The Polar Vortex Arrives
000
FXUS61 KCAR 030335
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
1035 PM EST Thu Feb 2 2023
.SYNOPSIS...
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/...
Dangerously Low Wind Chills and Blowing Snow Friday through
Saturday…
1035 pm update...
Arctic front is moving very quickly twd the FA with snow squalls
moving btwn 50-55 mph and should enter into the North Woods
right around midnight tonight. The snow squalls will be the
beginning of the extreme cold, dangerous wind chills and
blizzard conditions expected to last through the day Saturday.
Whiteout conditions are expected across nrn and central areas
with fropa as winds increase to between 25-35 mph tonight from
the northwest. Ground blizzard conditions still look to be on
track through the day tomorrow and into Saturday with winds
being maximized Sat morning. Wind chills will be dropping
throughout the day on Friday and likely reaching their lowest
values on Sat morning, somewhere on the order of 50 to 60 below
and worse on the higher terrain.
Prev discussion blo...
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. Brief snow squalls will accompany the front and may
cause whiteouts, mainly in the northern half of the CWA.
Temperatures plummet with the frontal passage and continue to
fall relentlessly into Friday night. With steep low level lapse
rates, 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.
The air mass descending from Hudson Bay towards Maine is the
coldest in the Northern Hemisphere as measured by 925mb temps.
925mb temps are expected to drop towards -35C in northern
Aroostook County by later Friday. 850mb temperatures are still
expected to drop towards -40C and challenge the all-time record
at Caribou when our 04/00Z radiosonde is launched.
It is a very dry air mass with precipitable water at the very
lowest end of climate around two-hundredths of an inch. This is
fortunate in limiting snow shower activity. The only source of
moisture will be the St Lawrence River. Maintained mention of
isolated snow showers in portions of Aroostook County much of
the day based on the premise of the extremely cold air advecting
southward picking up some of that moisture and poor model
performance in past situations.
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.
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.
As we said in our last discussion, 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.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
Friday night and
Saturday will be the most dangerous time frame for windchills as
the overnight lows hit their minimum. As the Arctic air mass
moves in, it will be accompanied by a LLJ nearing 50 to 60 knots
at 850 hPa. The coldness of the air aloft should help these
winds mix down, and gusty winds will continue behind the Arctic
front through at least midday on Saturday. Although ambient
temperatures will be cold, they will not reach record breaking
lows. The amplifying factor will be the wind, which will reach
peak gusts of 35 to 40 mph early Saturday morning, bringing
windchills dangerous lows of -50 to -55F across the entire
forecast area. Winds will finally begin to subside in the
afternoon as the ridge moves overhead and the LLJ moves off to
the east. The cold air will remain in place, so although wind
chills will significantly warm, ambient temperatures will remain
below zero for most of the area and some places may see record
low max Ts on Saturday, followed by low temps from 0 to -20F
again Saturday night.
This will be a short-lived deep freeze, however, as the ridge
moves eastward on Sunday and the air mass aloft begins to warm.
By Sunday morning, temps at 850 hPa will have warmed to -10 to
-15C, and surface temperatures on Sunday will be much more
seasonable. A weak surface low will develop along the coast
Saturday night and move northward into the Bay of Fundy,
bringing a quick shot of snow for Sunday afternoon. This will
mostly fall over the Downeast region, but snowshowers are
possible through northern Maine as well. Very little QPF is
expected, and even with high snow ratios, accumulations will
generally range from 1 to 3 inches area wide.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A northern stream
trough approaches Sunday night, then crosses the area on
Monday. Depending on model of choice, this could actually end up
being a full latitude trough, but for now that detail should
not have much, if any impact on our sensible weather in this
time frame. It appears that the surface based cold front
associated with this trough should be ana-frontal in nature, so
would expect any snow showers (possibly mixed with rain showers
near the immediate coast) to occur behind the front from Sunday
night into Monday.
A deep layered ridge crosses the area Monday night than exits to the
east on Tuesday. It should be dry Monday night into Tuesday as a
result. Depending on exactly how fast the ridge axis slides to the
east on Tuesday, there is some chance for some light snow
North/light rain/snow elsewhere late in the day.
A northern stream trough crosses the area Tuesday night and
Wednesday morning, with a chance of snow across Northern Aroostook
and Somerset and Northern and Central Piscatiquis counties, with and
a chance of rain or snow elsewhere. Northern stream shortwave
ridging builds in later Wednesday, so it should be dry then.
