National Weather Service Raw Text Product

707 
FXUS61 KCAR 021758
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
1258 PM EST Thu Feb 2 2023

.SYNOPSIS...
High pressure will move south of the region today. A 
powerful arctic cold front will cross the area Friday morning. 
Frigid arctic high pressure will build in from the west Friday into 
Saturday. A warm front will lift across the area Sunday. Weak low 
pressure will track north of the area Monday.

&&

.NEAR TERM /THROUGH FRIDAY/...
1230pm update...
The Blizzard Warning was issued in response to the blowing snow
and whiteout threat in the warned area. Snow accumulations will
be an inch or less. The blowing snow threat will be in open
terrain where whiteouts are most likely to affect motorists.
Discussions with state and county authorities involved in 
public safety this week, and after similar events in past years,
have favored this stronger alert/messaging.

The arctic front arrives later tonight with plunging 
temperatures, blowing snow and dangerous wind chills. The front 
crosses after midnight and is expected to be exiting the state 
by 4am. Temperatures plummet with the frontal passage and 
continue to fall relentlessly into Friday night. Winds kick up 
immediately with frontal passage with gusts reaching the 35 to 
45 mph range. Blowing snow will start with the frontal passage 
and continue all day and into Friday night. The worst will be in
Aroostook County where the Blizzard Warning was issued due to 
the blowing snow/ground blizzard threat in open terrain. Wind 
chills drop steadily all day into the evening, reaching below 
minus 50F by late afternoon in the Saint John Valley and 
dropping towards minus 45F at Bangor by late evening.

Interestingly, using CIPS analogs, a top analog is the Jan 14, 
1988 event when Caribou last experienced a wind chill of less 
than minus 50F. The lowest recorded wind chill at Caribou was
minus 58.6F in 1951.

Previous discussion...
High pressure will slide south of the area today. A return 
southwesterly flow behind the high and ahead of the approaching 
Arctic front will increase throughout the day. Moisture in this 
return flow will increase clouds. Snow showers in the warm advection 
will push across the north from midday into the afternoon. Most of 
the snow showers will be across western Aroostook, Northern Somerset 
and northern Piscataquis counties where up to an inch may fall by 
days end. Snow showers will continue across the north this evening 
ahead of the Arctic front, mostly across the west and north. The 
tight gradient ahead of the front will bring an increasing south 
southwesterly wind as midnight approaches. 

Our attention late tonight turns to the very powerful Arctic front 
which will push into the western part of our region around midnight 
then quickly roar across the rest of the region soon after. 
Convergence along the front combined with steep lapse rates will 
produce snow showers and potentially some locally heavier snow 
squalls. The best chance for heavier snow showers or squalls will be 
over western parts of the area around and soon after midnight where 
the steepest lapse rates are advertised. Following the frontal 
passage, strong gusty northwesterly winds and intense cold advection 
will set in. The very cold air will keep the snow crystals brittle 
allowing them to powder easily in the gusty winds. Blowing snow with 
white-out conditions is expected in open areas as dawn approaches. 
Temperatures will plunge into the teens below over the north and 
near zero Downeast by dawn.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
Extremely Low Wind Chills and Blowing Snow Friday and Saturday…

An extremely cold arctic air mass with 850mb temperatures below
-40C will moderate only slightly before moving into northern
 Maine from Quebec on Friday, leading to rapidly falling
 temperatures despite clearing skies. Low pressure strengthening
 over northeastern Quebec and Labrador will create a very strong
 pressure gradient between it and the arctic surface high
 building across the Great Lakes. The unusual combination of
 very cold temperatures in the teens to 20s below zero and
 strong winds will create wind chills rarely seen in northern
 and eastern Maine as low as 45 to 65 below zero. Most stations
 are forecast to see their lowest wind chills in decades or, in
 some cases, the lowest ever recorded. The lowest wind chills
 will occur later Friday night and early Saturday morning.

In addition to the wind chills, blowing and drifting snow will
cause significant travel problems, especially across 
northeastern portions of the forecast area where land use is 
more agricultural. The very cold temperatures will cause snow to
become dry, brittle and more easily lofted. Transport of snow
across roads will be exacerbated by seasonably high snow berms
due to the recent snowy January. Recent trends towards a 
slightly further south surface low across Labrador have caused 
wind gusts to trend upward slightly due to the stronger pressure
gradient with gusts to 45 to 50 mph now possible. Travel over 
open areas exposed to northwest winds will be dangerous at best 
and impossible at worst due to ground blizzard conditions and 
significant drifting making some roads impassable. Those who 
must travel across open areas Friday through Saturday morning 
should be prepared if they become stranded with a full tank of 
gas and winter survival supplies. It is also critical people do 
not leave their vehicles in whiteout conditions and very cold 
wind chills. As we unfortunately saw in Buffalo earlier this 
winter, many fatalities during severe winter weather can occur 
when people run out of gas and leave their vehicles. A winter 
storm watch for possible ground blizzard conditions continues 
for northeastern portions of the forecast area. A decision
whether or not to upgrade this to a blizzard warning is 
expected later today.

