Early December Wind & Rain Storm Update One

10:22 PM AST Saturday 9 December 2023

Rain and strong winds are expected on Monday. 

Maximum wind gusts: southerly 70 to 80 km/h except 100 km/h over exposed areas.

Location: Nova Scotia

Time span: Monday morning until late Monday evening.

Remarks: The strongest winds will occur over the western parts of the province from Monday morning until late Monday afternoon. Over eastern Nova Scotia, the strongest winds are expected from mid-afternoon Monday until late Monday evening. 

At this time, total rainfall amounts are not expected to be significant. However, a period of heavy rain is possible during the strongest winds.

In addition, elevated water levels and large waves are expected along the Atlantic coast.

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.

10:09 PM AST Saturday 9 December 2023

Significant rainfall and strong winds are expected. The frozen ground has reduced ability to absorb this rainfall. 

Total rainfall: 30 to 50 mm. Locally higher amounts possible.

Maximum wind gusts: southerly 60 to 70 km/h except 90 to 100 km/h over exposed areas. (Mainly over the southern and eastern parts of the province).

Location: southern and northeastern New Brunswick.

Time span: Sunday evening until late Monday.

Remarks: The heaviest rainfall is most likely to occur over the central and western parts of the province. The strongest winds are most likely to occur in the southern and eastern parts of the province.

In addition, very mild temperatures and rapid snowmelt are expected, contributing to water runoff.

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.

10:06 PM AST Saturday 9 December 2023

Rain, heavy at times is expected. The frozen ground has a reduced ability to absorb this rainfall.

Total rainfall: 30 to 40 mm by Monday morning. Possibly exceeding 80 by Monday night.

Location: northwestern New Brunswick

Time span: beginning Sunday evening and continuing until Monday evening.

Remarks: Strong winds and mild temperatures will accompany the rain, leading significant snowmelt and run-off. The rain is likely to change to snow over parts of the northwest before ending Monday night.

Localized flooding in low-lying areas is possible.

If visibility is reduced while driving, slow down, watch for tail lights ahead and be prepared to stop.

Rainfall warnings are issued when significant rainfall is expected.

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.

10:06 PM AST Saturday 9 December 2023

Strong winds are expected on Monday. 

Maximum wind gusts: southerly 70 to 80 km/h except 100 km/h over exposed areas.

Location: Prince Edward Island.

Time span: near noon Monday through Monday evening.

Remarks: The strongest winds will likely occur from late Monday afternoon until early Monday evening.

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.

Flood Watch

National Weather Service Caribou ME

944 PM EST Sat Dec 9 2023

MEZ002-004>006-010-011-015>017-029>032-101100-

/O.CON.KCAR.FA.A.0009.231211T0600Z-231212T1200Z/

/00000.0.RS.000000T0000Z.000000T0000Z.000000T0000Z.OO/

Northeast Aroostook-Northern Piscataquis-Northern Penobscot-

Southeast Aroostook-Central Piscataquis-Central Penobscot-

Southern Penobscot-Interior Hancock-Central Washington-Coastal

Hancock-Coastal Washington-Southern Piscataquis-Northern

Washington-

Including the cities of Eastbrook, Bar Harbor, Smyrna Mills,

Cherryfield, Great Pond, Topsfield, Dedham, Princeton, Castine,

Orono, Danforth, Houlton, Baxter St Park, Bangor, Ellsworth,

Hodgdon, Vanceboro, Chamberlain Lake, Springfield, Machias,

Eastport, Greenville, Van Buren, Presque Isle, Medway, Blanchard,

Mount Katahdin, Amherst, Calais, Wesley, Milo, Grand Lake Stream,

Howland, Aurora, Caribou, Churchill Dam, Old Town, Guilford, East

Millinocket, Mars Hill, Ashland, Bucksport, Dover-Foxcroft,

Orland, Millinocket, Monson, Lincoln, Patten, Brewer, Perry, and

Sherman

944 PM EST Sat Dec 9 2023

...FLOOD WATCH REMAINS IN EFFECT FROM LATE SUNDAY NIGHT THROUGH

TUESDAY MORNING...

* WHAT...Flooding caused by rain and snowmelt continues to be

  possible.

* WHERE...Portions of Central Highlands, Coastal DownEast, Far

  Eastern, Far Northern, Interior DownEast, North Woods, and

  Penobscot Valley Maine, including the following areas, in Central

  Highlands Maine, Central Piscataquis, Northern Penobscot and

  Southern Piscataquis. In Coastal DownEast Maine, Coastal Hancock

  and Coastal Washington. In Far Eastern Maine, Northern Washington

  and Southeast Aroostook. In Far Northern Maine, Northeast

  Aroostook. In Interior DownEast Maine, Central Washington and

  Interior Hancock. In North Woods Maine, Northern Piscataquis. In

  Penobscot Valley Maine, Central Penobscot and Southern Penobscot.

* WHEN...From late Sunday night through Tuesday morning.

