347 AM EDT Sun Apr 23 2017
High pressure and drier air will finally build into the region
today. A cold front will drop south into northern New England
tonight into Monday and stall. Low pressure will slowly move up
the Eastern Seaboard Tuesday and Wednesday with drizzle and
periods of rain. A cold front will slowly approach from the
west Thursday into Friday, before finally crossing the region on
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Overall look for a clearing trend today as high pressure builds
in from the west. At 3 AM, clouds remained in place over much
of Maine with a few pockets of clearing in New Hampshire. These
clouds will move east and as they do areas which are able to
clear before sunrise may see fog form. Augusta is the usual
culprit here with visibilities already decreasing. Any fog will
be patchy and brief as the sun rises and quickly burns off the
moisture. The sun will allow for temperatures to climb to the
mid to upper 50s by mid morning.
High pressure crests over the region this afternoon, which will
allow a sea breeze to develop. With a weak pressure gradient the
sea breeze should be able to push inland as far as Sebago lake.
This south flow will keep high temperatures cooler along the
coast, especially from Portland east through Penobscot bay.
South of Portland, highs will still approach 60 along the water
and be in the low 60s inland.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
The evening will start off with clear skies across the region. A
cold front will approach from Quebec, but the high pressure to
our south will push it off to the north. The result is just a
slight chance of showers along the northern border and
increasing clouds through the mountains. Monday the same high
pressure will be in control for much of the day with high
temperatures once again getting into the 60s. Clouds will
increase from the south ahead of an approaching low pressure
system on Monday night.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Models continue to slowly lift an upper level low pressure
system to the northeast. By Monday night, models in good
agreement with surface low pressure near the North Carolina and
South Carolina border. As the system moves northeast,
precipitation will spread northward through our forecast area.
Patchy drizzle may form along the coast as onshore winds begin
By Tuesday night, models remain in relatively good agreement
with the 00Z suite, bringing low pressure to the New Jersey
coastline. Latest ensemble information supports this track as
Thereafter, the system begins to fill as it reaches New
England on Wednesday, however there will be plenty of moisture
in place for areas of rain and drizzle to continue especially
along the coast.
QPF: Best estimates show about an inch to 1.5 inches along the
coast. Lessor amounts will occur inland near the headwaters.
Therefore, river flooding is not expected at this time.
The system moves east Thursday as a cold front remains well to
our west. Lots of low level moisture will remain in place with
a developing southerly flow, so not much clearing expected.
Latest models suggest that the long awaited cold front will
cross the region Friday. Thunder will be possible with these
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
Short Term...Patchy IFR in fog through the next few hours with
all locations improving to VFR after sunrise. The region will
remain VFR through Sunday and into Monday.
Long Term...An onshore flow will lead to lowering ceilings into
the MVFR or IFR category during the day Tuesday as rain and
drizzle begins. Conditions continue to lower Tuesday night
through Wednesday night possibly locally to LIFR. Conditions
slowly begin to improve Thursday as a light southerly flow
Short Term...Easterly waves of 5 to 7 feet remain just off shore
and so have extended the Small craft through midday. Expect
waves to continue to diminish as high pressure builds in for the
Long Term...Onshore flow increases Monday night into Tuesday as
low pressure slowly moves up the Eastern Seaboard. Winds will
increase Tuesday night and waves will gradually build into early
Wednesday as the persistent onshore flow continues. Wave
forecasts may be underdone by the current model solutions with
such a persistent onshore flow.
High pressure builds in for Sunday as sunny skies help to dry
out conditions. RH will drop to near 30 percent across much of
New hampshire but with little to no wind, no fire weather
headlines are needed. The drier air will linger through Monday
before another system approaches tuesday spreading rain into the
High astronomical tides will continue for the week, increasing
during the midweek period. At Portland the astronomical tide is
forecast at 11 FT Tuesday night and 11.5 FT Wednesday night.
With a prolonged period of onshore flow expected, the ESTOFS
prediction for minor storm surge values of about a foot appears
to be reasonable. Winds decrease Wednesday night, however high
water anomaly`s will likely continue.
Nearshore waves will not be overly large during this period,
mainly ranging in the 5 to 9 foot range. However, with such high
astronomical tides, NART wave runup matrices and in-house
matrices suggest erosion and minor splash-over may occur
beginning as early as Tuesday night.
Very high astronomical tides will continue for the rest of the
week, with tides peaking out at 11.7 feet on Thursday and Friday
night in Portland Harbor.
MARINE...Small Craft Advisory for hazardous seas until 5 AM EDT early
this morning for ANZ150-152-154.