815 FXUS63 KDLH 090529 AAA AFDDLH Area Forecast Discussion...UPDATED National Weather Service Duluth MN 1129 PM CST Tue Jan 8 2019 .UPDATE... Issued at 1121 PM CST Tue Jan 8 2019 Updated for the 06z Aviation Discussion below. && .SHORT TERM...(This evening through Wednesday) Issued at 328 PM CST Tue Jan 8 2019 Winds gradually decrease into tonight as colder arctic air filters into the Northland. Snow showers/flurries diminish, except along the south shore and particularly the Wisconsin Snow Belt region of northern Iron/Ashland county where 3-6+ inches of snow will fall tonight through Wednesday night. Mainly cloudy skies persist into the morning Wednesday, then clearing from west to east as high pressure builds in from the west but a cold day with highs in the single digits above zero, about ten degrees below normal. Cold Wednesday night, with winds near calm in most spots preventing dangerous wind chills, with the except for the tip of the MN Arrowhead where wind chills of 20 to 30 below are possible towards Thursday morning. Increasing clouds from west to east towards Thursday morning will result in temperatures not falling as cold as they might otherwise fall in northern MN outside the MN Arrowhead. On the synoptic scale a mature low over northwest Ontario continues to track eastward while a broad ridge aloft and associated surface high pressure builds over Manitoba into northwest Ontario and Upper Midwest tonight into Wednesday. Low level northwest winds become favorable for lake effect snow along the south shore tonight, and while drier air begins to move in from the west through the day Wednesday, there will be a period of light to moderate snowfall causing around 2-4 inches of snow tonight with another 1-2 inches through the day Wednesday. Wind directions more out of the northwest than a more ideal north-northwest and a dry airmass workings its way in will likely prevent any prolonged period of heavy snowfall rates and thus will hold off on a Winter Weather Advisory, but further east into the U.P. these wind directions are more favorable, which is why our neighboring office in Marquette has issued an advisory. Beyond the winds today, the primary hazardous weather concern in the short term is wind chills. Tonight the winds will persist around 10 to 15 mph for much of the night, which cloud cover combined with the wind causing temps not to fall all that low below zero, wind resultant wind chills just approaching advisory criteria (-25F) in parts of north-central MN. Given the marginal nature and the time of year, a Wind Chill Advisory does not seem warranted given the current trends in observations and model data. Wednesday night will be colder as skies clear out, but then winds will be nearly calm due to the area of high pressure nearby. Still it will take little wind to produce wind chills of 20 to 30 below zero across the MN Arrowhead, so it's possible a Wind Chill Advisory may be needed there on Wed night. .LONG TERM...(Wednesday night through Tuesday) Issued at 328 PM CST Tue Jan 8 2019 Thursday a ridge of high pressure slides across the area, with some lingering flurries ending for Ashland and Iron counties during the morning hours. The cold temperatures over the Arrowhead will produce a cold start to the day, so only expect highs in the teens to low 20s. Thursday night through Friday night is the next weather maker as a weak clipper moves through the area, with snow chances increasing over the Arrowhead during the evening, continuing overnight and Friday, before ending Friday night and early Saturday. The wave is not very strong and there is not a lot of moisture, though the mid level baroclinic zone is fairly tight which would serve to enhance frontogenesis. Model guidance has been shifting this wave farther north with time, and some models have a pretty weak depiction of it. Onshore flow should enhance snowfall rates along the North Shore, but otherwise this just does not look like a very significant snowfall event for the area, and am only looking at an inch or two with maybe two to four inches along the North Shore where the lake enhancements should develop. Flurries with little/no accumulation should continue into Saturday, similar to today though with less wind to cope with. Temperatures to be similar on Friday and Saturday, with not much airmass change behind this system either. The rest of the weekend and early next week to be relatively quiet and mostly dry, with an upper level ridge building across the midwest during the early part of next week to help moderate temperatures and keep the track of weather system north of the forecast area. The latter half of the week could be more interesting, but we will revisit those periods in the next few days. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1129 PM CST Tue Jan 8 2019 Mostly MVFR conditions are expected overnight as a low stratus deck persists for a large portion of the region. The only exception is KBRD, where some breaks in the stratus have been observed via GOES-16 satellite imagery. Strong northwest winds will continue through the morning hours Wednesday before gradually diminishing by the late afternoon and evening hours. Widespread VFR conditions will return Wednesday afternoon and evening as high pressure builds into the region. Some clear skies will be possible for a time in the evening. && .MARINE... Issued at 948 PM CST Tue Jan 8 2019 A Gale Warning continues across western Lake Superior this evening due to strong northwest winds. Latest reports from ships and fixed buoys have indicated wind speeds between 30 and 40 knots. The strong northwest winds have lead to large waves along the South Shore, and wind gusts up to 40 knots are anticipated along the North Shore due to cold air drainage winds as temperatures fall overnight. The latest model guidance indicates that the stronger winds along the North Shore could linger for several hours through Wednesday morning, so have extended the end time of the Gale Warning from Silver Bay to Grand Portage. Due to the large waves, strong winds, and falling temperatures, have also continued the Heavy Freezing Spray Warning for the South Shore. Winds will gradually weaken throughout the day Wednesday, but gusts should be sufficient for Small Craft Advisories, so expect these to be issued when the Gale Warning ends. Winds will diminish below Small Craft Advisory criteria Wednesday evening as high pressure builds into the region. && .PRELIMINARY POINT TEMPS/POPS... DLH 2 9 -4 17 / 30 10 0 0 INL -1 7 -14 13 / 30 10 0 0 BRD 0 8 -4 18 / 10 10 0 0 HYR 5 11 0 21 / 20 10 10 0 ASX 10 14 6 20 / 40 30 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...Heavy Freezing Spray Warning until 10 AM CST Wednesday for LSZ121-145>148. Gale Warning until 4 AM CST Wednesday for LSZ121-143>148. Gale Warning until 10 AM CST Wednesday for LSZ140>142. && $$ UPDATE...JTS SHORT TERM...JJM LONG TERM...LE AVIATION...JTS MARINE...JTS