Deep layered ridging crosses the area Wednesday night then exits to
the east on Thursday. It should be dry Wednesday night, then
depending on exactly how fast the ridge axis slides off to the east,
there is the chance for some snow showers across the North and rain
or snow showers elsewhere by late in the day.
Temperatures start out near normal Monday, and should be above
normal Tuesday-Thursday.....
URGENT - WINTER WEATHER MESSAGE
National Weather Service Caribou ME
1022 PM EST Thu Feb 2 2023
MEZ005-006-031130-
/O.CON.KCAR.BZ.W.0001.230203T0600Z-230205T0000Z/
/O.CON.KCAR.WC.W.0001.230203T1700Z-230205T0000Z/
Northern Penobscot-Southeast Aroostook-
Including the cities of East Millinocket, Hodgdon, Sherman,
Millinocket, Medway, Smyrna Mills, Houlton, and Patten
1022 PM EST Thu Feb 2 2023
...BLIZZARD WARNING REMAINS IN EFFECT UNTIL 7 PM EST SATURDAY...
...WIND CHILL WARNING REMAINS IN EFFECT FROM NOON FRIDAY TO 7 PM EST
SATURDAY...
* WHAT...For the Blizzard Warning, ground blizzard conditions
expected. Total snow accumulations up to one inch. Winds gusting
as high as 50 mph. For the Wind Chill Warning, dangerously cold
wind chills expected. Wind chills as low as 60 below zero.
* WHERE...Northern Penobscot and Southeast Aroostook Counties.
* WHEN...For the Blizzard Warning, until 7 PM EST Saturday. For the
Wind Chill Warning, from Noon Friday to 7 PM EST Saturday.
* IMPACTS...Plan on slippery road conditions. Widespread blowing
snow could significantly reduce visibility. The hazardous
conditions could impact the Friday morning and evening commutes.
Isolated to scattered power outages are possible. The dangerously
cold wind chills could cause frostbite on exposed skin in as
little as 5 minutes.
* ADDITIONAL DETAILS...In addition to low wind chills, areas of
blowing snow could cause whiteout conditions, particularly across
open areas exposed to northwest winds. Blowing and drifting snow
could make travel very difficult. If you must travel have a winter
survival kit and if you get stranded, stay in your vehicle.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Wind Chill Warning means the combination of very cold air and the
wind will create dangerously low wind chill values. Frostbite can
occur quickly and even hypothermia or death if precautions are not
taken.
Persons should consider delaying all travel. If travel is absolutely
necessary, drive with extreme caution. Consider taking a winter
storm kit along with you, including such items as tire chains,
booster cables, flashlight, shovel, blankets and extra clothing.
Also take water, a first aid kit, and anything else that would help
you survive in case you become stranded.
Keep pets indoors as much as possible.
&&
$$
URGENT - WINTER WEATHER MESSAGE
National Weather Service Caribou ME
1022 PM EST Thu Feb 2 2023
MEZ005-006-031130-
/O.CON.KCAR.BZ.W.0001.230203T0600Z-230205T0000Z/
/O.CON.KCAR.WC.W.0001.230203T1700Z-230205T0000Z/
Northern Penobscot-Southeast Aroostook-
Including the cities of East Millinocket, Hodgdon, Sherman,
Millinocket, Medway, Smyrna Mills, Houlton, and Patten
1022 PM EST Thu Feb 2 2023
...BLIZZARD WARNING REMAINS IN EFFECT UNTIL 7 PM EST SATURDAY...
...WIND CHILL WARNING REMAINS IN EFFECT FROM NOON FRIDAY TO 7 PM EST
SATURDAY...
* WHAT...For the Blizzard Warning, ground blizzard conditions
expected. Total snow accumulations up to one inch. Winds gusting
as high as 50 mph. For the Wind Chill Warning, dangerously cold
wind chills expected. Wind chills as low as 60 below zero.
* WHERE...Northern Penobscot and Southeast Aroostook Counties.
* WHEN...For the Blizzard Warning, until 7 PM EST Saturday. For the
Wind Chill Warning, from Noon Friday to 7 PM EST Saturday.
* IMPACTS...Plan on slippery road conditions. Widespread blowing
snow could significantly reduce visibility. The hazardous
conditions could impact the Friday morning and evening commutes.
