Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Gray ME
333 PM EDT Sat may 30 2015
a cold front will approach from the west and slowly sag south
through the region tonight...stalling over southern New England on
Sunday. Low pressure over the Ohio Valley will slowly move
northeast along the front Sunday night through Tuesday. Low
pressure over eastern Maine Tuesday night will continue to drift
off to the northeast on Wednesday as high pressure builds in from
the west. High pressure will crest over the area Thursday before
shifting offshore. A weak cold front will drop south from Canada
Near term /through tonight/...
clear skies have allowed temperatures to climb well into the 80s across
much of the western forecast area...with dewpoints in the low 60s. A
corridor of modest instability has developed within this
region...supporting the development of scattered pre-frontal
convection across the New York capital region. These should gradually
move into New Hampshire zones in the next several hours. Cold front will take
longer to arrive in the forecast area...with any convection
associated with that feature delaying until closer to 00z. Until
day time heating wanes the threat is there for a stronger storm or
two...with damaging wind the main threat. Will keep gusty winds and
heavy rain in the grids for these storms through about 01z. With poor
lapse rates aloft...loss of heating will limit the amount of
instability available for any stronger storms overnight.
Will also have to monitor fog potential tonight. Winds turning
more southwesterly will keep the bulk of it off shore...but hi-res guidance
does suggest some may be able to work back into the midcoast
region late this evening. At this time it is too low probability
to include in the forecast.
Short term /Sunday through Sunday night/...
by early sun cold frontal precipitation will be arriving near the coast.
Winds turn northerly behind it...and temperatures will begin falling as strong
high pressure builds to the north. Expecting cool temperatures...especially with
widespread precipitation over the area. It is going to be an ugly end of
may with cool temperatures and plenty of rain. Convection allowing models
do indicate thunder redeveloping again middle Morning Sun...so will
keep a chance in the grids.
Thunderstorms will be much less likely overnight sun...though rain will
continue especially for southern and western zones. There should be a brief
break at some point during this period...while a wave forms on the
front to the west and drifts towards the area by early Monday.
Long term /Monday through Saturday/...
welcome rain coming to the area as cool high pressure to the north
battles with very warm and moisture laden airmass to the south.
Heaviest rain will fall in southern portions of the forecast area
on the cold side of the front. Low pressure will move along the
front south of New England anf then northeast into the Gulf of
Maine. Have lowered high temperatures for Monday by 5 to 8 degrees and
that may not be enough as models are showing high temperatures of around
50 with a gusty northeast wind. Rainfall expected to be on the
order of 2 to 3 inches with lesser amounts to the north and east.
Low pressure will move east of the forecast area with clearing
skies expected in southwest portions of the area Tuesday night.
Sunny skies return Wednesday. A cold front will will move trough
the area Saturday morning.
Aviation /19z Saturday through Thursday/...
short term...VFR conditions will slowly give way to MVFR as
showers/thunderstorms approach the northern zones this evening. Coast should
remain VFR into the late evening with slow frontal movement. There
is a low probability that coastal fog/stratus tries to work back
into coastal ME this evening...but southwesterly winds should keep this
mostly confined to the midcoast/krkd if anything. Widespread MVFR
or lower conditions are expected late tonight through sun...as rain
overspreads the region.
Long term...expect IFR/LIFR Monday and Tuesday in rain. VFR
returning for Wednesday and Thursday.
short term...Small Craft Advisory remains in effect for the outer waters for wind
gusts near 25 kts and seas building over 5 feet. Bays may see an
occasional gust to 25 kts today...but generally expected to see
sub-Small Craft Advisory conditions. Flow becomes northeasterly sun into Monday...but Small Craft Advisory
conditions will continue on the outer waters.
Long term...Small Craft Advisory will likely be needed for Monday
and Tuesday with a stiff east to northeast wind.
southwesterly winds will continue to transport increasing moisture
into the region ahead of an approaching cold front. As the front
slowly sags through the forecast area widespread wetting rains are
likely for all zones. Wetting rains are possible each day through
Marine...Small Craft Advisory until 6 PM EDT Sunday for anz150-152-154.