textproduct: Caribou

WHAT HAS CHANGED

-Reduced storm total snow forecast based on slight eastward QPF and storm track trends. -System for Thursday night appearing more likely to track to our south and miss us.

KEY MESSAGES

1) The significant winter storm will continue into tonight for Bangor and the Downeast region with heavy, blowing snow that will continue to severely limit visibility and quickly accumulate snow near the coast.

2) Weak system on Wednesday will bring a few inches of snow, impacting the Wednesday afternoon commute.

3) Heavy convective snow showers over the north Thursday, likely to reduce visibility.

4) Small possibility of a winter storm Thursday night, though it is more likely to pass to our south.

5) Much colder weather likely Sunday and Monday.

DISCUSSION

KEY MESSAGE 1... The significant winter storm will continue into tonight for Bangor and the Downeast region with heavy, blowing snow that will continue to severely limit visibility and quickly accumulate snow near the coast.

KEY MESSAGE 1 DESCRIPTION... As of 1 PM, the low pressure system is centered east of Massachusetts with min pressure around 970 mb. The rapid decrease in pressure has slowed some over the last 3 hours, but the pressure gradient north and west of the low remains tight. Wind gusts up through the Downeast coast have sat around 35 mph for the past several hours, and gusts will remain 30 to 40 mph into the evening hours. Meanwhile, heavy snowfall has quickly dropped visibility up into the Bangor and Interior Downeast regions, with many areas seeing visibility drop from unlimited to one quarter to one half mile in less than half an hour. These conditions will last into the evening hours as well before the heaviest snowfall finally shifts eastward, leading to an improvement in visibility overnight. Winds will remain gusty through the night, however, so brief periods of very low visibility will remain possible until winds begin to decrease more into Tuesday morning.

As for the Bangor region in particular, this zone remains on the edge of the heaviest snowfall. There is a chance (around 60 percent) that visibility will fall to a quarter mile or less, however this could depend greatly on slight shifts of the deformation zone of just a few miles.

For the northern half of the forecast area, less snowfall is expected, with only a few inches of storm total snow expected. Winds will also be more manageable across the north, with peak winds around 25 to 30 mph lingering into the overnight hours. These winds, combined with falling snow, will lead to patchy blowing snow though, and this could limit visibility in the north as well, particularly around any open fields.

Snow will quickly exit to the east overnight tonight, though a few snow showers may linger across the north through the day on Tuesday. Winds will gradually decrease through Tuesday, though gusts 25 to 30 mph remain likely through the first half of the day, and patchy blowing snow may continue behind the storm before winds settle.

KEY MESSAGE 2... Weak system on Wednesday will bring a few inches of snow, impacting the Wednesday afternoon commute.

KEY MESSAGE 2 DESCRIPTION... A weak system moving in from the west will bring light snow to the whole area, perhaps mixed with rain near the coast. We are pretty confident in a timeframe of Wednesday afternoon/evening. We aren't quite as confident in snow totals, but regardless, it's not looking like a warning-level event. Most likely we are looking at 1 to 3 inches, though we can't rule out a few spots approaching 4 inches. Not much wind expected with the storm. The biggest impact will be travel late Wednesday, such as around the afternoon commute. Snow should taper off for the most part by late Wednesday night.

KEY MESSAGE 3... Heavy convective snow showers over the north Thursday, likely to reduce visibility.

KEY MESSAGE 3 DESCRIPTION... There should be enough instability during the day Thursday in westerly flow that there could be a few heavier snow showers, primarily in Northern Maine. Went with chance of snow showers, which was much more than the NBM was going. Model soundings show pretty good instability and some CAPE in the north. Winds not quite enough for snow squalls, but there will still be enough of a breeze with the snow showers to briefly impact travel in the north.

KEY MESSAGE 4... Small possibility of a winter storm Thursday night, though it is more likely to pass to our south.

