textproduct: Caribou

WHAT HAS CHANGED

- 6 AM Update: Locally dense fog continues for a couple more hours. Updates to aviation section below with the 12z TAFs. Reduced marine wind gusts for Tuesday slightly after further evaluation of marine stability.

- Increased fog coverage for early this morning and again tonight. Reduced forecast rain totals in the north with slight southern shift in the track of the low pressure system tonight.

KEY MESSAGES

1) Locally dense fog remains through the early morning hours. Meanwhile, a deepening low pressure system will approach today, tracking along the coast tonight into Tuesday, bringing moderate to heavy rainfall to the Downeast region.

2) Continued unsettled Wednesday and Thursday, with the next system approaching Friday.

DISCUSSION

KEY MESSAGE 1...Locally dense fog remains through the early morning hours. Meanwhile, a deepening low pressure system will approach today, tracking along the coast tonight into Tuesday, bringing moderate to heavy rainfall to the Downeast region.

KEY MESSAGE 1 DESCRIPTION... Current GOES Nighttime Microphysics RGB channel indicates a wide swath of fog and low stratus currently across Hancock and Washington counties, and actively advecting across southern Aroostook county. By sunrise, this area of fog and low stratus may spread across the majority of the forecast area, before increased sun angle and the return of diurnal mixing aids in dissipating this layer.

The next surface low pressure system will approach from the west through the day today, and is likely to begin moving into our forecast area overnight tonight. Recent hires guidance has settled on a low track where the center of the low will move along the Maine coast through Tuesday morning, exiting into the Bay of Fundy by Tuesday night. Highest rainfall amounts should be confined to around the center of this low, and so exact track will have an impact on how much rainfall our forecast area receives versus how much falls over the Gulf of Maine. There will likely be a sharp gradient in rain amounts further inland and away from the low center. The immediate coast has the greatest chance at rain totals exceeding 1 inch, potentially over 1.5 inches of total rain. Bangor and the Interior Downeast region could see rain amounts exceeding 1 inch, but any wobbles offshore of the low may result in these amounts being significantly less. By the northern half of the forecast area, most rainfall through this time period will likely be due to showers and storms north of and ahead of this low pressure system, not directly tied to the coastal low.

At this time there does not appear to be a significant flash flood threat with FFG in this region being over 2 inches in one hour, however there remains the risk across Downeast Maine and the Bangor Region for the minor flooding of known poor drainage areas and other flood prone locations with the heaviest rainfall from late tonight into early Tuesday afternoon.

KEY MESSAGE 2...Continued unsettled Wednesday and Thursday, with the next system approaching Friday.

KEY MESSAGE 2 DESCRIPTION... As an upper level low near the Great Lakes Wednesday makes its way into the region by Friday, there will be showers, and the possibility of thunderstorms, Wednesday and Thursday afternoons. Modest CAPE and mid level lapse rates could support some pop-up thunderstorms, mainly in the north, though a lack of shear should limit thunderstorm strength. The upper level low enters the region Friday morning bringing more widespread rain showers, though track and timing are uncertain. The Euro and GFS are in general agreement with the surface low passing just to the north, while the Canadian is much more disorganized. Current precip estimates are around 0.5 inches, with up to 1 in in some places in heavier showers.

AVIATION /09Z MONDAY THROUGH FRIDAY/

Through the early morning...VFR conditions may continue to trend towards IFR/LIFR in fog. Downeast terminals remain LIFR in fog at this time, while low stratus and fog advects northwards through Aroostook terminals. All northern fog to dissipate over the next 1 to 3 hours, and Downeast fog will mostly dissipate in this time as well, though coastal fog and Washington county could hang onto lower vis for a little longer this morning.

Today...Conditions will improve to VFR across all terminals. Afternoon showers and storms, mostly across the north, could lead to brief MVFR cigs. S winds 5 to 10 kts with gusts 15 to 20 kts at KBGR and coastal terminals.

Tonight...Cigs may rapidly fall back to IFR/LIFR in fog and low stratus. Moderate rainfall at coastal terminals could limit visibility due to rain, while further north vis would be limited by another round of fog. Winds shifting SE at 5 to 10 kts with gusts to 20 kts possible at KBGR and coastal terminals.

Tuesday - Tuesday night: MVFR or lower likely, with the best chance for IFR or lower early Tuesday morning and again late Tuesday night. Some fog is possible at all terminals Tuesday night. A chance of thunderstorms at KFVE in the afternoon. E/SE winds 5-10G15-20KT, shifting to NW 5-10KT.

Wednesday - Wednesday night: Mainly VFR. Possible MVFR at KFVE/KCAR/KPQI/KHUL in the afternoon with showers and chance of thunderstorms. NW winds at 5 to 10 kt, gusts to 20 kt. Become light and variable overnight.

Thursday: Possible MVFR at KFVE/KCAR/KPQI/KHUL/KBGR, in the afternoon with showers and chance of thunderstorms. S/SE winds at 5 - 10 kt, becoming light overnight.

Friday: MVFR in scattered rain showers and possible thunderstorms. S winds around 10 kt, gusts to 20 kt.

MARINE

Winds remain below 25 kts and seas below 5 ft through the day today. Fog may limit visibility through the day today. Winds will increase late tonight as a storm system begins to cross the waters, and approach 25 kts across our intracoastal waters and coastal waters out to 25 NM, with the outer waters seeing gusts approaching 30 kts. Seas may begin to climb towards 5 ft late tonight.

Marginal SCA winds and seas on the coastal waters early Tuesday, then below SCA criteria on all waters through Friday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...None.