NWS Forecast Discussion

For Fremont, NH

FXUS61 KGYX 160310 AAB

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1010 PM EST Tue Jan 15 2019

Low pressure tracks east across Quebec on Wednesday. Some light
snow is possible near the Canadian border, but otherwise a west
wind will bring warmer weather. A cold front drops south across
the region Wednesday night with much colder air returning. It
will be 15 to 20 degrees colder on Thursday as cold high
pressure builds in. The next wave of low pressure tracks across
the region on Friday bringing a widespread light snowfall. A
larger storm will bring wintry weather this weekend.


10 PM Update...
Further adjustments to cloud cover as low decks are now covering
all of Maine and most of NH except for far southern and coastal
NH. This is impacting temperatures, which in some cases have
already dropped to their minimums and have increased again.
Temperatures are tricky but have used the latest blend of short
term models with a higher weight towards the CMC guidance which
has a better handle on cloud cover.

530 PM Update...
Stratus continues to bank against the northern and western
facing slopes of the higher terrain. Some of this deck has
spilled onto the coastal plain and reached Kennebec and
Cumberland County. Cloud cover was increased for this update. It
still looks like a slight thinning out overnight initially
followed another wave of stratus towards morning. Tweaked hourly
temperatures a bit which will largely depend on cloud cover;
ranging from 10 to 20F above.

Previous discussion...
Cloud cover will be the primary factor affecting the forecast
tonight. A lower cloud deck which has shoved itself into the
mountains from the north will likely remain there through the
evening and into the overnight. However, as the night goes on
the pressure gradient turns southwesterly and these clouds may
disperse a bit by morning, only to be replaced by more cloud
cover associated with the wave of low pressure tracking through
Canada. South of the mountains where there are not as many
clouds we could see the temperature drop to around 10 degrees
again tonight in sheltered spots. Elsewhere low to mid teens are
expected for lows, apart from the warmer cities in NH.


As fast moving low pressure tracks across Quebec, a warm front
slides across New England followed by a cold front from the
northwest Wednesday evening. The warm front is not very well
defined so it won`t be able to force a lot in the way of
precipitation. However, some light snow is possible near the
Canadian border especially as winds turn northwesterly behind
the cold front in the afternoon/evening. Across the coastal
plain and the southern half of New Hampshire, expect a warm day
with temperatures warming above freezing. Some low 40s are
possible as westerly winds promote a bit deeper mixing. But as
the cold front plows through in the evening the temperature will
start dropping. By morning it will be below zero again north of
the mountains. Downwind of the mountains winds through the night
will keep things well mixed, but the air mass moving in is quite
cold on its own so temperatures will still drop into the single
digits and teens.


Active weather conditions expected after Arctic high pressure
crests over the region Thursday. This will allow for well below
normal temperature readings Thursday, with areas below zero in
the north by late Thursday night.

A weak and disorganized area of low pressure will cross the
region Friday. This system is relatively moisture starved and
will have a brief period of warm air advection induced
precipitation. For the most part, the snowfall will be
relatively light, but there is also a low probability for a few
pockets of moderate amounts, mainly along and near the Penobscot
River Valley.

Strong cold air advection Friday night will begin to ease as
temperatures begin to modify on Saturday. Nevertheless, plenty
of cold and dry Arctic air will be in place initially as low
pressure intensifies and moves across or near the spine of the
Appalachians in the Mid Atlantic region. Snow will overspread
New Hampshire and Maine Saturday night, becoming heavier later
at night.

On Sunday, all deterministic and ensemble models within the 12Z
model suite begin to shift the storm northeastward towards
southern New England. Models have trended towards a warmer
solution aloft, allowing for the snow to change to sleet and
possibly freezing rain over southern areas during the day.
Temperatures at the surface should remain below freezing over
southern areas which could potentially allow for a relatively
thick layer of ice. However, model trends will continue to
dictate the forecast track within this fast moving and
positively tilted trough. Confidence levels do not remain high
with little run to run consistency.

Tides will need to be monitored this weekend and through the
work week next week as we will be at the peak of the
astronomical cycle.

Bitter cold follows the departing storm as Arctic air remains
stored up to our northwest.


Short Term...MVFR ceilings in the mountains may briefly disperse
by morning, but will likely move in again on Wednesday. VFR
conditions expected south of the mountains. A northwest wind
behind a cold front Wednesday evening could be briefly gusty
into the overnight.

Long Term...Areas of IFR conditions in snow on Friday. LIFR and
IFR conditions Saturday night into Sunday, initially in snow,
then mixed precipitation south.


Short Term...Some larger 5 to 6 FT swells are currently
affecting the Gulf of Maine. Expect winds to shift to the west
southwest on Wednesday and gust to 25 to 30 KT. Then behind the
cold front Wednesday evening winds will shift to the northwest
with gusts to 35KT primarily over the eastern Gulf of Maine
where the pressure gradient and cold advection are both
strongest. Gale Warning has been issued for the central and
eastern coastal zones while Small Craft Advisories are in effect

Long Term...SCAs possible with a departing system on Saturday. A
stronger system may produce gale force winds Saturday night
through Tuesday.


MARINE...Small Craft Advisory from 4 PM Wednesday to midnight EST
     Wednesday night for ANZ153.
     Gale Warning from 7 PM Wednesday to 7 AM EST Thursday for
     Small Craft Advisory from 7 AM Wednesday to 7 AM EST Thursday
     for ANZ151.
     Small Craft Advisory until 7 AM EST Thursday for ANZ154.



LONG TERM...Cannon

NWS GYX Office Area Forecast Discussion