textproduct: Caribou

WHAT HAS CHANGED

-Snow amounts have increased for tonight for the Bangor area and Downeast Maine. A Winter Weather Advisory was issued for coastal Hancock County.

-Snow chances and winds have increased Monday into Monday night, especially Downeast.

-A storm watch has been issued for the offshore waters and a gale watch for the intracoastal waters Monday into Monday night.

KEY MESSAGES

1) Snow is expected tonight for the Bangor region and Downeast Maine. Impacts to travel are expected mainly after 8PM into early Saturday morning.

2) Strong gusty winds and some snow likely over Downeast Maine Monday into Monday night. This may impact travel, especially over southern areas during the Monday evening commute, and possibly over eastern areas Tuesday morning.

3) Snow is possible Wednesday night into Thursday. The snow may mix with or change to rain in southern and eastern areas on Thursday. This has the potential to impact travel, especially during the Thursday morning commute.

DISCUSSION

KEY MESSAGE 1...Snow is expected tonight for the Bangor region and Downeast Maine. Impacts to travel are expected mainly after 8PM into early Saturday morning.

KEY MESSAGE 1 DESCRIPTION... A shortwave trough and associated surface low over the Great Lakes will progress eastward tonight, lifting an occluded front towards the area. Meanwhile, high pressure over northern Quebec will ridge in across northern Maine, reinforcing low level cold air. While this will keep precipitation suppressed to the southern half of the area, it will enhance isentropic ascent and low level convergence across western Maine through Bangor and Downeast Maine. Recent trends have converged towards a higher QPF solution, with around a quarter inch of liquid equivalent for Bangor and over a third of an inch for coastal Hancock County. Snow ratios slightly greater than 10 to 1 will yield snow amounts generally 2 to 4 inches for Bangor and Downeast Maine, with the highest totals of 3 to 5 inches for coastal Hancock County where a Winter Weather Advisory has been issued. The start time will be late this evening after about 8PM, which may impact Friday evening travel. Snowfall rates around 1 inch per hour are possible, mainly between 3z/10PM and 6z/1AM. Most of the snow will fall over a short period of time overnight, with dry air moving in and precipitation tapering to flurries shortly after daybreak Saturday. A modest north wind with gusts to around 25 mph overnight into Saturday morning could lead to some minor drifting over open areas, but significant blowing snow is not anticipated with tonights system.

KEY MESSAGE 2...Strong gusty winds and some snow likely over Downeast Maine Monday into Monday night. This may impact travel, especially over southern areas during the Monday evening commute, and possibly over eastern areas Tuesday morning.

KEY MESSAGE 2 DESCRIPTION... Low pressure will develop over the southern states this weekend in response to a shortwave progressing east in the southern branch jet stream. As this low approaches the East Coast Saturday night, a northern branch shortwave diving southeast through the Midwest is expected to phase in with it. The eventual track and intensity of this storm will depend on how much northern branch energy can engage with the system. Strong northern branch phasing backed by a core of deep cold air dropping in behind the low will result in a more negatively tilted trough and a stronger low tracking further north. Weak phasing in which much of the northern branch energy misses the system, or fails to lock in with the trough, will result in a weaker low tracking further south. Forecast models were trending a little weaker and further south with the system earlier this week, but have now begun trending a bit stronger and further north with the system during the last couple of runs.

The greatest chance for some impacts from this system are Downeast Monday into Monday night, especially along the coast. Northeast winds will increase on Monday and some snow may move onto the coast midday Monday as the low center tracks southeast of the Gulf of Maine by late in the day. This has the potential to impact travel Downeast and possibly along the I-95 corridor in the vicinity of Bangor during the Monday evening commute. Some blowing snow is likely across open areas. The strongest winds will be right along the coast. The low will track south of Western Nova Scotia Monday evening, possibly bringing additional snow to the eastern edge of our forecast area overnight with the best chances Downeast. Any snow should gradually taper off early Tuesday morning. Patchy blowing snow is possible late Monday into Monday night, especially across open areas.

KEY MESSAGE 3...Snow is possible Wednesday night into Thursday. The snow may mix with or change to rain in southern and eastern areas on Thursday. This has the potential to impact travel, especially during the Thursday morning commute.

KEY MESSAGE 3 DESCRIPTION... Low pressure is expected to approach from the Great Lakes on Wednesday and possibly spread snow from south to north across the area Wednesday night. Forecast models show the low tracking across the central or northern part of our region on Thursday. This track would favor warmer air coming in south of the low changing snow over to a mix or rain Downeast and possibly a mix over central parts of the area.

This storm system has the potential to impact travel during the Thursday morning commute, especially over the north with snow covered roads over the north and possibly slushy roads in southern areas. Some minor travel problems are may still be possible across the north for the Thursday afternoon commute. Roads over southern areas may just be wet Thursday afternoon.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

Through tonight: Mainly VFR late this afternoon, becoming MVFR/IFR with tempo LIFR at BGR and Downeast terminals in snow. NE 5 to 10 kts gusting to 20 kts, strongest for southern terminals.

Saturday: MVFR possible at northern terminals, otherwise VFR. N winds around 10 kts gusting to 20 kts.

Saturday Night: VFR. N winds 5 to 10 kts.

Sunday...VFR all sites. N wind around 5 kt.

Sunday night...VFR. NE wind around 5 kt north, 10 kt increasing to 15 kt south.

Monday...VFR across the north. MVFR possibly dropping to IFR over the south. NE wind 5 to 10 kt over the north and 15 to 20 kt over the south with possible gusts to 30 kt at BHB.

Monday night...MVFR possibly dropping to IFR north and IFR south, possibly improving to MVFR late. N wind 10 to 15 kt north and 15 to 25 kt over the south with higher gusts along the coast.

Tuesday...MVFR becoming VFR all sites. NW wind 10 to 15 kt.

Tuesday night...VFR. W wind around 5 kt.

Wednesday...VFR, possibly dropping to MVFR north. S wind around 5 kt.

MARINE

Winds and seas will increase to Small Craft Advisory levels tonight as snow overspreads the waters. A few gusts to gale force are possible for the outermost waters for a 2 to 3 hour period overnight tonight. Light freezing spray is expected Saturday morning. Winds decrease below advisory levels first over the intracoastal waters during the day Saturday, then the rest of the waters late Saturday night.

A strong storm tracking offshore will result in NE winds increasing to SCA Sunday then a strong gale Sunday night. A strong gale and possibly a storm will impact the waters Monday into Monday evening as low pressure tracks south of the Gulf of Maine. Winds should diminish to a weaker gale late Monday night then a SCA early Tuesday and below SCA late Tuesday. Winds should be below SCA on Wednesday. Seas will build to around 6 ft Sunday night, up to 9 ft Monday and 13 ft Monday night. Seas will back off to around 5 ft by late Tuesday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Winter Weather Advisory from 7 PM this evening to 7 AM EST Saturday for MEZ029. MARINE...Small Craft Advisory from 9 PM this evening to 5 AM EST Sunday for ANZ050-051. Storm Watch from Monday morning through late Monday night for ANZ050-051. Small Craft Advisory from 9 PM this evening to 5 PM EST Saturday for ANZ052. Gale Watch from Monday morning through late Monday night for ANZ052.