Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
953 PM EDT Sat Apr 25 2015
upper level low pressure will keep unsettled conditions across
the region through the weekend. A brief break in the unsettled
weather is expected by the middle of the week.
Near term /through Sunday/...
953 PM update...the diurnally forced showers have pretty much
dissipated with nothing more than a few sprinkles or a very
isolated shower remaining in northern Penobscot and southeast
Aroostook counties. Attention turns to a shortwave to the
northwest of the area the will likely clip the Saint John valley
and parts of the Allagash overnight with some showers. Snow will
be favored over rain...and there is the potential for around an
inch...locally even a couple of inches of snow overnight into
early Sunday morning. Only minor tweaks from the earlier updated
based on the latest observations...radar...and near term model
upper low is spinning in the Gulf of Maine and will begin to shear out
late tonight but subtle lobes of shortwave energy expected to remain through
end of near term and bynd. Expect diurnally-driven showers to die
off after sunset tonight over most of County Warning Area with most of the upper level
energy concentrated on extreme northwest zones.
Expect snow to begin to mix in with showers after 00z then become all
snow after midnight. Best accums across higher terrain of Northwest Aroostook
and northern Somerset may amount to one-half inch through morning though forcing
does not appear to be strong enough to see the amnts that were seen
Cyclonic flow continues drg the day tomorrow leading to lingering cloudiness.
This will likely result in maximum temperatures below normal values for this time
Short term /Sunday night through Tuesday/...
unsettled weather continues for early next week as the upper low
that has plagued the region sticks around. Lobes of energy will
pivot around this low, bringing rounds of showers, especially over
northern Maine. The best chances for precipitation will be Sunday
night into Monday with one of these aforementioned shortwave
troughs. Expect much of the precipitation will be in the form of
rain, but western and northern Maine, especially the higher
terrain, will likely see a changeover to at least a rain/snow mix
during the nighttime hours. Some light accumulation is possible,
though it won't linger long past daybreak. Monday will be another
cool day with highs in the middle 40s to lower 50s. Tuesday will only
be a few degrees warmer.
Long term /Tuesday night through Saturday/...
persistent cyclonic flow and unsettled weather finally begins to
give way early Wednesday as upper level ridging builds in from
west. Temperatures rebound to normal Wednesday and Thursday under partly
sunny skies but another round of unsettled showery weather
redevelops under another approaching upper low. This round
appears to be short-lived though as another upper ridge approaches
by late Saturday. Made very few adjustments to superblend...mainly
reduced probability of precipitation across central and eastern zones on Wednesday and
Aviation /01z Sunday through Thursday/...
near term: VFR conditions through sun at bgr and bhb. MVFR/IFR
ceilings at northern terminals overnight will improve to VFR by
late Sun morning.
Short term: VFR conditions early Sunday night will give way to
MVFR ceilings as rain showers spread across the region. The
northern terminals will have the best chances of prevailing MVFR,
which will linger through Monday night. Improving conditions on
Tuesday, with all sites to return to VFR by 18z. Sites will remain
VFR through Thursday morning, then MVFR returns along with the
chances for showers.
near term: waves and winds will remain below Small Craft Advisory
criteria next 24 hours.
Short term: a Small Craft Advisory will likely be needed Monday
night and Tuesday as winds increase in response to low pressure
dropping southward through the Maritimes. Gusts of 25-30 knots are
expected along with seas of 4 to 6 feet.