NWS Caribou, Maine Area Forecast Discussion
731
FXUS61 KCAR 151837
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
237 PM EDT Sun Mar 15 2026
.WHAT HAS CHANGED...
-A High Wind Warning has been hoisted for the Downeast Coast of
Maine from Monday Night into Tuesday AM.
-A Wind Advisory has been hoisted for the Bangor Region and
Interior Downeast Maine from Monday Night into Tuesday AM.
-A Flood Watch has been hoisted for Downeast Maine, Bangor
Region, Central Highlands and S. Aroostook County from Monday
Evening through Tuesday Afternoon.
-The Storm Watch for the Coastal Waters has been upgraded to a
Storm Warning from Monday Night into Tuesday AM.
-The Winter Weather Advisory has been cancelled for Southern
Penobscot, Central Washington, and Interior Hancock.
Precipitation is now expected to begin after temperatures warm
above freezing over these zones.
-Winds have increased for both Monday night along the coast and
for Tuesday across the north.
&&
.KEY MESSAGES...
1) A period of sleet and freezing rain is expected Monday
morning across northern Maine. A period of snow is possible
across the Saint John Valley overnight. Slippery travel is
possible for the Monday morning commute before precipitation
changes to rain.
2) Strong to damaging winds are likely along the coast Monday
night, with gusty winds extending over inland areas. Additional
gusty winds are likely on Tuesday, especially across the north.
Scattered power outages are possible along the coast with a few
power outages farther inland.
3) Heavy Rain and snow melt Monday into Tuesday will lead to
the potential of excessive runoff, poor drainage and small
stream flooding, and elevated risk of ice jams.
4) Strong southerly winds will generate high seas which could
lead to wave runup and coastal flooding impacts, particularly
if timing lines up with tidal surges.
&&
.DISCUSSION...
KEY MESSAGE 1...
A period of sleet and freezing rain is expected Monday morning
across northern Maine. A period of snow is possible across the
Saint John Valley overnight. Slippery travel is possible for the
Monday morning commute before precipitation changes to rain.
KEY MESSAGE 1 DESCRIPTION...
A warm front will cross northern Maine late tonight with a
period of snow likely, mainly across the Saint John Valley where
around an inch is possible. Precipitation then breaks for a
period as the area enters a dry slot. Northward moisture
transport/IVT and warm advection increase quickly Monday morning
after about 13z, with another batch of precipitation expected to
arrive. Temperatures are expected to already be warming across
Interior Downeast where lack of terrain does not favor cold air
damming. With a later onset of precipitation and temperatures
already expected to be above freezing, the Winter Weather
Advisory has been canceled for Bangor and interior Downeast.
Farther to the NW, cold air damming will be more robust,
allowing precipitation to fall as freezing rain before changing
to rain by around noon from south to north. Some sleet is
possible mainly across the Saint John Valley where the low level
refreezing layer is deeper and colder. Impacts to the Monday
morning commute are likely, especially for the northern areas of
the advisory. Precipitation onset timing relative to
temperatures warming above freezing leads to more uncertainty in
impacts to travel southeast of the Katahdin Region, but
confidence is not sufficient to remove additional zones from the
advisory.
KEY MESSAGE 2...
Strong to damaging winds are likely along the coast Monday
night, with gusty winds extending over inland areas. Additional
gusty winds are likely on Tuesday, especially across the north.
Scattered power outages are possible along the coast with a few
power outages farther inland.
KEY MESSAGE 2 DESCRIPTION...
Surface low pressure will deepen to around 970mb Monday evening
across Quebec with a strengthening low level jet across all of
northern and eastern Maine. LLJ strength will be between 90 and
100 kt below 850mb, along with a steep pressure gradient greater
than 10mb between western and eastern Maine. Based on local
studies this is sufficient for wind gusts to around 60mph on the
coast, even with a relatively stable layer around 2kft above
ground level. Funneling of stronger winds northward along the
Penobscot Bay to the Penobscot Valley may also lead to a gust or
two to around 60mph in Bangor, especially with mixing
enhancement from any heavier rain showers or thunderstorms as
the LLJ peaks in intensity. For now a High Wind Warning has been
issued along the coast for gusts up to 60mph, with a wind
advisory inland for slightly lesser gusts, but if confidence
increases the warning may need to be expanded to include Bangor.
Thawing ground may also lead to more susceptibility than usual
to trees being uprooted. Scattered power outages are possible.
Farther inland, snow and ice, as well as generally cooler
conditions will lead to more stability and less mixing of LLJ
winds towards the surface across northern Maine while the area
is within the warm sector Monday night.
