Area forecast discussion
National Weather Service Caribou ME
625 am EDT sun may 19 2013
Synopsis...
high pressure will remain over the area today. The high will move
east this evening as a small wave of low pressure slides in from
central Canada. The low will cross the area early Monday morning
followed by high pressure later Monday through Tuesday.
&&
Near term /through tonight/...
625 am update...the big challenge this morning is the stratus
which has now expanded north of Caribou. The stratus now covers
a large area from southern Maine to northeast Maine...with breaks
downeast and a generally clear sky across the northwest portion of the
County Warning Area. Expect most of the stratus to lift middle-late morning...but
patches may hold on along and near the coast. Made some
adjustments to the sky grids for this morning and will cancel the
remainder of the freeze warnings as temperatures are on their way up. The
cold spot early this morning was Estcourt Station with a low of
22f.
452 am update...canceled the freeze warning in southeast Aroostook
County and the frost advisories central Penobscot and Washington
counties early as an extensive area of stratus has formed and
temperatures are well above freezing. Will also make some tweaks to the
sky grids based on the latest satellite picts and observations.
Previous disc... a surface ridge covers the northern and western
Maritimes and into the Gulf of Maine early this morning. A very
tricky sky forecast as an area of status with ceilings around 2 k
feet above ground level has developed from about Houlton-Millinocket and points southeast
across central Penobscot County and much of Washington County.
Outside of this area of stratus most areas will start clear and
frosty with some increase in clouds late in the day across the
western zones. The ridge will slowly drift to the southeast through ton.
A weak surface low and frontal boundary will move into the County Warning Area ton
with most of the support in the middle/upper levels as shortwave
energy and an area of lift moves out of Canada and across the
area. The models all have an area of 1/2 inch of quantitative precipitation forecast across the
western zones from 06-12z Monday...and the GFS and NAM have bulls-
eyes in excess of an inch across the western mountains which looks
overdone. The models do still differ some on the timing and
location of the heaviest qfp late ton into early Monday morning.
Confidence is high enough to spread categorical probability of precipitation in from west
late ton along with patchy fog downeast where the flow off the
water will result in some low clouds. The clouds/rain will make
for a much milder night than the last several...with lows mostly
in the 40s and no threat of frost.
&&
Short term /Monday through Tuesday/...
Monday will dawn with rain across the area as a small low dropping
in from central Canada pulls a surge of warm advection rain out
ahead of it. The low is fast moving and rain will quickly move
southeast and away during the middle morning Monday. Skies will
likely remain mostly cloudy through midday with stratocumulus
clouds. Skies will then becoming increasingly clear late in the
day and into the evening as high pressure and drier air press in
from the northwest. Canadian high pressure will bring a mostly
clear and cool night Monday night followed by a sunny to partly
cloudy day on Tuesday as the high builds over.
&&
Long term /Tuesday night through Saturday/...
Tuesday night will be clear and cool across the area with high
pressure in place. The high will likely bring a dry start to the
day on Wednesday. Our focus then turns to a large area of low
pressure in the upper Midwest. Forecast guidance has been very
ambivalent about whether this storm would make it into our area
with some guidance keeping the moisture to our south along a
frontal boundary and some guidance lifting the moisture into our
area. The key feature in guiding this system east seems to be a
large upper trough in eastern Canada. If this trough digs back to
the southwest it could capture and lift the plains storm east
northeast into our region. However...if the Canadian trough just
drops south into New England it would suppress the moisture to our
south keeping our area cool and dry. Currently the guidance is
indicating that enough of the Canadian trough will drop back
southwestward to pull some moisture and rain into our area later
Wednesday into Thursday. Eventually the trough digs down across
our region pushing the remaining moisture east and bringing a
return of drier and moderately cooler air late in the week.
&&
Aviation /10z Sunday through Thursday/...
near term: mostly MVFR at the terminals early this morning as a
fairly extensive area of stratus developed overnight. Conditions
are expected to improve the VFR by 14-15z...but patches of stratus
may linger near the coast into the afternoon. Conditions lowering
to IFR around 04z at kbgr and kbhb in low stratus tonight...and
after 08z at the northern terminals in stratus and rain.
Short term: IFR conditions in rain Monday morning will improve to
MVFR by midday Monday then VFR Monday afternoon. VFR conditions
are expected Tuesday into Wednesday morning. Conditions may lower
to MVFR or IFR late Wednesday into Thursday as clouds and rain
move in.
&&
Marine...
near term: a light wind regime today with the wind picking up
ton as the high drifts southeast of the area and weak low pressure
passes well northwest of the waters. Sustained wind of 15 to 20 knots
developing late ton with gusts to 25 knots. Will start a Small Craft Advisory at 08z
ton. Fog will likely develop late this evening and may limit the
visibility to under 1 nm at times tonight.
Short term: an Small Craft Advisory will be needed for wind gusts over 25 knots
Monday morning. Some fog may limit visibility early Monday. Winds
will diminish Monday afternoon and remain below Small Craft Advisory through
Tuesday. Winds may reach Small Craft Advisory again late Wednesday as low pressure
approaches again.
&&
Car watches/warnings/advisories...
ME...none.
Marine...Small Craft Advisory from 4 am to 2 PM EDT Monday for
anz050>052.
&&
$$
Near term...cumulonimbus
short term...Bloomer
long term...Bloomer
aviation...cb/Bloomer
marine...cb/Bloomer
