textproduct: Caribou

WHAT HAS CHANGED

-The heaviest precipitation and snow has shifted south slightly Friday night into Saturday.

KEY MESSAGES

1) A period of snow is expected for much of the area Friday evening and Friday night. A light accumulation of snow will result in slippery travel Saturday morning.

2) Snow is possible Sunday night and Monday, especially for the Bangor region and Downeast areas, with possible impacts to the Monday morning commute.

DISCUSSION

KEY MESSAGE 1...A period of snow is expected for much of the area Friday evening and Friday night. A light accumulation of snow will result in slippery travel Saturday morning.

KEY MESSAGE 1 DESCRIPTION... Surface low pressure will develop within the left exit region of a strong upper level jet maxima across southern Ontario and move east-southeast across New Hampshire into the southern half of Maine Friday night. Generally light precipitation will overspread the area late Friday afternoon and evening, starting as snow for most areas. Precipitation may mix with rain closer to the coast. There is still some uncertainty in both the low track and intensity, but guidance has generally shifted south slightly from the previous forecasts, leading to the heaviest QPF along the coast and more snow farther to the south. A general 1 to 3 inches of snow is expected across the forecast area. If a stronger low solution develops, enhanced frontogenesis banding could result in a localized swath of totals of 3 to 5 inches from the Central Highlands east towards northern and central Washington County. NBM, HREF, and LREF blended probabilities indicate about a 30 percent chance of this scenario occurring. Even a light accumulation of snow could cause slippery roads, especially later Friday night and Saturday morning as road surfaces fall below freezing overnight.

KEY MESSAGE 2... Snow is possible Sunday night and Monday, especially for the Bangor region and Downeast areas, with possible impacts to the Monday morning commute.

KEY MESSAGE 2 DESCRIPTION... Low pressure will approach from the west Sunday night. The low is then expected to move east across the Gulf of Maine early Monday and then pass to the south of Nova Scotia by Monday evening. Meanwhile, strong high pressure at the surface will remain anchored to our north across Quebec.

The low has the potential to bring some snow to the region Sunday night into Monday. It appears as if the best chance for measurable snow with this system will be closer to the Bangor region and Downeast areas, with lesser chances to the north. In fact, with cold high pressure anchored to the north across Quebec province, it possible that far northern areas of Aroostook County, especially the Saint John valley could receive little, if any snowfall, with this system.

It is also possible that the low passes even farther south, as some ensembles suggest, suppressing the snow even farther to the south a cross southern New England. If this were to happen, much of our area could miss out on measurable snow entirely. At this point in time, the best chances for any travel impacts later Sunday and Monday will be for the Bangor region and Downeast.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

VFR through this evening, followed by a period of MVFR ceilings between approximately 4 and 10z tonight with light to moderate snow showers, heaviest and most numerous across northern terminals. Tempo IFR or LIFR is possible in heavier SHSN. S winds 5 to 10 kts.

Friday: VFR. WSW winds 5 to 10 kts.

Friday night: MVFR/IFR with -SN, changing to -RA at some coastal terminals. SE winds around 5 to 10 kts, shifting NNW late.

Saturday through Sunday...VFR/MVFR. Scattered snow showers, mainly Aroostook County terminals.

Sunday night and Monday...MVFR or lower in snow. Highest probability of the lower conditions at KBGR/KBHB. Gusty N wind.

Tuesday...VFR.

MARINE

Winds and seas below advisory criteria are expected through Friday. Winds and seas increase Friday night to advisory levels. There is a low to moderate (20 to 40 percent) chance of gale force winds over the outer waters. There is also a moderate (30 to 40 percent) chance of advisory level winds over the intracoastal waters. For now, confidence was only sufficient for a Small Craft Advisory over the outer waters.

A Small Craft Advisory is in effect through Saturday. Small Craft Advisory conditions are possible Sunday night through Monday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...None. MARINE...Small Craft Advisory from 6 PM Friday to 8 PM EDT Saturday for ANZ050-051.