Mid-January Ice Storm

000

FXUS61 KCAR 150204

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

904 PM EST Sat Jan 14 2023

.SYNOPSIS...

High pressure builds to the north into early next week. Meanwhile, A

strong storm system moves from off the Mid Atlantic Coast Sunday

evening to Near Nova Scotia by Tuesday morning. This low then slowly

lifts north into the Canadian Maritime Provinces through the middle

of next week.....

......Prev Disc: The deep upper trough along the Atlantic coast will

make a subtle shift eastward tonight. This will push the warm

conveyor belt and the clouds streaming northward along it a bit

further east. High pressure over northern Quebec will strengthen

overnight as an upper ridge axis builds eastward from the Great

Lakes region. Ridging from the high will extend southward into

the forecast area and is expected to slowly erode the persistent

stratocumulus fields over the area. The gradual clearing and a

shallow wedge of colder air advecting southward will drop lows

into the single digits north and teens to lower 20s for Bangor

and Downeast. The 14/12Z GFS was treated as an outlier on the

cold side. Nonetheless, a steep and somewhat shallow inversion

will set up. As the high in Quebec strengthens, low pressure

well east of the Virginia coast will deepen. The pressure

gradient between these two features will tighten and northeast

winds will increase through tonight and into Sunday. This means

gusts to 25-30 mph for most of the area on Sunday...and gusts to

40 mph on the coast. This north to northeasterly flow will keep

the shallow wedge of cold air over the area Sunday with highs

ranging from the low 20s north to upper 20s Downeast.

The low off the Virginia coast will become vertically stacked on

Sunday and slowly drift northward. A warm occluded front will

approach the coast later in the day with precipitation in the

form of mostly sleet. There will be a decent amount of Atlantic

moisture streaming northward with PWs surging over three-

quarters of an inch along the Downeast coast by late Sunday. Critical

thicknesses do not suggest much snow. A strong easterly low

level jet in the H925 to H850 range will ensure warm advection

and development of a warm nose for melting. The warm nose looks

high enough to prevent too much in the way of freezing rain

into Sunday evening, but will be sufficient for sleet.

Precipitation will be mostly confined to the Downeast region for

Sunday afternoon. The remainder of the area will be dry...and

sunny in the north.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...

A cutoff low tracks from off the mid Atlantic Coast Sunday evening

to the vicinity of Nova Scotia by Tuesday morning. Ahead of this

storm initially snow, quickly changing to a wintry mix of mainly

sleet, with some freezing rain, will overspread the area from

southeast to northwest from Sunday night into Monday morning, then

continue into Monday night, before tapering off from SW to NE. While

the entire region starts out with the entire vertical column of the

atmosphere below freezing, a deep warm layer moves in from SE to NW

Sunday night between about 800-700 hPa. At the surface though, cold

low level air will continue to advect in on low level N-NNE flow.

This set up continues through Monday, before colder air moves in

again aloft from N to S Monday night.

This should lead to a significant accumulation of sleet (1 inch or

more) across at least portions of Downeast Maine and possibly

southern Aroostook, with at least 1/2 an inch of sleet possible

farther to the west to around state route 11. In addition freezing

rain is also possible, with the potential for a tenth or two of an

inch of freezing rain across most of Downeast Maine, with Washington

County possibly seeing 1/4 to 1/2" of freezing rain. The heaviest

accumulations of sleet and freezing rain should occur from late

Sunday night through Monday.

There is also the potential for 3 to 5 inches of snow across the

North, falling in two waves. The first inch or so Sunday night

before changing over to the wintry mix and the second 2-4 inches

Monday night as colder air begins to work back in aloft.

In addition a 45-55kt low level jet could bring wind gusts up to 35

mph across Downeast Maine, this coupled with the sleet and freezing

rain could cause widespread power outages.

As a result have issued a winter storm watch from 19z Sunday-10z

Tuesday for Downeast Maine and Central Penobscot and Southern

Penobscot Counties and a winter weather advisory from 00z Monday-10z

Tuesday for Southern and Northern Penobscot, Southern Piscatiquis

and Northeastern Aroostook Counties. Note as confidence

increases in the outcomes outside of the current watch and

advisory area, there is some potential for advisories to be

expanded with future forecast issuances.

Northern stream ridging builds in on Tuesday as the cutoff low lifts

N into the Canadian Maritime Provinces. So while some linger snow

showers cannot be ruled out, more than likely the day should be

dry.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

The region should be under W to NW flow aloft Tuesday night through

Wednesday night, with dry low to mid levels, even with a few passing

shortwaves, it should be dry.

A northern stream ridge builds into the area Thursday, so it should

be dry, with minimal cloud cover. This ridge exits to the east

Thursday night, how fast its axis moves to the east will determine

how quickly high and mid clouds build in during the night ahead of

the next system.

A closed mid level low tracks from near the Great Lakes Friday

morning to the eastern Canadian Maritime Provinces by Saturday

morning (there is some differences in the models as to how far E and

N this feature gets and if it ends up opening up into a trough). For

now it appears that there could be a period of snow from Friday into

Friday night, and at this time, the heaviest snow appears more

likely for areas along and east/south of I-95. There is still quite

a bit of uncertainty with this system, so its to early to specify,

what impacts it might cause.

Northern stream ridging should then build in for Saturday, with it

being dry.

Temperatures should be above normal through the mid-long term.

