Area Forecast Discussion
Issued by NWS Portland, ME
FXUS61 KGYX 240744
Area Forecast Discussion
National Weather Service Gray ME
344 AM EDT Sat Sep 24 2016
An area of high pressure moving out of central Canada
will bring cooler temperatures and drier air to the region
through Sunday. Many towns in the area may see their first frost
or freezing temperatures tonight or Sunday night. Gradually
moderating temperatures are expected Monday before another
approaching cold front brings the threat for showers for Monday
night and Tuesday. Cool weather will return for Wednesday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Clouds continue to move south through southern New Hampshire and
extreme southwest Maine early this morning as high pressure
continues to push into the area. By morning, skies should be
mostly sunny across the region...although a patch of high clouds
may catch the mountains of Maine. With sun and colder air
advecting into the area, winds will become gusty this afternoon.
The unstable conditions and upslope flow will lead to a bit more
cloudiness in the mountains during the afternoon with clouds
gradually diminishing toward the coast. Temperatures today will
reach the upper 50s to near 60 in the mountains today and in the
upper 60s in southern areas and along the coast.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
With cold high pressure over the area, temps will drop to
freezing in the valleys of Coos County and parts of the western
Maine mountains tonight...so a freeze warning is being issued for
NH1-2 and ME7-8 zones. There is still some uncertainty based on
wind...any fog development...and moisture rotating around the
upper low to the northeast. A frost advisory is being issued
surrounding the Warning as temps will drop into the mid 30s.
Greatest concern in the advisory will be sheltered valleys as
elevated areas will likely maintain some wind.
Sunday should be partly to mostly sunny across the region with
high temperatures mainly in the 50s...to lower 60s along the
coast. Winds will again become a bit gusty during the afternoon
with gusts of 15 to 20 mph.
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
In the next few days anomalously meridional pattern will shift
east/northeast with time. The upper low currently over eastern
Canada will shift towards Iceland while high amplitude ridging
builds in ahead of another cutoff low. Behind this ridging
another bowling ball upper low (currently over the 4 corners
region) will be headed our way.
Large Canadian high pressure system will dominate the
surface weather pattern through Monday night keeping things dry.
Much drier and the coldest air of the season will move into New
England Sunday night into Monday morning. Most of the guidance is
hovering around 850mb temperatures right around 0 degrees C for
most of ME and NH. Lighter winds during this time along with clear
skies will boost radiational cooling processes. All this will
translate to the coldest night we have seen so far with overnight
lows in the upper 20s/lower 30s across the north with some of the
colder air also draining into the Connecticut River Valley. Mid
to upper 30s to near 40 degrees will be more likely closer to the
coast. Will need to issue freeze advisories and expect to see
During the day Monday cirrus begins to move in as a warm front
approaches from the west. Temperatures will be in the 60s
with southerly winds in place. The warm front sweeps through late
Monday followed quickly by a cold front as the second upper low
nears and becomes stationary. This will bring scattered showers
to the region.
Confidence immediately after this point wanes with model solutions
differing. Blocking downstream will keep the upper low over the
eastern U.S. The cold front which moved offshore Monday may move
north again later in the week bringing rain to southern areas.
High pressure over Canada will attempt to hold strong over
northern New England. At this point it is hard to tell the exact
locations of all these features, and thus the mid to late week
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
Short Term...VFR conditions expected. Winds will gust to 20 to 25
mph this afternoon at many of the airports.
Long Term...VFR conditions Sunday and Monday. There will be patchy
valley freezing and non-freezing fog Sunday and Monday mornings
which may briefly bring HIE and LEB down to IFR. Otherwise rain on
Tuesday may be heavy at times and cause MVFR ceilings and
visibility before improving late in the day. Fog will be likely
Wednesday morning before conditions return to VFR.
Short Term...Winds and seas expected to be below sca criteria
although some gusts may approach 25 kts this afternoon and evening.
Long Term...Winds and seas will likely approach or exceed small
craft criteria Tuesday. Later in the week winds may be near
criteria again as a frontal boundary wavers in the area.
ME...Freeze Warning from 2 AM to 8 AM EDT Sunday for MEZ007-008.
Frost Advisory from 2 AM to 8 AM EDT Sunday for MEZ009-012-013.
NH...Freeze Warning from 2 AM to 8 AM EDT Sunday for NHZ001-002.
Frost Advisory from 2 AM to 8 AM EDT Sunday for NHZ003-004.