Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
1203 am EST Sat Nov 28 2015
a cold front will move into northern Maine this evening then cross
the region overnight. High pressure will build across the region
Saturday through Monday. A cold front will cross the region
Near term /through Saturday/...
1203 am update...a cold front continues to push south and will
sweep off the coast by morning. Rain has changed to snow as far
south as Houlton as of 1145 PM. There has been a band of enhanced
snowfall, and amounts of 1 to 2 inches are expected in many areas
from Houlton north to the Saint John valley. We measured 1.1" at
the weather forecast office as of midnight. As temperatures continue to drop below
freezing many untreated surfaces will become icy and this is
mentioned in a Special Weather Statement. Temperatures as of
midnight are still in the 50s in the Bangor area, but will quickly
drop off overnight with a quick period of rain. Only minor tweaks
to the ongoing forecast based mainly on the latest radar and near
term model trends.
Orgnl disc: the cold front is currently in the Saint Lawrence
valley and will sag into the Saint John valley in the coming
hours. With temperatures in the upper 40s to around
50f...precipitation will begin as rain ahead of the front. Frontal
passage will bring a very sharp decrease in temperatures and a
changeover to snow. The front is generally weakening as it moves
south and most of the precipitation will likely be in the warm air ahead
of the front. Thus...do not expected the snow to last more than a
few hours nor is intensity expected to easily overcome the warm
surface conditions. As a result...will continue to forecast an
inch or less with the best chance of these accumulations in the
Saint John valley...or at least north of Presque Isle. As always
in these early season events...higher terrain above 1000 feet will
also be at the upper range of accumulations. Snow on the back side
of the front will cease to be a feature south of Houlton. The rain
will reach Bangor late in the evening and wrap up in the predawn
hours. The last of the rain will exit the coast early Saturday
morning. The down east region and Bangor will stay above freezing
all night...the areas north of Houlton and Millinocket will drop
into the 20s overnight. This could generate some icy roads and
sidewalks as moisture quickly freezes without the benefit of
strong winds to speed evaporation.
The high will provide some sunshine on Saturday with thin fair
weather cumulus remaining due to h925 moisture. Temperatures will
rise little from morning readings and then fall off by middle
afternoon. Highs will be near 30f in northern Aroostook and middle to
upper 30s for Bangor and down east.
Short term /Saturday night through Monday/...
high pressure will build across the region Saturday night through
Monday. A cold front will cross the region Sunday. Generally
expect mostly clear skies across the forecast area Saturday
night...though clouds will begin to increase late across
northern areas in advance of the approaching cold front. Expect
partly/mostly cloudy skies along with a slight chance of snow
showers across northern areas Sunday...with partly/mostly sunny
skies across the remainder of the forecast area. Cloud cover will
decrease across northern areas early Sunday night. Otherwise...high
pressure will bring mostly clear skies to the region Sunday night
through Monday. Temperatures will be at near normal...to slightly
below normal...levels Sunday. Temperatures will be at below normal
Long term /Monday night through Friday/...
a shortwave ridge moves across eastern New England Monday night into
Tuesday which results in dry and warmer conditions.
A powerful upper low pushes through the Great Lakes Wednesday and
into northern New England on Thursday. This system pushes an
occluded front across Maine Tuesday night into Wednesday. Any
snow should switch to rain Wednesday morning as warmer air surges
northward. A weak surface low tries to form along the
front...however the low trajectory is through downeast Maine which
keeps the maritime air across eastern Maine. Rain should change
back to snow across the northern Maine Woods Wednesday evening.
Colder air returns to the region Thursday into Friday with a
northwest flow aloft.
Aviation /06z Saturday through Wednesday/...
near term: the cold front will bring IFR conditions to sites
north of hul due to ceilings and then snow. When the front reaches bgr
and bhb later tonight...ceilings and visible should drop to MVFR. All
sites will have periods of MVFR ceilings behind the front into midday
Saturday. The trend will be towards VFR across the entire area
Short term: occasional MVFR conditions are possible across
northern areas Sunday. Otherwise...generally VFR conditions are
expected across the region Saturday night through early Tuesday.
IFR/LIFR conditions will develop Tuesday night...then persist
near term: have extended the Small Craft Advisory until early Saturday afternoon.
There will likely be a decrease in winds as the front enters the
waters late tonight...but winds will again increase behind the
front Saturday morning. Winds and seas are forecast to decrease
below Small Craft Advisory criteria Saturday afternoon.
Short term: conditions are expected to be below Small Craft
Advisory levels Saturday night through Sunday. Small Craft
Advisory conditions are expected Sunday night. Conditions are
expected to be below Small Craft Advisory levels Monday.
Marine...Small Craft Advisory until 1 PM EST Saturday for anz050>052.