textproduct: Caribou

WHAT HAS CHANGED

- Increased snowfall totals across Northern Maine for Sunday night into Monday.

- Lowered temperatures slightly for Monday AM across interior Downeast Maine to Downeast shoreline. Then additionally lowered temps across far Northern Maine and North Woods to follow trends in model guidance.

KEY MESSAGES

1) Areawide rain Sunday changes to snow Sunday night into Monday morning across Northern Maine leading to the potential of slick Monday AM commute.

DISCUSSION

KEY MESSAGE 1...Areawide rain Sunday changes to snow Sunday night into Monday morning across Northern Maine leading to the potential of slick Monday AM commute.

KEY MESSAGE 1 DESCRIPTION... During the day Sunday a potent parent storm system will lift north out of the Great Lakes into Ontario then Quebec dragging an occluded front into New England. A strong 500mb shortwave will dig south dragging significantly colder air in its wake with large scale upper level divergence overhead leading to surface convergence. As the front pushes towards Maine during the morning hours rain will develop across the area Sunday AM and last throughout the day. Expecting generally 0.5-0.75 inch of rain during the day Sunday into early Sunday evening but cannot rule out higher amounts up to 1 inch. This will allow for continued slow rise of area rivers/streams but flooding is not expected. Across Northern Maine with frozen soils cannot rule out water getting into basements.

Sunday night significant agreement in global model guidance of a weak surface low developing on a triple point across the Gulf of Maine waters near the Maine coast. As this happens and the occluded front slides through expecting Sunday night a significant surge of colder air with a moist DGZ. As the boundary layer cools to near freezing precipitation will change from rain to snow across Northern Maine especially in the North Woods to St. John Valley first then eventually reaching as far south as Moosehead Region, Baxter SP region and Southern Aroostook County. The uncertainty lies in how much precipitation will be available behind FROPA and how quick the cold air works into the region. GFS is slower on the cold air while ECMWF/Canadian is much faster but the GFS has more QPF available with the ECMWF/Canadian with less. Expecting a dusting up to potential 1-2 inches across Northern Maine. The heaviest totals likely will be in the North Woods to St. John Valley where temperatures can fall the quickest.

Temperatures will be falling below freezing for most areas from Bangor to Calais along The Airline northward to the St. John Valley which may lead to black ice simply from refreezing wet roadways. This could lead to a slick Monday AM commute even if there is no snowfall.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

Today...IFR this morning, improving to MVFR around midday then VFR this afternoon. Winds N 5 to 10 kt.

Tonight...VFR, dropping to IFR in fog at times after midnight, especially in the valleys. Winds NE less than 5 kt.

Saturday...IFR possible in fog in some sites early in the morning. Otherwise, VFR. Winds SE around 10 kt.

Sunday...MVFR/IFR, occasional LIFR. Rain. South winds 10 to 15 knots, becoming west/northwest.

Sunday night...MVFR/IFR. Rain changing to snow north. Rain Downeast. Northwest winds 10 to 15 knots.

Monday...Occasional MVFR early. Otherwise, VFR. Northwest winds 10 to 15 knots with gusts up to 20 knots.

Monday night and Tuesday...VFR. Northwest/north winds 5 to 10 knots Monday night. Variable 5 to 10 knots Tuesday.

MARINE

Winds will be below SCA through Saturday and seas around 2 to 3 ft. Fog will likely limit vsby today, especially this morning, followed by some improvement tonight into Saturday. Winds/seas below SCA conditions through Sunday afternoon. Sunday night winds increase and gust >25kt. Winds fall back below SCA conditions by Monday midday. Rain/fog will reduce vsby Sun into Mon AM.

CAR WATCHES/WARNINGS/ADVISORIES

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