Destructive Subtropical System Update One

9:48 PM AST Saturday 16 December 2023

Rain and strong winds expected early next week.

Maximum wind gusts: southerly up to 80 km/h, higher gusts over the Fundy region.

Rainfall amounts: 50 to 80 mm over Fundy and southwestern regions, elsewhere 25 to 50 mm.

Time span: beginning overnight Sunday and persisting Monday into Tuesday.

Locations: western, central, and southern New Brunswick.

Remarks: A large area of rain will spread across the province Sunday night and Monday morning. Rainfall rates will likely peak Monday evening.

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.

000

FXUS61 KCAR 170257

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

957 PM EST Sat Dec 16 2023

.SYNOPSIS...

High pressure will build over the area this evening and then

slide to the east on Sunday. Strong low pressure will track up

the East Coast on Monday then pass to our west and continue

north into Canada Monday night into Tuesday. High pressure will

return on Wednesday and Thursday.

&&

.NEAR TERM /THROUGH SUNDAY/...

Update...

Temperatures have continued to fall due to the combination of

calm winds and mainly clear skies. Thus, have lowered min

temperatures a few more degrees, especially in the normally

colder valleys of the north. Higher and mid level cloudiness

will continue to increase from the west after midnight. This

will result in temperatures ultimately leveling off, or even

slowly rising after midnight. As high pressure continues to move

to the east out into the open Atlantic late tonight, the flow

will become more southerly. This could bring some patchy lower

clouds toward Downeast areas and the Bangor region toward

daybreak Sunday. Other than overnight low temperatures, no other

changes were needed as remainder of the overnight forecast

remains on track.

previous discussion

The center of the high pressure system will move across the

region this evening and tonight. This will drastically decrease

winds and shift to a southerly flow, increase moisture and cloud

cover on the backside of the high. Temps will decrease quickly

after sunset, but should become fairly stagnant around midnight

when the clouds move in. By Sunday, the high pressure will move

off over the waters, putting the region in the backside of the

high with moist warm air advection, per 925-850mb model temps.

Upper air model soundings show a very moist inversion through

the morning and afternoon, thus producing drizzle along the

upslope side of the terrain. Cooler temps in the higher terrain

will produce freezing drizzle, though expect to be fairly brief

with the quickly warming surface. By the afternoon, temps will

climb with stronger S flow and increasing winds. Expect upper

30s to near 40 in the north, and mid 40s in the south with upper

40s to near 50 along the coast. Drizzle will switch over to more

showery rain as the moisture from the strong low in the mid-

Atlantic states starts to feed into the area. Winds will

continue to increase into the evening making for a breezy

afternoon.

&&

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

Major wind and rain storm Sunday night into Monday night...

A blocking high in the Atlantic will generate a meridional upper

level flow that will draw low pressure from Florida northward

towards New England with an anomalously deep plume of Caribbean

moisture. The low will intensify as it moves up the East Coast

and its associated southern stream upper trough phases with a

northern stream upper trough moving out of the Great Lakes

region. As the low deepens and the high over the open Atlantic

strengthens, a very tight pressure gradient will develop over

the area later Sunday night into Monday.

Rainfall will intensify later Sunday night as a powerful low

level jet moves towards the area and PWs climb well above an

inch to as much as 1.4 inches. These values would likely

represent a daily record in sounding climatologies. Temperatures

will climb all night, following an anti-diurnal curve, and

continue rising to record high temperatures on Monday. This is a

Grinch storm, also known as the annual Solstice Soaker in the

office, that will likely wipe out all remaining snow in the

forecast area. We have issued a Flood Watch that corresponds to

our highest precip totals in the upslope portions of Piscataquis

County and southern Penobscot County. In these locations, we

expect 2 to 3 inches of rain now. Most of the forecast area

remains in a Slight Risk per the latest WPC ERO.

Expect the strongest lift...and heaviest precip...to move

through the area late Monday morning through the afternoon. This

will be in conjuction with the arrival of the RRQ of a powerful

H3 jet. By mid to late Monday afternoon, urban and small stream

flooding will become more likely in response to the heavier

rain. Streams are still running high from last week`s event. Response

from rivers will follow Tuesday night and Wednesday as

indicated in NERFC projections.

The low level jet continues to be progged around 100 kt at 850mb

and up to 100 kt in some guidance along the coast. Unlike last

Monday`s storm where only the coast saw temperatures in the 50s

and some mixing, this storm will feature highs in the mid 50s

for the entire area and sufficient mixing to generate high winds

for the entire forecast area. We have highlighted the areas with

the highest expected winds in a new High Wind Watch for Monday,

but expect that headlines will be needed for the entire forecast

area as we draw closer to the event. We are already specifying

gusts over 50 mph for most zones. As we previously noted, this

event ticks all the boxes on local studies on high wind events

with widespread power outages. The max winds will be Monday

afternoon across the entire forecast area and slowly diminish

Monday evening.