Isolated to scattered power outages are possible. The dangerously
cold wind chills could cause frostbite on exposed skin in as
little as 5 minutes.
* ADDITIONAL DETAILS...In addition to low wind chills, areas of
blowing snow could cause whiteout conditions, particularly across
open areas exposed to northwest winds. Blowing and drifting snow
could make travel very difficult. If you must travel have a winter
survival kit and if you get stranded, stay in your vehicle.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Wind Chill Warning means the combination of very cold air and the
wind will create dangerously low wind chill values. Frostbite can
occur quickly and even hypothermia or death if precautions are not
taken.
Persons should consider delaying all travel. If travel is absolutely
necessary, drive with extreme caution. Consider taking a winter
storm kit along with you, including such items as tire chains,
booster cables, flashlight, shovel, blankets and extra clothing.
Also take water, a first aid kit, and anything else that would help
you survive in case you become stranded.
Keep pets indoors as much as possible.
&&
$$
Hazardous Weather Outlook
National Weather Service Caribou ME
256 PM EST Thu Feb 2 2023
MEZ005-006-032000-
Northern Penobscot-Southeast Aroostook-
256 PM EST Thu Feb 2 2023
...BLIZZARD WARNING IN EFFECT FROM 1 AM FRIDAY TO 7 PM EST
SATURDAY...
...WIND CHILL WARNING IN EFFECT FROM NOON FRIDAY TO 7 PM EST
SATURDAY...
This Hazardous Weather Outlook is for Central Highlands Maine and
Far Eastern Maine.
.DAY ONE...This afternoon and tonight.
Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.
Blizzard Warning.
.DAYS TWO THROUGH SEVEN...Friday through Wednesday.
Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.
Blizzard Warning.
Wind Chill Warning.
.SPOTTER INFORMATION STATEMENT...
Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.
$$
11:13 PM AST Thursday 02 February 2023
Extreme Cold Warning in effect for:
Halifax Metro and Halifax County West
A period of very cold wind chills is expected.
On Friday, an arctic airmass will combine with strong northwest winds to give bitterly cold conditions. Windchill values of minus 35 to minus 42 are expected to develop Friday night and will persist into Saturday morning before beginning to moderate Saturday afternoon as winds subside.
Watch for cold related symptoms: shortness of breath, chest pain, muscle pain and weakness, numbness and colour change in fingers and toes.
Cover up. Frostbite can develop within minutes on exposed skin, especially with wind chill.
Extreme cold warnings are issued when very cold temperatures or wind chill creates an elevated risk to health such as frost bite and hypothermia.
Information is provided on the Nova Scotia Department of Health and Wellness website at https://novascotia.ca/nse/environmental-health/staying-warm-in-winter.asp.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to NSstorm@ec.gc.ca or tweet reports using #NSStorm.
11:11 PM AST Thursday 02 February 2023
Extreme Cold Warning in effect for:
Fredericton and Southern York County
The coldest wind chill values will be near minus 45.
On Friday, an arctic airmass will combine with strong northwest winds to give bitterly cold conditions. Windchill values of minus 35 to minus 45 are expected to develop Friday afternoon and will persist into Saturday morning before beginning to moderate Saturday afternoon as winds subside.
Watch for cold related symptoms: shortness of breath, chest pain, muscle pain and weakness, numbness and colour change in fingers and toes.
Cover up. Frostbite can develop within minutes on exposed skin, especially with wind chill.
Extreme cold warnings are issued when very cold temperatures or wind chill creates an elevated risk to health such as frost bite and hypothermia.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to NBstorm@ec.gc.ca or tweet reports using #NBStorm.
11:11 PM AST Thursday 02 February 2023
Extreme Cold Warning in effect for:
Queens County P.E.I.
A period of very cold wind chills is expected.
On Friday, an arctic airmass will combine with strong northwest winds to give bitterly cold conditions. Windchill values of minus 35 to minus 40 are expected to develop Friday night and will persist into Saturday morning before beginning to moderate Saturday afternoon as winds subside.
Watch for cold related symptoms: shortness of breath, chest pain, muscle pain and weakness, numbness and colour change in fingers and toes.
Cover up. Frostbite can develop within minutes on exposed skin, especially with wind chill.
Extreme cold warnings are issued when very cold temperatures or wind chill creates an elevated risk to health such as frost bite and hypothermia.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to PEstorm@ec.gc.ca or tweet reports using #PEStorm.
posted by Advackia at 8:02 PM
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