2014
high pressure will build across the region today and move east of
the area Saturday. A cold front will approach northern New England
Sunday...and cross the area Sunday night. A second cold front
will cross the area Tuesday.
Near term /through tonight/...
canceled the frost /freeze headlines as minimum temperatures have
now occurred and any frost/freeze damage has taken place.
Pushed up lows for tonight to the 2-3am time frame with southerly
winds developing on the backside of the high. These winds will
become fairly strong by 12z Saturday with a good low level jet. This also
prompted a refinement in the frost forecast for tonight with most
of the frost sandwiched between Houlton and the down East Coast.
The best frost setup appears to be for interior Washington
County...but will have to strongly consider frost advisories for
all southern zones on Friday night.
cold and dry high pressure will move from Quebec to the Gulf of
Maine today and tonight with the coldest air of the season to
date. Little or no low level moisture will produce generally
clear skies today with highs ranging from the low 50s north to the
upper 50s for Bangor and down east. With dew points in the low
20s...the air will have a very dry and crisp fall-like feel.
The high will remain in place tonight...allowing a radiation
inversion to form with frost and freeze conditions affecting down
east the most. Expect another night of frost/freeze
headlines...but will hold off until the current headlines are
canceled. Most of the model guidance appears too high for
tonight's lows down east where skies will remain clear most of the
night while cirrus thickens in northern zones. Anticipate
temperatures to drop quickly with some decoupling of the boundary
layer and low temperatures being reached not too long after
midnight. The return flow on the backside of the high will provide
a rapid warm up towards the coast later tonight with some
stratocu fields possible.
Short term /Saturday through Sunday/...
high pressure will continue to retreat into the Atlantic Sat with
a mild return flow on the back side of the departing high. A cold
front will begin to organize well to the west of the region with a
weak warm front to lift across western Maine. This may touch off a
shower across parts of northwest Maine and into the Saint John
valley...but for most of the County Warning Area it will be a dry day. The cold
front continues to make slow progress toward the area sun. The
flow aloft is nearly parallel to the surface front and the front will
remain west of the area through 00z Monday. The chance of showers
will increase sun with the best chance across western and
northern Maine. Much of the down east region may remain mainly dry
into sun. Temperatures will rebound to above normal levels with
highs near or even a little above 70f in most areas.
Long term /Sunday night through Thursday/...
still some question as to how things will play out. The Canadian
is by far the most aggressive at developing a low along the New
England coast and would bring a soaking rain to the County Warning Area Sun night
into Monday morning. The GFS keeps the low further east and more or
less just has a strong frontal passage with some showers. Given
the uncertainty stayed close to a model consensus for now with
high chance/low likely probability of precipitation Sun night. A much cooler air mass in
the wake of the front Monday with a brisk west wind. A strong
secondary cold front and upper trough work across the area Tuesday and
Tuesday night with clouds and a few showers...especially so across The
Crown of Maine where highs will not get out of the 50s Tuesday. High
pressure will build across New England Wednesday into Thursday with dry and
clear weather. Temperatures will be on the cool side Wednesday and
moderate to seasonable levels Thursday.
Aviation /12z Friday through Tuesday/...
near term: VFR...slight chance of MVFR ceilings at bhb by Saturday morning.
Short term: mostly VFR over the weekend...with pockets of MVFR
possible Sat night into sun at the northern terminals. MVFR/IFR
possible in showers/rain Sun night. Conditions should improve to
VFR Monday. Pockets of MVFR possible Tuesday at the northern
near term: Small Craft Advisory over waters will wind down this morning. Gusts this
morning to 25 kts will drop off to the 10 to 15 knots range as the
high pressure system builds over the waters.
Short term: the seas will gradually build ahead of an approaching
cold front over the weekend and may reach Small Craft Advisory levels by Sat night
over the coastal waters.
the temperature at Caribou fell to 31f shortly before
midnight last night. This was the first time the temperature fell
below freezing at Caribou this fall. The last time the temperature
fell below freezing was on 5/13/14 for a total of 128 days this year
when the temperature remained above freezing.
Marine...Small Craft Advisory until 10 am EDT this morning for anz050-