Temperatures will remain very mild Monday night into Tuesday

with readings remaining in the 40s. The high winds and rain

move out of the area later Monday evening. The weak cold front

that arrives later Tuesday will feature nominal cooling and the

risk of rapid freezing of residual moisture looks very limited.

&&

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

After a very eventful start to the week, the remainder of the

week looks very benign. There is still a chance of light rain

showers transitioning to snow showers Tuesday night as a weak

surface low lifts north from the Atlantic in association with

the filling upper trough. Odds of any accumulating snow have

diminished across the area. Temperatures will remain seasonably

mild with little or no precip expected.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...

NEAR TERM: VFR conditions overnight with light and variable

winds, becoming light S after midnight.

VFR conditons expected Sunday morning, then ceilings lowering

to MVFR during the afternoon, and then IFR toward sunset at all

the terminals. SE to S wind 5 to 15 kts. Low Level Wind Shear

begins to impact the terminals during Sunday afternoon.

SHORT TERM:

Sunday night...IFR tempo LIFR due to cigs and vis in

rain/drizzle/fog. LLWS expected.  South winds 15 to 25 kt.

Monday...IFR tempo LIFR due to cigs and vis in heavy rain.

Very hazardous LLWS with winds over 80 kt likely between FL010

and FL020.  South winds 25 to 50 kt.

Monday night...IFR due to cigs and vis in rain. LLWS continues

in the evening. South winds 20 to 40 kt, decreasing after

midnight.

Tuesday...IFR due to cigs in the morning, improving to MVFR in

the afternoon.  Light west winds.

Tuesday night...IFR due to cigs, rain and fog. Possible

reductions to vis in snow north of GNR and HUL.

Wednesday and Thursday...Prevailing VFR with tempo MVFR cigs

north of GNR and HUL. Light NW winds on Wednesday, becoming

north at 10 to 15 kt on Thursday.

&&

.MARINE...

NEAR TERM: Winds and seas will remain below SCA conditions

tonight. By Sunday morning, winds will increase to SCA levels

and continue throughout the day. Seas 1-4 ft.

SHORT TERM: The Storm Watch continues to look solid with winds

exceeding 60 kt and seas building to over 25 feet offshore.

Winds will decrease fairly quickly Monday night, but seas will

remain elevated throughout the week. Winds will increase again

Wednesday through late week with a possible gale Wednesday night

into Friday. Bottom line is that an advisory or warning will

likely be in place all week.

&&

.HYDROLOGY...

Heavy rains later Sunday night through Monday raises the threat

of another round of urban and small stream flooding issues. Two

to three inches of rainfall may fall during the period in

upslope portions of Piscataquis and Penobscot counties. While

little snowmelt will contribute to this round, partially frozen

ground will still cause rapid runoff, especially in areas with

more complex terrain. At this point, river ice does not look

like a serious threat to produce any jams. Nonetheless,

confidence is the threat is high enough to issue a Flood Watch

for much of Piscataquis County and southern Penobscot County.

The watch may need to be expanded as the event draws closer.

While faster response rivers such as the Piscataquis are

expected to rise rapidly quickly Monday and Monday night, main

stem rivers such as the Penobscot River may also respond by

Tuesday.

&&

.TIDES/COASTAL FLOODING...

Confidence has increased in coastal flooding and wave runup

issues on Monday at the high tide near 245pm. While not a

particularly high astronomical tide, maximum storm surge

corresponds with the high tide. Surge is now expected to be

over 2 feet with potential to be close to 3 feet. Combined with seas

over 20 ft, minor coastal flooding and wave runup issues are

increasingly likely. At this time, the combined tide and surge

looks sufficient to cause minor issues on the Deer Isle Causeway

and in Machias. With the strong southerly push, will also have

to look for a 3 to 4 foot surge up the Penobscot River to Bangor

at high tide. The magnitude of the waves and the total water

level at high tide brings strong potential for significant splashover

on coastal roads such as Seawall Road and along the Schoodic

Peninsula. A Coastal Flood Watch will need careful consideration

as the event draws closer.

&&

.CLIMATE...

Record high temperatures are possible on Monday Dec 18th.

The current forecast high at Caribou is 54F. The record high is

54F in 2000.

