NWS Caribou, Maine Area Forecast Discussion



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FXUS61 KCAR 240900
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
500 AM EDT Wed Apr 24 2019

.SYNOPSIS...
Low pressure will approach from the west today, redevelop along
the coast this afternoon then exit across Nova Scotia tonight.
Weak high pressure will build over the area Thursday then
another low will approach from the southwest on Friday.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
A small surface low and well defined upper low will approach
from the west today producing some rain and drizzle across the
area, mostly over the north. The rain will generally be light
and spotty with less than a quarter inch expected over the north
and less than a tenth of an inch elsewhere. Secondary low
pressure will form near the coast then move east this evening.
Lingering rain showers may change to some snow showers over the
north tonight. Very weak high pressure will follow on Thursday
as weak upper level ridging moves over the area. Moisture
lingering across the region will keep the sky mostly cloudy over
the north and partly cloudy Downeast with temperatures closer
to normal on Thursday. Thursday night will be partly cloudy then
clouds will begin to increase late at night ahead of a new
system approaching from the southwest.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
More rain looks to be on the way for the weekend.

Low pres moving in from TN Valley on Friday is expected to
re-intensify as as it moves across the Downeast region on
Saturday. Rain looks like it moves into the western areas late
Friday morning and then overspreads the rest of the region
Friday afternoon and continues right into Saturday. This system
has the potential to bring rainfall amounts of 1.50 to 2.00
inches across the region. This will to more rises on the rivers
and streams, which are already running high. See the Hydrology
section below for further details. The heaviest band of
rainfall looks like it hits on Saturday as the low intensifies.
This system looks to move along fairly quick w/the rain winding
down by Saturday evening. Cooler air behind the departing system
could allow for any residual rain or showers to change to brief
period of snow before ending. All the long range guidance
including the ECMWF/GFS and Canadian Global are in line w/this
scenario. Therefore, decided to throw a mention of snow Saturday
evening, mainly across the n and w. Not expecting any
accumulation due to the wet ground. Temperatures during this
time period will be near to slightly below normal for late
April.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
Some dry wx for Sunday, but yet another system could affect the
region by Monday w/more rain.

The long range guidance showing the potential for more rain come
Monday but there are some differences in strength of the low
and the amount of rainfall. The 00z GFS coming out of the Great
Lakes region and really winding up as it crosses Maine, dumping
up to an inch of rain. The GFS Ensemble Mean is close the
operational run w/its placement but not as strong. The 00Z
ECMWF is much different w/an open upper wave and pushing the low
through the region w/less rainfall. Given the discrepancy and
confidence being low, decided to go w/a blend of the guidance
and leaned w/30% pops. Would like to see more consistency w/the
long range guidance for this event before committing to higher
precip chances. Temps are expected to continue the trend of
running near to slightly below normal.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: Generally IFR conditions are expected today into
this evening, improving to MVFR Downeast this evening. MVFR
conditions across the north and VFR conditions Downeast are
likely Thursday into Thursday night.


SHORT TERM: MVFR conditions by Friday afternoon w/conditions
deteriorating to IFR/LIFR Friday night into Saturday. Heavy rain
potential is there for Saturday for all terminals. Conditions
improving slightly to MVFR Saturday night, especially for the
northern terminals. KBGR & KBHB will most likely see a trend to
VFR.

&&

.MARINE...
NEAR TERM: Seas early this morning may be near 5 ft over the
offshore waters. Otherwise, winds and seas should be below SCA
through Thursday night.


SHORT TERM: SCA expected Friday afternoon right into Saturday as
ssw winds increase ahead of the low at 25 kts w/gusts nearing 30
kt, especially over the outer zones. Seas will be building to
heights of 7-8 ft. SCA conditions look like they hold on right
into Saturday night winds shift to the nnw behind the departing
low. Seas are expected to stay around 6 ft despite the offshore
component of the wind due to a residual swell.

&&

.HYDROLOGY...
River Flood Warnings remain in effect for the Saint John and
along with the Mattawamkeag River near Mattawamkeag. The Saint
John and Fish Rivers near Fort Kent are slowly falling w/the
Fish River going below FS. The Mattawamkeag River is holding
steady. Ice has pushed out of the headwaters of the St. John
River.

Areal Flood Advisories continue for Eastern Aroostook County
and along the East Branch of the Penobscot River below Grand
Lake Matagamon Dam. Some roads are still closed due to flooding
in the advisory areas including along portions of Route 11 near
Grindstone. Smaller rivers and streams in the advisory areas
are starting to recede with some flooding still ongoing in
lowland areas.

The Fish River chain of lakes will need monitoring through the
next week at least, since water levels are rising and ice could
be breaking up during this timeframe. Concerned about potential
for flooding as the lakes are high, w/a situation possibly
similar to last Spring.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...None.

&&

$$

Near Term...Bloomer
Short Term...Hewitt
Long Term...Hewitt
Aviation...Bloomer/Hewitt
Marine...Bloomer/Hewitt
Hydrology...Hewitt

NWS CAR Office Area Forecast Discussion