textproduct: Caribou

SYNOPSIS

A weather disturbance will cross the area tonight. Low pressure will approach on Wednesday...cross the area Wednesday night...then continue into Eastern Canada on Thursday. High pressure will build south of the region Friday into Saturday. A new low may approach on Sunday.

NEAR TERM /THROUGH WEDNESDAY NIGHT/

A weak ripple in the upper flow will cross the area tonight. Enough moisture is expected to pull north from this system to bring an inch or two of light snow to Coastal Downeast areas tonight. However, moisture will likely not make it north to produce anything more than a chance for patchy light snow. The disturbance will quickly continue on into the Maritimes early Wednesday morning.

Our focus on Wednesday turns to a more substantial low approaching from the Great supported by a trough sliding through the Midwest. Snow ahead of this system, with rain along the coast, will push into Downeast areas around midday and reach the north around mid afternoon. The rain/snow line will migrate north changing precipitation over to all rain for the rest of Downeast and the lower Penobscot Valley by the end of the day with snow continuing across the north. There will be a slight chance for some light patchy freezing rain in the transition zone. There is some uncertainty how for north the change-over to rain will progress, but it could reach just north of Houlton Wednesday evening. This is a fast moving system and snow, with rain Downeast, will begin to taper off by mid evening Wednesday. A light to moderate snowfall of 4 to 6 inches seems likely across Eastern Aroostook and northern Penobscot Counties with around three inches to the west, and little or none Downeast. The greatest uncertainty in amounts may be over Southeastern Aroostook County where a mix or change to rain may limit amounts to around 2 to 4 inches.

Low pressure will lift away to the northeast late Wednesday night as the upper trough approaches from the west. Some divergence aloft and lingering moisture may result in continued snow showers over the north toward Thursday morning. Otherwise, Wednesday night will remain mostly cloudy and milder than recent nights with lows from near 20 north to 30 Downeast.

SHORT TERM /THURSDAY THROUGH FRIDAY/

*Key Messages -Cloudy with Snow Showers Thursday -Cold and Breezy Friday

Discussion... A deep 500mb trof will be pivoting overhead during the day Thursday with scattered snow showers and cloudy skies. Westerly winds increase throughout the day with temperatures barely budging and will fall in the afternoon as cold air advection increases. Highs top out in the mid 30s for the Downeast coast, low 30s for the Bangor region and 20s for the rest of Northern & North-Central Maine. Westerly winds begin to get gusty 15-25mph by sunset in the late afternoon.

Thursday night opted to increase winds with the NBM90th percentile and increased gusts 3-8mph given increased confidence in a deepening low over the Maritime. This will result in an increased pressure gradient than previously seen operational model runs. Winds gusting 20-30mph with isolated higher gusts up to 40mph across the higher terrain near Greenville. Any fluffy 20-25:1 ratio snow that falls will blow around in the open fields of Northern Maine and opted to add patchy blowing snow.

Friday snow showers will come to an end and temperatures start out in the 9-12F range north and 12-16F range south. Wind chills will bottom out in the -9F to 0F range for most locations. Friday westerly winds gusting 20-30mph with temperatures topping out around 20F across the north and mid to upper 20s for central and Downeast regions.

LONG TERM /FRIDAY NIGHT THROUGH MONDAY/

*Key Messages: -Unsettled weather pattern, chance for snow this weekend

Discussion... Low continues to move northeast away from Maine on Friday night. Wind gusts relax through the evening and overnight hours into Saturday AM. Weak ridging builds in Saturday morning, as another low to the west begins to move towards Maine. Generally highs in the 20s and teens, and lows in the teens to single digits. Significant differences with a potent northern stream trof working into the area Sunday into Monday. Increasing jet streak and upper level divergence will give way to surface cyclogenesis. There is a ton of differences in the operational, ensemble members and AI modeling. There is a potential for a coastal storm system but nothing to latch onto right now with numerous operational solutions varying with storm types.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

NEAR TERM: VFR conditions will lower to MVFR around midnight over the south tonight and after midnight across the north late tonight. Conditions may lower to IFR over the south late tonight. MVFR conditions north and IFR to MVFR conditions south Wednesday morning will lower to LIFR conditions across the area Wednesday afternoon into Wednesday night. Conditions may improve to MVFR late Wednesday night.

Winds south around 5 kt tonight, southeast 5 to 10 kt Wednesday, then light and variable across the north and southwest around 5 to 10 kt Downeast Wednesday night.

SHORT TERM: Thursday...IFR improving to MVFR by mid morning in snow showers in the north, and rain showers Downeast. VFR south and MVFR north in the afternoon. W wind 5 to 15 kt. Gusts up to 25 kt.

Thursday night...MVFR north and VFR south. W wind 10 to 15 kt with gusts up to 30kt.

Friday...MVFR north and VFR south. W wind 10 to 15 kt gusting to 30 kt.

Friday night...MVFR north becoming VFR. VFR south. W wind 10-15 kt.

Saturday...MVFR, possibly lowering to IFR at times south. SW wind 5 to 10 kt.

Sunday...VFR/MVFR, potentially lowering to IFR by late day. W-NW 5-15 kt.

MARINE

NEAR TERM: A SCA will be up tonight into Wednesday followed by a gale late Wednesday into Wednesday night. Seas building up to 5 ft tonight, 7 ft Wednesday and 8 ft Wednesday night.

SHORT TERM: SCA winds Thursday increasing back to westerly Gales from Thursday late day into Friday night. Gusts up to 40kt possible. Waves 7-10ft through much of this period. Winds/seas fall below SCA late Friday night into Sunday AM before potentially another set of SCA to Gales by early next week.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Winter Weather Advisory from 3 PM Wednesday to 3 AM EST Thursday for MEZ001>004. Winter Weather Advisory from 1 PM Wednesday to 1 AM EST Thursday for MEZ005-006-010. MARINE...Gale Warning from 1 PM Wednesday to 1 AM EST Thursday for ANZ050-051. Small Craft Advisory from 9 PM this evening to 1 AM EST Thursday for ANZ052.