textproduct: Caribou

WHAT HAS CHANGED

Winter Storm Warning for Aroostook County, nrn Penobscot, nrn Piscataquis and nrn Somerset Counties. Winter Weather Advisory issued for Central and srn Piscataquis County, central Penobscot and northern Washington Counties.

KEY MESSAGES

1) Significant winter storm bringing all but the kitchen sink Wednesday and Wednesday night with treacherous travel expected north of the Downeast area.

2) A fast moving storm system may bring snow late Friday night into Saturday morning. This could impact travel with slushy and slippery roads Saturday morning.

3) A large storm system approaching late in the weekend may bring snow north and a mix Downeast Sunday night, changing to rain across the area early Monday. Strong south winds may accompany the storm. This could bring some messy travel across the north early Monday.

DISCUSSION

KEY MESSAGE 1...Significant winter storm bringing all but the kitchen sink Wednesday and Wednesday night with treacherous travel expected north of the Downeast area.

KEY MESSAGE 1 DESCRIPTION... Light echoes showing up on regional radars associated with H8 front just to our north. Weak lopres has developed over central areas leading to sunny skies and temps warming up into the 70s for the first time this year. In fact, the 70 degree reading at Bangor today is the earliest it has been reached since records began, dating back to 1925.

Weak sfc boundary looks to be fairly stationary this afternoon before being pushed over the waters this evening. 1035mb hipres will build thru Canada overnight with northeasterly flow supplying a steady supply of cold low-level air across northern and central areas. How cold surface temps can fall in the Bangor Region and Downeast tonight continues to remain in question, but it is looking less likely that they will fall to the freezing mark by sunrise.

Sfc boundary extends back toward stronger sfc low sitting back over the Central Plains near the Kansas City area. This low is associated with RFQ of upr level jet streak. Have included very light pops this afternoon and evening along H8 front however as dry air moves in with building high pressure there will likely be a break for a good chunk of the overnight hours.

Precipitation looks to move in around sunrise acrs wrn areas, though dry air associated with high may delay the start time by an hour or two. Forecast soundings are showing a cold layer from the surface up toward 5-6Kft with a warm nose right around 750mb. Winds will be veering thru the column toward the south with warm advection aloft through most of the day and into the evening hours.

Precip looks to begin as snow over the north in the morning with a freezing rain/sleet mix over central areas and rain in Downeast. Cannot rule out a brief period of mixed precip from Bangor over towards Calais but how long wintry mix continues acrs these areas will determine accumulation of sleet and/or accretion of ice, thus have left this area out of the winter weather advisory.

Further to the north it appears that there will be a significant accumulation of sleet in the afternoon as warm air lifts north with below freezing layer remaining deep. Even as surface temps warm toward freezing temps will be quite a few degrees colder just above the surface, enough to refreeze any melted snowflakes into ice pellets.

As the warm air continues over the far north late afternoon and early in the evening the same scenario will be playing out. Overall this winter storm looks to be more of a sleet producer than freezing rain just based on atmospheric profiles.

Overall we are looking at 3-6 inches of snow in the St. John Valley at onset Wednesday morning. The snow will be heavy and wet. As the day wears on snow changes to sleet with a total of 1-2 inches on top of the heavy and wet snow, locally up to 3 inches of sleet possible. And to top it off will be one to two tenths of an inch of ice moving from south to north Wednesday and Wednesday night. All this to say is that not only will travel be very treacherous but clean up will also be tough. Extra caution should be taken after the storm. Pace yourself and take frequent breaks.

Winds will be out of the east and gust upwards of 25 mph Wednesday evening. With heavy wet snow, sleet and freezing rain falling there is the potential for tree damage along with isolated power outage.

KEY MESSAGE 2... A fast moving storm system may bring snow late Friday night into Saturday morning. This could impact travel with slushy and slippery roads Saturday morning.

KEY MESSAGE 2 DESCRIPTION... A clipper type system will approach Friday with snow overspreading the region Friday evening and continuing into Saturday. It appears as if this system has the potential to bring a light to moderate snowfall across the area Friday night into Saturday. Depending on the track of the low, a rain snow mix is possible Downeast. The main impacts will be the potential for hazardous travel, especially late Friday night and Saturday morning.

KEY MESSAGE 3... A large storm system approaching late in the weekend may bring snow north and a mix Downeast Sunday night, changing to rain across the area early Monday. Strong south winds may accompany the storm. This could bring some messy travel across the north early Monday.

KEY MESSAGE 3 DESCRIPTION... Another storm system approaches later Sunday and Monday. This storm looks like it will pass to the northwest of the region. This would result in warmer air surging northward in advance of the low, with any frozen precipitation at the onset going over to all rain Monday. The warm temperatures and rainfall would result in continued melting of the snowpack across the north, as well as continued ice rot on rivers and lakes.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Tonight...VFR, though may see brief MVFR cigs this evening over Aroostook terminals.

Wednesday...Conditions deteriorate to MVFR and eventually IFR/LIFR in snow at northern Aroostook terminals early and then mixed precipitation in the afternoon and evening. HUL will see mixed precipitation all day. BGR mixed precipitation early and then going to rain early afternoon. BHB all rain. ENE 5-15kts gusting to 20kts in the afternoon.

Wednesday night...IFR/LIFR in mixed precipitation northern Aroostook terminals, becoming all rain at HUL after midnight and all rain BGR and BHB. SE 5-10kts, gusting to 20kts.

Thursday..MVFR/IFR early, then VFR by afternoon.

Thursday night and Friday...VFR.

Friday night and Saturday...MVFR or lower conditions expected in snow.

Saturday night and Sunday...MVFR/VFR.

MARINE

Winds and seas will remain below small craft levels tonight, before northeast winds increase by morning. Winds will be approaching gale force late Wednesday night with seas climbing to between 7 to 10 ft Thursday morning.

SCA or possible minimal gale force winds are possible Thursday into Thursday night. SCA conditions are the possible Friday, with gales possible Friday night into Saturday.

CLIMATE

CAR WATCHES/WARNINGS/ADVISORIES

ME...Winter Storm Warning from 8 AM Wednesday to 8 AM EDT Thursday for MEZ001-002. Winter Storm Warning from 8 AM Wednesday to 2 AM EDT Thursday for MEZ003>006. Winter Weather Advisory from 8 AM to 11 PM EDT Wednesday for MEZ010-011-031-032. MARINE...Small Craft Advisory from 6 AM Wednesday to 6 AM EDT Thursday for ANZ050>052.