textproduct: Caribou

SYNOPSIS

Low pressure moves into the northern Canadian Maritimes through tonight. High pressure builds in Saturday and Saturday night, then exits to the east on Sunday,as low pressure approaches from the west. A warm front crosses Sunday evening, followed by a cold front crossing Maine late Sunday night and Monday morning. High pressure then moves in from the west through Monday night. A coastal low approaches from the south on Tuesday.

NEAR TERM /THROUGH SATURDAY NIGHT/

Key Message...Localized heavy snow showers with briefly reduced visibilities and locally hazardous travel conditions possible through late afternoon.

Upper level low pressure tracks to the northeast of the state overnight. Scattered snow showers are expected through early this evening. Localized accumulations up to an inch are possible. But as this feature tracks away from the region expect any scattered snow showers will end by early this evening. Otherwise expect mainly to partly cloudy skies overnight. Lows will range from the low to mid 20s. Saturday is a mainly dry day with increasing sunshine expected by afternoon. Afternoon highs will range from the upper 20s to lower 30s north and mid to upper 30s for the Bangor region and Downeast. High pressure builds in Saturday night with mainly clear to partly cloudy skies. Lows will range from the mid to upper teens north and low to mid 20s for the Bangor region and Downeast.

SHORT TERM /SUNDAY THROUGH MONDAY/

Key message...Light snow expected across the north Sunday through Sunday night with possible travel impacts.

On Sunday, low pressure will cross southern Ontario and move northward through Quebec, bringing a frontal system across Maine. The warm front will cross Maine from the south during the day on Sunday, accompanied by light precipitation. Cold air will linger in northern Maine through early afternoon, and the precip should fall as snow through most of the day. Blocking from the mountains will keep the precip as snow across the west, but rain will mix in in the evening across the eastern side of the forecast area. This will bringing some light snow accumulation to the north through early afternoon. Chances are low, around 20%) that advisory level snow will fall, and the general expectation is 2 to 4 inches across the north. Accumulation will be limited by rain mixing in and then melting previously fallen snow. South of Millinocket, the period of all frozen precipitation will be very brief, so fewer impacts to travel are expected with mostly rain.

Behind the front, air will dry and cool quickly as a strong cold air mass moves in. Fortunately, moderate winds should dry out the roads ahead of the rapid drop in temperature, so the risk of ice forming on hard surfaces is fairly low.

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/

Key message...Another accumulating snow event expected Tuesday into Wednesday, impacting travel. Moderate likelihood that an advisory or warning will be needed.

Monday night will be quite a bit colder with the colder thermal profile and the potential for decoupling, and this may bring the coldest air so far this season. Lows will be in the single digits across the north, and in the teens across the rest of Maine. This cold air will stick around through mid week, greatly impacting the storm system moving up on Tuesday and Tuesday night. Forecast models are still disagreeing on the exact track, but are mostly keeping the low center just offshore, which would bring northerly flow and keep the precipitation as all snow for most of the forecast area. The Downeast coast may mix with rain, but NBM temperatures may be a little warm given the northerly flow, so there is a possibility precip will stay snow all the way to the coast. There is a moderate to high chance (35 to 40%) that more than 6 inches of snow will fall somewhere in the forecast area, with the most likely area falling south of the I-95 corridor and east of Bangor. The location is highly dependent on how close to the coast the main low center tracks, so there is still some uncertainty on where it will likely line up.

After this low moves through, colder air will return again, and temps are expected to remain below freezing through the end of the week. Some chance exists for snow showers across the north Thursday into Friday, but this does not look like a significant event.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

NEAR TERM: Localized brief MVFR/IFR conditions are expected through early this evening in any scattered snow showers, mainly at the northern terminals. Otherwise, VFR conditions are expected at the terminals through Saturday night. SW wind around 10 kt tonight, becoming NW 10 to 20 kt Saturday. Light variable wind Saturday night.

SHORT TERM: Sunday and Sunday night...VFR early Sunday, becoming IFR/MVFR in the afternoon and into Sunday night. Some potential for LIFR in snow for northern TAF sites Sunday evening. Snow and rain, with rain more favored for BGR/BHB. S winds 10-20 kts with gusts 20-30 kts, strongest winds BHB/BGR. LLWS likely.

Mon...VFR, except possible MVFR north. NW wind gusting 20-30 kts.

Tue...MVFR or lower possible in snow, especially south. Confidence is increasing, but confidence in the details of this event, including location, is still low.

MARINE

NEAR TERM: A Gale Warning remains in effect through Saturday afternoon for the outerwaters and a Small Craft Advisory is in effect for the intra coastal zone through Saturday afternoon. Winds/ seas remain below SCA.

SHORT TERM: South gales expected (greater than 75 percent chance) late Sunday and Sunday night, with seas to around 10 ft. Winds switch to the west Monday but remain near the border of small craft and gale. Much improved winds/seas Monday night/early Tuesday, but about a 50 percent chance of gales around Tuesday night from a possible Nor'easter. Seas could also build back up to around 10 ft, depending on the track of the Nor'easter.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Gale Warning until 6 PM EST Saturday for ANZ050-051. Small Craft Advisory until 6 PM EST Saturday for ANZ052.