656 FXUS63 KDLH 261533 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 933 AM CST Thu Dec 26 2019 .UPDATE... Issued at 933 AM CST Thu Dec 26 2019 Dense fog no longer being reported or seen on area web cams and have dropped the advisory. Accumulating snow has ended in Cass and Crow Wing counties and have been dropped from the Winter Weather Advisory. Rest of the headlines unchanged. Made some other minor adjustments. && .SHORT TERM...(Today through Friday) Issued at 423 AM CST Thu Dec 26 2019 A wintry mix changes to snow this morning as precipitation ends from south to north across northeast Minnesota, then colder, more seasonable air moves in and skies clear out for Friday. This morning a wintry mix of rain/drizzle, freezing rain/freezing drizzle, snow, and even some sleet is occurring across northeast Minnesota along a warm frontal boundary lifting north, but by daybreak most of the mix will be north of the international border. Colder air moving in from the northwest will cause precipitation to change to just a plain rain/snow mix (though used drizzle wording in the forecast since intensity will be very light), with precipitation ending from south to north in the afternoon hours. Will be relying on spotters for reports of freezing rain this morning, but suspect at least some spots saw a glaze of ice from the overnight/early morning mixed precip. Total snowfall amount forecast is on track as well with totals around 1 to 3 inches, highest amounts north and west of the Iron Range. Given fairly warm surface temperatures, it will be a wet and heavy snowfall, but again amounts are on the low end. Winter Weather Advisory will remain in effect due to the risk for roads becoming slippery as temperatures fall, but suspect we might be able to cancel the advisory early in some spots as precipitation comes to an end. For the Twin Ports, I-35 corridor and across northwest Wisconsin the main weather hazard continues to be areas of dense fog, and plan to continue the Dense Fog Advisory in place through mid morning. Think this foggy area will be able to get by without having too many issues with icy roads for the morning commute, but this afternoon/evening commute could see some surfaces refreezing. This afternoon into tonight west winds around 10 to 15 mph will bring in colder air, with temps falling to the mid 20s to near 30 by 6pm, into the upper teens to mid 20s by midnight. Wind chill values will be as low as the single digits above freezing, with lows around the mid teens to low 20s by Friday morning. Skies will gradually clear out as high pressure builds to the south across the Mid Mississippi River Valley, with the high then building to the east towards the Ohio River Valley on Friday. Mainly sunny and seasonable on Friday with highs in the mid 20s - still technically a few degrees above normal for most locations. Southwest wind around 5 mph - not a bad day to enjoy the great outdoors, but watch out as surfaces refreeze after the mild stretch of weather we have had the past few days that caused a lot of melting. .LONG TERM...(Friday night through Wednesday) Issued at 423 AM CST Thu Dec 26 2019 A major winter system will impact the Northland during the weekend and linger into the new week. Temperatures will warm above normal this weekend and lead to a messy system with rain, snow and freezing rain all possible. Another chance for snow will then be possible later next week as temperatures return to near to slightly above levels. A longwave trough will move through the Rockies at the start of the period with a surface low developing in the Panhandle region. The low will move to the northeast through the day Saturday and reach southern Minnesota by Sunday morning. Precipitation will spread northward during the day Saturday and is expected to be mainly snow at the onset. Heading into the afternoon hours, surface temps across northwest Wisconsin will warm to right around or just above the freezing mark with warm air moving in aloft as well. P-type will then change over to a wintry mix of rain, freezing rain and snow across northwest Wisconsin and into east-central Minnesota. As the low moves into southern Minnesota early Sunday morning, warm air will continue to move northward and move that wintry mix to the Twin Ports area and up the North Shore and into the Iron Range. All rain is then expected across much of northwest Wisconsin. The low will then slowly drift across Wisconsin on Sunday. There is the potential for a dry slot to work into the Northland during the day Sunday which could lead to areas of freezing drizzle with a loss of ice aloft. Even if this dry slot doesn't move in, temperatures will support a wintry mix over much of our Minnesota zones with rain and snow over northwest Wisconsin. As the low moves to the east Sunday night, cooler air will arrive and change the wintry mix over the snow with snow then lingering through Monday and into Tuesday as the low becomes cutoff over the northern Great Lakes. Travel will be impacted by this system over the weekend with many returning from the holidays. Current snowfall amounts of 3 to 6 inches will be possible across much of the Northland with higher amounts from the Brainerd Lakes area to the western Iron Range to Koochiching County and also along the higher elevations along the North and South Shores of Lake Superior. Ice accretions of a few hundredths to 0.20 inches will be possible as well. Winter headlines will most likely be needed across much of the Northland for this system. Models diverge for the latter half of the period with the ECMWF and GEM remaining generally dry while the GFS brings a clipper through Wednesday into Thursday. Temperatures will warm above normal for the weekend before cooler air arrives at the start of the new week on the backside of the low. This will bring more seasonal air to the region for the remainder of the period. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 534 AM CST Thu Dec 26 2019 IFR to LIFR conditions will prevail through the TAF period at most sites. Dense fog/reduced visibility will be the primary concern this morning, then ceilings will drive the flight conditions through the rest of the TAF period. Some sites may briefly improve to MVFR ceilings this afternoon before returning to IFR tonight. Winds becoming westerly today at around 10 knots with some sites gusting as high as 20 knots. && .MARINE... Issued at 423 AM CST Thu Dec 26 2019 Northeasterly winds will diminish this morning and turn southwesterly by midday. Waves along the North Shore will be slower to diminish and Small Craft Advisories remain in effect this morning along the North Shore with waves of 3 to 6 feet. Southwesterly winds will then increase this afternoon as a pressure gradient sets up between low pressure over St. James Bay and high pressure over Iowa. Winds will be sustained from the southwest at 10 to 20 knots with gusts to 25 to 30 knots along the northern Bayfield Peninsula and Apostle Islands this afternoon and into Friday morning before diminishing. These winds will lead to waves of 3 to 6 feet along the northern Bayfield Peninsula through daybreak Friday. A Small Craft Advisory has been issued for this area due to the winds and waves. Southwest winds of 10 to 20 knots will linger across western Lake Superior Friday afternoon before diminishing to 6 to 12 knots Friday night. A strong storm system will move near western Lake Superior Saturday night into Sunday with gale-force winds expected with storm- force gusts being possible as well depending on the track of the storm. && .PRELIMINARY POINT TEMPS/POPS... DLH 33 20 25 17 / 60 0 0 10 INL 31 16 26 13 / 100 0 0 0 BRD 34 17 26 17 / 20 0 0 20 HYR 35 22 28 17 / 40 0 0 10 ASX 36 24 30 19 / 50 0 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...Winter Weather Advisory until 6 PM CST this evening for MNZ010>012-018>021-026. LS...Small Craft Advisory until 10 AM CST Friday for LSZ146-147. Small Craft Advisory until 10 AM CST this morning for LSZ140>142. && $$ UPDATE...GSF SHORT TERM...JJM LONG TERM...BJH AVIATION...JJM MARINE...BJH