NWS Gray, Maine Area Forecast Discussion
835
FXUS61 KGYX 152336
AFDGYX
Area Forecast Discussion
National Weather Service Gray ME
736 PM EDT Sun Mar 15 2026
.WHAT HAS CHANGED...
No significant changes were needed with this evening update as
the forecast remains on track. Just adjusted near term trends
based on observations and updated the aviation discussion.
&&
.KEY MESSAGES...
1. Slippery conditions possible late tonight and Monday morning
in the Winter Weather Advisory area as light freezing rain is
expected, mainly at higher elevations.
2. A potent low pressure system will bring heavy rain to most
of the forecast area early Monday morning through Tuesday
morning. Some flooding is possible to to the excessive runoff
from heavy rain and snowmelt. There is a non-zero risk for ice
jam flooding in the mountains and northern basins.
3. Strong southerly winds will also be increasing through the
day on Monday, peaking overnight into Tuesday morning. Winds
shift to out of the west Tuesday but remain gusty through the
day, gradually diminishing in the evening. There is an elevated
power outage threat Monday evening through early Tuesday morning
along coastal areas as well as the interior Midcoast of Maine
and up into portions of the southern Kennebec Valley.
&&
.DISCUSSION...
KEY MESSAGE 1 DESCRIPTION...
With today`s suite of guidance, the potential for some light
freezing rain still seems likely across much of west central
and northern New Hampshire as well as the western Maine
mountains and portions of the foothills. A Winter Weather
Advisory remains in effect for these locations tonight through
early Monday morning, when precipitation should change over to
all rain.
KEY MESSAGE 2 DESCRIPTION...
Not much has changed regarding the broad details of the coming
rain storm other than increased confidence. Ensembles continue
to suggest highly anomalous moisture and very high probabilities
for at least an inch of rain across nearly all of New Hampshire
and western Maine. Increasing that threshold to 2 inches and we
see medium to high probablilites centered on the White
Mountains and the Midcoast of Maine. Localized amounts of more
than three inches will be possible in and around these areas,
but especially over the White`s which could see some enhancement
from persistent upslope flow. These factors will lead to some
flooding concerns Monday into Tuesday which has led to the
issuance of Flood Watch. For more information on the flooding
threat, please the Hydrology section below. Widespread
precipitation will gradually move out of the area the first part
of the day on Tuesday, but some light showers could linger,
especially in the mountains (and likely changing over to snow).
KEY MESSAGE 3 DESCRIPTION...
The other main concern from the strong early week system will
be from the wind. Models continue to suggest the development of
a low-level jet in the 70 to 90+ knot range that will spread
across the region ahead of an approaching cold front. The core
of the jet should propagate through the forecast area sometime
in the 00z Tuesday to 12z Tuesday time frame, which will be the
main window to expect the strongest southerly wind gusts. For
now, the expectation is that we will see the strongest winds
along the coast, and then up into the interior of the Midcoast
and portions of the southern Kennebec River Valley. There will
be a strong inversion in place so there still remains some
uncertainty about how much momentum will be able to mix down,
but we should see widespread gusts in the 40 to 50 mph range
over the aforementioned areas and this is where we have issued
a Wind Advisory Monday evening through early Tuesday morning. It
is not out of the question that we could end up seeing higher
gusts here, especially as broken line of convection (with
possible thunderstorms) moves in through the evening and
overnight hours. There are scenarios where we may have to end up
issuing a localized short fused High Wind Warning or convective
warnings to account for this threat, but confidence is not high
enough at the moment for high wind products. Downsloping winds
on the north side of the mountains could also be an area to
watch for some locally enhanced winds.
Winds shift to out of the west after the cold front moves on
through Tuesday morning. For most, winds will not be as strong
on the back side but they will remain gusty through most of the
day on Tuesday.
A taste of winter returns Tuesday night into Wednesday morning
behind the departing system and lows will range from the low to
mid single digits above zero across the north, to the mid to
upper teens south. With some blustery winds lingering, we could
see some wind chill values dip into the double digits below zero
over northern locations and down to the single digits above
across the south. We will then have another fairly chilly
morning on Thursday before a return to normal or slightly above
normal temperatures Thursday afternoon and into the weekend.
After the early week storm moves out, expect only low chances
for light precipitation with a slightly better chance Friday
into Saturday.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Through 00Z Tuesday...VFR should prevail through this evening.
