Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Caribou ME
1208 am EDT sun Apr 22 2018
low pressure off the Newfoundland coast will continue to move
east into the open North Atlantic overnight. High pressure to
the west of the area will build into New England Sunday. The
high will crest over the area Monday then exit to the east
Near term /through Sunday/...
12:08 am update: satellite pictures show a few patches of mid
level clouds across mainly the far north and along and near the
New Brunswick border. Otherwise, the sky is mainly clear. The
wind has become very light and in some spots calm. Temperatures
as of midnight have dropped back into the mid 20s in some of the
colder northern valleys, and into the upper 20s to low 30s for
some of the colder interior downeast locations. Other than a few
minor tweaks to the hourly temperatures and overnight lows, the
ongoing forecast is in great shape.
Prev discussion blo...
Sat imagery shows the greatest cvrg and deepest cld depth ovr
the SW two thirds of the forecast area this mid aftn. Latest radar ref
imagery also shows a relatively narrow band of lgt shwrs ovr
cntrl and southeast ptns of the fa, but with dry sub-cld air ovr all of
the fa, it's likely that little if any precip is reaching the
sfc attm. Subsequently, we lowered pops a little faster going
into the evening than the prev fcst.
Otherwise, models are indicating a little faster clrg across the
forecast area from west to east ovrngt as the back edge of the cld cvr erodes due
to low and mid lvl dry air. Winds, which have been gusting up to
30 mph will subside sig after sunset, spcly ovr broad rvr Vly
areas. Sun should be msly sunny, breezy (but not as windy as
tdy) and a little milder with neutral to weak llvl cold advcn.
Sun ngt will be clr with lgt winds with good radiational cooling/
sfc base invsn potential allowing for one last cold ovrngt lows
Erly Mon morn before a strong warming trend begins later in the
Short term /Sunday night through Tuesday night/...
Spring will make a very strong appearance for the start of next
work week. Highs are forecast to surge well into the 50s on
Monday and then many locations should reach into the 60s on
Tuesday. This pleasant weather will be courtesy of an area of
high pressure sliding over New England on Mon, then moving south
of Maine and Nova Scotia on tues. Abundant sunshine is expected
Monday as the core of the high slides across the region, with
increasing clouds later tues as the next system approaches. Some
cooler temps aloft and lesser mixing due to lighter winds will
likely limit temps to the 50s on Mon. Stronger S-sw'ly winds,
more mixing, and 850mb temps around or a bit above freezing
point toward highs likely in the lower 60s, provided dense cloud
cover doesn't develop too early.
Long term /Wednesday through Saturday/...
the long-term forecast is messier and more complicated for
sure, with a series of systems possibly impacting the County Warning Area.
However, with the 12z cycle, models have come into better
agreement on the timing and number of waves for the second half
of the week. One can only hope that this agreement holds as we
go forward. As a 500mb cut-off low moves toward the County Warning Area Wed and
Thu, rain likely reaches the County Warning Area Wed afternoon, with heavier
rain seeming most likely Wed eve and night. Rain showers will
persist during the day and evening on Thu as the cut-off crosses
over the area. Some brief and weak upper-level ridging may allow
for a bit of clearing Fri and Fri night. Models then disagree on
the timing of the arrival of the next cut-off system, due to
differences on how far south of the main jet the cut-off low
gets. The forecast currently brings in chance pops during the
day Saturday, with low-end likely pops for the Central Highlands
and North Woods Sat afternoon.
Aviation /04z Sunday through Thursday/...
near term: VFR next 24 hours. Northwest winds will pick up again mid-
Short term: VFR conditions expected for all sites through Tue
night. MVFR cigs expected to develop during the day Wed as rain
spreads in from the west. Cigs may drop to IFR at times Wed
night into Thu, with MVFR vis likely in areas of heavier rain.
near term: winds and wvs, which are currently below Small Craft Advisory
thresholds, will cont to slowly subside ovrngt thru sun ngt.
Kept close to ww3/nwps guidance for fcst WV hts, with two WV pd
spectras, a swell group arnd 10 sec and wind driven group arnd
Short term: light offshore winds Mon will turn more sw'ly Mon
night into Tue and increase as high pressure moves east of the
area. Wind gusts Tue and Tue night may approach Small Craft Advisory levels, but
as of now they were kept below criteria. Seas will build later
Tue into Tue night with the shift to strengthening onshore flow,
but should remain in the 3 to 5 ft range.
aside from the risk of other isolated ice jams forming on one
of the northern rivers no flooding is expected this weekend into
early next week. The ice should finally get flushed out next
week with a significant warmup that will lead to a lot of
snowmelt. By mid- late next week, the rivers will be running
high due to snowmelt, but whether there is any flooding will
likely depend on how much rain falls late in the week. The
situation will need to be closely monitored through the week.