* IMPACTS...Excessive runoff may result in flooding of rivers,

  creeks, streams, and other low-lying and flood-prone locations.

  Creeks and streams may rise out of their banks. Flooding may occur

  in poor drainage and urban areas. The Piscataquis River is

  expected to reach minor flood stage with a rapid response to

  snowmelt plus rainfall in complex terrain.

* ADDITIONAL DETAILS...

  - Flooding caused by a combination of rain and snow melt

    continues to be possible.  Heavy rainfall combined with warm

    temperatures will melt most, if not all snow. The heavy rain,

    snowmelt, and high rainfall rates over a partially frozen

    ground will create a scenario promoting small stream, creek

    and river flooding.

  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be alert for possible Flood

Warnings. Those living in areas prone to flooding should be prepared

to take action should flooding develop.

&&

$$

CB

URGENT - WEATHER MESSAGE

National Weather Service Caribou ME

906 PM EST Sat Dec 9 2023

MEZ029-030-101015-

/O.CON.KCAR.HW.W.0004.231211T0600Z-231212T0000Z/

Coastal Hancock-Coastal Washington-

Including the cities of Ellsworth, Bar Harbor, Bucksport, Orland,

Castine, Eastport, Perry, Machias, and Cherryfield

906 PM EST Sat Dec 9 2023

...HIGH WIND WARNING REMAINS IN EFFECT FROM 1 AM TO 7 PM EST

MONDAY...

* WHAT...South winds 30 to 50 mph with gusts up to 70 mph

  expected.

* WHERE...Coastal Hancock and Coastal Washington Counties.

* WHEN...From 1 AM to 7 PM EST Monday.

* IMPACTS...Damaging winds will blow down trees and powerlines.

  Numerous to widespread power outages are likely. Travel will

  be difficult, especially for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should avoid being outside in forested areas and around

trees and branches. If possible, remain in the lower levels of

your home during the windstorm, and avoid windows. Use caution if

you must drive.

&&

$$

Special Weather Statement

National Weather Service Caribou ME

829 PM EST Sat Dec 9 2023

MEZ001>006-010-011-015>017-031-032-100900-

Northwest Aroostook-Northeast Aroostook-Northern Somerset-

Northern Piscataquis-Northern Penobscot-Southeast Aroostook-

Central Piscataquis-Central Penobscot-Southern Penobscot-

Interior Hancock-Central Washington-Southern Piscataquis-

Northern Washington-

Including the cities of Allagash, Clayton Lake, Madawaska,

Fort Kent, Frenchville, Presque Isle, Caribou, Van Buren,

Mars Hill, Ashland, Baker Lake, Billy-Jack Depot, Baxter St Park,

Chamberlain Lake, Churchill Dam, Mount Katahdin, Millinocket,

East Millinocket, Patten, Medway, Houlton, Hodgdon, Sherman,

Smyrna Mills, Greenville, Monson, Blanchard, Lincoln, Howland,

Springfield, Bangor, Brewer, Orono, Old Town, Amherst, Aurora,

Dedham, Eastbrook, Great Pond, Calais, Grand Lake Stream, Wesley,

Princeton, Dover-Foxcroft, Milo, Guilford, Danforth, Vanceboro,

and Topsfield

829 PM EST Sat Dec 9 2023

...Areas of Fog and Patchy Freezing Drizzle Tonight...

Areas of fog are expected across the region tonight with locally

poor visibility. Motorists should use caution and be prepared for

areas of reduced visibility. In addition to the fog, patchy

freezing drizzle is expected. The freezing drizzle will cause

patches of ice on any untreated surfaces. If you have travel plans

tonight, please use caution and be aware that travel conditions

may change rapidly over short distances.

$$

CB

000

FXUS61 KCAR 100200

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

900 PM EST Sat Dec 9 2023

.SYNOPSIS...

A warm front crosses the region overnight into Sunday.

Intensifying low pressure tracks across Maine Monday and will

draw a cold front across the region Monday evening. High

pressure builds Monday night into Tuesday. A cold front moves

through Wednesday. High pressure builds to the south of the

region Thursday.

&&

.NEAR TERM /THROUGH SUNDAY/...

9 PM Update: Low clouds along with fog/freezing fog and patchy

drizzle along the coast and freezing drizzle inland the

remainder of tonight. Temperatures will slowly moderate

overnight with the freezing drizzle to transition to drizzle by

Sunday morning for all areas. A special weather statement was

issued for both the fog and freezing drizzle through early

Sunday morning for all inland areas. No significant changes

planned at this time.

Previous discussion:

A warm front will slowly lift through the area tonight into

early Sunday. While there is strong warm advection and decent

thermal gradients, there is little lift and no precip outside of

drizzle or freezing drizzle. Not expecting measurable

precipitation, so will continue to handle with Special Weather

Statements. Nonetheless, the freezing drizzle has caused traffic

troubles this afternoon and can be expected to continue

delivering locally treacherous conditions tonight. The warm

advection will cause temperatures to slowly rise overnight.

