textproduct: Caribou

WHAT HAS CHANGED

-Snow amounts have increased for southern areas.

-Issued winter weather advisories for the entire region from very late tonight into Saturday afternoon.

KEY MESSAGES

1) A moderate snowfall is expected throughout the area beginning overnight tonight across the south and early Saturday morning over the north. This will likely impact the region with slippery travel, especially Saturday morning.

2) Snow will develop Sunday night then transition to a wintry mix and eventually all rain, from south to north, into Monday morning. The wintry mix could impact the Monday morning commute across northern areas. Strong south/southeast winds are likely Monday into early Tuesday, with the strongest winds along the Downeast coast. The strong winds could lead to power outages, particularly along the Downeast coast.

DISCUSSION

KEY MESSAGE 1... A moderate snowfall is expected throughout the area, beginning overnight tonight across the south, and early Saturday morning over the north. This will likely impact the region with slippery travel, especially Saturday morning.

KEY MESSAGE 1 DESCRIPTION... A clipper low will rapidly approach from the Great Lakes on Friday and spread snow from south to north across the area late Friday night into early Saturday morning. The latest forecast guidance is now focusing the heaviest snow across the interior south. Locally strong dynamic lift including a sharp vorticity max and upper level divergence will work with the surface convergence of the surface low to produce moderate to perhaps occasionally heavy snow, especially across interior Downeast early Saturday morning. The latest forecast snow totals have a few central and interior southern areas with over six inches of snow which could require a winter storm warning. However, these heavier areas are rather blotchy with no large scale definitive area of heavier snow so will initially issue a winter weather advisory for all areas which may have to be upgraded to a warning in some zones later today. Across the north, the dynamics are less focused. In additional, easterly winds lined up from surface to aloft over the far north may result in some downsloping off the New Brunswick Highlands. Therefore, amounts will be less over the north where only 3 to 4 inches is expected. Snow will taper off over southern areas around midday Saturday then across the north late Saturday afternoon into Saturday evening.

The primary impact from this system will be snow covered and slippery roads, especially early Saturday morning. By early Saturday afternoon many roads, especially primary roads, may just be wet as temperatures nudge near to above freezing and mid-March insolation warms the roads a bit. However, some slushy and messy surfaces will still be likely through Saturday mainly on the secondary roads.

KEY MESSAGE 2... Snow will develop Sunday night then transition to a wintry mix and eventually all rain, from south to north, into Monday morning. The wintry mix could impact the Monday morning commute across northern areas. Strong south/southeast winds are likely Monday into early Tuesday, with the strongest winds along the Downeast coast. The strong winds could lead to power outages, particularly along the Downeast coast.

KEY MESSAGE 2 DESCRIPTION... Intensifying low pressure will track northeast across the Great Lakes Sunday night through Monday then lift across Quebec province Monday night. The low will draw a warm front across the region Monday. A series of cold fronts will then cross the region Monday night into Tuesday. Overrunning snow will develop Sunday night, then transition to a wintry mix and eventually rain Sunday night through early Monday. Rain, possibly heavy at times, will then persist Monday into Tuesday. Rain and temperatures in the 50s will also lead to significant snowmelt Monday into Tuesday which could lead to flooding.

A strong south/southeast low level jet will also cross the region later Monday into Tuesday in advance of the cold fronts. The strongest winds are expected across Downeast areas, particularly along the Downeast coast, where gusts in excess of 50 mph are possible. Gusty winds are also expected northward across the remainder of the forecast area.

Persistent strong south/southeast winds could also lead to high surf and possible coastal flooding Monday into Tuesday.

AVIATION /08Z FRIDAY THROUGH TUESDAY/

Today...VFR. W wind around 10 kt, becoming light and variable over the north and S around 5 know across the south.

Tonight...MVFR dropping to IFR over the south. VFR dropping to MVFR then IFR late over the north. SE wind around 5 kt.

Saturday...IFR, possibly improving to MVFR over the south late. N wind around 5 to 10 kt.

Saturday night...MVFR/IFR with a chance of snow early. VFR/MVFR late. Northwest/west winds 10 to 15 knots.

Sunday...VFR. Northwest/west winds around 10 knots, becoming east/southeast.

Sunday night...VFR/MVFR early. IFR/LIFR late. Snow transitioning to a wintry mix then rain, from south to north. East/southeast winds 5 to 10 knots, becoming south/southeast 10 to 20 knots with gusts up to around 25 knots.

Monday...IFR/LIFR, possible VLIFR. A wintry mix possible north early. Otherwise, rain. South/southeast winds 15 to 25 knots with gusts up to 30 to 40 knots. Low level wind shear likely.

Monday night...IFR/LIFR, possible VLIFR. Rain. South winds 20 to 30 knots with gusts up to 40 to 45 knots, possibly higher along the Downeast coast. Low level wind shear likely.

Tuesday...IFR/LIFR early, then VFR/MVFR late. Rain early, tapering to showers. South winds 15 to 25 knots with gusts up to 30 to 35 knots, becoming west/southwest 10 to 15 knots with gusts up to around 20 knots. Low level wind shear possible early.

MARINE

A SCA will continue for both intracoastal and offshore waters early this morning then just for the offshore waters through late morning. Winds will drop below SCA through midday today. Winds increase back to SCA over the offshore waters late today then to a strong SCA, with a few wind gusts up to 35 kt over the offshore waters, tonight through Saturday.

A few wind gusts could approach gale levels Saturday night. Otherwise, small craft advisory conditions are expected Saturday night into early Sunday. Small craft advisory conditions develop again Sunday night. Storm force conditions are then likely later Monday into early Tuesday, with gale conditions later Tuesday. Rain Sunday night into Tuesday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Winter Weather Advisory from 6 AM to 7 PM EDT Saturday for MEZ001>006. Winter Weather Advisory from 2 AM to 2 PM EDT Saturday for MEZ010-011-015>017-029>032. MARINE...Small Craft Advisory until 2 PM EDT this afternoon for ANZ050- 051. Small Craft Advisory until 8 AM EDT this morning for ANZ052.