NWS Gray, Maine Area Forecast Discussion



000
FXUS61 KGYX 291206
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
806 AM EDT Fri Mar 29 2024

.SYNOPSIS...
Rain continues today, changing to snow in the mountains, before
ending this evening. Winds will be gusting to 30 mph Friday
night and Saturday behind the departing low pressure. Light snow
showers possible early Sunday morning, mainly over New Hampshire,
before our pattern becomes drier and warmer into Monday. The
pattern becomes unsettled again Tuesday, with a chance for a
significant system midweek.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update...Cold/drier air moving in the northwest is undercutting
the rainfall rates, so have trimmed the flood watch to all but
the midcoast region. Rain will continue along with snowmelt
supporting small stream rises and isolated flooding through
later today.

Previous discussion...Rain shield continues to slide parallel
to the coast this morning...while low pressure continues to
deepen south of New England. The back edge of rain is beginning
to pull away from the NJ coast now...and that trend will
continue from southwest thru the northeast parts of the forecast
area thru this afternoon. Rainfall rates remain
manageable...but rivers are beginning to rise so I have not
changed the flood watches. Rain should generally be confined to
the Midcoast by midday and should allow for some clearing of
counties from the watch area by then.

Also helping to wind down the rain threat are northwest winds
increasing and bringing in some drier air. Winds are already
picking up and will only increase thru morning. By midday gusts
of 30 to 35 mph are possible.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Winds will remain gusty tonight thru Sat. Strongest gusts are
expected to be immediately in the lee of the mtns...where
downslope may gust above 35 mph even with the loss of daytime
heating. Some upslope snow showers are possible...but the drier
air mass will limit the coverage. Little change is expected
Sat. Slightly warmer temps but still gusty.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Overview: A weak wave passes mostly south of the area early
Sunday morning before a ridge builds in for the remainder of the
day and Monday. Unsettled weather returns Tuesday with the
potential for a significant system midweek.

Impacts:
* Confidence is increasing in a significant system affecting
  the region midweek, however confidence on precipitation type
  and resulting impacts remain low.


Details: Breezy winds begin to relax Saturday night, but
increasing clouds ahead of a weak system should keep most areas
from decoupling. Weak cold air advection will still get low
temperatures into the 20s across the area, save for southeastern
New Hampshire where they can hold on to low 30s. The
aforementioned weak system looks to clip central and southern
New Hampshire early Sunday morning with some light snow showers.
Southern zones should see little to no accumulations as surface
temperatures rise above freezing. Central zones could see some
light accumulations but again temperatures will be just below
freezing and rising so it will hardly be impactful. Clearing
skies should get most of the area into the 40s, or very close,
with southern New Hampshire and southwestern Maine standing a
good chance of low 50s. Stronger cold air advection will get low
temperatures below freezing across the area Sunday night, with
the range of 20s making it just short of the immediate coast.

High pressure directly overhead Monday will allow high
temperatures to warm into the upper 40s and low 50s south of the
mountains with low 40s to the north. Increasing clouds ahead of
our next system will keep low temperatures in the mid 20s and
30s. Global models seem to agree that the ridge holds for the
better part of Tuesday, but precipitation in some form moves in
during the night. Global model ensemble means suggest that 850
mb and surface temperatures remain just on either side of
freezing so things will probably look like a rain snow mix
outside of the mountains to start. The bulk of the system occurs
on Wedensday and might last into Thursday. Preliminary thoughts
are that this ends up a mostly rain event south of the
mountains with better chances of accumulating snow to the north.
We will continue to monitor the Tuesday night through Thursday
window as some details have become clearer, but many aspects of
this system remain low confidence.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Short Term...Despite the rain conditions are mostly VFR and
patchy MVFR at this time. I anticipate that will continue thru
the morning hours...and then primarily remain VFR into the
afternoon. Northwest winds will increase towards daybreak...and
surface gusts up to 30 kt are possible this afternoon. Winds
will diminish slightly overnight...but are expected to remain
gusting around 25 kt thru Sat.

Long Term...Some MVFR ceilings possible with a quick weak
system early Sunday morning, otherwise VFR prevails through at
least Monday night. Ceilings lower on Tuesday with the potential
for some flight restrictions by Tuesday night ahead of what
could be our next significant system.

&&

.MARINE...
Short Term...Northwest winds will steadily increase this morning
as low pressure moves thru the Gulf of ME. Gale force gusts are
forecast for all waters except Casco Bay. Gusty winds will
continue thru Sat.

Long Term...High pressure settles over the waters Sunday into
Tuesday keeping conditions below those hazardous to small craft.

&&

.HYDROLOGY...
Rain rates continue to be on the light side this
morning...especially as northwest winds bring in drier air to
undercut the precip. The primary impact continues to be small
stream and river rises, and flooding along low water crossing
and urban areas due to rain and snowmelt. Additional rainfall
around 0.5" is possible near the coast and into the lower
Kennebec River Valley. Moderate river flooding is not expected
at the time of this issuance, with probabilities less than 10%.
Note: Many climate sites are in the top 5 wettest on record,
with this late month event expected to approach all time records
for Augusta and Portland. Portland`s record 11.24" in 2010,
Augusta`s is 9.71" in 1953.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch through this evening for MEZ014-019>022-024>028.
NH...None.
MARINE...Gale Warning from 2 PM this afternoon to 8 AM EDT Saturday for
     ANZ150>152-154.
     Small Craft Advisory until 4 PM EDT Saturday for ANZ153.

&&

$$

SYNOPSIS...
NEAR TERM...Legro
SHORT TERM...
LONG TERM...Baron
AVIATION...
MARINE...
HYDROLOGY...

NWS GYX Office Area Forecast Discussion