NWS Caribou, Maine Area Forecast Discussion

FXUS61 KCAR 200106

Area Forecast Discussion
National Weather Service Caribou ME
906 PM EDT Tue Sep 19 2017

High pressure will remain over the area tonight while Hurricane
Jose approaches southeastern New England. Jose will turn
eastward and track south of the Gulf of Maine Wednesday into


9:06 PM Update...A mild and muggy night. Low clouds cover the
area from the Central Highlands south to the Downeast coast.
There are some areas of fog and patchy drizzle across the
Downeast Region. The low clouds will likely advect north to the
Saint John Valley overnight along with areas of fog. Area radars
show a few showers, mainly across portions of central
Washington County. Additional showers offshore in the Gulf of
maine will likely move into Downeast areas overnight. Only minor
tweaks to the ongoing forecast based mainly on the latest
observations, satellite and radar trends.

Previous discussion...
High pressure will be ridged across northern Maine tonight,
with Hurricane Jose located south of Cape Cod. Skies will remain
cloudy across central and Downeast portions of the forecast
area tonight. An area of rain will move northwest toward the
Downeast coast tonight. However, the high to the north will
limit the northward movement. The best chances of rain tonight
will be along the Downeast coast, with lesser chances northward
across the remainder of the region. Only isolated showers are
possible across northern portions of the forecast area tonight.
Clouds have thinned across northern portions of the forecast
area this afternoon. However, with lingering low level moisture
expect clouds will re-develop tonight. Fog will move back
onshore across Downeast areas tonight, with fog re-developing
across the remainder of the region, which will linger early
Wednesday. High pressure will begin to build south across the
region Wednesday afternoon. After a mostly cloudy morning,
expect decreasing clouds across northern areas during the
afternoon. Rain could linger Downeast, particularly closer to
the coast, early Wednesday. The rain will then end through the
morning into the afternoon with skies remaining mostly cloudy.
Low temperatures tonight will range from the mid 50s to around
60 north, to around 60 to the lower 60s Downeast. High
temperatures Wednesday will range from the lower to mid 70s
across much of the forecast area, with around 70 to the lower
70s along the Downeast coast.


Jose is expected to move to the southeast of Nantucket Island
Wednesday evening. At the same time strong high pressure will
be located to the north of the state. Jose is then expected to
drift very slowly to the east and south Thursday and Friday
which will allow the strong high to dominate most of the region.
Expect clouds in coastal areas Wednesday night but clearing
should take place Thursday in all areas as high pressure builds
in. Some clouds are expected in the north and along the coast
later Friday as the high pressure system starts to weaken.


At this point, no significant weather systems are expected in
the long term part of the forecast. Surface high pressure and a
weak ridge aloft will keep it dry and sunny on Saturday. The
upper ridge looks to keep Jose (or its remnant low) well south
of the area before it either drifts back west or gets pushed
east, depending on which model solution you favor. Either way,
Jose looks to have little or no impact on Maine weather in the
long-term, aside from seas perhaps remaining a bit rough through
the weekend.

Between Saturday night and Monday morning, various models have
indications of weak troughs or fronts pushing across the area,
but none have much in the way of precipitation or a sizable
cold air push behind them, so POPs were kept fairly low. There
may be a bit more agreement on a possible front and a weakening
of the upper ridge later Monday into Tuesday, but may questions
remain, so POPs were limited to low - end chance at best.


NEAR TERM: Generally IFR/LIFR conditions are expected with low
clouds and fog Downeast tonight into early Wednesday, with
MVFR/IFR conditions Wednesday afternoon. VFR conditions are
expected across northern areas this evening, but IFR/LIFR
conditions will develop overnight and persist early Wednesday.
Conditions will then improve to VFR levels across northern areas
Wednesday afternoon.

SHORT TERM: Generally expect VFR conditions Wednesday night
through Sunday, with the exception of variable conditions with
any late night fog.


NEAR TERM: A Small Craft Advisory for Hazardous Seas is in
effect tonight through Wednesday afternoon. The Visibility will
be reduced in rain and fog through Wednesday.

SHORT TERM: For winds: Have used a 50/50 blend of the NAM and
GFS. Expect northeast winds to increase Thursday as gradient
tightens in the juxtaposition between Jose and strong high
pressure to the north. Winds will then decrease Friday as Jose
drifts to the south. For Waves: Southeasterly swell from Jose
will continue to build into Wednesday. As winds increase a
secondary northeasterly wind wave system will develop across the
Gulf of Maine Wednesday into Thursday. This wave system will
combine with long period southeasterly swell. Will initialize
the waves with the Nearshore Wave Prediction System (NWPS) and
will then lower wave heights 1 foot to adjust for expected high


Currently long period swell from Jose which is running at 14
seconds/5-6 feet continues to enter the Gulf of Maine. Waves are
expected to increase in height through Wednesday. So will
extend the high surf advisory. Concern is that long period waves
high impact in the surf zone, and can run up much higher on the
shore than shorter period waves resulting in the danger of
spectators being washed into the ocean. Dangerous Rip Currents
are also expected.

The astronomical tide will be at the highest levels of the
month as well over the next few days. Northeasterly winds are
expected to increase Late Wednesday and Thursday resulting in an
additional 1 foot of storm surge. The largest waves are
expected to arrive Wednesday and Wednesday Night. Therefore the
Wednesday Night at 11:50 PM and Thursday Afternoon at 12:13 AM
high tide cycles are of greatest concern for runup and splash-
over along coastal areas directly exposed to large ocean waves.

Since the expected storm surge is going to be only around 1
foot, the total water levels inland from the coast are NOT
expected to be high enough for flooding resulting from storm
surge alone.


Month to date this September ranks as the 6th warmest on record
at Caribou. Four of the top 7 warmest (September 1-18) have
occurred since 2012.


ME...High Surf Advisory until 8 AM EDT Thursday for MEZ029-030.
MARINE...Small Craft Advisory for hazardous seas until 6 PM EDT
     Wednesday for ANZ050>052.



Near Term...CB/Norcross
Short Term...Mignone
Long Term...Kredensor
Tides/Coastal Flooding...Mignone

NWS CAR Office Area Forecast Discussion