Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
330 PM EDT sun Mar 16 2014
cold high pressure will build east toward the region tonight through
Tuesday. The high will move into the Maritimes Wednesday with a
strong occluded front to sweep across the region Thursday.
Near term /through Monday/...
currently intense low pressure over the Maritimes is working in
conjunction with strong high pressure centered over the Great Lakes
to produce tight pressure gradient resulting in strong gusty
winds. Expect the gradient to weaken as high pressure builds in
from the west this evening. At same time very cold air being
advected into the region. Although winds expected to diminish a
little this evening still expect the combination of cold
temperatures and winds to result in wind chill so will continue
the advisory later tonight into Monday. Do not expect any
precipitation tonight or Monday. For winds...temperature and dew
point will make only minor adjustment to current numbers. Blowing
snow confined to areas that received snow squalls this morning as
previous snow cover has become packed.
Short term /Monday night through Wednesday/...
the northwest flow will persist Monday night into Tuesday as high
pressure will be over Quebec with low pressure over Atlantic
Canada. Lows will once again be quite cold for this time of year
Monday night and generally be in the -5 to -10 range across the
north except as low as -10 to -15 in the North Woods. Lows
downeast should generally be in the 0 to 5 above range. The
airmass will moderate Tuesday under plenty of sunshine but still
be below average for this time of year with highs in the 20s to
low 30s. Fair but cold conditions persist Tuesday night with
increasing clouds and further moderation in temperatures occurring
for Wednesday as southerly winds increase ahead of the next
system. Any precip, however, looks to hold off until late day.
Long term /Wednesday night through Sunday/...
the next system will affect the area with rain and snow for the
Wednesday night into Thursday time frame. There are still some model
discrepancies with the timing and exact evolution of this system
with the Gem depicting the fastest solution and the European model (ecmwf) being
the slowest. The track of the primary low well west of the area
along with the modified airmass ahead of the system will result in
this system bringing mixed precipitation and rain right along the
coast with snow, potentially going to a mix by Thursday, across
the north where several inches of accumulation will be possible.
The low moves out for Friday with generally fair and seasonal
conditions expected. The next system to affect the area could
arrive by next Saturday however there are significant differences
in the forecast models regarding the track of this low. A return
to fair but cold weather looks to return for end of next weekend
as the next Arctic high settles into the Great Lakes.
Aviation /19z Sunday through Friday/...
near term: expect VFR conditions next 24 hours.
expect VFR Monday night through Tuesday night. Some stratus could
bring MVFR conditions as early as during the day Wednesday to the
southern sites with widespread IFR expected by Wednesday night
into Thursday as the next system moves in with rain and snow. This
system will depart by Friday with improving conditions.
near term: have used the nam12 for sustained wind speed and will
use 125 percent of the sustained wind for gust speed. Will keep
same timing for Gale Warning. For waves: currently combined seas
consist of southerly long period wave (3 feet/8 seconds) and off-
shore wind wave. Since most of combined sea resulting from off-
shore wind expect combined sea to subside quickly with winds later
tonight. Have used the NAM/Swan to generate wave grids. Will
continue current timing of freezing spray advisory.
winds diminish Monday night into Tuesday with conditions expected
to be below Small Craft Advisory levels into midweek. Winds/seas pick up for
Wednesday night into early Thursday as the next system moves
through with a good potential for Small Craft Advisory conditions to develop.
ME...Wind Chill Advisory from 4 am to 10 am EDT Monday for mez002-
Wind Chill Advisory from 11 PM this evening to 10 am EDT
Monday for mez001-003-004.
Marine...freezing spray advisory from 7 PM this evening to 11 am EDT
Monday for anz050>052.
Gale Warning until 2 am EDT Monday for anz050>052.