textproduct: Caribou

SYNOPSIS

High pressure will build in from the northwest today and be to our north over the weekend. Low pressure will approach on Monday and exit to the northeast Tuesday.

NEAR TERM /THROUGH SATURDAY/

12:29PM UPDATE...Aviation update only. See below.

10:07AM UPDATE...Have made changes to the Marine Headlines see the Marine section below. Made adjustments for the low-mid level clouds stuck across Northern Maine. This is thanks to low level moisture streaming SSE into Maine from the open St. Lawrence River to our north. Expecting isolated-scattered snow showers under these clouds. Expecting a general trend towards drying out the boundary layer but with the peak sun angle at around 20 degrees make it difficult to mix or heat up this layer and dry it out. Have made adjustments to call today a partly sunny day across the north. Elsewhere, forecast remains on track with this arctic day. NOAA Hysplit Backward trajectory shows this airmass originated over the Northwestern Passages in far Northern Nunavut Canada. No other changes...

Previous Discussion...

Key Message... 1) Gusty winds and blowing and drifting snow this morning 2) Anomalously cold temperatures through Saturday

Key Message 1... Surface low deepening over the Canadian Maritimes will keep a tight pressure gradient over the CWA as 1035mb sfc high builds twd the area from Quebec. 30-35 kt LLJ remains over eastern areas through 15z this morning before decreasing as the day wears on. Expect wind gusts at the surface to peak between 25-30 mph this morning before diminishing. This will continue to result in blowing and drifting snow downwind of open areas, especially over the north and east. Use caution when traveling this morning and be prepared for reduced visibilities along with snowdrifts in the roads that may cause you to lose control of your vehicle.

Key Message 2... High pressure and northerly flow will keep cold Canadian air over the area during the near term. High temps will only climb into the single digits over the north and into the teens for srn zones. Strong high pressure will keep sfc low south of the region tonight with gradient of precipitation confined to NH and srn New England with only mid cld deck possibly getting into wrn areas late tonight. Skies remain moclr to pcldy over the north and with light winds and/or near calm winds, along with a fresh snowpack, temps will fall below zero for areas north and west of the I95 corridor.

Temps will recover slightly on Saturday under sunny skies. Highs will be 3-5 degrees warmer than Friday but still average around 10-15 degrees below seasonal norms.

SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/

Main point: * Cold temperatures continue Saturday night

Discussion: Northwest winds behind a departing trough will continue to advect cold air into our forecast area Saturday night, leading to temperatures falling into the single digits throughout the forecast area. Skies will be clear under high pressure, and should the winds taper off overnight with the development of a nocturnal inversion, efficient radiational cooling could allow for temperatures to quickly drop even further, potentially falling to near 10 below zero in the north, and around zero Downeast. If the boundary layer remains well mixed, however, lows are more likely to remain above zero, aside from some typically colder spots in the north which could dip just below zero.

The ridge of high pressure will begin to shift eastward Sunday into Sunday night as the next strong low pressure system approaches from the west into the beginning of the next work week.

LONG TERM /MONDAY THROUGH THURSDAY/

Main points: * Storm Monday-Monday night to bring snow across the north, rain Downeast * Potential wintry mix along the rain/snow line late Monday into Monday night * Gusty winds possible on Tuesday

Discussion: An occluding low pressure system will make its way through New England through early next week. The exact evolution of this storm continues to lack resolution, as there are a few key details that remain uncertain. The track of the parent surface low will likely move out of Quebec and cross the northern portion of the CWA, or just to the north of the area. A triple point low will develop along the occluded front as it lifts through northern New England, though the exact track of this secondary low remains uncertain. Recent runs of the GFS and ECMWF bring this triple point low through the center of our forecast area, while the CMC keeps this secondary low closer to the coast. The further north the triple point tracks, the further the warm sector of that low will be able to intrude into our region, and the further north the warm sector shifts, the more rain will be found in our forecast area. Based on current runs of global models, as well as referencing both the NBM 4.3 and NBM 5.0 trends, this forecast leans towards the solution with the triple point moving through the middle of the forecast area. This leads to warm air creating a change to rain Downeast through the day on Monday, while the north remains all snow.

With a lifting warm front late Monday into Monday night, the atmospheric profile will begin to develop a warm nose. The question remains if this warm nose will be strong enough while the surface remains cold enough for freezing rain to exist along the rain/snow line. At this time frame, there is no clear signal for freezing rain, though the synoptic setup is conducive for at least brief periods of freezing rain before a switch to warm rain. The location of the rain/snow line is also difficult to pinpoint at this time range. For these reasons, the forecast remains a rain/snow mix along the warm front, though a wintry mix cannot be ruled out.

The low pressure system will move out of the area on Tuesday, and a tightened pressure gradient aloft between the departing low and an incoming ridge of high pressure will lead to gusty surface winds, potentially reaching 25 to 30 mph, especially over higher terrain.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

NEAR TERM: 18z TAF UPDATE...

Rest of Today. SCT to brief BKN MVFR cigs at northern terms. Otherwise VFR. NW winds 10-15kt gusting 15-25kt at times. Winds will relax and shift N at sunset.

Tonight...VFR cigs to SKC for sites. N winds 5-10kt.

Saturday...VFR. N-NNW winds 5-15kt.

SHORT TERM: Sat night - Sun: VFR across all terminals. NW winds 5 to 10 kts.

Sun night: Conditions gradually falling to MVFR late. Winds light and variable.

Mon: Conditions deteriorating into the afternoon, becoming IFR/LIFR in snow in the north and in rain at Downeast terminals. Winds ESE 5 to 10 kts.

Mon night: IFR/LIFR early, improving towards MVFR late from south to north. Winds shifting W at 5 to 10 kts.

Tues: VFR/MVFR. W winds 10 to 15 kts gusting 20 to 30 kts.

MARINE

NEAR TERM: UPDATE...Freezing Spray Advisory has expired as of 10AM. Light freezing spray is expected throughout the day into the evening. The Gale Warning has expired as of 10AM and winds have fallen to SCA levels gusting 30-33KT. Have issued a Small Craft Advisory until 2PM EST for the Intra-Coastal Waters and 7PM EST for the Coastal Waters out 25nm. Expecting gusts up to 30KT and seas 4-7ft.

Previous Discussion... Gale force winds continue through mid-late morning with small craft headlines likely continuing into this afternoon. North winds will be marginal thru the day on Saturday but remain aob 25 kts with seas ranging from 1 to 3 feet.

SHORT TERM: Winds gusting over 25 kts on the coastal waters Saturday night through Sunday morning, leading to small craft advisory conditions. Seas will remain mild at 1 to 3 ft through this time. A low pressure system will bring rain across the waters Monday into Monday night. Strong gale strength winds are likely behind the next low pressure system, with these winds picking up Monday night into Tuesday. Seas will lift to 7 to 12 ft through the middle of the week.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 7 PM EST this evening for ANZ050- 051. Small Craft Advisory until 2 PM EST this afternoon for ANZ052.