Marine Weather and Tide Forecast for Bena, MN

DISCUSSION
Issued at 402 PM CST Sat Dec 7 2024

Current Conditions/Tonight:

A weak clipper is exiting to our east across northern Lake Superior this afternoon with west to southwesterly winds filtering in behind the system. Skies have rapidly cleared faster then previously forecasted allowing for temperatures to over achieve this afternoon with highs in the 40s across much of the region. Cloud cover is expected to return tonight ahead of an approaching system which should help to insulate some of these temperatures with overnight lows staying in the 20s. We may also see some advection fog come into play briefly across north central MN before day break.

Sunday Next Wintry System Setup:

Sunday a pair of lows will bring a mix of rain and snow back to the Northland. The primary low is of the clipper variety traversing across Saskatchewan Sunday and entering MN on Monday. The secondary Low is set to move into southern MN Sunday afternoon before weakening on Monday and rejoining the parent circulation over Lake Superior. Looking at the ALPW we can see a plume of moisture extending from the Cascades and across southern Canada. This added moisture pushes our PWATs to around 0.70 inches which is over the 95th the percentile of climatology.

Mixed Bag of Precipitation (Sunday morning/afternoon):

These higher PWATs and ample forcing would normally translate into a simple snow forecast but we can't get that lucky. For this upcoming set up we have several wrenches being thrown into the forecast.
Above freezing surface temperatures with a warm nose aloft will lead to some mixed precipitation issues. There is also a dry slot forecasted to move in Sunday evening which could eat away at overall precip totals or lead to some widespread freezing drizzle. Factoring in the over achieving temperatures today we have seen quite a reduction in ice accumulations for tomorrow based on surface temperature alone. The latest high res guidance suggests having the rain snow line stretching from Cass down through Burnett. Within this sector stands our best chance of seeing some freezing rain and ice accumulations. While the overall total ice has been reduced it seems Cass County could see a tenth of an inch of ice and has been added to a Winter Weather Advisory.

Snow (Sunday):

As mentioned previously the warmer temperatures throw numerous problems into the snowfall forecast but for the most part northern MN is favored to see mostly snow. Our SLRs are going to be on the low side leading to more of a wet concrete type of snow that tends to stick to trees and powerlines. A tight temperature gradient over the region will also lead to strong FGEN bands. Some banded snow segments will also be possible in northern MN as the parent surface low moves across the International Border through Monday. The current forecast package captures the initial push of snow well with the highest rates coming in Sunday afternoon and evening. Snowfall rates largely drop as we head into Monday but this may be slightly underdone as favorable mid level lapse rates coincide with a band of FGEN at 925mb across northern MN.

Winter Weather Headlines:

Overall, wet heavy snow is expected across northern MN with some mixed bag precipitation across north central MN into NW WI. Terrain and lake effect boost for the North Shore will lead to the highest snowfall totals in excess of 6 inches along the elevated terrain of Cook county. The preponderance of warm air at play associated with this system will lead to a sharp gradient in snowfall totals across northern MN. A Winter Warning has been issued for southern Cook County and Winter Weather Advisories have been issued for northern MN and Cass County.

More snow chances (Monday):

Monday will see the clipper system moving over Lake Superior with a cold front sweeping in from the west. Gusty winds and wrap around moisture will be falling as snow through the day. As mentioned above there is some concern for some over achieving snow showers as steeper mid level lapse rates interact with a FGEN band around 925mb across northern MN. Temperatures will be flirting around freezing for the day before tanking with the passage of the cold front.

Blast of Arctic Air (Wednesday):

Through the remainder of the week we will maintain our NW flow with embedded moisture in the pattern. Off and on light snow and flurries will be abound. Warm Lake Superior will be producing ongoing snow chances for the South Shore once again. A blast of arctic air is expected to barge in from the north on Wednesday with highs in the single digits across most of the Northland.
This may lead to a Cold Weather Advisory on Thursday morning.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/
Issued at 1105 PM CST Sat Dec 7 2024

MVFR ceilings have spread quickly south this evening and will remain in place but should remain just north of KBRD overnight. An area of low pressure will lead to the precipitation Sunday with mainly snow over far northern areas and a wintry mix south including freezing rain or just rain. The precipitation will become all snow for most Sunday night into Monday as colder air moves into the region.

Ceilings for much of the area will lower through the day Sunday to IFR or lower. The snow will be heavy at times in far northern Minnesota during Sunday afternoon and overnight. The snow for most will be wet and heavy.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/
Issued at 1000 PM CST Sat Dec 7 2024

Westerly winds will slowly diminish tonight and we dropped the Small Craft Advisories that were in effect through 10 pm this evening. Easterly winds will develop and increase on Sunday and conditions will become hazardous for small craft for portions of the North Shore and Outer Apostle Island and Small Craft Advisories have been issued from late Sunday afternoon into Monday morning.

Another wind shift will occur with increasing west or northwest winds Monday continuing into mid to late week. Hazardous conditions for smaller vessels will continue

For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt.

DLH WATCHES/WARNINGS/ADVISORIES
MN...Winter Weather Advisory from 6 AM Sunday to 6 AM CST Monday for MNZ010>012-018-019.
Winter Weather Advisory from noon Sunday to noon CST Monday for MNZ020.
Winter Storm Warning from noon Sunday to noon CST Monday for MNZ021.
Winter Weather Advisory from 6 AM Sunday to midnight CST Sunday night for MNZ025-033.
WI...None.
MARINE...Small Craft Advisory from 5 PM Sunday to 10 AM CST Monday for LSZ140>142.
Small Craft Advisory from 5 PM Sunday to midnight CST Sunday night for LSZ150.