Scientific Forecaster Discussion
fxus61 kcar 240433
Area forecast discussion
National Weather Service Caribou ME
1233 am EDT Thu Oct 24 2019
high pressure will build south of New England overnight and
Thursday. Weak low pressure will approach Friday and remain
south of the area early Saturday. High pressure will return
briefly Saturday night with low pres from the Great Lakes
approaching the region Sunday.
Near term /through today/...
1225 am update...
added patchy fog the overnight hours otherwise no other
significant changes to previous forecast overnight.
may see vry patchy fog along the river vlys if skies can clear
and if winds can lighten enuf but chcs of that happening are vry
slim, thus hv not included in the fcst.
Weak area of low pressure wl mv thru tomorrow with mainly clds
expected along it, however cannot rule out a vry brief shower.
Highs ahd of the trof wl top out abv normal in the m50s acrs the
north and u50s/nr 60 ovr downeast areas.
Short term /tonight through Saturday/...
a weak cold front crosses Thursday night with clouds and a few
showers towards the Saint John valley. The front will progress
through the state by Friday morning and stall in the Gulf of
Maine. Cold air advection on Friday will reduce highs by at
least 5 degrees from thursday's readings. A wave forming on the
stalled front will increase the risk of precipitation along the
coast on Friday night. This wave will be accompanied by an upper
level trough. The upper level trough will bring a slight chance
of showers as far north as Aroostook County by late Friday
night. Some of these showers may be in the form of snow towards
Aroostook County by early Saturday morning, but no accumulation
is expected. Clearing will occur across the entire area as the
day progresses and highs will reach the upper 40s to lower 50s.
Long term /Saturday night through Wednesday/...
radiational cooling is expected Saturday night with low dropping
into the 20s for much of the area...and towards the freezing
mark all the way to the coast. Clouds from sunday's system will
arrive later in the night. On Sunday, clouds will thicken and
lower with a weakening southern stream system propagating
northeastward along an amplifying upper ridge in Atlantic
Canada. Surface low will pass well south of the region on Sunday
night. Isentropic lift will produce modest amounts of
rainfall...generally under a half inch. As the surface low pulls
away, an inverted trough and easterly low level flow will remain
over the area Monday into Tuesday while the upper ridge
continues to strengthen over the Maritimes. This means clouds, light
rain and drizzle will be very slow to move out until Tuesday
night or Wednesday. The big question towards the end of the
forecast will be where a large scale upper trough digs in the
midwestern or western US. At this point, the 23/12z GFS and
gefs look a bit to far east and will lean towards a
European model (ecmwf)/gems/GFS blend.
Aviation /06z Thursday through Monday/...
near term: 1225 am update...
VFR conditions overnight outside of local IFR in patchy fog.
VFR Thursday except scattered late day showers and MVFR
Thursday night into Saturday night...mostly VFR outside of
possible MVFR cigs during mornings north of a hul-gnr line
Sunday into Monday...conditions will deteriorate towards IFR
tempo LIFR cigs during Sunday into Sunday night. Slight
improvement expected by Monday...but probably still IFR.
near term: 1225 am update...
small craft advisories remain up through 8 am Thursday, then
winds/seas remain below Small Craft Advisory level through the rest of the day.
Short term: on Thursday night, southwesterly waves near 4 ft are
forecast, but not anticipating advisory criteria. The weekend
should feature benign winds and seas under high pressure. Long
period south to southeast swell arrives Monday into Tuesday and
seas could reach over 5 feet during that period. Winds are
expected to remain under 25 kts during the period.
Marine...Small Craft Advisory until 8 am EDT this morning for