Along with rising temperatures from south to north, the freezing

drizzle will progress northward and exit the entire forecast

area by daybreak. The drizzle is very low level and will not

show up on radar.

The frontal inversion will persist tonight through Sunday. The

strong warm temperature and moisture advection will produce

increasing coverage of fog tonight into Sunday. It is possible

that a Dense Fog Advisory will become a consideration as dew

points well into the 40s surge northward over the cold, snow-

covered ground. With south winds, upslope effect will accentuate

fog and drizzle in Piscataquis and northern Penobscot counties.

Winds aloft will increase Sunday, but with the steep inversion,

expect minimal mixing.

A weak cold sags southeast into the forecast area from the

northwest on Sunday afternoon. The cold front will cause

steadier rain to develop in the afternoon except Downeast where

the fog and drizzle regime will linger.

With the warm advection, highs will creep into the mid 40s north

and low to mid 50s towards Bangor and Downeast. These highs will

not be achieved until late day.

&&

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

Significant Storm to Impact Maine Sun Night into Monday...

Setup...A boundary will be in place across the St. John Valley

southward to around the Moosehead Region. 12z operational runs

have shifted this boundary slightly more east which complicates

the forecast. If this trend continues we will need a shift in

wind, rain and snow axes. Opted to take a blend of the NBM, 12z

GFS and NAM shifting this boundary from Van Buren to Moosehead.

Extremely potent energy will be diving around the base of the

trof over the Ohio Valley and will tilt the trof negatively

quickly Sun night. At the same time strengthening jet stream

will set up upper level divergence over the NYC area where

surface cyclogenesis will rapidly take shape. At the same time

strengthening low-level jet will develop and push north towards

Maine increasing into Monday. Surface low pressure as it track

towards Boston by Mon AM and Maine by Mon midday will be

"bombing" out with extremely rapid deepening. This low will

track through Maine during the and into New Brunswick by mid to

late afternoon and into the Maritimes by early Tuesday AM.

Precip...Given deepening surface convergence along the front

over Maine combined with the potent shortwave and low pressure

expecting moderate to heavy rain to develop Sun night into Mon

midday. Southerly winds will favor increased upslope along the

Longfellow Mtns in the Central Highlands to Baxter region.

Widespread rainfall totals by Mon afternoon expected to be 2-2.5

inches with 1.5-2.0 inches along the immediate coast and

2.5-3.25 inches in the upslope areas of the Central Highlands.

Rain will be falling on the snowpack causing significant runoff

into the area rivers, creeks and streams causing significant

rises, see the hydrology section below. Across the North Woods

west of the front the low pressure tracks on will have increased

low-level cold air advection. This will result in a much colder

sounding, based on the latest operational runs. This will

result intially rain changing to wet snow late Sun night into

Mon AM with light to moderate snow expected into Monday before

tapering late day. This is a complex part of the forecast with

models trending east with the boundary which could cause more

snow east to the Route 11 corridor north of Patten. Rain will

change briefly to snow across much of the northern zones late in

the day Monday as temperatures crash to freezing. This will

likely result in refreeze on untreated surfaces. At this point

given the uncertainty will not hoist winter headlines for now.

Given the increasing confidence in heavy rainfall + snowmelt and

rapid river responses opted to expand the Flood Watch to

include everyone except the far North Woods and western St. John

Valley.

Winds...Late Sun Night the 925mb low-level jet will increase

80-95kt over the Gulf of Maine waters and work into Downeast

Maine. The majority of this low-level jet will be below the

inversion and decent mixing suggests large chunk of these winds

will make it to the coastal areas of the Downeast. Friction will

cut this jet down as it penetrates inland over Maine but still

expecting some winds to mix down. The caveat to this will be

the exact track of the low pressure. With a slight shift today

combined with uncertainty on the strongest winds have opted to

keep High Wind Watches up for Southern Aroostook into interior

Downeast including Bangor region. Confidence is high for

southerly wind gusts reaching 60-70mph at the Downeast coast

opted to upgrade to a High Wind Warning. Significant to

widespread power outages from tree damage is likely in these

areas. Inland for the watches will give it another model cycle

before deciding if we upgrade to advisories or warnings. Winds

after the shift in the wake of the storm Monday night will be

gusty from the W-NW gusting up to 30-35mph all night.

&&

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

Looking out into the long term ensembles have the NAO turning

positive around +1SD and also the PNA turning positive +1SD as

well. This within a positive ENSO pattern will keep much of the

area with more progressive systems with less precipitation and

temperatures generally around normal. A few isolated snow

showers on Wednesday with a weak clipper-like boundary sliding

through the area with a 500mb shortwave transitioning over the

area. Thursday into Friday we have generally 500mb ridging

moving overhead but significant timing differences between the

global operational runs. Thursday AM lows might be the coldest

with high pressure overhead and full decoupling. Opted to keep

near the NBM blend for now but cannot rule out negative single

digit lows across the northern 1/3rd of the CWA......