textproduct: Caribou

SYNOPSIS

A coastal low tracks into the western Maritimes tonight through Friday night. Weak high pressure builds in for the weekend as a weak low passes to the south. Canadian high pressure builds in Sunday night and Monday. Another weak low passes south of the area on Tuesday.

NEAR TERM /THROUGH FRIDAY NIGHT/

Key Messages... 1) Gusty winds increase behind cold front this evening leading to blowing snow 2) Frigid airmass moving in for tonight through Saturday

Key Message 1... Snow is beginning to blossom over sern areas this afternoon with a baroclinic leaf starting to take shape. Trof has gone negative this afternoon and shud capture the surface low over the Gulf of Maine. Unfortunately, or fortunately depending on how you look at it, it will not be in time for heavy snow over nern zones this evening.

Expect the area of snow with the front to move thru the advisory and warning areas late this afternoon before heading off into the Gulf. Cannot rule out an additional 1-3 inches over most of the advisory areas, especially with the fluff factor, however will be stretching it for northeast Aroostook.

Once fropa occurs and winds mix down from aloft west winds increase late evening. Winds gusting to 30-35 mph will be common during the overnight hours as pressure gradient tightens as low deepens over the St. Lawrence. This will lead to blowing snow downwind of open areas, especially with the fluffy nature of the snow.

Key Message 2... Very cold temperatures will filter out of Canada tonight with temps dropping blo zero in the northwest and around zero elsewhere. When combined with strong winds, wind chill temps will easily drop toward minus 30 over the North Woods and portions of the Central Highlands later tonight. Have issued a Cold Weather Advisory from 08-15z tonight.

Little relief from the cold is expected thru the end of the period with highs in the single digits on Friday over the north, and lower teens south. Wind chills may climb above zero in the afternoon, mainly along the coast, but just barely. Nrn areas can expect wind chills to remain in the minus teens throughout the day and with a cold airmass still in place a Cold Weather Advisory may need to be issued again for tomorrow night over the north.

SHORT TERM /SATURDAY THROUGH SUNDAY/

Main Point: * Very cold temperatures through the weekend under arctic airmass

Discussion: High pressure returns to the forecast area this weekend, with light winds and a drier weather pattern in store for our forecast area. The arctic air mass in place, however, will lead to very cold temperatures through the weekend. Temperatures on Saturday may only peak in the lower teens Downeast, and just above zero in the north. For Saturday night, temperatures will drop well below zero, with lows just below zero Downeast and in the teens below zero across the north. How far temperatures drop will depend on how much cloud cover builds in late Saturday night, as a low pressure system crosses south of our region overnight. Depending on how strong the high pressure is over our area, cloudy skies and possibly even some light snow may spread over the Central Highlands through the Bangor region and prevent temperatures from dipping quite as low. That said, even at warmest temperatures will still fall to around zero Saturday night. Cold temperatures continue again through the day on Sunday with highs only lifting into the single digits to lower teens above zero under continued arctic air.

Light winds through this time period will do little to lower wind chills much, though during peak diurnal mixing on Saturday min wind chills could fall to around 20 below zero.

LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/

Main Points: * Continued very cold temperatures through the first half of the week under arctic airmass * Dangerously cold wind chills possible again early Monday morning

Discussion: Cold temperatures will continue into Sunday night, with lows falling into the single digits below zero Downeast and teens to 20 below zero across the north. A low pressure system lifting north through the eastern Canadian Maritimes will tighten the pressure gradient just enough early Monday morning that wind chills could drop to 20 to 30 below zero for a few hours, though the extent to which winds pick up will greatly depend on how close said low pressure passes compared to our forecast area.

Another low pressure system could pass south of our forecast area on Tuesday, and the approach of this system will once again have impacts on just how cold temperatures can fall Monday night into the day on Tuesday. The next widespread precipitation event for the region will likely be through the middle of next week as a low pressure trough crosses the CWA.

AVIATION /19Z THURSDAY THROUGH TUESDAY/

NEAR TERM: IFR snow over terminals this afternoon into early evening before improving to MVFR. LIFR cannot be ruled out for the first several hours at BGR and BHB. BLSN/DRSN expected tonight under VFR cigs. WNW winds gusting to 20-30 kts overnight into Friday afternoon.

Winds remain strong Friday night with VFR conditions expected.

SHORT TERM: Sat - Sat night: Mainly VFR across all terminals. W winds 5 to 10 kts and gusts to 20 kts, becoming light and variable overnight.

Sun - Sun night: VFR/MVFR with a slight chance of light snow. Best chance for reduction in vis due to snow at KGNR through KBGR. Light W winds around 5 kts shifting NW.

Mon: Mainly VFR across all terminals. NW winds 5 to 10 kts.

Tues: MVFR/IFR, with chance for light snow. Best chance for snow at KGNR through KBHB. Winds light and variable.

MARINE

NEAR TERM: Winds will pick up to gale force out of the WNW later this afternoon in wake of cold frontal passage. Intracoastal should diminish to small craft conditions Friday morning with the outer waters in the afternoon. Cannot rule out marginal gale force winds offshore thru the end of the period. Moderate freezing spray expected over all waters this evening into Friday afternoon before becoming light through Friday night.

SHORT TERM: Small craft advisory criteria will likely last through the rest of the day on Saturday, before gusts drop off into Saturday night and seas fall to at or below 3 ft. Winds will increase once more out of the NW Sunday night as a low pressure system passes south of the area, with gusts increasing to 25 to 30 kts. Light freezing spray Saturday through Sunday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Cold Weather Advisory from 3 AM Friday to 10 AM EST Saturday for MEZ001-003-004-010. Winter Weather Advisory until midnight EST tonight for MEZ002- 005-006. Winter Weather Advisory until 7 PM EST this evening for MEZ011- 015. Winter Storm Warning until 7 PM EST this evening for MEZ016- 017-029-030-032. MARINE...Gale Warning until 1 PM EST Friday for ANZ050-051. Freezing Spray Advisory from 8 PM this evening to 1 PM EST Friday for ANZ050>052. Gale Warning until 10 AM EST Friday for ANZ052.