textproduct: Caribou

SYNOPSIS

Low pressure slowly exits through the Maritimes as high pressure builds in from the west tonight through Monday night, with the high also exiting to the east on Tuesday. An area of low pressure passes to the north Tuesday night into Wednesday night, followed by high pressure on Thursday, then a second low passing to the north Thursday night though Friday night. High pressure builds in on Saturday.

NEAR TERM /THROUGH MONDAY NIGHT/

Quiet weather through Monday night.

Rest of the Afternoon and Tonight... A strong upper level trough is approaching from the west. All the snow has been south of the state, and it should stay that way. Can't rule out some intermittent light snow the rest of this afternoon and early this evening along the Downeast coast, but odds favor even the coast staying dry. Across the north, the upper trough moving through late this afternoon and evening with cold advection could ignite a few snow showers, and have 20 PoPs from about Presque Isle north to account for this. NW winds tonight will pick up as the upper trough moves through and as low pressure south/southeast of our area strengthens.

Monday... Main story Monday will be the gusty NW winds, with gusts around 30 mph for many areas. Could be just strong enough for a little blowing snow in the agricultural areas of Aroostook and Northern Penobscot, but the snow is a bit windblown from the previous event and winds won't be potent enough to lead to any significant blowing issues, just minor localized blowing/drifting. Cold with highs in the mid teens north and low 20s Downeast. Mostly cloudy north, and mostly sunny/partly cloudy south. Should be dry.

Monday Night... Weak high pressure begins to build in from the west, with winds beginning to slacken. No precipitation, and lows generally in the single digits.

SHORT TERM /TUESDAY THROUGH WEDNESDAY/

Weak northern stream ridging builds over the area on Tuesday, then exits to the east Tuesday night. Associated subsidence should keep things dry Tuesday and Tuesday evening, then an approaching surface-850 mb warm front could bring some light snow to portions of the North, depending on how much low level moisture is actually available to work with. Models differ on this, so have pops at slight chance for now. Highs on Tuesday should be around 5-10 degrees below normal. With the surface/low level warm front lifting to the north, should see a non-dirunal temperature trend Tuesday night. Blended in CONSRaw guidance with the NBM to help accentuate this, especially across Downeast Maine and the Bangor region where this should be most pronounced. Lows should occur mainly in the evening as a result, with values near to slightly above normal. With dewpoints well below freezing, should not see any fog, except for maybe near the immediate coast. Could see some gusts of 20-35 mph Tuesday night, strongest near the immediate coast and over higher elevations.

A northern stream shortwave approaches Wednesday morning, then moves into Maine Wednesday afternoon. This brings with it some mainly isolated to possibly scattered snow showers across the North - where the best forcing will be. Highs on Wednesday should be around 5 degrees above normal. Could see wind gusts of 35-40 mph over mainly Downeast Maine on Wednesday. At this time it appears most likely that winds will remain below advisory criteria, however this possibility cannot be ruled out. Confidence in this occurring at this time is too low to mention in the HWO.

LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/

The northern stream shortwave exits to the east Wednesday evening, bringing on end to the isolated to scattered snow showers as it does so. Threat for wind gusts 35-40mph over mainly Downeast Maine continues Wednesday night, with a low chance for wind gusts to advisory level (but too low a chance to mention in the HWO at this time).

Deep layered ridging builds in Thursday, with its axis exiting to the east Thursday evening. It should be dry on Thursday, then pops increase from W to E Thursday night, as SW flow sets up aloft, with strong low level warm advection. Precipitation could start as a brief period of snow across the north, but change to all rain by around midnight, so little in the way of accumulating snow is expected. With warm moist air crossing over a decent snow pack, should see at least patchy fog develop across most of the region by late Thursday night.