Surface low pressure will continue to deepen north of the area,
possibly getting down to around 950mb. A cold front will sweep
through the area Monday morning, shifting winds WSW and
decreasing winds initially, especially Downeast. However, later
in the morning the pressure gradient will be strong across
northern Maine with low level lapse rates becoming dry adiabatic
up to around 850mb, where winds are projected to be around 40 to
45 kts. Winds will approach advisory criteria across the north
during the day Tuesday and a few additional power outages are
possible.
KEY MESSAGE 3...Heavy Rain and snow melt Monday into Tuesday
will lead to the potential of excessive runoff, poor drainage
and small stream flooding, and elevated risk of ice jams.
KEY MESSAGE 3 DESCRIPTION...
A Flood Watch is in effect from Monday into Tuesday for the
Downeast, Bangor Region and into the Central Highlands including
Southern Aroostook County. This is due to the threat of
excessive runoff driven by heavy rain and rapid snowmelt.
Additionally, there is a localized elevated risk for ice jams
in the Downeast, Penobscot, Piscataquis, Mattawamkeag and
Meduxnekeag river basins. An anomalously moist airmass with
PWATs exceeding 350 percent of normal will interact with a
ripened snowpack, setting the stage for potential hydrological
impacts. Confidence is high for 1 to 2 inches of widespread
rainfall in the Central Highlands to Downeast Maine, with some
ensemble models highlighting the Route 9 (The Airline) corridor
and south upslope of the Longfellow Mtns getting 2-3 inches of
rain.
Initially, cold air damming in the Central Highlands and
Northern Maine will limit snowmelt. However, this cold layer
will erode late Monday as a powerful 70100 knot low-level jet
ushers in a massive moisture surge. Precipitable water (PWAT)
values are forecast between 1.20 and 1.40 inchesnear the 99th
percentile for mid-Marchheavily favoring intense rainfall
rates. This late-Monday surge of heavy rain will provide the
primary catalyst needed to rapidly flush water out of the
snowpack. We expect a snowmelt water loss of 1 to 2 inches to
occur in a condensed 6 to 12-hour window between Monday evening
and early Tuesday morning.
The coinciding of peak rainfall rates with rapid snowmelt will
lead to swift rises on smaller streams and rivers. While
mainstream rivers currently have ample channel capacity due to
lingering drought conditions, confined mountain channels and
small streams could easily be overwhelmed, resulting in
localized minor flooding. Our latest forecast on the Piscataquis
River in Dover-Foxcroft is approaching the Action Stage. Any
additional water from snowmelt could lead this river to approach
flood stage. Latest GEFS and HEFS ensembles give DOVM1 gage a 5
percent or less chance of flooding while the NAEFS has a 40
percent chance. NAEFS is responding to the higher potential of
runoff and heavier rainfall totals. Furthermore, a deep frost
will severely limit soil infiltration; the sheer volume of
runoff is expected to overwhelm culverts, low-lying areas, and
low-water crossings, likely leading to urban street flooding and
drainage issues.
Finally, while many rivers are seeing significant thermal river
ice rot the significant runoff is expected to raise water
under the ice. As flows increase Monday night into Wednesday AM
there is a limited to elevated risk of mechanical break-ups and
unpredictable ice jams. The greatest risk of ice jams will be
across the Downeast to Central Highlands including northeastward
into S. Aroostook County. Across Northern Maine the ice jam risk
is limited but even here increasing flows will lead to localized
ice break up. A complete flushing of ice is unlikely in Northern
Maine while the potential does exist in southern zones.
KEY MESSAGE 4...Strong southerly winds will generate high seas
which could lead to wave runup and coastal flooding impacts,
particularly if timing lines up with tidal surges.
KEY MESSAGE 4 DESCRIPTION...
Models continue to show the LLJ ramping up Monday afternoon and
reaching its peak Monday night into Tuesday AM. As the pressure
gradient tightens, surface winds range from 30-35 kts Monday
afternoon with an increase in sustained speeds between 35-40kts
on Monday night. These will gradually shift toward the southwest
Tuesday morning and drop back down toward 30kts on Tuesday
afternoon.
Storm Surge: The probabilistic storm surge shows the peak
during Monday night towards the early morning hours of Tuesday.
The range of the peak storm surge is between 1.0 to 1.6ft with
lower amounts during the ramp up and cool down period.
Winds: Winds over the waters and along on coast will be from
the SSE on Monday during the increasing of the LLJ. The winds
will shift from the S during Monday night during the peak
periods.
