363
FXUS61 KCAR 121447
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
947 AM EST Wed Feb 12 2025

.SYNOPSIS...
High pressure will cross the region today. Low pressure
approaches tonight, crosses the region Thursday, then exits
across the Maritimes Thursday night through Friday. High
pressure crosses the region Saturday. Low pressure will cross
the region Sunday.
&&

.NEAR TERM /THROUGH TONIGHT/...
Update...
No change to any winter weather headlines. High pressure will
cross the region today with mostly sunny skies. High
temperatures will range from around 10 north, to around 20 to
the lower 20s Downeast. Have updated to adjust for current
conditions along with expected clouds and temperatures.

Previous Discussion...
By tonight, high pressure will start to move out of the area
with the system exiting after midnight. Skies will be mostly
clear at the beginning of the night, then increasing as the next
large low pressure system approaches. Radiational cooling will
bring temps down into the single digits below zero in the north
and single digits above zero in the south. As clouds move in,
these temps will warm slightly. High res models show the initial
snow will move into the west in the early morning hours of
Thursday, so adjusted the precip forecast to show a later start
time for the snow.
&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Thursday Synoptic setup...
An occluding low pressure system will move through the area on
Thursday. Aloft, the jet stream is centered over northern New
England, with a strengthening jet streak of around 170 kts
building over southern New England. This will put our CWA in the
left exit region of a deepening jet streak, generating
increasing divergence aloft and driving the deepening of the
surface low underneath as it passes through.

Thursday Hazard Details...
Snow will begin to move in Thursday morning, with onset delayed
some as compared to previous guidance due to easterly winds
maintaining low to mid level dry air ahead of the approaching
low from the west. Once snow moves into the area, it will
quickly spread across the entire forecast area. A triple point
low will setup along the coast as the parent occluded low center
passes north of the state. It is this triple point low which
will maintain SE to SW winds along the coast, advecting warmer
marine air into the Downeast region. This may result in a warm
nose just long enough for a brief period of sleet and freezing
rain before wind shift further west. The immediate coast will
likely see enough warming to switch to all rain by Thursday
evening.

For the north, as the triple point low continues to strengthen
and move eastward towards the Canadian Maritimes, an area of 850
to 700 mb frontogenesis could set up across northern Aroostook
county, developing a deeper band of heavy snow through Thursday
afternoon. Snowfall rates in this band have the potential to
approach 2 inches per hour. Though the location of these
mesoscale bands is often difficult to pin down at this time
range, there is excellent consistency across all hires and
global models that an area of higher QPF will likely setup in
this area, increasing confidence for forecast snow totals to
approach the one foot mark across northern Aroostook.
Additionally, southeast winds during this time could lead to
orographic enhancement west of Route 11, further supporting
heavier snowfall amounts.

Friday...
As the occluded low pushes eastward and exits our area, the
pressure gradient aloft will tighten between the departing low
and the building ridge of high pressure to the west. This will
result in increasing winds into the day on Friday. 850 mb winds
may approach 45 to 50 kts, and with elevated mixing heights due
to clearing skies and increasing sun angle, surface gusts may
easily reach into the 30 to 40 mph range. Despite most snowfall
having ended Thursday night and allowing for a bit of a crust to
build up, these winds may be able to break through this crust,
at least enough to cause significant drifting and impact cleanup
efforts.

There could be some lingering snow showers through the day on
Friday, mainly north, where snow showers develop over the St
Lawrence River and stream into our forecast area. Any areas
which see snow showers could see an additional drop in
visibility due to blowing snow at that time. Winds and snow
shower chances will gradually decrease through Friday night.
&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Weekend Synoptic setup...
Brief high pressure will return on Saturday, then shift eastward
Saturday night. Another occluded low system will approach from
the southwest Sunday morning. Aloft, the jet stream will begin
to lift north of the state of Maine, with a deepening jet streak
that could approach 190 kts in strength. Heading into the day on
Sunday, this jet streak may reposition such that our forecast
area sits in the right entrance region of the jet streak,
increasing divergence aloft and leading to a deepening low at
the surface.

Sunday Hazard Details...
As the low moves into the area and begins to deepen, snow will
likely spread across the forecast area. There still exists some
uncertainty with how this storm will evolve at this time range,
but there is better consistency across guidance in the track of
this system, which appears to follow the coast before it moves
into the Canadian Maritimes.

There are some similarities between this system and the Thursday
system discussed in the Short Term above, but it should be noted
there are also some stark differences, such as the synoptic
pattern aloft. Additionally, the coastal low on Sunday so far
appears to be the dominant low circulation. Though trending
stronger, it lacks the northern support, which may result in
more downsloping influence with northeast winds in the northern
half of the CWA, which may lead to lower snow totals than
modeled. That said, near the coast, there do exist some
impressive signals for the potential for banding with this
storm, potentially for a more impactful storm for Downeast. This
system will continue to be closely monitored over the next
several forecast cycles.

Monday - Tuesday...
High pressure returns for early next week, but between the
departing deepening low and the incoming ridge of high pressure,
another period of tightened pressure gradient aloft could lead
to another day of strong wind gusts and potential for a return
of blowing and drifting snow.
&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: Generally VFR today through much of tonight. However,
MVFR conditions possible late tonight with developing snow.
Variable winds 5 to 10 knots today. Variable winds 5 to 10
knots, becoming east around 10 knots tonight.

SHORT TERM:
Thurs: IFR/LIFR for Downeast terminals in light to moderate
snow, LIFR/VLIFR for norther terminals in moderate to heavy
snow. Sleet and freezing rain could mix in at Downeast terminals
in the afternoon. SE winds 10 to 15 kts, gusting 20 to 25 kts.

Thurs night: Improving to VFR at Downeast terminals, and
MVFR/IFR at northern terminals. W winds 10 to 15 kts with gusts
increasing to 20 to 30 kts.

Fri: VFR across all terminals, outside of brief MVFR/IFR in snow
showers and blowing snow, particularly across the north. W to NW
winds 15 to 20 kts with gusts 25 to 35 kts.

Fri night - Sat night: VFR across all terminals. NW winds
decreasing to 5 to 10 kts occasionally gusting to 20 kts.

Sun: Conditions decreasing to IFR/LIFR across all terminals in
snow. NE winds 5 to 10 kts with gusts to 20 kts.
&&

.MARINE...
NEAR TERM: Winds/seas below small craft advisory levels today
through much of tonight. Small craft advisory conditions then
develop late tonight. Light freezing spray this morning, then
again tonight.

SHORT TERM: Gale force winds are expected to build in over the
coastal waters on Thursday, and a Gale warning is in place for
this time period. Small Craft Advisory is in place for the
intra-coastals with gusts remaining below gales. There could be
a brief break Thursday evening, before winds increase once more
to gale strength, likely for all waters, into the day on Friday,
and only begin to gradually decrease Friday night. Light
freezing spray Thursday morning, potential for moderate freezing
spray Friday morning.
&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Winter Storm Warning from 5 AM Thursday to midnight EST
     Thursday night for MEZ001>006.
     Winter Weather Advisory from 5 AM Thursday to midnight EST
     Thursday night for MEZ010-011-015>017-029>032.
MARINE...Gale Warning from 7 AM to 4 PM EST Thursday for ANZ050-051.
     Small Craft Advisory from 7 AM to 4 PM EST Thursday for ANZ052.

&&

$$


Near Term...Norcross/LaFlash
Short Term...AStrauser
Long Term...AStrauser
Aviation...Norcross/AStrauser
Marine...Norcross/AStrauser