URGENT - WINTER WEATHER MESSAGE

National Weather Service Caribou ME

841 PM EST Sat Jan 14 2023

MEZ006-011-016-017-029-030-032-151200-

/O.CON.KCAR.WS.A.0002.230115T1900Z-230117T1000Z/

Southeast Aroostook-Central Penobscot-Interior Hancock-Central

Washington-Coastal Hancock-Coastal Washington-Northern Washington-

Including the cities of Springfield, Ellsworth, Vanceboro,

Hodgdon, Aurora, Houlton, Howland, Great Pond, Castine, Perry,

Wesley, Topsfield, Sherman, Machias, Bucksport, Dedham, Bar

Harbor, Grand Lake Stream, Calais, Lincoln, Princeton, Danforth,

Cherryfield, Orland, Amherst, Eastbrook, Smyrna Mills, and

Eastport

841 PM EST Sat Jan 14 2023

...WINTER STORM WATCH REMAINS IN EFFECT FROM SUNDAY AFTERNOON

THROUGH LATE MONDAY NIGHT...

* WHAT...Heavy mixed precipitation possible. Total snow

  accumulations between 2 and 4 inches, sleet accumulations around 1

  inch and ice accumulations up to four tenths of an inch are

  possible. Winds could gust as high as 35 mph.

* WHERE...Portions of Coastal DownEast, Far Eastern, Interior

  DownEast, and Penobscot Valley Maine

* WHEN...From Sunday afternoon through late Monday night.

* IMPACTS...Roads, and especially bridges and overpasses, will

  likely become slick and hazardous. Power outages and tree damage

  are likely due to the ice. Travel could be nearly impossible. The

  hazardous conditions could impact the Monday morning and evening

  commutes. Gusty winds could bring down tree branches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant snow,

sleet or ice accumulations that may impact travel. Continue to

monitor the latest forecasts.

&&

$$

VJN

URGENT - WINTER WEATHER MESSAGE

National Weather Service Caribou ME

841 PM EST Sat Jan 14 2023

MEZ002-005-015-031-151200-

/O.CON.KCAR.WW.Y.0004.230116T0000Z-230117T1000Z/

Northeast Aroostook-Northern Penobscot-Southern Penobscot-

Southern Piscataquis-

Including the cities of Guilford, Brewer, Presque Isle, East

Millinocket, Bangor, Millinocket, Orono, Ashland, Van Buren,

Milo, Patten, Medway, Mars Hill, Caribou, Dover-Foxcroft, and Old

Town

841 PM EST Sat Jan 14 2023

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 7 PM SUNDAY TO 5

AM EST TUESDAY...

* WHAT...Mixed precipitation expected. Total snow accumulations

  between 3 and 5 inches, sleet accumulations around three quarters

  of an inch and ice accumulations up to one tenth of an inch.

* WHERE...Northern Penobscot, Southern Piscataquis, Northeast

  Aroostook, and Southern Penobscot Counties.

* WHEN...From 7 PM Sunday to 5 AM EST Tuesday.

* IMPACTS...Roads, and especially bridges and overpasses, will

  likely become slick and hazardous. Plan on slippery road

  conditions. The hazardous conditions could impact the Monday

  morning and evening commutes. Gusty winds could bring down tree

  branches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory means that periods of snow, sleet or

freezing rain will cause travel difficulties. Expect slippery roads

and limited visibilities, and use caution while driving.

The latest road conditions for Maine can be obtained by going to

newengland511.org.

&&

$$

8:11 PM AST Saturday 14 January 2023

Freezing rain warning in effect for:

Saint John and County

Freezing drizzle will re-intensify to freezing rain Sunday evening.

Locations: southern New Brunswick.

Time span: Sunday evening through Monday morning.

Remarks: A persistent weather system stalled south of the Maritimes will push another round of freezing precipitation into New Brunswick later on Sunday and into Monday. Precipitation will start as ice pellets in the afternoon and gradually transition to freezing rain Sunday evening. Freezing rain and ice pellets will continue into Monday morning before warmer air finally changes the precipitation to rain.

There is a risk of significant ice accretion in some areas before this changeover.

This warning will likely be expanded further.

Poor weather conditions may contribute to transportation delays. Ice build-up may cause tree branches to break. Utility outages may occur. Public Safety Canada encourages everyone to make an emergency plan and get an emergency kit with drinking water, food, medicine, a first-aid kit and a flashlight. For information on emergency plans and kits go to http://www.getprepared.gc.ca.

Freezing rain warnings are issued when rain falling in sub-zero temperatures creates ice build-up and icy surfaces.

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.

9:19 PM AST Saturday 14 January 2023

Freezing rain warning in effect for:

Halifax Metro and Halifax County West

Freezing rain is expected or occurring.

Locations: all of Nova Scotia except for southeastern Cape Breton Island.

Time span: tonight and Sunday.

Remarks: Many parts of the province will see a prolonged period of freezing drizzle tonight. Freezing rain is expected during the day on Sunday. Freezing rain will changeover to scattered showers by Monday morning.

Precipitation along the coast is expected to remain as rain on Sunday, with the main risk for freezing rain remaining inland.

Surfaces such as highways, roads, walkways and parking lots may become icy and slippery. Be prepared to adjust your driving with changing road conditions. Ice build-up may cause tree branches to break.

Freezing rain warnings are issued when rain falling in sub-zero temperatures creates ice build-up and icy surfaces.

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.