textproduct: Caribou

SYNOPSIS

Low pressure approaches from the west today. A warm front crosses early Sunday evening, followed by a cold front late Sunday night. A secondary cold front crosses the area on Monday, followed by high pressure building in Monday night. A coastal low approaches from the southwest on Tuesday, passes offshore Tuesday night, then exists into the southern Canadian Maritimes on Wednesday. A cold front then moves in Thursday.

NEAR TERM /THROUGH MONDAY/

Key Messages 1) Light snow in Northern Maine this afternoon and evening 2) Gusty south winds coastal Downeast this afternoon and evening 3) Snow squalls possible Monday morning Northern Maine

Key Message 1... Warm front moving through from SW to NE brings light precipitation this afternoon and evening. While models are in good agreement, there are a few uncertain items we'll need to watch. One is the onset time. Our best shot at start time ranges from late morning in the west around Moosehead Lake, to around 1-2pm toward the New Brunswick border. There are a few hours of uncertainty in this, depending on how quickly the dry layer a few thousand feet off the ground can saturate. Either way, precipitation rates aren't that impressive today, with only around a tenth of an inch of precip by early evening. That said, with it being a heavier travel day and with the threat of wintry precip, it's important to get it right. Which brings us to the other slightly uncertain item...precipitation type. Most of the precip in the far north will be snow except perhaps at the very end of the evening mid to late evening. However, Bangor and toward the coast could start as rain or snow. If it does start as snow Downeast, think it'll change to rain pretty fast, fast enough to keep accumulations less than a quarter inch. While it starts as snow north of Bangor, we will see the rain snow line march northward through the afternoon and into the early evening, making it to Millinocket around 6pm (plus or minus 1-2 hours), to Houlton around 7pm, and it may briefly change with or mix with rain up toward Presque Isle, Caribou, and Madawaska mid-late evening before the precip ends. This is looking like a minor snow event for the north overall, with just 1-3 inches expected. The general trend in thinking has been for slightly lesser accumulations. No freezing rain or sleet expected.

Key Message 2... Pretty potent low level southerly jet this afternoon and evening mainly east of the highlands, from Aroostook County south along I-95 and to the coast. Gusts to 25 mph are possible inland, but the coast could see a few gusts to 40 mph which may be enough for an isolated power outage. Opted not to issue a wind advisory as in general gusts look to be just below criteria and impacts look minimal. Winds slacken toward midnight as the low level jet shifts east of the area and a weak cold front moves through with surface winds switching to the southwest.

Key Message 3... With the secondary cold front moving into Northern Maine Monday morning, a bit concerned there could be some snow squalls mainly with the front itself, but possibly briefly behind the front as well. Instability is there, but isn't the best for a potent snowfall rates with the potential squalls. That said, most CAMs do have a line of showers along the front, and think that winds could gust to 30 mph with the snow showers as the front passes. Temps should be around freezing just ahead of the front and then drop into the upper 20s, which could be a setup for a quick flash freeze for places that do get the snow shower. The highest risk for snow squalls is north of Millinocket and Houlton. Snow accumulation from any showers/squalls in the north should be a half inch or less.

SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/

Key Messages -High uncertainty remains with the track of the system Tuesday through Wednesday -Cold temps Monday night and Tuesday night

High pressure should remain for Monday night, which will keep a mainly clear sky at the beginning of Monday night. With calm winds and a fresh snow pack, temps should drop into the single digits in the north and teens in the south.

By Tuesday morning, the low pressure system is expected to track towards the region. Unfortunately, there is still high uncertainty with the track of the storm. As of this update, the ensemble probabilities give a wide swath of snow totals mainly concentrated in the Central Highlands and south. The NBM prob of greater than 6 inches snow amount shows low-moderate confidence (30-40 percent). This will all depend on if the ensembles southerly track is correct or the deterministic northerly track is correct.

By Tuesday night, winds are expected to increase as the system begins to exit the region. Though clouds should be exiting to the E throughout the night, it should remain long enough to keep temps in the teens with single digits in the North Woods. With the breezy winds and cold temps, there is a concern of wind chills reaching the single digits.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

-A possibility of snow squalls on Thursday, impacting daytime travel in the north with low visibility and gusty winds.

The next system to move for the region should come in the form of a cold front on Thursday. Snow amounts should be fairly low, however, upper air models soundings indicate instability along the frontal boundary. There is concern for snow squalls with the front in the afternoon causing issues for the Thursday commute. After the front passes, very cold arctic air should move into the region, causing Thursday night temps to drop into the single digits below zero in the north and single digits above zero in the south. Gust winds behind the front could drop wind chill temps into the teens below zero or even colder. Closer models runs will give a better idea of cold temps and snow squall potential.

AVIATION /06Z SUNDAY THROUGH THURSDAY/

NEAR TERM: Generally VFR this morning, but as precipitation develops today, expect MVFR to take over, with likely IFR this evening for most sites. Precipitation will be mostly snow from HUL north, with perhaps a brief changeover to rain as it ends after 0z. Precip may start as snow BHB/BGR, but quickly change to rain. South winds increase and will be quite gusty BGR and especially BHB, with gusts over 25 kts possible this evening. LLWS at all TAF sites late afternoon into the evening, abating overnight. Also expect IFR to generally lift to VFR late tonight, except perhaps remaining MVFR north.

Monday should be mostly VFR HUL, BGR, and BHB, but MVFR at times PQI, CAR, FVE. Snow squalls possible PQI/CAR/FVE as well mainly between 12-16z. NW winds increasing to around 15 gusting 25 kts.

SHORT TERM: Monday Night...VFR with light wind.

Tuesday -Tuesday Night...MVFR/IFR in snow, especially south. Confidence is still low in this event. N/NE wind 10-15 kts.

Wednesday-Wednesday night...Probably VFR. NW winds 10-20 kts becoming SW 10 kts.

Thursday...MVFR tempo IFR/LIFR in snow showers. Winds SW 10 kts becoming W 10 to 20 kts. Possible gusts 25 to 30 kts.

MARINE

NEAR TERM: Very high confidence in southerly gales late today into this evening. Winds switch to westerly late tonight and remain W/NW into Monday. As the switch happens, winds ease a bit, and will be borderline gale/small craft. Seas build close to 11 ft late tonight then ease to around 6 ft later Monday.

SHORT TERM: Much improved winds/seas Monday night/early Tuesday. Moderate likelihood of gales late Tuesday night/early Wednesday. Seas could also build back up to around 10 ft, but most likely 8 feet, with the highest seas further offshore.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Gale Warning from 4 PM this afternoon to 4 PM EST Monday for ANZ050>052.