Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Gray ME
621 am EDT Monday Mar 30 2015
high pressure will shift offshore as a cold front approaches from
the west today. After the front crosses the area...high pressure
will build in from the west Tuesday through Wednesday. High
pressure will shift offshore on Thursday as a warm front
approaches from the southwest. A cold front will push east through
the region Thursday night. High pressure will try to build in
from the west into the weekend...though the front will loiter
Near term /until 6 PM this evening/...
update...minor changes to account for current observational
trends. ASOS equipment around the Hudson Valley are just now
starting to detect precipitation...despite the radar presentation. Expect
that much of the precipitation this morning will be very light or not at
all...with the better chance later this afternoon with showers on
the cold front itself. Have adjusted pop to show this trend.
Previous discussion...a cold front...currently back across the
eastern Great Lakes...will push towards the area today. Southerly to southwesterly
flow ahead of the front will allow southern New Hampshire and parts of the
interior of western ME to warm to near normal. Winds off the water
however will likely keep coastal ME below normal.
More or less moisture starved...quantitative precipitation forecast amounts are light...and best
chance for greater than 0.1 inch will be confined to the higher
terrain. Air mass is dry enough that most precipitation should fall as
snow...though a mix with rain across southern zones is possible during the
Along the front...especially northern zones...the isallobaric component
of the wind may help to produce a brief period of stronger
gusts...near 35-40 miles per hour.
Short term /6 PM this evening through 6 PM Tuesday/...
front will cross the area tonight...with low pressure pulling north through
Quebec. What moisture remains trapped in the cyclonic flow on the
backside will be forced over the high terrain and result in areas
of shsn continuing into Tuesday. A couple inches of accumulation is
possible for northern zones.
Atmosphere remains more or less mixed overnight...keeping temperatures on
the milder side. Coldest air will delay until Tuesday to arrive...so
temperatures may actually be able to climb towards 40 near the coast with
some sunny skies. Across the far interior temperatures may struggle for
freezing however...as cold front will have already worked into
Long term /Tuesday night through Sunday/...
weak low pressure will move east to the south of the southern New
England coastline. Any precipitation with this feature should
remain south of the New Hampshire state line while cold air
continues to spill into the region. As the low moves east it will
strengthen and combine with high pressure approaching from the
west to produce some stronger winds on Wednesday... though gusts
should stay well below advisory criteria... only in the 20 to 30
miles per hour range. It will make it feel colder though as temperatures
struggle to rise out of the 30s.
High pressure shifts to the east Wednesday night. Expect a warming
trend to commence on Thursday with southwest flow developing
through the low levels of the atmosphere. A warm front will form
primarily to our west... but could extend eastward into New
Hampshire and northern Maine on Thursday and aid in the production
of some light rain or snow showers.
Upper trough axis crosses the area on Friday though most of the
forcing stays to the north. Expect a chance of showers on Friday
with temperatures reaching their warmest levels of the season so
far. Readings in the 50s will be widespread with some 60 degree
readings possible in southern New Hampshire before colder air
arrives Friday night.
Surface cold front will cross the area late Friday but will stall
somewhere offshore. Both GFS and European model (ecmwf) now in agreement that upper
trough will generate surface low pressure over the Ohio River
valley Friday night and track near southern New England on
Saturday. New Hampshire and Maine would be on the cold side of
this low track... and thus there is a chance that precipitation
Friday night and Saturday could fall as snow. It may be difficult
to get enough cold air at the surface for significant accumulation.
Aviation /10z Monday through Friday/...
short term...cold front will push towards the area today. For the
most part this system will be moisture starved...and thus do not
expect much in the way of showers for most terminals. Greatest
chance for a period of MVFR or lower shrasn will be at kleb and
khie late this morning through the evening. Otherwise expect just a
broken deck of MVFR ceilings to transition across the forecast area
today. Gusty southwesterly becoming westerly winds will pick up behind the
front. This will prolong upslope shsn near khie into Tuesday.
Long term...VFR conditions expected Wednesday with strengthening
northwest winds. High pressure crosses the area Wednesday night.
Could see MVFR or IFR conditions Thursday into Friday as showery
weather is possible.
short term...winds and seas will remain above Small Craft Advisory thresholds into
Long term...increasing pressure gradient between strengthening
offshore low and high pressure moving in from the west will allow
northwest winds to strengthen on Wednesday. Gusts to 25 or 30 knots
are possible and will diminish Wednesday night with high pressure
cresting over the Gulf of Maine.
Marine...Small Craft Advisory until 8 am EDT Tuesday for anz150>154.