textproduct: Caribou

WHAT HAS CHANGED

-Increased confidence for snow squalls Thursday and Friday.

-Issued a Gale Watch for the Coastal Waters Thursday PM through Friday AM.

-An Extreme Cold Watch has been issued Friday night into Saturday morning.

-Low chance of a winter storm Sunday night into Monday.

KEY MESSAGES

- Light snow tonight into Thursday AM to make for slippery travel for Thursday AM commute.

- Snow squalls possible Thursday and likely on Friday.

- Frigid arctic air brings extremely dangerous wind chills this weekend.

- Low chance of a winter storm Sunday night into Monday with the greatest threat to southern areas.

DISCUSSION

KEY MESSAGE 1...Light snow tonight into Thursday AM to make for slippery travel for Thursday AM commute.

KEY MESSAGE 1 DESCRIPTION... A weak low pressure system will track across the CWA tonight into Thursday AM along a triple point associated with the larger system in Quebec. Expecting an area of light snow to develop tonight across much of the southern 1/2 of the CWA and across portions of Northeast Aroostook county. Steady snow will taper in the morning hours. Expecting 2-4 inches across the Bangor Region, Southern Aroostook to the Downeast coast with 1-3 inches north of there in Aroostook closer to the border with New Brunswick. The least amount of snow expected in the North Woods where a Dusting to 1 inch is possible and this includes the Moosehead region. This is expected to make things a little slippery overnight but much of the snow will be light and fluffy and given the cold ground expecting no significant travel impacts.

KEY MESSAGE 2...Snow squalls possible Thursday and likely on Friday.

KEY MESSAGE 2 DESCRIPTION... A ton of uncertainty on Thursday on the likelihood of heavy snow showers or potentially squalls. A weaker surface cold front will push through the area in the afternoon into the evening. Significant uncertainty lies in how unstable the atmosphere will be in the afternoon. Much of the morning will be overcast and the front strength is questionable. Hi-Res CAMs this afternoon are showing a little bit steeper lapse rates, the RRFS/NAM3km/HRRR, while the globals still struggling on how unstable the boundary layer will be. For now did raise POPs higher than NBM and blended in much of the CAMs to focus the greatest heavy snow shower and squall risk to the north. Additional uncertainty lies in how much wind can mix down as much of the modeled soundings show 25-30kt available in the globals with hi-res showing 25-40kt. The BTV snow squall parameter has significantly jumped up significantly with the latest hi-res models while remaining 1-2 with the global models. Have messaged in social media and HWO about the threats of heavy snow showers and squalls.

The greatest threat for snow squalls will be on Friday as an arctic cold front passes through the region during the afternoon. Snow squalls may begin in the North Woods around mid-day before spreading east through the early evening. Currently expecting the greatest chance for snow squalls to be in the Central Highlands, North Woods, and Aroostook county as model soundings show this is where the greatest instability will be. Still, some strong snow showers and possibly a snow squall or two are possible further south. Currently expecting this to be one of the higher end snow squall events of the winter so far as models show ample instability exceeding 100 J/kg in some northern areas, sufficient lift from a cold front, decent moisture, and a deep mixed layer up to about 650mb with winds in excess of 30 mph that could easily be mixed down to the surface.

KEY MESSAGE 3...Frigid arctic air brings extremely dangerous wind chills this weekend.

KEY MESSAGE 3 DESCRIPTION... Behind the cold front exiting to the east late Friday, arctic air will get funneled into the region through this weekend. The cold is expected to persist through Monday before beginning a warming trend early next week. The coldest temperatures are expected Saturday night into Sunday morning where lows may dip to near -20 in the north and near -10 further south. Some areas could even get colder if winds stay light and skies remain clear. However, the period of greatest wind chills is expected Friday night into Saturday morning, reaching as low as -40 in northern Maine and -25 further south. This is due to a pressure gradient persisting over the area Friday night as low pressure departs over the maritimes and high pressure builds in from the west. Temperatures will warm slightly during the day on Saturday but will still be very cold, possibly not getting above 0 in the north, and winds will remain elevated resulting in wind chills as low as - 25 degrees. Slightly warmer Sunday with temperatures in the single digits and lighter winds. Remember that exposure to these frigid temperatures can quickly result in frostbite and hypothermia.

KEY MESSAGE 4...Low chance of a winter storm Sunday night into Monday with the greatest threat to southern areas.

KEY MESSAGE 4 DESCRIPTION... Global deterministic models and their ensembles are showing a low potential for a winter storm beginning Sunday night as low pressure initially positioned in the mid-Atlantic region redevelops offshore and moves northeast off the New England coast. Ensembles emphasize there is considerable uncertainty in when and if such a storm reaches us. A large margin of members keep the system well offshore but some bring it into the Gulf of Maine resulting in accumulating snowfall, especially in the Bangor and Downeast regions. The overall evolution of the system will be dependent on how persistent high pressure is over us on Sunday as a stronger high will keep the storm further from our area.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Tonight...VFR this evening, becoming IFR/LIFR with -SN later this evening into early Thursday AM. S-SE winds 5-10kt tonight. LLWS likely at HUL and BGR overnight into early Thu AM.

Thursday...Expecting -SN becomes VCSH tomorrow and generally MVFR cigs except VFR cigs south. Low confidence potential of brief IFR/LIFR due to +SHSN at northern terms in the afternoon. S-SW winds 5-15kt with gusts up to 20kt in the afternoon.

Thursday night...VFR cigs but low potential of FEW-SCT MVFR cigs north. W winds 5-15kt.

Friday...VFR/MVFR north with mainly VFR south. Brief IFR with any snow showers. Slight chance for blowing snow at northern terminals. Chance for snow squalls during the afternoon/evening on Friday at all terminals but especially at northern terminals. Southwest/west winds 10 to 15 knots with gusts up to 20 to 25 knots.

Friday night through Saturday...VFR/MVFR north. VFR Downeast. West/northwest winds 10 to 15 knots with gusts up to 25 to 30 knots.

Saturday night through Sunday...VFR at all terminals. West/northwest winds 5 to 10 kts.

Sunday night through Monday...Becoming MVFR and possibly IFR by morning at southern terminals with light snow. VFR/MVFR northern terminals. Light N/NW winds Sunday night, increasing to 5 to 10 kts Monday.

MARINE

Small Craft Advisory in effect for the Intra-Coastal Waters through 7PM Friday. Small Craft Advisory for the Coastal Waters until 1PM Thursday then a Gale Watch from 1PM Thursday through 7AM Friday. For the SCA SW winds 15-25kt with a few gusts up to 35kt and seas 6-9ft. For the Gale Watch, W winds 20-30kt with gusts up to 45kt and seas 7-10ft.

Friday through Monday...Gales Friday with the peak winds Friday night before decreasing below gale criteria Saturday night and below small craft criteria by Sunday morning. Winds increase above small craft criteria Sunday night into Monday. Seas peak at 6 to 10 ft Friday night and decrease to 2 to 4 ft by Sunday morning. Moderate to heavy freezing spray Friday night through Sunday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Extreme Cold Watch from late Friday night through Saturday morning for MEZ001>006-010. MARINE...Small Craft Advisory until 1 PM EST Thursday for ANZ050-051. Gale Watch from Thursday afternoon through Friday morning for ANZ050-051. Small Craft Advisory until 7 PM EST Friday for ANZ052.