Intense Ocean Storm Rages At Sea Update Three

880

FXUS61 KCAR 300235

AFDCAR

Area Forecast Discussion

National Weather Service Caribou ME

935 PM EST Fri Jan 29 2021

.SYNOPSIS...

High pressure will build toward the region through Saturday and

move east on Sunday. Low pressure will approach from the south

Monday and track northeast through Wednesday.

&&

.NEAR TERM /THROUGH SATURDAY/...

935 PM Update: With still some very faint low top ref returns

on radar, we added a mention of scattered flurries to most of

the Rgn thru the remainder of the late eve. Otherwise, fcst

hrly temps/dwpts were updated into the late ngt hrs from latest

avbl sfc obs with no chgs to fcst low temps posted arnd 7 am

Sat morn.

Prev Disc: There will be enough of a pressure gradient between

the exiting trof of low pressure and high pressure building in

from the west to keep the atmosphere mixed enough to prevent any

widespread radiational cooling. Nevertheless, the air mass is

quite cold, and this will allow for overnight lows to fall to

near zero across the north, with even a few sub zero readings

possible across the north Maine Woods. Elsewhere, expect lows in

the single digits above zero all the way down to the coast.

Saturday will be a partly to mostly sunny and dry day. Afternoon

high temperatures will be in the lower teens across the north and

mid teens to around 20 central and downeast, which is a bit below

normal.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

Appendage of cold air will remain across western New England

through Monday morning. Overnight lows will largely fall into

the single digits above and below zero. The cold air is

filtering in around high pressure centered over James Bay. The

tighter pressure gradient over the eastern CWA keeps much of the

greater CAA to the west, over the Central Highlands and North

Woods. Although, with slackening winds in valley locations under

mostly clear skies, low temps Sat night stand to be cold across

the region regardless.

Sunday will be clear and cool with high pressure to the north.

Flow around the high will keep the chance for some stratocu deck

across the far north, but otherwise dry conditions forecast.

Light N winds continue Sun night with little net temperature

advection aloft. This lull comes ahead of a Mid-Atlantic low

pressure system set to redev along the East Coast.

Dry conditions are set to hold through the day Monday, with

cloudiness thickening and lowering ahead of the system.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

First steps into the long term highlight a potential winter

storm for the region. However, there remains a few outcomes that

leave room for greater confidence in the mid-week forecast.

Initial intensification of the low begins Sat across the

Central Plains, with it`s forecast track owning to it`s

origin...flat. It will be embedded in otherwise zonal flow

aloft which limits its track N/S. Redevelopment of the low is

forecast to take place across the Mid-Atlantic Monday night.

Here, there begins differing trends in guidance. At this stage

in the low`s cycle, air lifting aloft is caught by a SW jet

aloft, fracturing deeper clouds and moisture into the Atlantic

and Nova Scotia. For the GFS, this places much of the lift over

the waters with the potential for light accumulating snow

Downeast as the jet is placed further east due to a neutral

trough angle.

ECMWF and GEM remain fairly lock step, pushing the trough in a

slightly negative tilt which keeps the entrance region of the

exiting jet aloft over the area. This opens the chance for

accumulating snow Downeast and further inland, but the area of

lift works quickly across the region, keeping QPF generally

limited.

As a result, have kept PoPs highest Downeast, while increasing

them a bit further inland. Precip type will hinge on how much

cold air remains in place, however have sided to keep the area

all snow as WAA is generally weak when going against otherwise

ENE low level flow. Accompanying the system will be strong

winds along and over the waters.

Snow showers look to linger through the day Wednesday as

remaining moisture pivots out of the region. Dry conditions

shape up through the end of the week before another event

approaches heading into the weekend....