Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
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FXUS61 KCAR 232240
Area Forecast Discussion
National Weather Service Caribou ME
640 PM EDT TUE AUG 23 2016
A weak weather disturbance will cross far northern Maine this
evening with isolated showers. Another weak weather system could
produce an afternoon shower in the Saint John Valley Wednesday
afternoon. A cold front will cross the region Friday with showers
and thunderstorms and will be followed by high pressure this
.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --640 PM Update. Minor adjustments to the HRLY temps and SKYCON,
otherwise no major changes to the previous forecast.
. Previous discussion. A shortwave seen on satellite pictures
moving across southern Quebec early this afternoon will clip
northern Maine this evening with clouds and the chance of a
shower. The best chance of a shower will be to the north of a
Clayton lake to Presque Isle line before 00z, but can`t entirely
rule out a shower until around midnight. The sky will be partly to
at times mostly cloudy across far northern Maine and mainly clear
Down East after daytime cu dissipates. Lows tonight will mostly be
in the mid to upper 50s. Wednesday will be a warmer day with
west/southwest flow. A weak weather disturbance could touch off an
isolated afternoon shower in far northern Maine, mainly in the
Saint John Valley. Otherwise, it will be partly sunny in the north
and mostly sunny across the southern half of the CWA. Temperatures
will be a good 5 to 8 degrees warmer than this afternoon as 925h
temps climb from +16-18C this afternoon to +20-22C tomorrow. Highs
will top out in the low to mid 80s for most inland areas, but
cooler along and near the shoreline where the flow will turn
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.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
Wed night should have mostly clear skies, though S`ly breezes will
keep temps in the 60s as dewpts hold around 60F. Shortwave upper
trof with associated sfc low will move east across the region
Thurs, with some shwrs and perhaps a few storms psbl thru the day.
Better POPs will be further north, with the S`ward extent of the
chc POPs dependent on the exact track of the sfc Low - a source of
minor disagreement btwn models.
Very brief upr ridging behind this feature may allow for a brief
break in precip, but shwrs may linger in the St. John Valley.
Friday is starting to look like an interesting day - Perhaps one
of our last chances at strong to psbly severe storms. Multiple
models are pointing toward psbl CAPE over 1000 J/kg, with the
potential for some strong shear as the upper feature swings over
the area. For now, did not put in any enhanced wording, but will
need to closely monitor - the timing of the front will be crucial,
with a slower front more favorable to strong storms. POPs for Fri
aftn & eve are high-end Chc to Lkly. Temps will remain abv nrml
for the short term, ahead of the front before dropping off in the
long term period. A faster front would likely lead to a decrease
in the fcst high temps for Fri.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
It looks like a great weekend across the CWA as a broad upr ridge
moves off the Mid-Atlantic Coast and a sfc high moves from Quebec
to the Gulf of Maine and Nova Scotia. High will range from the low
70s in the North Woods to around 80 for interior Downeast, and
dewpts should be noticeably lower. However, the previous
expectations of the ridge and sfc high to hold on into Monday
appear to be in doubt, with both the GFS and ECMWF showing a
breakdown in the ridge as a shortwave 500mb trof moves from the
Great Lakes toward the coast. The CMC currently stands alone
showing a stronger ridge and slower progression of the trof. At
this time, did not put any thunder in the forecast for Monday, but
will need to keep an eye on that as well.
If this system does indeed come through on Monday, then Tuesday
looks to be a nice day, with seasonable high temps and offshore
winds. However, until the timing of the Monday feature gets locked
down a bit more over the next few model runs, will need to keep an
eye on the potential for Tuesday`s weather to deteriorate.
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR for the next 24 hours with the only exception very
brief MVFR north of KPQI this evening and again Wed PM in any
VFR conditions across the area expected Wed night. That should
continue for KBGR and KBHB on Thu, but KHUL thru KFVE could have
some showers and perhaps a tstorm bringing MVFR or brief IFR
conditions to those sites. The chance for periodic MVFR or IFR
conditions will continue thru Thu night, and more widespread
reductions appear likely on Friday, when more showers and psbl
strong storms are expected across the entire area. As that system
clears out, a return to VFR conditions expected at all areas,
though will need to monitor for psbl patchy fog both nights, due
to the clear skies and recent moisture.
NEAR TERM: The wind and seas will remain below small craft advisory
levels through Wednesday.
Wind gusts will be near SCA criteria levels Thu afternoon thru Fri
morning. Fresh onshore winds are forecast to build seas Thu into
Fri, with seas currently expected to peak at 5-7 feet from later
Thu afternoon thru Fri evening. A small craft advisory will be
needed if this forecast pans out.
Since June 1st it has been the 10th wettest summer to
date on record at Caribou, and since the 1st of the year it ranks
as the 6th wettest year to date on record.