Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
1156 am EST sun Jan 25 2015
low pressure will continue to move into the northern Maritimes
today. High pressure will build in behind the low tonight into
Monday. Another low will intensify off the middle Atlantic and
southeast New England states on Tuesday.
Near term /through tonight/...
1155 am update...the cold front has just about pushed across our
entire forecast area, with the last of the clouds and snow showers
rapidly moving off shore. Expect temperatures will now begin to
fall, though downeast may warm up another degree or two. Satellite
imagery shows a streamer is coming off the Saint Lawrence,
meandering across the Saint John valley. Have therefore kept a
mention of isolated snow showers there through middle afternoon.
Otherwise, expect plenty of sunshine and a cold northwest wind.
The forecast had a lot of this covered, so just made adjustments
to sky, pops, and temperatures to match current trends.
Previous discussion...the upper trough could touch off some light
snow showers. The GFS soundings are much more potent west/the snow
shower potential showing some sb cape of around 40 joules for the
northern 1/2 of the County Warning Area. The NAM is much weaker west/its instability
by does point to some decent positive vorticity advection at 500mbs which would aid in the
forcing. Decided to carry 20% probability of precipitation into early afternoon and then
things will shut down as northwest flow takes over and forcing weakens.
That colder air will pour into the County Warning Area in earnest by the afternoon
after daytime highs are hit early. We are talking temperatures
down to near zero and possibly below zero across portions of the
north and west. Further south into central and downeast, readings
are expected to be 10-15f by late afternoon. Northwest winds will kick up
as well west/gust potential to 30+ miles per hour into early evening.
Skies begin to clear this evening and temperatures will continue
to fall. Sustained winds of 10-15 miles per hour and gusts to 25 miles per hour early
will wind chill concerns into early Monday morning. This will will
be mainly across the northern 1/2 of the County Warning Area. Temperatures by
early Monday morning are forecast to be below zero all the way to
the downeast region which could include the immediate coast. High
pressure is forecast to build across the state quickly and the pressure
gradient relaxes west/winds forecast to drop off by 12z Monday. Given
that wind chill readings will drop to a range -25 to -30 across
the north and west, decided to go west/a Wind Chill Advisory for
tonight into Monday morning.
Short term /Monday through Tuesday/...
major winter storm may impact the region Tuesday into
Cold Canadian high pressure will build across to our north on
Monday with plenty of sunshine expected before high clouds begin
to increase Monday afternoon. Highs on Monday will range from zero
to 10 above north and central areas and 10 t0 15 above downeast.
Clouds will increase Monday night in advance of low pressure tracking
north across the western Atlantic. Expect snow to start to break
out across central and downeast areas after midnight Monday and
then reach far northern areas around or shortly after daybreak
Tuesday. Winter storm watches are in effect for central and down
East Maine beginning late Monday night and beginning early Tuesday
morning for the remainder of northern Maine.
Expect snow to become heavy at times during Tuesday as the low
tracks slowly northeast. Areas of blowing snow can be expected on
Tuesday with whiteout conditions possible especially across down
east areas where a low level jet of around 50 knots at 925 mb will
cross the area. Northeast winds may gust to 35 to 40 miles per hour at times
on Tuesday with even higher gusts possible across the down East
Long term /Tuesday night through Saturday/...
winter storm watches are in effect through Wednesday afternoon
for all of northern and downeast Maine. The snow will continue
Tuesday night and then begin to diminish by Wednesday afternoon as
the low tracks across Nova Scotia. Dry weather can then be
expected Wednesday night through Thursday. Another system may
bring more snow to the region Friday and into Saturday.
Aviation /18z Sunday through Friday/...
near term: MVFR ceilings across the northern terminal this morning west/a
period of IFR possible especially for kfve. Conditions are
expected to improve this afternoon into tonight across the
northern terminals W/VFR. Gusty northwest winds reaching near 30 kts will
lead to some turbulence this afternoon and early evening.
Short term: VFR Monday into Monday night. Widespread LIFR/IFR
developing Tuesday and continuing into Wednesday in snow and
blowing snow. Significant runway snow accumulations are possible.
Gusty northeast winds will result in blowing and drifting snow on
VFR conditions will return Wednesday night and Thursday.
near term: the Gale Warning has been extended into this evening.
The reason for this is for the second surge of winds coming in on
a northwest flow as the upper trough moves across the waters later today
into the evening. Stayed west/sustained winds of 25 to 30 kts
west/gusts to 35 kts. The best potential for gales will be across the
outer zones. Issued a freezing spray advisory as cold
temperatures coming across the waters on the northwest flow will lead to
freezing spray. Local freezing spray program indicates moderate
freezing spray tonight into early Monday morning.
The other concern is some overwash for seawall Road in Hancock
County. The local wave runup program indicates some minor
overwash at the time of high tide this afternoon(around 1 pm).
Higher waves(8-10 ft) and a southeast swell component could lead to some
spillover. The negating factor is the northwest wind that is forecast to
increase this afternoon which would offset the runup of the waves.
Attm, decided not to go west/any coastal advisory as the expectation
of the overwash appears to be minor. This will need to be
monitored by the daycrew.
Short term: a storm watch has been issued for the outer waters for
Tuesday with the potential for northeast winds gusting as high as
50 to 55 knots. Seas will be building to 15 to 20 feet. Visibility will
be reduced to less than 1 nm in snow late Monday night and into
ME...Winter Storm Watch from Tuesday morning through Wednesday
afternoon for mez001>006-010.
Wind Chill Advisory from 8 PM this evening to 8 am EST Monday
Winter Storm Watch from late Monday night through Wednesday
afternoon for mez011-015>017-029>032.
Marine...freezing spray advisory from 9 PM this evening to 7 am EST
Monday for anz050>052.
Gale Warning until 10 PM EST this evening for anz050>052.
Storm watch from Tuesday morning through Tuesday evening for