Waves: During the peak period of Monday night, waves are
expected to reach 12-17 feet along the shoreline with periods
of around 10 seconds.
Tides: High tide times will be around 9:30AM Monday morning,
10PM Monday night and 10:30AM Tuesday morning. Though the peak
of the storm surge will be a few hours after the 10PM Monday
night high tide, any shift in storm track will change the timing
of the peak of the storm.
As of this update, the total water levels and wave runup levels
continue to only reach statement criteria. However, this could
quickly change once the peak of the storm approaches as
increasing input from high res model guidance. At this time we
do not expect any tidal issues in Bangor thanks to the delay in
peak surge from high tide Monday night.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR through most of tonight. A period of -SN develops at far northern
terminals, mainly FVE, and possibly briefly at CAR or PQI. This
snow could briefly reduce visibility to IFR and ceilings/VV to
MVFR. LLWS develops late. S winds increasing to 10 to 15 kts.
Monday:
MVFR ceilings overspread the area Monday morning, quickly
followed by IFR. -FZRA is possible at northern terminals, with
a moderate chance (50 to 60 percent) at HUL and high chance (80
percent) at northern Aroostook terminals. Brief IP is also
possible at KFVE. Precipitation changes to RA by noon from south
to north. LLWS is expected. S winds 10 to 20 kts, gusting to 30
kts. Slightly stronger winds closer to the coast.
Monday Night:
IFR ceilings/visby and strong LLWS continues into Monday night
with RA and increasing S winds 15 to 25 kts with gusts up to 35
kts north and 20 to 30 kts with gusts to around 45 kts south. A
couple gusts to 50 kts are possible at BGR and BHB.
Tuesday:
Improving to VFR quickly during the morning. Winds shift W at 10
to 20 kts with gusts to 35 kts, possibly slightly stronger at
northern terminals.
Tuesday Night...VFR south. VFR north, low chance of MVFR cigs
before midnight. All terms W winds 10-15kt gusting 20-25kt.
Wednesday...VFR all terms. W winds 5-15kt gusts up to 20kt.
Wednesday Night...VFR. Possible MVFR cigs develop late night.
Winds light and variable becoming SE around 5kt.
Thursday...VFR, possible MVFR cigs. S winds 10-15kt with gusts
up to 25kt. Slight chance of snow at northern terms.
Thursday night...VFR, possible MVFR cigs. S winds 5-15kt.
Chance of snow at BGR and all north terms.
Friday...VFR. SW winds 5-15kt.
&&
.MARINE...
Winds and seas start below advisory levels this evening and
increase to advisory levels after midnight tonight and to Gale
levels Monday. Storm force wind gusts to around 50 kt are likely
Monday night, and the Storm Watch has been upgraded to a Storm
Warning with this update. Periods of heavy rain and fog will
reduce visibility through early Tuesday morning. Seas up to 20
feet are possible over the outer waters. Winds and seas decrease
Tuesday morning as winds shift from south to WSW, but remain at
Gale force.
Looking beyond Tuesday...Westerly Gales will subside Tuesday
night into early Wednesday AM to SCA conditions. Winds fall
below SCA conditions by midday Wednesday. Tuesday night seas
subside to 6-10ft for the Intra-Coastal Waters and 10-12ft on
the Coastal Waters. Wednesday seas subside below 5ft on the
Intra-Coastal waters with 5-8ft on the Coastal Waters. Winds
expected to be below SCA conditions Thursday and Friday with
just a few gusts 20-24kt possible. Seas on Thursday subside to
3-4ft for Intra-Coastal Waters and 5-6ft on the Coastal Waters
then becoming 2-4ft on all waters by Friday. Next potential of
SCA conditions with possible Gales will be with a storm system
next weekend, significant uncertainty exists.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory from 4 AM to noon EDT Monday for
MEZ001>006-010.
Flood Watch from Monday evening through Tuesday afternoon for
MEZ005-006-010-011-015>017-029>032.
Winter Weather Advisory from 6 AM to 10 AM EDT Monday for
MEZ011-031-032.
Wind Advisory from 8 PM Monday to 8 AM EDT Tuesday for
MEZ015>017.
High Wind Warning from 8 PM Monday to 8 AM EDT Tuesday for
MEZ029-030.
MARINE...Storm Warning from 8 PM Monday to 8 AM EDT Tuesday for
ANZ050>052.
&&
$$
DISCUSSION...MWS/JS
AVIATION...MWS/JS
NWS CAR Office Area Forecast Discussion
