Area Forecast Discussion
Issued by NWS Portland, ME

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FXUS61 KGYX 281245
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
845 AM EDT Tue Mar 28 2017

.SYNOPSIS...
Low pressure will pass to our south later today and tonight. A
cold front will cross the area of Wednesday. Northwesterly flow
will continue on Thursday behind the front with a few showers
possible in the northern mountains. High pressure will build
into the region through Friday. Low pressure will approach the
region Friday night into Saturday with snow and rain possible in
the south.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...

845 AM...Minor ESTF update to reflect current radar and
observational trends in near term grids.

Prev disc ...
635 AM...MAde some tweaks to temps and pops based on current
obs, but overall forecast is unchanged. A few radar echoes
moving across mid-coast, but no ground truth to go along with
them, although should be moving over KRKD shortly. Other than
that should be mostly dry through mid-morning with just some
spotty DZ/FZDZ in the mtns, but this too looks limited.

Previously...Stagnant flow is the main feature for today as
weak mid lvl ridging between twos systems combines with weak sfc
cold air damming to allow for clouds and fog to persist thru
today. As weak low pressure passes to our south and north could
see a few shra pop up this afternoon, although the best chc for
any precip will be this evening. Highs will range from the upper
30s in the north to 40 along the coast, and into the mid to
upper 40s in srn NH and the CT vly, where some southerly flow
will warm things up a bit ahead of the cold front.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Models are coming into a little better agreement that precip
from the sf low passing to ours south should bring at least
some showers into southern parts of the region a few hours
either side of 00Z. Also cold front should produce some showers
in the mtns this evening as well. The lowest chance for any
precip is in the central zones, but still cannot rule out a few
showers here either. Upslope showers in the mountains should
transition to snow showers late this evening and overnight.
Lows will range from around 30 in the north, to the mid 30s in
the south.

The cold front will cross the region by Wed morning and winds
will shift to NW and pick up. This should allow for some
clearing on the coastal due to downslope, and, also allow for
highs to rise well into the 40s to around 50 in the warm spots
in the south. The mountains will remain mainly cloudy with sct
snow or rain showers.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
The relatively fast moving zonal flow continues through the
extended period with a series of disturbances affecting our
region. This fast moving flow with lots of waves leads to a
relatively low predictability and low confidence forecast
through the extended.

Northwesterly flow continues on Thursday as the upper low
departs to our east. With drying conditions just a few showers
along the international border are expected. High pressure again
builds into the region on Thursday night and into Friday.
Clouds will again be on the increase Friday night ahead of the
next developing low.

A low will develop in the midwest late thursday into Friday and
move northeastwards to impact our area late Friday night into
Saturday. There is still a lot of uncertainty with this system
as the fast paced zonal flow makes for small differences in
timing and strength of the waves being reflected in larger
changes in the forecast track of the low. Overall the trend is
south and out-to-sea as compared to yesterday however this would
still leave the southern portion of the forecast area in the
precipitation shield for Saturday with some showers extending
across the entire CWA. Still not confident in this track and
think we will need to actually see the low reforming out of the
rockies before any of the models can get a grip on it. Have
trending south with the mean for this update. As far as ptype
goes, it is late in the season to see any good damming so
expect a straight rain/snow mix.

&&

.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
Short Term...IFR to LIFR conds persist through today and into
tonight. Look for improvement to VFR during Wed morning, with NW
winds gusting to 20-25 kt in the afternoon.

Long Term...
Thursday will see just a chance for MVFR showers remaining in
the far north CWA. High pressure will move in resulting in VFR
through Friday morning. Friday evening southern NH will see a
decrease to MVFR in showers with IFR possible from PSM to CON
and along the extreme southern Maine coast.

&&

.MARINE...
Short Term...Winds continue diminish this morning and remain
light into tonight. Seas will continue to slowly subside, but
will still sea 506 ft thru this morning outside the bays so
have extended SCA thru noon. Cold front move thru late tonight,
and will likely need SCA again by Wed afternoon.

Long Term...
Northwesterly flow will continue on Thursday with small craft
conditions expected to persist through mid day. Another low may
move through the southern portion of the waters on Friday night.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory for hazardous seas until noon EDT today
     for ANZ150-152-154.

&&

$$

ES



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