textproduct: Caribou

WHAT HAS CHANGED

- Added patchy fog to remain along portions of the Downeast coast into this evening and persist tonight.

- Made some minor timing changes for the highest POPs tomorrow.

- Lowered seas for tonight into tomorrow over the Coastal Waters.

- Increasing confidence of gusty westerly winds on Tuesday.

KEY MESSAGES

1) The next round of rain showers is expected Friday, though drought relief is unlikely.

2) Another round of rain is possible Monday followed by gusty westerly winds on Tuesday.

DISCUSSION

KEY MESSAGE 1...The next round of rain showers is expected Friday, though drought relief is unlikely.

KEY MESSAGE 1 DESCRIPTION... High pressure over the mid-Atlantic region results in dry conditions today. Low pressure to the northwest in Canada tracks eastward, bringing a cold front over the state Friday into Saturday. Latest trend in guidance has PWATs roughly 1.25-1.75 inches, with higher values concentrated around the Central Highlands and Downeast regions. Models continue to hint at precipitation generally moving in early Friday from the northwest, and moving to the southeast by Friday night. There is still some model discrepancies in the end timing, however improving agreement with the latest 12z operational runs. QPF is not that impressive with this system with most locations only seeing up to a quarter of an inch. Therefore, little if any impact on the ongoing D1-D3 drought conditions.

KEY MESSAGE 2...Another round of rain is possible Monday followed by gusty westerly winds on Tuesday.

KEY MESSAGE 2 DESCRIPTION... Sunday night a cold surface high pressure that will have brought widespread frost Sunday AM shifts to the east over the Maritimes. A potent vertically stacked low pressure system tracks into north-central Quebec with a trailing potent cold front. That front will swing across the CWA on Monday at the same time as a low pressure exits off the Mid-Atlantic coast. The interaction between the high pressure and the two lows provides significant uncertainty about rainfall. A few scenarios camps currently playing out in the ensemble models. 1. The high pressure could dominate forcing the lows to stay to the north and south, limiting precip. 2. The Canadian low could enhance the coastal low as it rides the coast north, bringing more substantial precip to coastal areas. 3. The Canadian low could dominate, bringing enhanced precipitation along its cold front from the moisture over the southeast low. At this time, uncertainty from the models is high, so forecast confidence is low, with a wide range of precipitation values.

Increasing confidence that Tuesday as the low pressure system deepens in the Northern Maritimes we can expect strong surface high to dive over the eastern Great Lakes. This will lead to a strong pressure gradient between the low and high resulting in gusty W-WNW winds developing in the morning and peaking midday. Probabilities for 35+ mph wind gusts have increased to 60-80% with 40+ mph probabilities now 35-55% which have come up significantly in the last 24 hours modeling. There is ensemble guidance suggesting a potential of wind headlines but still uncertainty exists on exacted expected wind speeds/gusts. However, it is likely that significant leaf loss may be possible in areas of Northern Maine where peak foliage has been reached. Additional leaf loss in the Central Highlands to Downeast Maine where the foliage is moderate to high. Continue to monitor the forecast for updates, as models begin to get a better handle on the atmospheric set up.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Tonight...MVFR in low ceilings and rain showers moving NW to SE. LLWS overnight for northern terminals, that improves by early morning. LLWS introduced to southern terminals by late Friday/early Saturday. Chance for IFR conditions at KBHB, with low ceilings/fog development. SW winds 5-10 kts, gusting to roughly 20 kts this afternoon, before relaxing overnight.

Friday...MVFR in low ceilings, that begins to improve by mid- morning. KBHB may have MVFR/IFR ceilings until mid-morning. LLWS at KBGR/KBHB until early afternoon. Rain showers linger into the evening. SW winds shift NW Friday evening.

Friday night...MVFR or lower possible along/south a KHUL-KGNR line, VFR elsewhere. Light and variable winds.

Saturday-Sunday...VFR. NW winds G15KT possible Saturday. S winds G15KT possible Sunday.

Sunday night-Monday...MVFR or lower possible in rain.

MARINE

SW winds remaining under 20 kt through Friday, and seas generally under 5 ft within 25 nm through Friday.

Chance for rain Friday into Friday night, which could limit visibility. Coastal-25nm, and 25nm-60nm zones could have seas approach 5 ft late Friday night, with SW winds.

From Saturday into Sunday, N/NW winds over the waters out to 60nm should be 20 kt or less and seas 4 ft or less. Sub-SCA conditions expected on the coastal waters Monday, with gusts to around 25 kt and seas around 5 ft possible on the waters from 25-60nm.

CAR WATCHES/WARNINGS/ADVISORIES

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