textproduct: Caribou

SYNOPSIS

Low pressure lifts north of the region tonight into Tuesday, remaining north of the region Wednesday through Friday. Disturbances rotate throughout the state into the weekend.

NEAR TERM /THROUGH TUESDAY NIGHT/

3:08PM UPDATE...Have allowed the Winter Weather Advisory to expire in S. Piscataquis, Central Penobscot and Northern Washington counties where air temperatures are above 32F in the 33-35F range and rain falling. Cannot rule out cold surfaces to be a little icy thanks to the frozen ground. However, with air temperature above freezing expecting the roads to improve. Winter Headlines north of there remain as is for now.

Previous Discussion...

Key Message... 1) Winter storm not panning out as expected but still bringing slippery conditions to the most of the area this evening 2) Gusty west winds will bring falling temps to the area Tuesday 3) Wind chills approach minus 20 on Tuesday night

Key Message 1... Regional radars showing steady precip over srn and eastern sections of the area as of 1830z. Precip runs the gamut from rain along the immediate coast to fzra and sleet over central sections to light snow over the north. Most of the ptypes worked out as expected with snow at onset, mixing with sleet and freezing ran before switching over to all rain as the boundary layer warmed. As of right now the winter weather advisory for the Bangor Region, Upper Penobscot Valley and interior Downeast has been cancelled as low level jet has drawn in warm air to these areas.

Further north the storm did not pan out as expected because of the dry air at onset, lesser qpf amounts than expected and the dry slot that is rapidly advancing twd the area from the west. Have downgraded nrn zones from Winter Storm Warning to Winter Weather Advisory, mainly for the threat for a glaze of ice from freezing rain as warm nose continues to advance north.

With triple point developing later this evening pulling cold air into the north, precip will be able to switch over to snow. Given the forcing associated with the front cannot rule out a quick 1-3 inches falling through late evening over northern Aroostook and into the North Woods.

Key Message 2... Occlusion moves through late in the evening with cold air following by morning. Pressure gradient tightens up as deepening low lifts north into Quebec and retrogrades tomorrow due to blocking pattern over the North Atlantic. Mixing up to 925mb tomorrow should be able to bring gusts down to the surface between 25-35 mph.

At the same time caa occurs with H8 temps dropping 10C throughout the day tomorrow. Air temps start off in the teens over the North Woods and in the lwr 20s east and fall some 10-15 degrees by evening.

Key Message 3... With west winds still remaining mixed overnight and temps in the single digits, wind chill temps will approach -20F twd daybreak. This will be most common over higher elevations acrs the north.

SHORT TERM /WEDNESDAY THROUGH THURSDAY/

Key Messages... *Light Snow Downeast for the Start of 2026 *Ringing in the New Year with Arctic Air

Key Message 1... Maine remains under the influence of long wave trofing thanks to the -NAO blocking in the North Atlantic near Greenland. Deep 500mb low remains locked over Quebec with shortwave energy at 500mb pivoting around the long wave. The next wave pivots around Wednesday night into Thursday to ring in 2026 with a period of Light Snow and snow showers. Wednesday is partly sunny and dry and cold with highs around 10F north and 22-26F for Bangor to Downeast coast. So, plenty cold for precipitation to be snow across the entire CWA Wednesday Night. Expect light snow to develop late evening to midnight along the Downeast coast and perhaps extending to the Route 9 corridor. There remains some uncertainty on the extent of inland push of light snowfall. Opted to go with chance to likely POPs pretty consistent with NBM into Thursday AM. Overall probabilities of >1 inch have increased to 60-70 percent Downeast and 40-50 percent for interior Downeast back west and north to I-95. There remains differences between ECMWF, GFS and Canadian operational and ensemble members on the weak low pressure placement but with probabilities increasing expecting decent likelihood of light accumulating snow. Now when we look at the far Downeast Washington county coast probability of >2 inch significantly have come up to >50 percent over the last 2 runs of operational/ensemble members. Given this trend have raised snow totals in far eastern Washington County from Machias to Eastport to advisory level snow totals. Modeled soundings show good agreement of 18-20:1 ratio fluffy snow falling so with that have an area of 2-5 inches from roughly Machias eastward to Eastport and north and west of there generally a Dusting up to 2.5 inches. Most areas north and west of I-95 expecting just snow showers with perhaps a dusting.

