Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Gray ME
909 am EDT Sat may 30 2015
a cold front will approach from the west today and will 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 /until 6 PM this evening/...
update...with fog mixing out have allowed the dense fog advisory
to expire on time. Otherwise no major changes to the current
forecast. Will be monitoring the potential for stronger storms
across the far northern zones late this afternoon. Latest convection
allowing models indicate that any development in our forecast area
will occur 21z or later.
maritime conditions will continue along and near the
coast due to a moist onshore flow early this morning.
However...southwest gradient increases today...allowing for
partial clearing and a significant warm up in temperatures.
Moisture will also arrive ahead of the approaching cold front in
the form of higher dew points.
00z suite of mesoscale models suggest that most of the organized
convection will remain over northern portions of the forecast
area...and will be limited to late in the day and into the evening
hours as model trends continue to show a slower progression to
the approaching cold front. Strong wind fields aloft will combine
with modest instability to produce showers and storms...some with
locally heavy rainfall and strong gusty winds that will last into
the evening hours.
Short term /6 PM this evening through 6 PM Sunday/...
shower and storms continue along and ahead of cold front. Front
continues to slow as winds aloft will remain out of the southwest.
A wave of low pressure will likely form along the boundary over
southern interior Maine. The possibility of locally heavy rainfall
will need to continue to be monitored closely.
By Sunday morning...moisture axis will be situated over and near
the coastline. Expect more shower activity with the potential for
a widespread significant rainfall...the first in several months.
Long term /Sunday night through Friday/...
stalled frontal boundary will be the focus for more rain
Sunday night as low pressure approaches from the southwest.
This is quite a change for the GFS from last nights run and
is trending more toward the wetter European model (ecmwf) from last night.
Would expect to see more changes to track and timing over the
next 24 hours but the situation is evolving toward a rather wet
24 to 36 hours with moderate to occasionally heavy rain Sunday
night and Monday. Both the GFS and European model (ecmwf) cranking out several
inches of quantitative precipitation forecast through the period although differences in location
of the heaviest quantitative precipitation forecast persist.
Rain will gradually wind down Monday night into Tuesday as low
pressure crosses the forecast area and lifts off to the northeast.
Expect mostly cloudy skies through the period and temperatures at or
Should see improving conditions Tuesday night and Wednesday as low
pressure continues to pull away to the northeast and high
pressure builds in from the west. Upper low crosses the region on
Wednesday keeping some instability cloudiness across the region.
High pressure will crest over threshold region early Thursday providing a
mostly sunny day with moderating temperatures. Expect highs to range
through the 70s to near 80.
High pressure will hold off the East Coast Thursday night and Friday
as a weak cold front approaches from the north. Should scrape out
one more nice day on Friday with highs similar to thursday's.
Will see a chance of showers and possibly some thunderstorms
Friday night and Saturday as the front slowly drops south through
Aviation /13z Saturday through Wednesday/...
short term...widespread IFR/LIFR will continue early this
morning...mainly for coastal locations before ceilings and
visibilities lift in an increasing southwest flow. Areas of IFR
conditions in showers and storms later today and tonight...mainly
over northern locations...before shifting south late tonight and
Long term...MVFR/IFR ceilings/visibility Sunday night through Tuesday.
short term...southwesterly gradient will be increasing today.
Expect Small Craft Advisory conditions across the outer waters...with the bays
being very close with wind gusts near 25 knots. There will be a wind
shift late tonight or Sunday morning and a lull in the gradient.
However...seas on the outer waters will remain up and therefore
scas will remain in place right through Sunday.
Long term...sca's likely Monday.
increasing humidity and southwesterly breezes
will lead to late afternoon showers and thunderstorms this afternoon
and tonight. Wetting rains will be most likely in the mountains
Saturday evening and overnight. The areas near the coast will be
more likely to see wetting rains Sunday.
Marine...Small Craft Advisory from 2 PM this afternoon to 6 PM EDT
Sunday for anz150-152-154.