textproduct: Caribou

WHAT HAS CHANGED

-Updated aviation section to reflect 0Z TAFs.

-Confidence has increased on the potential for moderate snowfall late Friday night into Saturday evening.

-Confidence has also increased on the potential for a significant storm system to impact the entire region from Sunday night into Tuesday, with multiple impacts becoming likely.

KEY MESSAGES

1) A moderate snow is likely from Friday night into Saturday evening, with several inches likely across central and northern areas. This will likely result in slippery travel.

2) Snow should develop Sunday night, changing to rain from south to north early Monday. Strong southerly winds are likely from late Sunday night into Monday night. Strong convection is also possible on Tuesday. This system has the potential to impact the Monday morning commute across the North, cause possible power outages, mainly across coastal Downeast from late Sunday night into Monday night, and could possibly locally impact travel on Tuesday.

3) Unseasonably cold weather expected through the middle of next week. This could bring a risk of hypothermia.

DISCUSSION

KEY MESSAGE 1... A moderate snow is likely from Friday night into Saturday evening, with several inches likely across central and northern areas. This will likely result in slippery travel.

KEY MESSAGE 1 DESCRIPTION... A clipper system approaches the area Friday evening. Snow looks to spread into southwestern portions of the area around midnight Friday night. Ensemble members are slowly coming into agreement that at some point on Friday night a triple point low begins to develop over the Downeast area. This will lead to enhanced lift over the Bangor Region and interior Downeast, up into the Central Highlands with potential for 1/2 to 1 inch per hour amounts. Snow accumulations early Saturday morning likely to result in slippery road conditions.

A developing closed low in the low to mid levels exits into the Maritimes from Saturday into Saturday evening. This could bring some additional 2-4" of snow across the North, with the bulk of this falling Saturday morning. It looks like in total, there is the potential for a 4-8" snowfall for all but coastal Downeast Maine, where 2-4" is possible. If the storm tracks further south or does not intensify as quickly as currently forecast, then lesser amounts of snow are possible, except for possibly over Downeast Maine and the Crown of Maine, where a more southern storm track could result in more (less) snow respectively.

KEY MESSAGE 2... Snow should develop Sunday night, changing to rain from south to north early Monday. Strong southerly winds are likely from late Sunday night into Monday night. Strong convection is also possible on Tuesday. This could impact the Monday morning commute across the North, cause possible power outages, mainly across coastal Downeast from late Sunday night into Monday night, and could possibly locally impact travel on Tuesday.

KEY MESSAGE 2 DESCRIPTION... Deep layered ridging on Sunday, will give way to a developing cutoff low aloft that tracks into the Great Lakes Region Monday, then up the east side of Hudson Bay on Tuesday as it weekend. This will result in diffluence aloft over the region from Monday night into Tuesday morning. At the surface a potent low tracks into the southern Great Lakes Sunday night, into Western Quebec Monday and Monday night, then into Labrador on Tuesday. This should bring a strong, but slow moving, cold front over the region from late Monday night into Tuesday evening. Ahead of the system, and the cold front, the low level jet increases to 70-80 kt, this has the potential to bring strong gusty winds to the region, with at this time the most likely outcome being the that advisory level winds are likely across coastal Downeast Maine and the probable elsewhere from late Sunday night into Monday night. There is also a 20-40% chance of warning level winds over coastal Downeast.

The aforementioned diffluent flow aloft, coupled with the strong low level jet, give the potential for locally heavy precipitation across the region from late Sunday night into Tuesday morning. This could bring a quick thump of heavy wet snow, mainly to the North Sunday night, before the precipitation becomes everywhere during Monday morning. There is then at least a 50% chance of over 1" of rain along and south of a Monson to Patten to Bridgewater line. This coupled with highs into the 50s on Monday and remaining above freezing for all but the North Woods Monday night, resulting in widespread snowmelt, could bring the potential for flooding as well.

In addition, persistent strong SE-S surface flow could result in high surf, beach erosion, and possible coastal flooding over multiple high tide cycles from Monday morning through Tuesday morning.

Last but not least, there is the potential for strong convection ahead of the cold front on Tuesday. Depending on how quickly low level cold air comes in on the backside of the system will determine if the threat is enhanced rainfall, or possible heavy snow showers. For now leaning towards convectively enhanced rainfall.

There is still some uncertainty on the exact timing, strength and track of this system. With the greatest uncertainty in terms of impacts being the impacts from coastal flooding and any strong convection on Tuesday.

KEY MESSAGE 3... Unseasonably cold weather expected through the middle of next week. This could bring a risk of hypothermia.

KEY MESSAGE 3 DESCRIPTION... Strong gusty NW winds behind this system will usher in significantly colder air, with highs on Wednesday only in the low-mid 20s across the north and around 30 across Downeast Maine and the Bangor/Penobscot Region. Wind Chills early Wednesday morning should be 0 to 10 below across most of the North. Given this rapid change in temperature, people caught off guard, especially Tuesday night risk hypothermia if exposed to the cold for prolonged periods.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Tonight...MVFR/VFR ceilings early tonight, becoming predominantly VFR late. W wind 10 to 15 kt.

Friday...VFR. W 5 to 10kts becoming S to SE late.

Friday night...MVFR early becoming IFR in snow late at all terminals. E to SE wind 5 to 15kts.

Saturday...IFR or lower likely, possibly improving to MVFR in the afternoon. W winds G15-30KT possible Saturday afternoon at southern terminals.

Saturday night...Becoming VFR throughout. W-NW winds G15-30KT possible.

Sunday...VFR.

Sunday night...Probably becoming IFR or lower. SE winds G15-25KT possible Sunday evening. LLWS likely late Sunday night.

Monday-Monday night...IFR or lower likely with VLIFR possible at times. LLWS likely. Peak wind gusts of 30-45+KT possible.

Tuesday...Slowly improving to VFR from W to E. W winds G20-35KT possible.

MARINE

Small craft conditions over the intracoastals tonight and over the outer waters through Friday afternoon. NW wind this evening will diminish Friday morning but seas will remain elevated into Friday. Seas and winds increase again Friday night over all waters.

Gales likely on the coastal ocean waters with SCA likely on the intra-coastals Saturday, then gales again likely on the coastal ocean waters with gales possible on the intra-coastal waters Saturday night. Winds become sub-SCA throughout Sunday afternoon. Winds ramp back up Sunday night with gales possible on all waters. Storm conditions are then likely on the coastal ocean waters and possible on the intra-coastal waters Monday and Monday night. Conditions should improve to gales on Tuesday.

Note seas build to 13-18ft on the coastal ocean waters by Monday night and 7-10 ft on the intracoastal waters.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 2 PM EDT Friday for ANZ050-051. Small Craft Advisory until 8 AM EDT Friday for ANZ052.