The current forecast high at Bangor is 57F. The record high is

53F in 2000.

Record warm low temperatures are also possible on Monday at

these locations.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...

ME...Flood Watch from late Sunday night through Tuesday morning for

     MEZ010-015-031.

     High Wind Watch from late Sunday night through late Monday

     night for MEZ015>017-029-030.

MARINE...Storm Watch from Monday morning through late Monday night for

     ANZ050>052.

&&

$$

Near Term...TWD/LaFlash

Short Term...MCW

Long Term...MCW

Aviation...TWD/LaFlash/MCW

Marine...TWD/LaFlash/MCW

Hydrology...

Tides/Coastal Flooding...

Climate...

Coastal Hazard Message

National Weather Service Gray ME

1020 PM EST Sat Dec 16 2023

MEZ023-NHZ014-171130-

/O.CON.KGYX.CF.A.0003.231218T1900Z-231219T0000Z/

Coastal York-Coastal Rockingham-

1020 PM EST Sat Dec 16 2023

...COASTAL FLOOD WATCH REMAINS IN EFFECT FROM MONDAY AFTERNOON

THROUGH MONDAY EVENING...

* WHAT...Minor coastal flooding and splash-over possible.

* WHERE...In Maine, Coastal York County. In New Hampshire,

  Coastal Rockingham County.

* WHEN...From Monday afternoon through Monday evening.

* IMPACTS...Numerous roads may be closed. Low lying property

  including homes, businesses, and some critical infrastructure

  may be inundated. Some shoreline erosion may occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If travel is required, allow extra time as some roads may be

closed. Do not drive around barricades or through water of

unknown depth. Take the necessary actions to protect flood-prone

property.

&&

Time of high total tides are approximate to the nearest hour.

Seavey Island / Portsmouth NH

MLLW Categories - Minor 11.5 ft, Moderate 12.5 ft, Major 13.5 ft

MHHW Categories - Minor 2.7 ft, Moderate 3.7 ft, Major 4.7 ft

             Total      Total    Departure

 Day/Time    Tide       Tide     from Norm   Waves    Flood

            ft MLLW    ft MHHW       ft       ft      Impact

 --------  ---------  ---------  ---------  -------  --------

 17/02 AM     8.4       -0.4        0.4        2       None

 17/02 PM     9.4        0.6        0.2       2-3      None

 18/03 AM     8.6       -0.2        0.5       5-7      None

 18/03 PM    10.6        1.8        1.7      12-15     None

 19/04 AM     7.7       -1.1       -0.5      10-11     None

 19/04 PM     8.4       -0.4       -0.2        9       None

Hampton Harbor NH

MLLW Categories - Minor 11.0 ft, Moderate 12.0 ft, Major 13.0 ft

MHHW Categories - Minor 1.5 ft, Moderate 2.5 ft, Major 3.5 ft

             Total      Total    Departure

 Day/Time    Tide       Tide     from Norm   Waves    Flood

            ft MLLW    ft MHHW       ft       ft      Impact

 --------  ---------  ---------  ---------  -------  --------

 17/02 AM     8.7       -0.8        0.4        1       None

 17/02 PM     9.6        0.1        0.2        1       None

 18/03 AM     8.8       -0.7        0.5        1       None

 18/03 PM    10.7        1.2        1.6        1       None

 19/04 AM     7.9       -1.6       -0.5        1       None

 19/04 PM     8.6       -0.9       -0.2        1       None

&&

$$

Flood Watch

National Weather Service Gray ME

942 PM EST Sat Dec 16 2023

.A potent storm system will bring widespread moderate to heavy

rainfall to western Maine and New Hampshire Sunday night into

Monday. Rainfall amounts of between 1-3 inches are likely with

localized amounts in excess of 4 inches possible across southern

facing mountain slopes. This will combine with snow melt and ground

frost across the north and mountains to exacerbate the flooding

threat. Minor to moderate flooding is possible along main stem

rivers as well as streams, many of which are still running high from

last week`s rainfall. Widespread low-land and poor drainage flooding

is also possible.