Conditions deteriorate overnight tonight as ceilings lower to
MVFR ahead of our next weather system. IFR conditions are
possible as early as 08Z Monday as precipitation begins to
enter the area. Enhanced low-level wind shear around 35-40 kts
will also be likely at almost all sites starting late this
evening. Widespread IFR is expected by 14Z Monday with lowering
ceilings and heavier bouts of precipitation expected. IFR to
LIFR conditions are expected to prevail through the evening
with lulls in the showers at times.
Outlook...
Monday night: High confidence in widespread IFR/LIFR cigs
continuing as a second round of rain arrives. LLWS continues
with many terminals seeing an increase to 45-50kts, with strong
SE to S surface gusts, 30-40 kts along at least coastal
terminals.
Tuesday: Cigs should be improving to VFR from MVFR through the
morning. W gusts 30-35 kts through the day.
Wednesday-Thursday: VFR expected, no sig wx.
Thursday night-Friday night: Chances of -SN with localized MVFR
possible.
&&
.MARINE...
Overnight tonight conditions will quickly deteriorate as a
strong weather system approaches. Easterly gales are possible
by Monday morning, with storm force winds expected by Monday
night. This will also build wave heights to 15-18ft at their
peak Monday night.
Gale force westerly winds Tuesday morning continue as low
pressure departs from the Gulf of Maine. Abnormally high surf is
expected, with seas of 10-16ft. Seas drop to 8-12ft by the end
of the day. Conditions start to improve by Wednesday morning,
with SCA level westerlies and 6-10ft seas expected by then. SCA
conditions continue through the day Wednesday. Sub-SCA
conditions return for the end of the week as high pressure moves
overhead.
&&
.HYDROLOGY...
A Flood Watch has been issued for Monday into Tuesday as an
anomalously moist airmass interacts with the ripe snowpack
across the area. The main focus is on excessive runoff when the
heaviest rainfall Monday night coincides with rapid melt,
leading to dramatic rises in area streams and rivers. There is
high confidence that we will see 1 to 2 inches of rain, with
some ensembles targeting the White Mountains and the Midcoast
of Maine with over 3 inches. Snowmelt will be limited initially
due to cold air damming in the mountains, but this will erode
late Monday as moisture surges north under a powerful 70 to 90+
knot low-level jet. Given the anamolous moisture, expected PWATs
should be in the 1.2 to 1.4 inch range (near the 99th
percentile for mid- March). Thus, the environment should be
primed for heavy rainfall. The late moisture surge Monday night
will be the real nudge needed to push water out of the already
ripened snowpack. The expected snowmelt water loss of 1 to 1.5
inches will mostly occur between Monday evening and early
Tuesday morning, about 6 to 12 hours. The coinciding of heaviest
rainfall with rapid snowmelt will lead to swift rises on small
streams and rivers. The mainstream rivers have a lot of channel
capacity due to lingering drought, but more confined channels in
the mountains or small streams could easily be overwhelmed
resulting in localized minor flooding. Deep frost will limit
infiltration, so for some areas the sheer volume of water could
overwhelm culverts, low-lying areas, and low-water crossings.
Expect urban street flooding and drainage issues. While many
southern rivers are ice-free, some ice remains in the mountains
and northern basins. There remains a non-zero risk for
mechanical break-up and unpredictable jams as flows increase.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory from 3 AM to noon EDT Monday for
MEZ007>009-012-013.
Flood Watch from Monday afternoon through Tuesday afternoon
for MEZ007>009-012>014-018>028-033.
Wind Advisory from 8 PM Monday to 8 AM EDT Tuesday for MEZ014-
021>028.
NH...Winter Weather Advisory from 3 AM to noon EDT Monday for
NHZ001>005-007.
Flood Watch from Monday afternoon through Tuesday afternoon
for NHZ001>015.
Wind Advisory from 8 PM Monday to 8 AM EDT Tuesday for NHZ014.
MARINE...Storm Warning from 8 PM Monday to 8 AM EDT Tuesday for
ANZ150>152-154.
Gale Warning from 8 AM Monday to 8 AM EDT Tuesday for ANZ153.
&&
$$
DISCUSSION...Baron/Hargrove
NWS GYX Office Area Forecast Discussion
