Area Forecast Discussion
Issued by NWS Caribou, ME
Issued by NWS Caribou, ME
640 FXUS61 KCAR 240029 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 829 PM EDT Sat Aug 23 2025 .SYNOPSIS... A cold front will slowly approach from the west through Sunday night, then cross the region Monday and Monday night, as its parent low passes well to the north. An upper level low remains over the area on Tuesday. Another cold front approaches from the NW on Thursday. && .NEAR TERM /THROUGH SUNDAY NIGHT/... 8:25 PM Update...Forecast remains on track at this time. A few echoes are showing up on radar. However, most of this is virga not reaching the ground given dew point depressions of around 20 degrees. Cannot rule out an isolated shower, and perhaps a rumble or two of thunder, towards the Quebec border later tonight. Previous Discussion... Isolated showers are possible this evening, mainly across the Crown of Maine as the warm front moves into Canada and Maine remains in the warm sector. Winds have switched to be southerly today ahead of the cold front and are picking up across the region. They will calm slightly overnight as the atmosphere decouples, but return tomorrow, gusting about 5 kts higher with the mixing of a LLJ ahead of the cold front. The cold front has slowed, and precip looks unlikely until late Sunday afternoon, and even then it will take a while for precip to spread across the state. A few thunderstorms are possible along the western border in the evening, but overall the greatest instability will not arrive until Monday. Sunday night will see increasing fog coverage from the south as the marine layer continues to filter in. && .SHORT TERM /MONDAY THROUGH TUESDAY/... Monday: The cold front off the large low pressure system over Quebec and the small low pressure system moving across the East Coast should meet on Monday. The models have trending towards pushing the southern low more to the east, thus decreasing chances of higher precip in Downeast. The cold front is expected to provide more precip for the north throughout the day. Afternoon instability may produce isolated thunderstorms, though CAPE values and lapse rates are low. Winds shear may be the the best parameter to produce thunderstorms. Temps in the 70s. Monday night: Models indicate that the south low and cold front should merge as the northern low pressure system occludes. This should decrease rain chances around midnight, though the far north could see scattered showers. The lighter W winds and moist soil should produce patchy fog as the clouds decrease. Tuesday: The occlusion should gradually exit out over the Maritimes as high pressure starts to move in. Wrap around moisture from the occlusion could produce some isolated showers in the north. Expect clearing skies in the south and temps in the 70s with a breezy W wind.&& .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... The rest of the week, in general, should be dry with the high pressure settling in. Cannot rule out some showers in the middle of the week with possible shortwaves moving across the area. The next system should move into the area as a cold front Thursday night and into Friday. Though extended models give confidence in the frontal boundary moving through, the intensity and timing are still uncertain. Decided to stay with the NBM and leave chance rain in the forecast. Temps near normal. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... NEAR TERM: Mainly VFR, although IFR is possible in fog at BHB and BGR after sunset Sunday. Confidence in this fog is moderate. Winds will be from the south, gusting 20 to 25 kts. LLWS will be possible at most sites tonight into Sunday AM as the atmosphere decouples but the LLJ remains in place. S winds will continue to gust tomorrow, possibly reaching as high as 30kts at southern TAF sites in the PM. SHORT TERM: Monday...MVFR/IFR possible in showers and patchy fog. LLWS possible Sunday night. S 5-15kts, gusting to 20kts. Monday night...MVFR/IFR, improving to VFR late over northern terminals. S 5-10kts becoming W late. Tuesday-Thursday...Mainly VFR. W 5-15kts. && .MARINE... NEAR TERM: Wave heights are dropping to 4 to 5 feet across the northern Gulf of Maine, and the wave period has dropped to 10 or 11 seconds. Expect this trend to continue overnight. Small craft gusts will continue overnight, diminishing by early Sunday morning. SHORT TERM: Cannot rule out seas approaching 5ft Monday night and Tuesday in southerly swell. Wave heights should remain marginal Tuesday night into Wednesday, before diminishing Wednesday evening. && .FIRE WEATHER... Fire weather forecast is panning out this afternoon, with winds gusting 20 to 25 mph and humidities dropping into the 40 - 45% range except for the near coastal regions, where the sea breeze is increasing humidity. Tomorrow looks fairly similar to today but breezier. Widespread S winds 10-15mph with gusts 20-30mph likely. Scattered showers and a few thunderstorms will develop later in the afternoon from the Moosehead Region northward to the St. John Valley posing an elevated lightning risk. Wetting rains are still expected Monday into Tuesday, although the trend in confidence continues to go down. It looks like highest rainfall amounts will be over the northwest portion of the state, with Downeast barely receiving enough to call it a wetting rain. The trend for this system has been drier and drier, particularly over the southeastern corner of the state, so if we get more rain than forecast it will be a pleasant surprise. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory until 8 PM EDT Sunday for ANZ050>052. && $$ Near Term...Clark/LF Short Term...LaFlash Long Term...LaFlash Aviation...Clark/LF/LaFlash Marine...Clark/LF/LaFlash Fire Weather...LF