MEZ007>009-012>014-020>022-033-NHZ002>007-011-171445-

/O.CON.KGYX.FA.A.0025.231218T1000Z-231219T0600Z/

/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

Northern Oxford-Northern Franklin-Central Somerset-Southern

Oxford-Southern Franklin-Southern Somerset-Androscoggin-Kennebec-

Interior Waldo-Interior Cumberland Highlands-Southern Coos-

Northern Grafton-Northern Carroll-Southern Grafton-Southern

Carroll-Sullivan-Cheshire-

Including the cities of Coburn Gore, Ossipee, Marlow, New Sharon,

Roxbury, Milton, Waldo, Livermore Falls, Oquossoc, Avon,

Montville, Rumney, Grantham, Newry, Keene, Milan, Bryant Pond,

Littleton, Rangeley, Wakefield, Phillips, Tuftonboro, Croydon,

Norway, Lewiston, York Pond, Harrison, New Portland, Seboomook,

Goshen, New Vineyard, Kingfield, Thornton, Lebanon, Brookfield,

Upton, Middle Dam, Embden, Vassalboro, Charlestown, North Conway,

Claremont, Farmington, Waterville, Lincoln, South Arm, Brassua,

Lancaster, Jackson, Chesterville, Pittston Farm, Davis, Knox,

Waterville Valley, Palmyra, Moosehead, Oxford, Bridgewater,

Bethel, Windsor, Brooks, Ashland, Wales, Hanover, Palermo,

Bethlehem, Madison, Conway, Albany, Minot, Morrill,

Moultonborough, Temple, Augusta, Winterport, Jaffrey, Surry,

Sabattus, Crawford Notch, Jay, Liberty, Cornish, Bridgton,

Turner, Bingham, Cornville, Skowhegan, Naples, Locke Mills,

Byron, Wilsons Mills, Pittsfield, Gilsum, Woodstock, Wilton,

Sugar Hill, Greene, Holderness, Wolfeboro, Fryeburg, China,

Athens, Sidney, Ellsworth, Andover, Rumford, Chatham, Plymouth,

Newport, Dummer, Auburn, Sullivan, Berlin, Jackman, Long Pond,

Unity, Lyme, and Lempster

942 PM EST Sat Dec 16 2023

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

MONDAY NIGHT...

* WHAT...Flooding caused by excessive rainfall continues to be

  possible.

* WHERE...Portions of Maine, including the following areas,

  Androscoggin, Central Somerset, Interior Cumberland Highlands,

  Interior Waldo, Kennebec, Northern Franklin, Northern Oxford,

  Southern Franklin, Southern Oxford and Southern Somerset and New

  Hampshire, including the following areas, Cheshire, Northern

  Carroll, Northern Grafton, Southern Carroll, Southern Coos,

  Southern Grafton and Sullivan.

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

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

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

  Area creeks and streams are running high and could flood with more

  heavy rain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor the latest forecast and be alert for possible

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

prepared to take action should flooding develop.

&&

$$

Baron

URGENT - WEATHER MESSAGE

National Weather Service Caribou ME

936 PM EST Sat Dec 16 2023

MEZ015>017-029-030-171045-

/O.CON.KCAR.HW.A.0004.231218T0600Z-231219T0600Z/

Southern Penobscot-Interior Hancock-Central Washington-

Coastal Hancock-Coastal Washington-

Including the cities of Bangor, Brewer, Orono, Old Town, Amherst,

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

Wesley, Princeton, Ellsworth, Bar Harbor, Bucksport, Orland,

Castine, Eastport, Perry, Machias, and Cherryfield

936 PM EST Sat Dec 16 2023

...HIGH WIND WATCH REMAINS IN EFFECT FROM LATE SUNDAY NIGHT

THROUGH LATE MONDAY NIGHT...

* WHAT...Southeast winds 35 to 45 mph with gusts up to 65 mph

  possible. The highest gusts are expected near the coast.

* WHERE...Southern Penobscot, Interior Hancock, Central

  Washington, Coastal Hancock and Coastal Washington Counties.

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

* IMPACTS...Damaging winds could blow down trees and power

  lines. Widespread power outages are possible. Travel could be

  difficult, especially for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this

situation. Fasten loose objects or shelter objects in a safe

location prior to the onset of winds.

&&

$$

Hazardous Weather Outlook

National Weather Service Caribou ME

255 PM EST Sat Dec 16 2023

MEZ001>006-011-032-172000-

Northwest Aroostook-Northeast Aroostook-Northern Somerset-

Northern Piscataquis-Northern Penobscot-Southeast Aroostook-

Central Penobscot-Northern Washington-

255 PM EST Sat Dec 16 2023

This Hazardous Weather Outlook is for Central Highlands Maine, Far

Eastern Maine, Far Northern Maine, North Woods Maine and Penobscot

Valley Maine.

.DAY ONE...This afternoon and tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Intense low pressure tracking through western New England into

Quebec has the potential to bring very strong southerly winds in

excess of 50 mph across the region on Monday. Moderate to heavy

rainfall is also expected Sunday night into Monday night. Urban and

small stream flooding is possible.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$