Area forecast discussion
National Weather Service Gray ME
452 PM EDT Wednesday may 22 2013
Synopsis...
a warm front will lift north through the region late tonight and
early Thursday. A cold front will approach from the west Thursday
afternoon and will slowly push offshore through Friday. Low
pressure will develop on the front south of New England Friday
night and it will intensify as it moves slowly northward into the
Gulf of Maine by Sunday evening. Low pressure will slowly continue
northeast into the Maritimes on Monday as high pressure builds in
from the west. High pressure will continue to build in from the
west on Tuesday.
&&
Near term /until 6 am Thursday morning/...
430 PM update...
have updated grids to relect current and forecast near term
weather. Have raised probability of precipitation across New Hampshire and western Maine for this
evening and included the threat of isolated thunderstorms with small hail
across western sections and isolated thunderstorms elsewhere.
Previous discussion...
warm front stalled over southern New England will gradually lift
northeast overnight and early Thursday. Weak over-running will keep
showers in the forecast for most areas but think the bulk of the
precipitation will be north of the border in better lift. Ocean
stratus will again close in much of the region downwind of the
mountains. Shower and thunderstorm activity back in eastern New
York and western New England may poke into portions of the
Connecticut valley this evening but marine layer will inhibit any
further eastward progress. Looking for low temperatures ranging through
the 50s overnight.
&&
Short term /6 am Thursday morning through Thursday night/...
warm front will lift north of the region on Thursday with unstable
and moist airmass settling into the region for the afternoon. More
southwesterly boundary layer winds should blow ocean stratus out
of most southern sections of New Hampshire and western Maine
during the morning and early afternoon. Expect showers and
thunderstorm to quickly develop during the late morning and early
afternoon. Best chances of precipitation will be in western zones. Wide
range in temperatures tomorrow with lower to middle 70s in New Hampshire and
southwest Maine. Southwest flow will middle coast areas in the 60s.
Slow moving cold front will gradually edge into the region Thursday
night with a steady rain over-spreading much of the region
overnight. Will also likely see some evening thunderstorms.
&&
Long term /Friday through Wednesday/...
upper level split pattern with trough lifting to the NE over NE Canada and
another digging to toward the middle Atlantic region. At the surface the cold
fnt slowly moves through then low pressure forms off the middle Atlantic coast
along the fnt in response to the digging upper level trough. This low then
tracks up the fnt providing hi probability prcp Friday and Friday night. The
upper level trough cuts off to our S then slowly lifts north Saturday through
Sunday with the surface low tracking up the East Coast which continue the probability
prcp Saturday and Saturday night. The low tracks up the ME coast and
to our NE on Sunday with still chance rain showers.
Finally the cutoff and surface lows lift far enough to the NE to see
slow improvement to our weather Sunday night and Monday. Upper level ridge
and surface high build in Tuesday for fair and milder weather.
Generally used blend of gfs40, gmos, HPC qpf, mex MOS and wna4 for
the long term forecast.
&&
Aviation /21z Wednesday through Monday/...
short term...IFR/LIFR ceilings/visibilities tonight...improving to VFR on
Thursday.
Long term /Friday through Sunday/...an extended period of
IFR/LIFR in rain showers Friday through Saturday night and still MVFR/IFR
likely to persist on Sunday.
&&
Marine...
short term...Small Craft Advisory in effect Thursday afternoon through Thursday night.
Long term /Friday through Sunday/...extended southerly flow
Friday ahead of approaching cold fnt may see wind gusts reach Small Craft Advisory
levels. Seas from persistent onshore flow likely to result in Small Craft Advisory
levels for hazardous seas Friday. Winds become northerly behind
the fnt Friday night through the weekend and again may see Small Craft Advisory gusts.
Seas continue to rough at Small Craft Advisory levels through the weekend as well.
&&
Fire weather...
no problems noted.
&&
Gyx watches/warnings/advisories...
ME...none.
New Hampshire...none.
Marine...Small Craft Advisory from noon Thursday to noon EDT Friday for
anz150>154.
&&
$$
Synopsis...
near term...jensenius
