Area forecast discussion
National Weather Service Caribou ME
628 PM EDT Sat may 25 2013
Synopsis...
low pressure in the Gulf of Maine will move slowly northeast and
into New Brunswick Sunday. The cool and wet weather will continue
into Sunday with some drying expected on Memorial Day.&&
Near term /through Sunday/...
update 1820l: low pressure continues to spin over the northwestern gom west/ deep southeast-
northwest conveyor belt of deep moisture to the east and NE of this system -
this affecting much of the northestern half of our forecast area west/ radar showing
widespread MDT to occasionally heavy rain for east central and northestern areas. Other
than a few minor adjustments...current forecast appears very wet and
cool and on track...
Low pressure will continue to slowly move NE across the Gulf of Maine
tonight and into New Brunswick Sunday keeping the weather
damp and cool. Moisture wrapping around the low will produce
periods of rain tonight with the heaviest rainfall across central
and northern portions of the County Warning Area...and especially in upslope
areas. The precipitation will be more showery downeast. In
coordination with the rfc and kgyx have issued a Flood Watch for
small streams for all of northern and eastern Maine with the
exception of zones 29 and 30 (see Hydro section below). All areas
will have some drizzle and fog tonight into Sunday. The 925 mb
temperatures are expected to drop below 0c across far western Aroostook
and northern Somerset counties where the rain could mix with or
even change to wet snow at times overnight into early Sun
morning. Temperatures tonight will bottom out in the middle 30s in
the far west to the l/M 40s downeast. The weather remains quite
unsettled Sunday although the precipitation will likely not be as
heavy with periods of light to occasionally moderate rain in the
north and showers and drizzle downeast. Temperatures will remain cool
with highs mostly 45 to 50 across the northern and western zones
to the l/M 50s downeast.
&&
Short term /Sunday night through Tuesday/...
slow moving low pressure will gradually lift north of the area
Sunday night. Any steadier precipitation will taper off in the
early evening with just some lingering scattered showers expected
for the overnight...mainly over northern areas where some wet snow
flurries could even mix over the higher elevations. Lows will be
quite chilly with some areas over the northwest potentially even
dipping to around freezing.
Considerable cloud cover will persist for Monday along with a few
continuing scattered showers in the north as the area will still
be on the back side of the departing upper trough. Also expect
conditions to be breezy and cool with highs ranging from the low
to middle 50s north to the upper 50s to around 60 south.
Skies will finally clear for Monday night into Tuesday as high
pressure finally moves in. Temperatures will also moderate
Tuesday with highs in the 60s.
&&
Long term /Tuesday night through Saturday/...
models continue to show the period of dry weather to persist
through Tuesday night. Models are also consistent in bringing the
next chance for rain into Maine beginning on Wednesday...as a
storm system moves east across the region. While the models are
consistent in timing this system...there are differences in
placement. The GFS is a little farther north...therefore it brings
rain through in two waves...one on Wednesday and another on
Thursday. It then drapes the associated surface-middle level boundary
across the northern portion of the state...which may be the focus
for additional periods of rain. The European model (ecmwf) and CMC are farther
south...and bring the system through Wednesday/Wednesday night/Thursday. The
surface-middle level boundary sets up south of the region leaving
predominantly dry weather to northern and eastern Maine. Due to
model differences there is significant uncertainty in the forecast
beyond Wednesday. For now have just kept probability of precipitation at a general 20/30
percent beyond Wednesday. Regardless of timing...this system
should not be a prolific rain producer with no direct link of
subtropical moisture.
Temperatures at or above normal are expected throughout this time
frame as the upper level trough moves east and is replaced by
broad ridging.
&&
Aviation /22z Saturday through Thursday/...
near term: mostly IFR/LIFR through Sunday in low stratus...rain &
fog.
Short term:
expect MVFR and potentially still even periods of IFR
Sunday night due to persisting low clouds. For Monday, conditions
should improve to VFR for the southern sites with MVFR still
continuing at times in the north. Skies finally clear for Monday
night and Tuesday with VFR for all sites.
&&
Marine...
near term: seas running about 8 feet with a 10 second period at the
eastern Maine shelf. A long period southeast swell will continue through
Sunday (and beyond) and will extend the Small Craft Advisory through 00z Monday.
A northeast wind of around 25 this afternoon with some stronger
gusts will become south and diminish tonight. At some point later
tonight the Small Craft Advisory should be able to be transitioned into one for
hazardous seas only.
Short term:
seas will still be near or just above Small Craft Advisory levels Sunday evening
before diminishing below Small Craft Advisory criteria for Monday and Tuesday.
Expect winds to be below Small Craft Advisory levels through this period.
&&
Hydrology...
update 1830l: made calls to wash County and appears no further
minor flooding issues as the heavier rain has moved north of this area
so will be dropping the flood advection shortly.
A Flood Watch was issued through Sunday morning for all zones
expect 29 and 30. Additional rainfall amounts in excess of an inch
on already saturated soils will cause many smaller streams and
creeks to overflow their banks. The heaviest rainfall tonight into
Sunday morning will be across the upslope areas of central and
northern Maine. The mainstem rivers will see significant within
bank rises during the next 24 hours.
&&
Tides/coastal flooding...
no flooding or splash over was reported with the high tide late
this morning. The Tides are expected to be about 1.5 feet higher
with the high tide late this evening and some splash over appears
likely.
&&
Car watches/warnings/advisories...
ME...Flood Watch through Sunday morning for mez001>006-010-011-
015>017-031-032.
Coastal Flood Advisory from 10 PM this evening to 1 am EDT
Sunday for mez029-030.
Marine...Small Craft Advisory until 8 PM EDT Sunday for anz050>052.
&&
$$
Near term...khw/cb
short term...fitzsimmons
long term...runyan
aviation...khw
marine...khw/cb/fitzsimmons
hydrology...khw/cb
tides/coastal flooding...cumulonimbus
