textproduct: Caribou

SYNOPSIS

A series of troughs of low pressure cross the region through Friday as a strong low tracks through the Canadian Maritimes. Weak high pressure builds in Friday night, then exits to the east on Saturday. Low pressure develops along the mid Atlantic coast Saturday night, then passes to the south on Sunday. High pressure then builds in from the west through Tuesday.

NEAR TERM /THROUGH FRIDAY NIGHT/

A cutoff low tracks from northern Maine this evening into Maritimes through Friday. The result will be another round of light snow across the north late this afternoon/evening, then more isolated to scattered snow showers, once again mainly across the North late tonight and Friday. Accumulations should generally range from 1/2 to 3 inches, with higher amounts of 4-8 inches possible along higher terrain along the western border with Quebec. Expect winds to increase this evening and remain gusty through Friday. Should see gusts of 30-45mph from late tonight through Friday. This will produce patches of blowing snow across the North, especially in areas receiving more than an inch or so of snow late this afternoon/tonight. For now expect winds to remain below wind advisory criteria, however cannot rule out some gusts towards 50 mph, with the best chance in the Central Highlands, but confidence in this is not high enough to reflect in the forecast at this time. Lows tonight should be mainly in the 10s, with wind chills from 0 to 15 below. Highs on Friday should be from the upper 10s to upper 20s, this is around 10-15 degrees below normal.

Northern stream ridging builds in Friday night, associated subsidence should keep things dry, with some thinning of the clouds, especially overnight as the ridge axis slides over Maine. Wind gusts of 25-45 mph (strongest Central Highlands) in the early in the evening, should decrease in strength through the night. Could still see some patchy blowing snow across the North in the evening as a result. Lows Friday night should be from a few to around 5 degrees below normal.

SHORT TERM /SATURDAY THROUGH SUNDAY/

Main Point: * Light snowfall possible Downeast on Sunday

Discussion: A narrow ridge of high pressure will cross the forecast area on Saturday, with dry weather and continued mostly cloudy skies as the low pressure system quickly approaches from the west. Southwest winds on the backside of this ridge will advect slightly warmer air into the region, with high temperatures on Saturday lifting into the low to mid 20s in the north and up to around freezing closer to the coast.

With the relaxed pressure gradient associated with the ridge, surface decoupling Saturday night may allow for temperatures to drop into the single digits in the north and lower teens Downeast. Lingering cloud cover may help in preventing temperatures from rushing towards zero, though if the forecast trends clearer, this may then be realized.

An occluded low will approach from the west into the day on Sunday, with a triple point coastal low developing over the Gulf of Maine as the system moves through our forecast area. The coastal low will enhance precip amounts for the Downeast region, but the entire system is currently on track to be fairly moisture starved and quick moving, so total snow amounts are likely to remain below an inch.

LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/

Main Points: * Gusty winds possible on Monday * Temperatures near zero Monday night

Discussion: As the previous low pressure system lifts out of our forecast area and off into the Canadian Maritimes, it will begin to rapidly deepen. Northwest winds over the St. Lawrence river could lead to bands of river-effect snow showers through Sunday night. The pressure gradient between the falling low pressure and the approaching ridge from the west will tighten, and could lead to gusty winds into Monday. The strength of these winds will depend some on how far east the low pressure travels before deepening, as if it makes it into the North Atlantic before plummeting towards 950 mb, the tightest pressure gradient will remain in Canada and winds may not increase much in our area. If the CMC 00z run is a more accurate representation of how events unfold, the low could deepen west of Newfoundland and winds could be stronger over our CWA.

As a ridge of high pressure returns to northern New England, winds will decrease Monday night into Tuesday. If winds drop off quick enough, surface decoupling could lead to temperatures Monday night falling below zero across the north and near zero Downeast. However, if enough of a LLJ remains aloft, temperatures will remain on the positive side of zero, though still cold in the single digits.

High pressure will remain the dominant synoptic pattern over the region through the middle of the week, with another shortwave low pressure system quickly moving through the CWA Wednesday night into Thursday, bringing with it the next chance for snow.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

NEAR TERM: High confidence in VFR at southern terminals through the TAF period. Northern terminals should vary between MVFR and VFR both respect to ceilings and visibilities. There is also a chance of IFR at KFVE late this afternoon/evening and again Friday morning. Winds become gusty out of the WNW-WSW this evening KHUL/KBGR/KBHB and during the overnight hours elsewhere. WInd gusts around 20-25KT, and remain so through early Friday afternoon. KFVE could see wind gusts to around 30KT Friday morning/early Friday afternoon.

Friday afternoon-night: VFR southern terminals, MVFR/VFR northern terminals, becoming VFR throughout by late Friday night. NW winds G15-25kt possible into Friday evening.

SHORT TERM: Sat - Sat night: MVFR north, VFR Downeast. SW winds 5 to 10 kts becoming light and variable overnight.

Sun: MVFR north, mostly VFR Downeast with a chance of snow showers. NW winds 5 to 10 kts.

Sun night: VFR/MVFR with a slight chance of snow showers. NW winds 10 to 15 knots with gusts up to 20 kts.

Mon: Mainly VFR across all terminals. NW winds 10 to 15 kts with gusts 20 to 25 kts.

Tues: VFR across all terminals. W winds 5 to 10 kts.

MARINE

NEAR TERM: Issued SCA for the intra-coastal waters for the remainder of this afternoon, followed by Gale Warning beginning there now at 23Z. Expect Gales on all waters tonight and Friday. Should see SCA conditions return ont he intra-coastal waters late Friday afternoon and on the coastal ocean waters around midnight Friday night. As a result, extended the gale warning there through 5Z Saturday. With the gusty winds, cold air temperatures and marginally cold SSTs, should see some light freezing spray on all waters.

SHORT TERM: Below small craft advisory conditions will last through most of the day on Sunday, though winds will begin to increase late as a low pressure strengthens as it moves through, and gusts will become gale strength Sunday night. Gales could last through the day on Monday, depending on how quickly the low exits to the east, and NW swell with seas 3 to 7 ft will carry through this time. Conditions gradually improve into the day on Tuesday, briefly falling below SCA criteria before increasing once more into the middle of next week with the next low pressure system.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Gale Warning until midnight EST Friday night for ANZ050-051. Small Craft Advisory until 6 PM EST this evening for ANZ052. Gale Warning from 6 PM this evening to 4 PM EST Friday for ANZ052.