Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Area Forecast Discussion (AFD)

Issued by Caribou, ME (CAR)

FXUS61 KCAR 241550

Area Forecast Discussion
National Weather Service Caribou ME
1150 AM EDT Mon Jun 24 2019

High pressure will cross the region through tonight with mostly
clear skies then exit across the Maritimes Tuesday. A warm 
front will approach later Tuesday then cross the region 

High pressure will cross the region this afternoon with 
sunny/mostly sunny skies. Northwest winds will gust up to 
around 25 mph through early afternoon. High temperatures will 
range from around 70 to the lower 70s north, to the lower to mid
70s Downeast. Have updated the forecast to adjust for current 
conditions along with afternoon temperatures and clouds.

Previous Discussion...
The upper ridge axis builds toward the western Maine/Quebec 
border late tonight as weak surface ridge settles over the area 
late in the evening and begins to slowly shift east overnight. 
The combination of a clear sky, a dry air mass, and calm wind in
the valleys will allow the normally colder northwest valleys to
drop in the l/m 30s, with 40s for most of the remainder of FA. 
Did lower the temps in the normally colder nw valleys and have 
added in some patchy frost. The patchy frost is not expected in 
the more agricultural areas and mainly the very rural valleys, 
so will hold off on a frost advisory.

Our prolonged active weather pattern will begin later on Tuesday
as a weak 500mb shortwave trough swings through the state.
Showers will hold off for most of the day timing wise with
chances increasing later in the afternoon for Central Maine and
not until late evening further east along the New Brunswick 
border. Onshore flow will develop with a marine layer expected 
to push into Downeast Maine. Model soundings aren't supporting 
any surface based CAPE at this point with very weak upper level
instability, so thunder threat is very low at this point. 
Warmest temperatures on Tuesday will be across the Crown of 
Maine with the least amount of clouds, cooler along the coast 
with the onshore flow developing. On shore flow continues with 
broad cyclonic flow aloft over the state Tuesday night through 
Wednesday. Looks like a prolonged marine layer push with coastal
fog development likely Tuesday night through Wednesday. Should 
be a mostly cloudy day for all areas with low stratus clouds 
most likely hanging on for most of the area. Could have some 
breaks across the higher terrain of the Central Highlands and 
Northwoods Wednesday afternoon. This could lead to some showers 
and even a few isolated thunderstorms across this area, with 
Downeast remaining dry. It will be cool with below normal 
temperatures expected.

Active weather period expected through the extended forecast
with a progressive upper level cyclonic flow pattern across the
Northeast. Virtually every day from Thursday through Sunday 
currently has the chance for daily showers and isolated 
thunderstorms. This period could have the potential for above 
average precipitation with slightly below normal temperatures. 
It will be difficult to time the numerous shortwave troughs for 
this period, but currently Thursday and Saturday afternoons look
like the best chance for convection. Thursday will most likely 
have the best shear dynamics, with lower atmospheric shear 
possible Friday into the weekend depending exactly where the 
upper level low develops. One thing that looks to have higher 
confidence is the cool pool aloft allowing for daytime 
instability. As of now next weekend isn't looking the best with 
upper level low progged to be centered over the state among most
ensemble mean guidance. Still time for this to change though.

NEAR TERM: VFR conditions are expected this afternoon through 
tonight. Northwest winds will gust up to around 25 mph through 
early afternoon.

SHORT TERM: VFR conditons expected Tuesday morning with ceilings
lowering through the day as a weak system approaches from New
Hampshire. Shower activity will begin to impact KBHB/KBGR
Tuesday afternoon, with showers reaching the Northern Maine TAF
sites by the evening. Marine layer will push in Tuesday night
and Wednesday with LIFR conditions possible for KBHB and KBGR,
conditions could be better further north. Showery activity is
expected both Thursday and Friday afternoon, with a slight
chance for thunder at this point.

NEAR TERM: Winds/seas will remain below small craft advisory
levels this afternoon through tonight. 

SHORT TERM: Seas will remain below SCA conditions for this
period with waves generally remaining in the 2 to 3 feet range.
South winds expected on Tuesday as a weak frontal boundary
crosses the coastal waters Tuesday night. Southerly winds will
allow for the development of fog Tuesday night into Wednesday.
Very light winds by Wednesday afternoon with generally westerly
winds expected by Thursday with the chance for showers later
Thursday evening as another weak frontal boundary travels across
the coastal waters.




Near Term...Norcross/CB
Short Term...Dumont
Long Term...Dumont