KEY MESSAGE 4 DESCRIPTION... Significant trend in models/ensembles to keep the Thursday night system to our south. There are still a few solutions that bring heavier precipitation this far north, but as of now, about three quarters of solutions keep impactful snow south of our area. If the system does make it this far north, it could produce fairly heavy snow, but as of now, that is not the most likely solution.

KEY MESSAGE 5... Much colder weather likely Sunday and Monday.

KEY MESSAGE 5 DESCRIPTION... Pretty high confidence in an Arctic front moving through sometime late Saturday or Sunday. There is uncertainty on the timing of the front, but reasonable confidence in a significant cooling trend late in the weekend and into Monday after high temperatures around 40 on Saturday. Wind chills early Monday should be well below zero, and could be to 20 below or colder in the north. We also could see some smaller snow accumulations with and behind the Arctic front when it does move through, but there is fairly low confidence in snow totals.

AVIATION /18Z MONDAY THROUGH SATURDAY/

Tonight: -Downeast terminals: IFR/LIFR conditions will continue into this evening, with heavy snowfall and blowing snow. BHB/EPO likely to see sustained vis less than one quarter mile and gusts 35 to 40 kts, while BGR could see intermittent one quarter mile vis with gusts 30 to 35 kts. NNE winds will gradually shift NW as the storm system shifts eastward. Winds 15 to 25 kts gusting 30 to 40 kts. Winds will begin to improve after around 03z tonight, with NW winds falling to 10 to 15 kts and gusts 20 to 30 kts.

-Northern terminals: VFR/MVFR conditions will fall to MVFR/IFR as light snow moves into the area this evening. NNE winds will gradually shift NW as the storm shifts eastward. Winds 10 to 15 kts gusting 20 to 30 kts, beginning to decrease some through the second half of the night.

Tuesday: Conditions will continue to gradually improve, returning to MVFR/VFR across all terminals through the day. Gusty NW winds will continue 10 to 15 kts with gusts 20 to 25 kts, and will begin to diminish late in the day Tuesday.

Tuesday night: VFR. Light winds.

Wednesday-Wednesday night: MVFR/IFR moving during the afternoon in snow. May see rain/snow mix at BHB during the day. SSE 5-10kts, becoming SW 5kts late Wednesday night.

Thursday: VFR BGR/BHB, but intermittent VFR and MVFR/IFR in locally heavy snow showers Aroostook terminals. W 10kts, gusts to 20kts.

Thursday night-Friday: VFR most likely, but a 30 percent chance of MVFR/IFR with snow if a system that appears to be tracking to our south comes further north than anticipated. Variable wind 10 kts or less.

Friday night-Saturday: Generally VFR, with MVFR possible Aroostook terminals. S 5-15kts.

MARINE

Storm force will continue into the night tonight with gusts 50 to 60 kts and seas 13 to 17 ft, along with heavy snow dropping visibility below one quarter mile. As winds shift NW and temperatures drop overnight, colder air will rush in leading to light freezing spray. Snow will move out of the area overnight. Winds will decrease into the day on Tuesday, falling back towards gale strength early Tuesday morning and then falling below 30 kts through the day on Tuesday. Seas will diminish towards 5 to 8 ft at this point.

Seas likely to be elevated around SCA levels over the outer waters Tuesday evening, before dropping below overnight. Southerly winds increase to SCA levels Wednesday afternoon into Thursday morning ahead of weak coastal low. Seas increase above 5ft Wednesday evening through Thursday evening in southerly swell. A stronger wave system moves in Friday night with seas climbing to around 8 ft over the outer waters with 10 sec periods. Small craft southerly winds are also likely Friday night and Saturday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Winter Weather Advisory until 7 AM EST Tuesday for MEZ005-006- 011-031. Winter Storm Warning until 7 AM EST Tuesday for MEZ015-032. Blizzard Warning until 7 AM EST Tuesday for MEZ016-017-029-030. MARINE...Storm Warning until 4 AM EST Tuesday for ANZ050-051. Storm Warning until 10 PM EST this evening for ANZ052.