textproduct: Caribou

WHAT HAS CHANGED

- Lowered QPF amounts as bulk of showers through Sun are further east and less numerous, and showers Mon stay further north.

- 12z TAF UPDATE...See aviation section below.

KEY MESSAGES

1) Rounds of showers through Monday. Rain may be heavy at times Sunday, especially across Downeast Maine.

2) Upper level low pressure keeps the chance of showers going into midweek, especially across Northern Maine.

DISCUSSION

KEY MESSAGE 1...Rounds of showers through Monday. Rain may be heavy at times Sunday, especially across Downeast Maine.

KEY MESSAGE 1 DESCRIPTION... Low pressure off of Cape Cod will move northeast this morning, passing just south of the Gulf of Maine. Given the track of the low think the best chance for pops will be north and east of the low center this morning with the bulk of the rain occurring near the New Brunswick border. PW values in far southeastern areas rising to close to 99th percentile with amounts between 1.50-2.00 inches. Any rainfall will be helpful to ongoing drought conditions given that we will be in a cloudy cool pattern for the next couple days. This will allow for rainfall to get into the soils, unlikely to help streamflows which are significantly below normal.

Weak low pressure will still be back over the western Gulf of Maine and becoming absorbed by the occlusion over Quebec. Although pwats remain high over the southern and eastern half of the area have reduced pops in the afternoon with parts of the area lacking forcing and the low pressure over the gulf weaker and further to the east. Given the 160- 180% of normal PWATs (95-99th percentile) showers may produce heavy rainfall at times. Showers will be more convective during the day so uncertain where the beneficial rainfall will occur. Then throughout Sunday night, the low becomes stationary over Quebec as it rotates the moisture through the state. By Monday, the low begins to gradually move north which will decrease rain chances throughout the day. However, best chance of showers and thunderstorms will be in the northern 1/2 of the CWA closer to the vertically stacked low in Quebec. QPF totals through Monday afternoon are mainly less than 0.25 inch, with up to 0.75 inch in Washington county. Isolated spots up to 0.5 inch possible in stronger/training showers.

KEY MESSAGE 2...Upper level low pressure keeps the chance of showers going into midweek, especially across Northern Maine.

KEY MESSAGE 2 DESCRIPTION... Low pressure stalls over Canada, slowly meandering to the east this week. Looking at chances of rain showers in the north, on Tuesday and Wednesday. There is some instability during the afternoons, with some models hinting at 500-1,000 J/kg of CAPE, 7C/km low level lapse rates, and 30-40 kts of effective shear. PWAT values roughly 1.00-1.25", so rain showers expected to be mostly light, with higher totals possible in any convection. That being said, not anticipating severe weather. Temperatures drop Tuesday into the upper-60s to low-70s, and raise back to the 70s on Wednesday.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Today...Widespread IFR/LIFR across all terminals in low cigs, -SHRA, and BR. Some MVFR is persisting now around 12z at northern terminals, but expect these conditions to fall to IFR later this morning into early afternoon. E to SE winds 5-10 kts. Gusts up to 15-20 kts possible at northern terminals, highest at KFVE.

Tonight...IFR/LIFR conditions persist at all terminals with low cigs, VCSH, and BR. Conditions dropping to VLIFR at KBHB late with 1/2SM FG. SE winds 5-10 kts, becoming light and variable across most terminals toward 06z.

Monday-Wednesday: MVFR or lower likely at northern terminals. MVFR possible at KBGR, with VFR likely at KBHB. S winds Monday, becoming SW Tuesday. LLWS possible Monday night. W-NW winds G15-20KT possible Wednesday.

Wednesday night-Thursday: VFR. Light winds overnight, becoming S/SW at 5-10 kts.

MARINE

Winds below 10kts through Sunday night with seas between 2-4 feet through the period. Rain and patchy fog reduce visibilities at times. Slight chance of winds or seas reaching 25 kts/5 ft Monday-Tuesday. Chance for fog late Monday night into Tuesday morning. Winds from the S on Monday, becoming SW on Tuesday.

CAR WATCHES/WARNINGS/ADVISORIES

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