textproduct: Caribou

WHAT HAS CHANGED

- Expanded the Cold Weather Advisory to include northeast Aroostook and northern Piscataquis Counties, where wind chills as low as 25 below zero are expected.

KEY MESSAGES

1) Unseasonably cold temperatures are expected tonight and early Monday morning with wind chills as low as 30 below zero across far northern Maine. Take extra precautions to protect yourself and pets from exposure to cold.

2) Chance for some snow Downeast Tuesday night into Wednesday, which could impact Wednesday morning commute.

3) Warming temperatures next week lead to potential for some mixed precipitation next week, which could impact Thursday night into Friday morning commute.

DISCUSSION

KEY MESSAGE 1...Unseasonably cold temperatures are expected tonight and early Monday morning with wind chills as low as 30 below zero across far northern Maine. Take extra precautions to protect yourself and pets from exposure to cold.

KEY MESSAGE 1 DESCRIPTION... An Arctic air mass will continue to overspread the area this evening as surface high pressure builds in from the west. 1000-500mb thicknesses will fall below 500dam along with 850mb temperatures in the low to mid negative 20s C. These values are colder than average even for January. The location of the surface high pressure center far to the west over northern NY and VT will prevent most areas from decoupling, but sheltered valleys could see temperatures fall well into the teens below zero to near 20 below. Most other locations are expected to fall to zero to 10 below for the south half of the area and 5 to 15 below across the north. Even the slight 5 to 10 mph breeze forecast will be enough to lower wind chills to at or below the -25F advisory criteria across the north and into the -10s to lower -20s elsewhere. HREF probabilities also indicate potential for advisory criteria wind chills over portions of northern Penobscot, central Piscataquis, and southeast Aroostook Counties, but coverage was not sufficient for an advisory over these zones. Frostbite times on exposed skin will be as little as 10 minutes across open areas of far northern Maine, and usual precautions should be taken to protect people and pets from cold. Temperatures will moderate very quickly Monday morning with plentiful sunshine expected.

KEY MESSAGE 2...Chance for some snow Downeast Tuesday night into Wednesday, which could impact Wednesday morning commute.

KEY MESSAGE 2 DESCRIPTION... Weak low pressure system develops off the coast of Maine Tuesday, sliding along the coastline Tuesday night. Weak cold front associated with this system moves through overnight, providing a little lift and instability for precipitation. Temperatures just below freezing along the coastline, so there is a chance for a rain/snow mix along the immediate coast. Models seem to be trending this storm to go south of Nova- Scotia, so not anticipating much accumulation inland. Could be a few inches along the coast, but totals overall below advisory level. Winds relatively calm at 5 to 10 mph, so little concern about blow/drifting snow. Snow ratios relatively low for this event, so there could be some heavier, wet snow. Temperatures raise into the 40s during the day on Wednesday, and with temperatures quickly falling again behind front, exercise caution on roads that could develop slick spots.

KEY MESSAGE 3...Warming temperatures next week lead to potential for some mixed precipitation next week, which could impact Thursday night into Friday morning commute.

KEY MESSAGE 3 DESCRIPTION... Upper-level shortwave kink, alongside warm air advection during the week, leads to a potential for mixed precipitation to occur in the region Thursday night into Friday. Exact timing is uncertain, as the GFS has a faster solution, and the ECMWF has the system move through later in the evening on Thursday. With the GFS, there could be be more rain, as temperatures raise into the 40s during the day. The ECMWF is a snowier solution currently, with most of the snow falling in the Downeast region overnight. Slightly chance for mixed precipitation Downeast with this event, which could cause slick travel conditions. Currently kept precipitation types as rain/snow due to uncertainty on system track and timing.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

VFR through Monday night at all terminals. NW winds around 10 kts through tonight, shifting W Monday, then shifting SW and decreasing to around 5 kts Monday night.

Tuesday...Generally VFR. SW wind 10 to 15 kts with 30 mph gusts.

Tuesday night...VFR, with a potential for MVFR at southern terminals as snow moves in along the coast. Light and variable wind.

Wednesday...VFR.. W wind around 5 kt.

Wednesday night...VFR lowering to IFR south and generally MVFR north. SW winds around 5 kt.

Thursday...VFR north. IFR becoming MVFR and possibly VFR south. N wind 5 to 10 kt.

Thursday night - Friday... MVFR/IFR possible in snow showers at all terminals. N/NE winds shifting SE during the day, at 5-10 kts.

MARINE

Wind gusts to 25 to 30 kts are expected tonight across all coastal waters and seas of 3 to 5 feet are forecast over the outer waters. Moderate freezing spray is also expected. Small craft and freezing spray advisories have been issued. Winds decrease below advisory levels Monday morning, but moderate freezing spray will persist longer, becoming light around midday. Light freezing spray continues into Monday evening before air temperatures moderate late Monday night. Southwest winds increase later Monday night towards advisory levels once again.

Potential for Gale Force conditions over the waters on Tuesday. Seas as high as 8 ft over the outer-waters are possible. Conditions fall below Small Craft by early Wednesday morning. Potential for a rain/snow mix along in intra-coastals, and rain over the outer-waters. Also a chance for some fog over waters Tuesday night. Winds from the SW Tuesday, shifting to the N/NW on Wednesday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Cold Weather Advisory from 1 AM to 7 AM EST Monday for MEZ001>004. MARINE...Small Craft Advisory until 7 AM EST Monday for ANZ050>052. Freezing Spray Advisory from 9 PM this evening to 1 PM EST Monday for ANZ050>052.