Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCAR 310406
Area Forecast Discussion
National Weather Service Caribou ME
1206 AM EDT TUE MAY 31 2016
A weak cold front will move across the region late tonight...
followed by a stronger secondary cold front Tuesday afternoon.
High pressure builds across the area Wednesday into Thursday.
Another cold front will approach northern New England Friday.
.NEAR TERM /THROUGH TODAY/...
-- Changed Discussion --update: Latest radar reflectivity imagery shows a few showers and
isolated thunderstorms still ongoing across the St. John Valley so
have extended the chance for an isolated shower or thunderstorm up
there for another hour or so. Otherwise current forecast still
Otherwise...fcst hrly temps thru the ovrngt were only slightly
modified using trends noted from obsvd 8-9pm to msly unchgd fcst
lows posted at 5am.
Orgnl Disc: We are still anticipating scattered showers and
thunderstorms to develop this afternoon and persist into the
evening. The warm front has crossed the region and we`re getting
plenty of clearing skies in the state. Cumulus clouds have already
started to pop up in the North Woods where the sun`s been around
the longest and temperatures have already risen into the mid 70s.
And in Quebec, where the time of heating has been even longer,
convection is already well underway. As such, expect convection
will spread eastward into northern Maine through this afternoon.
Although CAPE will be modest, topping out at around 800 J/kg,
0-6km shear is a more impressive 40 kt. This will allow some
storms to become organized and capable of producing gusty winds
and small hail. Given this amount of shear, would not be surprised
to see a few strong to possibly severe storms develop this
afternoon. SPC continues to keep the northwestern 2/3 of our area
in a marginal severe weather risk in their latest Day 1 outlook.
The storms will dissipate this evening as daytime heating is
lost. It`ll be a mild night with lows in the mid 50s to around 60.
A weak cool front will cross the region overnight, bringing in
some slightly cooler air. Skies will clear out, but with plenty
of lingering moisture from today`s rain, expect fog to develop
overnight, particularly along the coast.
For Tuesday, a secondary cold front will cross the state,
bringing another round of showers and thunderstorms for the north.
Moisture will be lacking a bit more with this activity, so don`t
expect it to be quite as widespread as today. Highs will be quite
warm though, especially Downeast where temperatures will top out
in the lower to mid 80s away from the coast. Northern and central
areas will be a little cooler since the front will pass through
there first; highs in the mid 70s will be common.
-- End Changed Discussion --
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
The cold front and upper level shortwave will speed east Tuesday
night with a northerly flow at the surface advecting cooler and
more stable air. Lows will dip into the mid to upper 40s north and
low to mid 50s for Bangor and Down East. High pressure builds
Wednesday...yielding mostly sunny skies, low humidity and highs
ranging from the upper 60s to mid 70s. The higher end of the range
will be found in the southern half of the forecast area where
downslope/offshore flow will keep cool sea breezes out of the
forecast until late day. On Wednesday night...the high moves east
and a southerly flow is expected to generate some coastal and
upslope fog and and stratus later in the night into Thursday
morning. This onshore flow means a reversal of the previous day`s
highs. This time, the warmest highs will be in the Allagash and
the coolest highs will be on the coast.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A dry and pleasant weekend is likely this weekend as shortwave
ridging moves over. However, the major weather story as we go into
the longer range, especially early next week, will be a big
amplification of the jet stream. This will include a ridge in the
western US and a deep trough in the eastern US which will bring
cool, wet and unsettled weather through much of next week. The
trough will be supported by a blocking ridge near Greenland; a
negative NAO pattern. Beginning with late this week, clouds will
increase Thursday night as low pressure tracking to our north pulls
a weak occlusion across the region. Some showers will be possible
late Thursday night through Friday. Skies will trend clearer on
Saturday then Sunday should feature plenty of sunshine and
comfortable temperatures as ridging briefly moves across our area. A
deep low pressure system will intensify and dig through the great
lakes late in the weekend. This low will approach on Monday bringing
increasing clouds and some rain to the area. Rain, drizzle and low
clouds will likely last through the middle of next week as the deep
low very slowly moves across our region.
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: Conditions are already improving to VFR across the
north as skies begin to clear out. Cumulus will quickly develop in
any clear spots, along with scattered showers and thunderstorms.
Localized IFR conditions will be possible in any thunderstorms
that develop. Patchy fog will develop overnight, leading to
occasional MVFR/IFR conditions. Otherwise, VFR is expected to
prevail at the northern sites. The southern terminals may briefly
see MVFR or perhaps even VFR conditions, but they will drop back
to IFR/LIFR this evening due to fog and remain so through 12z
Tuesday. The fog will dissipate and conditions will improve to VFR
SHORT TERM: There`s a chance of MVFR tempo IFR clgs for BHB and
BGR late Wednesday night into early Thursday morning. Otherwise,
VFR conditions are anticipated.
NEAR TERM: No headlines will be needed tonight or Tuesday. Southwest
winds will increase overnight as a cold front slowly approaches the
waters from the north. Gusts up to 20 kt are expected. Seas will
build to around 4 feet, but overall conditions are expected to
remain below Small Craft Advisory levels.
SHORT TERM: No significant weather is forecast. Patchy fog and
stratus is possible later Wednesday night, but confidence is not
high enough to include in the forecast at this point.