textproduct: Caribou

SYNOPSIS

Weak high pres builds in tonight, then exits to the E on Sat. Low pres tracks E of Nova Scotia Sun. High pres builds across the region Mon into Tue before another low pressure system passes to the north on Wednesday.

NEAR TERM /THROUGH SATURDAY NIGHT/

Main Point: * Reductions to visibility from blowing snow will quickly improve this evening; winds will taper off overnight

Discussion: A tight pressure gradient remains over the forecast area into this evening, resulting in gusty winds throughout the CWA and blowing snow across the north. This pressure gradient will begin to relax into the overnight hours. As winds begin to decrease, compaction and settling from the blowing snow earlier in the day will create a crust on the snow pack limiting the ability for snow to be lofted without a further increase in winds, and the reduction in visibility due to blowing snow will quickly improve. Patchy blowing snow and drifting snow may last for a couple more hours past sunset this evening, but all snow movement should rapidly cease into the overnight hours as winds improve and the snow pack crusts over.

A narrow ridge of high pressure will crest over the forecast area on Saturday, and return flow will lead to temperatures lifting into the low to mid 20s in the north and around freezing Downeast. Low pressure approaches from the west Saturday night, and another round of light snow showers could result over the CWA late overnight. The greatest chance for any light accumulation will be Downeast, closer to the developing coastal low pressure.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Key Messages -Breezy and cold Monday

On Sunday, a positively tilted upper level trough will be moving through the northeast. At the surface, weakening low pressure moving from the Great Lakes region will be just to our north. Further south over the waters, a strengthening low pressure system will pass well south of the Maine coast. The offshore low may get close enough for some light snow over the waters and snow showers along the coast but not expecting any notable impacts from the system. Over northern Maine, the weakening low may support some isolated snow showers but likely not snow squalls due to the minimal instability.

Precipitation should clear out by Monday morning as a ridge of high pressure briefly builds in to the area. A pressure gradient between the strengthening offshore low and the high moving in is likely to result in some windy conditions Monday. On Monday night, a weakening cold front approaches from the west. Even as the cold front falls apart there should be enough support for a few light snow showers over northern and central Maine.

LONG TERM /TUESDAY THROUGH FRIDAY/

Key Messages -Warming trend through late next week with above normal temperatures -A possible rain system late week (but considerable uncertainty right now)

Precipitation clears out Tuesday with high pressure building in. Low pressure passes to the north on Wednesday with a cold front crossing the state Wednesday night which should result in some snow showers, mainly over the north. Some timing differences still exist and there is some discrepancy in whether or not there will be enough warm air advection for some areas to see rain showers, rather than snow showers. Current thinking is that most areas will see snow. Regardless, the warm air advection ahead of the front should lead to above normal, and possibly above freezing, temperatures.

The warming trend is likely to continue Thursday as southerly flow ahead of another system fosters more warm air advection. There is considerable uncertainty in regards to what this late week system might look like. Currently, most of the GEFS and EPS ensemble members are showing a rain event as a strong low passes to our north while some GEFS members favor a more southerly track and a greater potential for snow.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

NEAR TERM: VFR cigs continue through this evening, while vis alternates between MVFR and VFR depending on BLSN across northern terminals. Downeast terminals remain VFR through this evening. W winds 10 to 20 kts with gusts 25 to 30 kts late this afternoon will gradually decrease into the night, resulting in a few hours of LLWS around 40 kts before a nocturnal inversion fully develops. Winds will continue to diminish Saturday, becoming SW 5 to 10 kts and then light and variable Saturday night. VFR conditions continue into Saturday night, with a lowering towards MVFR late in any snow showers.

SHORT TERM:

Sunday...VFR/MVFR, occasional IFR, with a chance of light snow or snow showers. Variable winds 5 to 10 knots, becoming northwest/north.

Sunday night...VFR/MVFR with a chance of snow showers. Northwest winds 10 to 15 knots with gusts up to around 20 knots.

Monday...VFR. Northwest winds 10 to 15 knots with gusts 20 to 25 knots.

Monday night...VFR/MVFR north. A slight chance of snow showers north Monday night through early Tuesday. VFR Downeast. Northwest/west winds 5 to 10 knots.

Tuesday...VFR/MVFR north with a slight chance of snow showers early. VFR south. West winds around 5 knots.

Tuesday night...VFR/MVFR north. VFR south. S/Southwest winds 5 to 10 knots.

MARINE

NEAR TERM: Gale conditions continue over the waters this afternoon with gusts 35 to 40 kts. Winds will gradually begin to taper off into this evening as high pressure rolls into the area, with the intracoastal waters falling to small craft advisory criteria this evening and the coastal waters falling to SCA criteria after midnight tonight. Conditions will continue to improve into the day on Saturday, with winds and seas falling below SCA Levels through the morning. Seas 4 to 5 ft and gusts 25 to 30 kts may return over the coastal waters briefly Saturday evening, but will be quick to disperse overnight Saturday night.

SHORT TERM: Winds increase to small craft advisory conditions Sunday afternoon with gales likely Sunday night through Monday. Seas peak at 5 to 7 ft Monday. Winds and seas subside below small craft advisory conditions Monday night. Winds increase again to small craft advisory conditions Tuesday night with gales also possible.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Gale Warning until midnight EST tonight for ANZ050-051. Gale Warning until 4 PM EST this afternoon for ANZ052.