Key Message 2... New Years Eve and New Years Day looking to be cold continuing the trend of 10-15 degrees below normal during the day and 5-10 degrees below normal at night. Latest running of the NOAA Hysplit Backward Trajectory model shows the airmass arriving for NYE/NYD will be originating from far northern Northwest Territories Canada near Alaska. Arctic air is moderating across Canada slightly but still will bring cold air to our region. Despite the light SW breeze Wednesday high temperatures will struggle to reach 10-14F across the North and 20-25F for southern portions of the CWA with 30F at the shoreline. Wind chills -5F to 0F across the North and Moosehead Region during the day and 5-10F for the Bangor Region and coast. Wednesday night will be cold but not as cold as it could be thanks to significant cloud cover and potential for precipitation. Lows around 0F across the North, 5-10F for central zones and 12-18F Downeast with the snow. New Years Day remains cold, partly sunny skies and light winds. Highs single digits above zero to around 12F in the north and Moosehead region. 15-20F for Bangor Region to Danforth/Topsfield area and 20-25F Downeast coast.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/

Key Messages... *Cold temperatures through the weekend *Potential for system late next week

Key Message 1... Cold temperatures linger Thursday night through the weekend, as low pressure to the north parks in central Quebec, continuing to push cold air masses towards Maine. Daytime highs generally staying in the single digits to low teens in the north, and the teens to 20s Downeast. Overnight lows below zero in the north, and generally in the low single digits to teens Downeast. Wind chills in the -20F to -10F ranges overnight could be possible late this week in the north. Strong signals within the global ensembles that Friday AM, Sunday AM and Monday AM may feature air temperatures dropping to -20F to -15F across much of the cold spots of the North Woods and rest of the Crown.

Key Message 2... Next chance for significant precipitation will be late weekend into early next week, as a primarily low in Canada potentially merges with another low, bringing a chance for another shortwave to swing through eastern Maine. The ECMWF and GFS have begun to come into agreement that a shortwave could go over Maine, but the exact location and movement of the system is still uncertain. GFS still indicates a little more moisture than the ECMWF. Kept with the idea that NBM POPs around slight chance to chance, until models get in better agreement. Overall GFS ensembles show a sign of NAO blocking to return to -0.5SD or less (near neutral) as PNA nears neutral and within weak La Nina typically brews a significant storm system but models struggle with NAO blocking breaking down. Will continue to monitor the probabilities of a storm system in this late weekend to early next week timeframe.

AVIATION /20Z MONDAY THROUGH SATURDAY/

NEAR TERM: IFR over all terminals tonight. Northern terminals diminish from MVFR early down below 1kft after 20z. Downeast terminals will mainly see rain through late this evening before improving to MVFR and eventually VFR.

Aroostook terminals will see a wintry mix throughout the early evening, before switching back to snow around 05z. Vsbys will vary from low end MVFR and IFR. Improvement at Aroostook terminals will begin after front moves through, becoming VFR after 12z Tuesday. LLWS expected early on ahead of fropa.

Cannot rule out ocnl MVFR during the day Tuesday over nrn Aroostook terminals. West winds 10-15kts will gust to 25-30kts in the afternoon.

SHORT TERM: Wednesday...VFR/MVFR with a slight chance of snow showers north. VFR Downeast. SW winds 10 to 15 knots with gusts up to 20 to 25 knots. Winds shift to the S by evening.

Wednesday night through Thursday...VFR/MVFR, occasional IFR. A chance of snow showers north, light snow at BGR and BHB. S/SW winds 5 to 10 knots, becoming W/NW Thursday.

Thursday night-Friday...Mainly VFR. Slight chance of light snow at KBHB. Light W winds at 5-10kts.

Saturday...VFR south, VFR or MVFR cigs north. W winds 5-10kt.

MARINE

NEAR TERM: South winds sporadically hit gale force this evening before becoming WSW and increasing to 40-45kts overnight. Gale force gust drop off over the intracoastals after midnight Tuesday night but maintain gale force over the outer waters through the end of the period. Seas increase to 7 to 12 feet Tuesday afternoon before decreasing to 4 to 10 feet by the end of the period.

SHORT TERM: SCA level winds/seas for Wednesday will fall below SCA criteria Wednesday night. Thursday afternoon wind gusts back up to 25kt and seas 4-6ft on the coastal waters may require another SCA. Winds/seas look to remain below SCA for Friday into the weekend. Uncertainty for late weekend into next week with any potential storm system developing across the region.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Winter Weather Advisory until 3 AM EST Tuesday for MEZ001-002. Winter Weather Advisory until 1 AM EST Tuesday for MEZ003>006- 010. MARINE...Gale Warning until 7 AM EST Wednesday for ANZ050-051. Gale Warning from 1 AM Tuesday to 1 AM EST Wednesday for ANZ052.