A northern stream trough, extending SE from a cutoff low over Hudson Bay, approaches Friday, with its axis passing to the east Friday night. Rain should taper off to showers from SW to NE Friday morning. The models differ on the exact timing of this system, with the CMC/GFS and its ensemble members generally faster than the ECMWF and its ensemble members. Leaned towards the faster solution given the fairly progressive pattern. As a result, would expect colder air to quickly work in from NW to SE on Friday, causing the rain showers to quickly change to snow showers across the North and Upper Penobscot Valley and to rain and snow showers elsewhere. There is the potential for strong to possibly damaging winds across Downeast Maine ahead of this system - with wind advisory criteria being reached likely and high wind warning criteria possibly being hit over coastal Downeast from Friday into Friday evening (with a 60-80 kt low level jet). A more widespread winds to around advisory level, with an even lower chance of winds approaching warning level is then possibly later Friday night behind the system (with a 35-50 kt low level jet and fairly steep low-mid level lapse rates allowing for a better chance for the stronger winds aloft to more fully mix down). Will highlight the wind threat in the HWO, as there is some potential for downed trees and power lines, with the highest risk of this over Downeast Maine.

Northern stream ridging builds in Saturday, so it should be dry, with the possible exception of some lingering snow showers early Saturday morning and isolated to possibly scattered snow showers moving into far NW zones late in the day, if the axis of the ridge slides east sooner than currently expected.

The ridge axis quickly exits to the east Saturday evening, followed by an approaching northern stream shortwave, that passes, Sunday morning, followed by the approach of a northern stream trough. This sets up for a period of light to possibly moderate snow across northern and eastern Maine Saturday night (possibly mixed with or all rain at the immediate coast). Then depending on if a coastal low develops or not, the snow could then continue across the North Sunday with a rain/snow mix changing to rain elsewhere.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

NEAR TERM: Mainly VFR through early this evening, with the exception of MVFR cigs at FVE. This evening, roughly around 1z, CAR/PQI are likely to develop MVFR cigs that should persist through most of the night until around 10z Monday. HUL could get MVFR cigs late tonight, but confidence is low. BGR/BHB are likely to remain VFR tonight, though can't totally rule out brief MVFR at BHB late this afternoon or early evening. For winds, expect NW winds to increase especially later tonight, with NW wind generally becoming 10-15 kts with gusts 20-30 kts during the day Monday. Generally VFR Monday except possible AM MVFR cigs from PQI north. Monday night, winds weaken and mainly VFR expected.

SHORT TERM: Tuesday-Tuesday evening: VFR. SW-SSW winds G15-25KT possible.

Late Tuesday night-Wednesday: Chance of MVFR or lower across the north in any light snow, with moderate-high confidence of VFR at southern terminals. SSW-SW winds G15-20KT possible at northern terminals. SW-WSW winds G30-35KT likely and G40KT possible at southern terminals.

Wednesday night: Chance of MVFR in the evening at northern terminals, otherwise VFR. SW-WNW winds G20-30KT probable at northern terminals and SW-W winds G30-35KT likely and G40KT possible at southern terminals.

Thursday: VFR. LLWS possible.

Thursday night-Friday: IFR or lower likely. LLWS likely Thursday night and possible Friday morning. W winds G25-40KT possible Friday afternoon, most likely strongest at southern terminals.

MARINE

NEAR TERM: Issued gale warning for all but the inner waters, with high confidence (90 percent) in NW gales tonight and Monday. Light freezing spray as well later tonight and Monday morning. Winds ease significantly through the night Monday night. Seas build tonight and Monday morning, peak as high as about 7 feet midday Monday, then ease to less than 4 feet late Monday night.

SHORT TERM: Tuesday should see sub-SCA conditions on all waters. Gales likely to develop on all waters by late Tuesday night and continue into if not through Wednesday night. SCA conditions probable on the coastal ocean waters Thursday, with sub SCA conditions likely on the intra-coastal waters Thursday morning, with SCA conditions possible there in the afternoon. Gales become likely on all waters Thursday night and should continue into Friday night. There is also a chance for gusts to storm force on the coastal ocean waters on Friday. These threats will be reflected in the HWO.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Gale Warning from 7 PM this evening to 7 PM EST Monday for ANZ050-051. Small Craft Advisory from 7 PM this evening to 7 PM EST Monday for ANZ052.