textproduct: Caribou

SYNOPSIS

High pressure builds in through tonight, then slides offshore on Tuesday. A weak area of low pressure crosses the Gulf of Maine Tuesday night, followed by a stronger low tracking from the Great Lakes Wednesday morning to across Maine Wednesday night into Thursday morning. This low then slowly lifts northeast through the maritimes into Friday night. Another storm system approaches from the Great Lakes on Saturday.

NEAR TERM /THROUGH TUESDAY NIGHT/

630PM Update (MS): Despite clear skies winds are remaining elevated, so some adjustments back towards the NBM were necessary tonight into Tuesday. Wind chills are currently as low as 14 below at Frenchville and 18 below at Saint Zacharie in northern Somerset County. Winds decrease proportionally with temperature overnight, so nearly all areas are still not expected to reach cold advisory criteria. No other significant changes were needed.

Previous Discussion: Northwest flow aloft tonight gives way to locally zonal flow on Tuesday. With no shortwaves progged to be embedded in this flow, it should be dry. After cold advection clouds dissipate early this evening, it should be mainly clear tonight. Should see an increase in mid-high clouds Tuesday afternoon ahead of the next system. Lows tonight should be from the low single digits below zero to the mid-upper single digits above zero, this is around 15-20 degrees below normal. Wind chills tonight should be around 5 below to 15 below across most of the North and from around 5 below to 5 above elsewhere. Highs on Tuesday should be from the mid teens to around 30. This is about 15 degrees below normal.

A northern stream shortwave approaches Tuesday evening, then crosses the area late Tuesday night. This should bring a round of light snow to at least Downeast Maine and the Bangor Region with the potential for 1-3" of snow - and highest totals over coastal Downeast Maine away from the immediate coast. There is some question as how far N/W the snow gets - with it likely that NW areas could remain snow free or get only some flurries. Lows Tuesday night should be around 5-10 degrees below normal.

SHORT TERM /WEDNESDAY THROUGH THURSDAY/

A weather disturbance will be lifting away to the northeast Wednesday morning. Our attention then turns to a new area of low pressure approaching from the Great Lakes supported by a trough of low pressure tracking through the Midwest. Snow ahead of this low will spread into our area Wednesday afternoon as the low quickly approaches. Most of the model guidance is bringing the low center across the central part of our region. This favors the low pulling enough warm air to the north to change precipitation over to rain Downeast and in the lower Penobscot Valley but keeping precipitation as all snow over the north. This is a fast moving storm with most of the snow expected between mid to late afternoon Wednesday into mid to late evening Wednesday night. A light to moderate accumulation of 3 to 6 inches looks probable across Northern Penobscot and Eastern Aroostook Counties with a bit less over the west where drier air will surge in a bit more quickly.

Low pressure will move away to the northeast late Wednesday night into early Thursday. However, some of the models are indicating that there could be a trailing shortwave and low crossing our area Thursday morning which could result in some light snow or snow showers persisting into Thursday. Otherwise, an upper trough lingering late Thursday will bring mostly cloudy conditions over the north with chances for snow showers across far northern areas.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/

Low pressure, both surface and aloft, will be nearby to the north Thursday night into Friday. This will bring cold gusty west to northwesterly winds and a chance for some snow showers over western and northern areas. Strong winds aligned from surface to aloft on Friday may result in a band of convergence forming downwind from the Laurentian Mountains in Quebec. This band typically runs southeast across Aroostook County, clipping northern Penobscot County, and impacting the Rt 1 Corridor from Mars Hill to Houlton with snow showers. Windy conditions may produce blowing snow in open areas. Gusty wind and a chance of snow showers will continue into Friday night.

Looking ahead to the weekend, we will remain in a cold longwave trough with mid-winter like temperatures continuing. Some of the forecast models are showing the potential for another weak weather system sliding in from the west through the trough. However, fast flow, limited moisture and limited ability to dig will mean any new system would likely only result in some renewed light snow.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

NEAR TERM: VFR. LLWS at northern terminals tonight. Winds W-WSW at 10KT or less. Gusts to around 15 kt are possible at northern terminals through early Tuesday morning.

Tuesday night...VFR through approximately 6z at all terminals, then IFR or lower likely at southern terminals. Chance of MVFR or lower at KCAR/KPQI/KHUL late - with best chance at KHUL, VFR at KFVE. Light snow accumulation likely KBGR/KBHB. SW-S winds G15KT possible.

SHORT TERM: Wednesday...MVFR lowering to IFR from south to north. S winds across the south and SE winds across the north around 5 kt.

Wednesday night...IFR to LIFR. Light and variable wind north. SW wind around 7 kt south.

Thursday...IFR improving to MVFR by mid morning. VFR south and MVFR north in the afternoon. W wind 5 to 10 kt.

Thursday night...MVFR north and VFR south. W wind 5 to 10 kt.

Friday...MVFR north and VFR south. W wind 10 to 15 kt gusting to 20 kt.

Friday night...MVFR north becoming VFR. VFR south. W wind 10 kt.

Saturday...MVFR, possibly lowering to IFR at times south. W wind 5 to 10 kt.

MARINE

NEAR TERM: SCA conditions across all waters through late this evening and continuing on the coastal ocean waters into the overnight hours, then sub-SCA conditions on waters through Tuesday. Gales are possible on the coastal ocean waters Tuesday night, with SCA conditions likely then on the intra-coastal waters. The threat of Gales is highlighted in the HWO.

SHORT TERM: A gale headline may be needed for the offshore waters Wednesday night for W winds gusting up to 35 kt. A SCA will likely need to continue for the rest of the week for winds gusting over 25 kt. Winds may drop just below SCA over the weekend.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory until 2 AM EST Tuesday for ANZ050-051. Small Craft Advisory until 11 PM EST this evening for ANZ052.