Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 200731
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
331 AM EDT Fri Apr 20 2018

.SYNOPSIS...
Low pressure centered southeast of Nova Scotia will drag several
weak troughs across the area through early Saturday. The circulation
around this system will produce cool weather today and tonight
along with a few rain and snow showers...especially across the
higher terrain. On Saturday...we`ll see some lingering clouds
mainly across the higher terrain. By Sunday...high pressure and
sunny weather arrives along with the start of a gradual warming
trend. By mid week...unsettled weather returns with the approach
of our next storm system.

&&

.NEAR TERM /THROUGH TODAY/...
At 06z...an 998 millibar low was centered southeast of Nova
Scotia with a surface trough extending into northern Maine. GOES
water vapor imagery showed an associated upper low over eastern
New England. NWS Doppler Radar mosaic showed several areas of
light return with a more significant area of echoes noted across
our favored upslope areas of Northern New Hampshire into western
Maine. For today...several weak surface troughs and associated
impulses will pivot around this system as it slides further
east. The cool cyclonic flow should result in mainly cloudy
skies with some lingering upslope snow and rain showers for the
higher terrain. Temperatures will recover into the 40s and lower
50s...but the northwest breeze will make it feel a bit cooler as
our below normal temperatures continue.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/...
Some lingering clouds tonight over the higher terrain as well as
over our eastern and northern Maine zones...with skies becoming
mainly clear elsewhere. There will be some lingering snow
showers across the higher terrain as well. Lows will range from
the upper 20s to mid 30s. On Saturday...we continue with the
cool cyclonic flow with one last impulse to pivot across the
area during the day. This should keep broken clouds across the
higher terrain as well as over our northern and eastern Maine
zones...with skies averaging partly sunny for the remainder.
There will be a bit less wind on Saturday along with temperatures
several degrees higher than today...so tomorrow offers some
slight improvement over today as we begin the weekend.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
There is some good news on the horizon as we start off the
extended period. A progressive ridge aloft will build towards
the region this weekend. As that ridge moves Ewd...building
ridging ahead of an upper low temporarily cut off from the Nrn
stream will replace it. That will give us several days of mostly
clear skies...dry wx...and near to above normal temps. Given how
below normal this month has been so far...this will seem awfully
mild for what is in actuality to be expected this time of year.
Aside from the desire to get out and enjoy the wx...the biggest
impact will be snow melt in the headwaters. The warm up is
marginal enough that snow melt should be gradual...and river
rises fairly typical. But considering flows are already high
from recent rain...it will be worth keeping an eye on for
flooding concerns.

The aforementioned upper low catches up with us by the middle of
next week...sometime Wed or Thu. The 20.00z GFS and ECMWF have
some timing difference...with the GFS on the faster side. The
CMC leans in favor of the ECMWF...but given the tendency for
modeling to handle cut offs poorly I am not willing to bite one
way or the other just yet. For now the multi-model consensus is
for likely PoP Wed night...and that seems a reasonable
compromise. I prefer to keep the likely wording in the forecast
as well...since it will rain sometime in that period...with
exact timing TBD. Beyond the late week ensemble model guidance
continues to favor Ern CONUS trofing...so the search for true
warm wx continues.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Short Term /through Saturday/...VFR with sct MVFR in mtn
-shra/-shsn with isold IFR in -shsn. Improving to VFR throughout
 aft 12z Sat.

Long Term...High pressure builds over the forecast area Sun into
early next week. VFR conditions will prevail with light
winds...which will likely allow for sea breezes to form. Enough
background gradient flow is likely Sun to keep sea breeze very
near the coast...but Mon and Tue winds are more likely to become
SEly at PSM and PWM...and Sly at RKD.

&&

.MARINE...
Short Term /through Saturday/...Gusty westerly flow will persist
through the period but should remain just below SCA even outside
the bays.

Long Term...High pressure in control of the coastal waters...and
generally light winds and small seas. Low pressure developing
over the Mid Atlantic midweek will allow flow to become more Ely
and help build seas above 5 ft outside of the bays.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.

&&

$$

NEAR TERM...Schwibs
SHORT TERM...Schwibs
LONG TERM...Legro



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