FXUS61 KCAR 261520

AFDCAR



Area Forecast Discussion

National Weather Service Caribou ME

1120 AM EDT Thu Jun 26 2025



.SYNOPSIS...

High pressure will remain across the region through early 

Friday, then exit across the Maritimes late. Low pressure 

approaches from the west Friday night and Saturday, crosses 

Maine Saturday night, then exits across the Maritimes Sunday 

and Sunday night. A weak warm front will cross the area on 

Monday.

&&



.NEAR TERM /THROUGH TONIGHT/...

Update...

Surface high pressure will remain ridged across the region 

today. Aloft, a disturbance moving around an upper low centered

near Labrador will cross the region this afternoon. High/mid

level clouds of various thicknesses will accompany the 

disturbance. High temperatures will range from the upper 60s to

around 70 north, to the lower to mid 70s Downeast. Have updated

to adjust for current conditions along with expected afternoon

temperatures and clouds.



Previous Discussion...

Today...

The clouds will be at fairly high levels, generally 15-20,000 

ft, though western portions of the area from Greenville to 

Bangor to Bar Harbor could briefly see clouds down to about 

12,000 ft. Can't rule out a light sprinkle, mainly in western 

portions of the forecast area, but that's about it and don't 

think it will be enough to wet the pavement. Light NW breeze, 

except light S breeze near the coast in the afternoon from a sea

breeze. 



Tonight...

Clouds decrease late afternoon into the evening from NW to SE, 

leaving mostly clear skies tonight with just a few high clouds. 

Another cool night, with light winds and good radiational 

cooling, and lows in the 40s to low 50s. Readings will be 

similar to Wednesday night over the north, and about 5 degrees F

cooler Downeast. Went cooler than NBM and most model guidance 

for low temperatures.

&&



.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...

Northern stream ridging builds across the area on Friday with

associated subsidence keeping things dry. There should be 

though an increase in mainly high clouds by afternoon, 

especially across western zones. Highs on Friday should be near

to slightly below normal.



The models differ in the timing of the onset of precipitation

Friday night. The ECMWF is most progressive, as it is most

progressive with a 700 mb northern stream shortwave, while other

models are much less progressive with the 700 mb shortwave. All

models show low level frontogenesis developing along an axis 

from the central/southern Central Highlands southeastward into 

Downeast Maine. Given the flow aloft, it makes sense given the 

flow aloft that precipitation would be mainly concentrated in 

the area with the frontogenesis. This aligns more with a non- 

ECMWF solution, so leaned strongly towards this for pops. As a 

result would expect most, if not all the rain Friday night to be

confined from the Central Highlands into Downeast Maine, with 

limited, if any rainfall to the north. Lows Friday night should 

be around 5 degrees below normal.



The aforementioned 700 mb shortwave does lift northward Saturday

followed by the 850 mb warm front lifting northeast through the

region Saturday night. This coupled with developing isentropic

lift should support a period of rain during this time frame.

Moderate, to possibly locally heavy rainfall should be focused

mainly along the 850 warm front/maximum of low level

frontogenesis/area of strongest isentropic lift, along with the

support of a 35-50KT low level jet, which overlap in this case 

over the central/southern Central Highlands into Downeast Maine 

for most of this time frame. 



Highs Saturday should be around 10-20 degrees below normal 

(largest departure over areas with the heaviest rainfall). Lows 

Saturday night should be near to a few degrees below normal.



From Friday night-Saturday night around 1-1.5 inches of rain is

forecast from Central/Southern portions of the Central Highlands

down into Downeast Maine. Lesser amounts are expected S of a

St Zacharie to Katahdin to Danforth line, with less than 1/4 of

an inch possible across the Saint Johns Valley. With this

rainfall below FFG, and expected to occur over 12-24 hours, no

significant hydrologic issues are expected, however, the 

ponding of water in roadways in low lying areas cannot be ruled 

out from the Central Highlands into Downeast Maine.



Last, but not least, showalter indices do support a slight 

chance of thunder along coastal Hancock late Saturday 

afternoon/early Saturday evening.

&&



.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

Northern stream ridging builds in Sunday-Monday, then exits to

the east Monday night. Models agree that an exiting 500 mb

trough ahead of the shortwave could bring some mainly scattered

showers on Sunday, then suggest that Sunday night-Monday should

be mainly dry. However, all models do bring through some weak

shortwaves (non-coherently) in this time frame, so account for

this with slight chance pops. Depending on how quickly the

northern steam ridging exits, there could be a chance for some

showers across far western zones late Monday night.



The models then all build in a mean northern stream trough into

the northeast Tuesday-Wednesday. However they differ on the

timing and coherence of the individual shortwaves which do this.

The GFS and ECMWF suggest the bulk of the energy moves through

Tuesday into Tuesday night, while the CMC delays this push until

Wednesday. For now leaned more towards the GFS/ECMWF consistent

with most ensemble members. Noting a slowing trend with this

system from last night, so would not be surprised though, if

things ultimately worked slower than currently forecast, which

is why pops were limited to likely.



Temperatures should be below normal on Sunday, near normal

Sunday night and Monday, then above normal Monday night-

Wednesday.

&&



.AVIATION /15Z THURSDAY THROUGH MONDAY/...

NEAR TERM: VFR this afternoon through tonight. North/northwest

winds 5 to 10 knots, becoming variable today except becoming

south/southwest along the Downeast coast this afternoon. 

Variable winds 5 to 10 knots tonight.



SHORT TERM: 

Friday-Friday evening: VFR.



Late Friday night-Saturday night: MVFR or lower likely at

southern terminals and possible at northern terminals, with the

best chance for MVFR or lower at northern terminals Saturday

night. S-SW winds G15-20KT possible late Friday night-Saturday.

LLWS possible Saturday-Saturday night at southern terminals.



Sunday-Monday: Mainly VFR, with a chance for MVFR in any 

showers. LLWS possible Sunday at southern terminals.

&&



.MARINE...

NEAR TERM: Winds/seas below small craft advisory levels this

afternoon through tonight.



SHORT TERM: A relaxed pressure gradient over the waters Friday

and Friday night will limit winds to 10 kt or less and seas to 2

ft or less. The pressure gradient increases on Saturday and

remains moderate into Saturday night, this should bring SCA

conditions to the coastal ocean waters during this time frame,

with conditions just below SCA levels on the intra-coastal

waters.



The pressure gradient relaxes again on Sunday, with winds

diminishing to 10 kt or less again, with this continuing through

Monday. Seas though on the coastal ocean waters could be slow 

to subside due to long period swells, so SCA conditions could 

linger over the coastal ocean waters on Sunday as a result.

&&



.CAR WATCHES/WARNINGS/ADVISORIES...

ME...None.

MARINE...None.



&&



$$





Near Term...Norcross/Foisy

Short Term...Maloit

Long Term...Maloit

Aviation...Norcross/Maloit

Marine...Norcross/Maloit

