Area Forecast Discussion
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FXUS61 KGYX 010200
Area Forecast Discussion
National Weather Service Gray ME
900 PM EST Tue Feb 28 2017
A warm front will approach from the south and west tonight. Warm
weather builds on Wednesday as the front lifts through the
region. Temperatures will be near record warm levels before a
cold front moves across the area Wednesday night. Showers and
thunderstorms will be possible as the front moves through.
Colder air rushes in behind the front Thursday morning and lasts
through the weekend.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
855 pm update: Radar showing some very light precipitation aloft
but so far none reaching the ground. Lower levels continue to
moisten up on developing ssely flow. POPS forecast for the rest
of the night looks good. Low stratus now forming to our south
and over southeast NH and will gradually spread north and west
over the next few hours with developing areas of drizzle and fog
expected. After inputting latest mesonet data only minor
adjustments to near term temps were needed.
540 am update: Input latest mesonet data and made some minor
adjustments to near term temps. Also adjusted pops for next few
hours slowing down eastward progress of rain. Attm radar shows
an area of echoes across NH but the precipitation is all aloft
as the overrunning moisture is moving into very dry low levels.
Over the next few hours this will change as lower levels
gradually moisten up.
Areas of light rain will advance eastward ahead of an
approaching warm front tonight. Initially the airmass will
remain dry as the moisture moves in late this afternoon and this
evening. This dew point depression will allow for a slight
delay in the onset of precipitation.
Low dew points in northern areas may allow the precipitation to
begin as a period of rain and snow mixture. There may also be
pockets of light freezing rain in north-central New Hampshire
overnight. The overall potential and areal coverage is small.
With this low confidence, a freezing rain advisory has not been
issued, however this region will need to be monitored tonight.
Patchy drizzle and fog is expected to develop overnight over
southern areas as winds arrive off the Gulf of Maine.
Created a non-diurnal curve. Temperatures will gradually drop
through midnight with the aid of low surface dew points, then
steady off or perhaps slowly rise late tonight.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
The warmth builds on Wednesday as a warm front crosses the
region. H850 temperatures will approach +6C to +10C across the
region on wind fields approaching 50 kts by late in the day.
This will allow temperatures to climb into the 50s across much
of the region, with low 60s over southern New Hampshire. Any
significant breaks in the cloud cover could yield even warmer,
potentially record breaking readings.
Height falls and the approach of a strong cold front late in the
day Wednesday and Wednesday evening may allow for the
development of thunderstorms in our increasingly unstable and
high shear environment. With such strong wind fields in place, a
few of the storms have the potential to produce damaging winds
over far southern New Hampshire. This is in good agreement with
the current SPC day two outlook
Strong gusty winds continue to be a potential issue over
southern New Hampshire Wednesday evening. Thereafter, all areas
will begin to have gusty westerly winds in a strong cold air
advection and increasing pressure gradient as the surface low
intensifies and begins to move east of New England.
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Progressive and deep upper trof with its associated cold front
exits into the Maritimes Thursday with downsloping colder northwest
winds in its wake. Scattered snow showers are possible in the
mountains otherwise partly to mostly sunny skies expected
elsewhere. The cold northwest flow will continue into the
weekend with continued advection of colder temps each day. By
Saturday high temps will be averaging well below normal with
highs only reaching the single number and lower teens in the
mountains to lower 20s over southern areas. By late in the
weekend the coldest pocket of arctic air moves off to the east.
On Monday a return lower level southerly flow will begin to
develop possible causing some light overrunning snow or mixed precipitation
to develop across the area.
Used superblend for this extended forecast cycle with little
reason for any deviation.
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Short Term...Conditions will be lowering to IFR and locally LIFR
conditions tonight into Wednesday morning with patchy drizzle
and fog, mainly over southern areas. Conditions will be slow to
improve Wednesday afternoon. Some LLWS expected with
increasing winds aloft.
A strong cold front will cross the region Wednesday evening
with a wind shift to the west and drying conditions downwind of
Mainly VFR conditions. A gusty northwest flow will continue
Thursday and into the weekend.
Short Term...Will continue with a gale watch for Wednesday night
into Thursday. Highest winds will likely be associated with the
cold air advection and increasing westerly gradient on Thursday.
Long Term...A strong northwest flow will persist Thursday into
Thursday night behind the cold front...thus Gale Watches
continue into Thursday evening. The northwest flow will continue
through the weekend. Another round of Gale force winds are
possible Saturday into Saturday night as a reinforcing shot of
arctic air behind a secondary arctic cold front moves across
There are currently no problems noted on the rivers as ice
movement from a few days ago has largely stopped. But continued
warm weather especially on Wednesday could get things flowing
again and will raise the possibility for more ice jam related
MARINE...Gale Watch from Wednesday evening through Thursday evening for