Winds will gradually weaken Saturday afternoon before more
rapidly diminishing after sunset as high pressure builds towards
the area and a weak surface inversion starts to form.
Temperatures Saturday night will still be cold with a narrow
window of radiational cooling allowing cooler spots across
northern Maine to drop back into the -20s, albeit with light
winds. Thickening clouds and return flow later in the night, as
well as the position of the high pressure center south of the
area should limit temperatures drops from their full potential.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Sunday: As the surface high pressure moves east, return flow
will bring a weak warm front across the area. Snow showers and 
light snow are expected with this with ensemble guidance 
suggesting a light accumulation for most areas. Temperatures 
will rebound to near normal for early February, ranging from the
mid to upper teens across the north to the 30s along the coast.

Monday: A weak cold front will move across the area with snow
showers possible across the north and higher terrain. High
pressure building in and clearing skies Monday night will lead 
to cooler low temperatures below zero across the north and in 
the single digits across most of the rest of the area.

Tuesday to Wednesday: The surface high pressure will move east
with return flow bringing in an even milder air mass with above
normal temperatures returning. A fast moving area of low
pressure late Tuesday afternoon into Tuesday night could bring a
brief period of precipitation to the area.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
NEAR TERM: 
North...VFR to occasionally MVFR today into this evening. 
Increasing SW winds. MVFR to IFR in blowing snow after midnight.
Strong gusty NW winds. 

South...VFR today into this evening. Increasing SW winds. VFR to 
MVFR late tonight. Gusty NW winds. 

SHORT TERM: 
Friday to Saturday morning: VFR with tempo MVFR visibility 
downeast and MVFR with tempo IFR or lower visibility at northern
terminals due to blowing snow. NW winds 15 to 20 kt with gusts 
to 35 to 40 kt.

Saturday afternoon and night: Visibility improving to VFR at 
all terminals. NW winds gusting to 35 kt early, becoming light 
by mid to late evening.

Sunday: MVFR developing with tempo IFR visibility in light 
snow. SSW winds 5 to 10 kt with gusts to 15 to 20 kt.

Monday: MVFR. NW winds 5 to 15 kt.

&&

.MARINE...
NEAR TERM: SW winds will increase today reaching 
gale this evening. Gale tonight for SW winds becoming W. 
Freezing spray beginning late tonight. Seas building up to 7 ft 
today then 10 ft tonight in response to the winds. 

SHORT TERM: Strong gale force winds will continue over the
waters Friday through Saturday. A few gusts to near 50kts are
possible, mainly over the outer waters Friday night into early
Saturday morning. Heavy freezing spray will develop during the
day Friday and continue through Saturday. Arctic sea smoke may
reduce visibility, along with ocean effect snow showers further
offshore.

&&

.CLIMATE...
The coldest air mass so far this winter is expected at the end
of the week. Although record low temperatures do not look likely
at this time due to wind, record low high temperatures are possible
across the area on Saturday.  Here are the forecast highs on 
Saturday, 2/5 along with the record low highs:

Caribou: -6F, record -4F, in 1963
Houlton: -4F, record -2F, in 1963
Millinocket: -2F, record 0F, in 1963
Bangor: +3F, record +4F, in 1963

It has been over 5 years since Bangor has had a day where the
high temperature failed to reach zero. The last sub-zero high
was -1F on January 6, 2018.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Blizzard Warning from 1 AM Friday to 7 PM EST Saturday for 
     MEZ001-002-005-006.
     Wind Chill Warning from 4 AM Friday to 7 PM EST Saturday for 
     MEZ001>004-010.
     Wind Chill Warning from noon Friday to 7 PM EST Saturday for 
     MEZ005-006-011-015>017-029>032.
MARINE...Gale Warning from 6 PM this evening to 4 PM EST Saturday for 
     ANZ050>052.
     Heavy Freezing Spray Warning from 10 AM Friday to 4 PM EST 
     Saturday for ANZ050>052.

&&

$$

Near Term...Bloomer/MCW
Short Term...MStrauser
Long Term...MStrauser
Aviation...Bloomer/MCW/MStrauser
Marine...Bloomer/MCW/MStrauser
Climate...