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Area Forecast Discussion (AFD)

Issued by Caribou, ME (CAR)

                            
000
FXUS61 KCAR 162252
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
652 PM EDT Tue Apr 16 2019

.SYNOPSIS...
High pressure will build across the region late tonight through
Wednesday. A warm front will lift toward the region Thursday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
640 PM Update: Not much chg in the going fcst. Just minor chgs
in fcst hrly cld cvr and sfc temps/dwpts based on derived trends
from latest sat imagery and sfc obs. Latest radar conts to show
msly sn shwrs still ovr the NW hlf of the FA, but this should 
trend downward after sunset. 

Orgnl Disc: A Flood Watch remains in effect across northern 
Aroostook county through early morning. High pressure will build
toward the region tonight, while the upper level trof exits to 
the east. Skies will remain mostly cloudy across the north and 
mountains tonight, with scattered evening snow/rain showers. An 
isolated evening rain shower is possible Downeast early tonight,
with decreasing clouds overnight. High pressure then builds 
across the region Wednesday with partly/mostly sunny skies 
across the north and mountains, with mostly sunny skies 
Downeast. Low temperatures tonight will range from the mid 20s 
to around 30 north, to the lower 30s Downeast. High temperatures
Wednesday will range from the upper 40s north, to the mid 50s 
Downeast.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
High pressure cresting over the area Wednesday night will bring
a clear, calm, moonlit and cool night with lows in most areas 
dropping to near, or just below freezing. The high will move 
away to the east on Thursday as a large and complex storm system
lifts a warm front north into the area. Showers will be likely 
with this front across the north Thursday afternoon and a bit of
sleet or wet snow may mix in across some spots at the start. 
Both the NAM and GFS are showing low level thicknesses near the
critical value for frozen precipitation Thursday afternoon. 
High pressure to the east combined with a strong trough and 
frontal system to the west will bring a warm and humid southerly
breeze Thursday night into Friday with showers continuing to be
likely, especially across the north near the warm frontal
boundary. Some misty breaks of sunshine will be possible 
Downeast Friday afternoon. Otherwise, the warm advection will 
bring low clouds over much of the area on Friday.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
The warm frontal boundary stalled nearby to the north will 
continue to be the focus of showers Friday night while Downeast 
has low clouds, mist and some fog as humid air pushes north over
the cooler Gulf of Maine waters. Saturday will remain mostly 
cloudy with showers again focused mostly across the north as 
the consolidating storm over the northern Appalachians continues
to channel warm and humid air over the region. An occluded 
front ahead of the low may push a band of more organized and 
heavier showers into the area late Saturday night through 
Sunday. The front should slip east of the state Sunday night 
into Monday as the large low lifts north into Canada. However, 
no strong high follows and plenty of clouds with a risk of 
spotty showers may continue Monday into Tuesday. Warm humid air,
showers and possibly some heavier bands of rain over the 
weekend into early next week may result in a continued flooding 
risk over the north.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: Occasional MVFR conditions are possible across the 
north and mountains tonight, with VFR conditions Wednesday. VFR
conditions are expected Downeast tonight through Wednesday.
Northwest winds will gust up to 25 to 30 mph early tonight. 

SHORT TERM: VFR conditions in high pressure are expected
Wednesday night through Thursday morning. Conditions will likely
lower to MVFR then IFR in lower clouds Thursday afternoon and
remain IFR in variable low clouds and some fog through Saturday.
There may, however, be some breaks Downeast Friday afternoon.

&&

.MARINE...
NEAR TERM: A Small Craft Advisory remains in effect tonight into
Wednesday morning. Conditions will then be below small craft 
advisory levels Wednesday afternoon.

SHORT TERM: Winds will be below SCA Wednesday night through 
most of Thursday as high pressure builds over. Winds will then 
increase to SCA late Thursday and likely remain SCA through the 
weekend as a strong southerly flow sets up between a large high 
off to the east and a big low lifting up to the west. Seas will 
build in response to the sustained south wind reaching close to 
10 ft by late Friday and remain high through the weekend. Humid
air over the colder waters will likely result in areas of dense
fog Friday through the weekend.

&&

.HYDROLOGY...
Ice out continues on the northern rivers with ice flows on the 
Aroostook and Saint John Rivers. The biggest trouble areas are 
at locations which had pre-existing ice jams from this past 
winter. This will most likely be the focus area for impacts over
the next 24 hours as ice flows begin to move into these areas. 
Hopefully the ice will flush before our next river flood 
concern heading into the weekend. The Mattawamkeag River is the 
only river that is currently forecast to reach flood stage that 
isn't impacted by ice. The small stream flood concern will 
decrease later tonight into Wednesday. 

Unseasonably warm and humid conditions, showers and possibly a
heavier band of rain Sunday night will continue to pose a
flooding risk, especially across the far north. Greatest
concerns at this time are for the Aroostook, Big Black, 
Allagash, St. John and Fish Rivers over the north where lots of
snow remains over the highlands.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch until 2 AM EDT Wednesday for MEZ001-002.
MARINE...Small Craft Advisory until 8 AM EDT Wednesday for ANZ050>052.

&&

$$

Near Term...VJN
Short Term...Norcross
Long Term...Norcross
Aviation...VJN/Norcross
Marine...VJN/Norcross
Hydrology...VJN