918 FXUS63 KDLH 282334 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 534 PM CST Mon Jan 28 2019 .UPDATE... Issued at 531 PM CST Mon Jan 28 2019 Bumped temps down a tonight and tomorrow night as guidance trend has been cooler and our forecast temps were falling towards the middle of guidance. Typically, in these air masses, all guidance is too warm. && .SHORT TERM...(This evening through Tuesday) Issued at 251 PM CST Mon Jan 28 2019 The focus remains on the extremely cold and historic air that will soon be moving into the Northland. This latest forecast has even colder wind chills than earlier forecast. Confidence is high for widespread dangerous wind chills. Wind Chill Warnings and Advisories have now been issued. An Arctic cold front will continue moving east through the Northland this afternoon through this evening, bringing an influx of extremely cold air out of Canada into the Northland into tomorrow. This will be a rare situation in which a deep upper level polar low will dive south into the Minnesota and Wisconsin region by tomorrow morning. This airmass will feature 850 hpa temperatures at least as cold as -40 degrees Celsius, with the coldest air across western into southern Minnesota. Gusty winds late tonight and Tuesday will cause widespread dangerous wind chills of 30 to 55 below zero across the Northland, with the coldest wind chills across central and northern Minnesota. Expect northwest winds of 10 to 20 mph gusting 20 to 30 mph. There will be little improvement of the winds and wind chills for the afternoon. The worst conditions will come Tuesday night through Wednesday morning. Air temperatures will plummet to 20 to 40 below zero. Northwest winds of 5 to 15 mph, and up to 20 mph along the Minnesota North Shore, will cause jaw dropping wind chills of 45 to 65 below zero which will continue well into Wednesday morning. These wind chills are on the order of an event that the Northland typically only sees at least once every 5 to 10 years. The latest comparable situations occurred in January 2014 and February 1996. Frostbite can occur within 5 minutes under these conditions! This overall forecast was by no means on the extreme side of model guidance. The temperature and wind forecasts were close to a consensus of available model guidance, especially the temperatures. That means there were other models that were significantly colder. It is possible we may need to forecast even colder temperatures with subsequent forecasts. If this were the case, the wind chills could be substantially, and incredibly, colder. .LONG TERM...(Tuesday night through Monday) Issued at 251 PM CST Mon Jan 28 2019 Near-record cold and dangerously cold wind chills are expected mid- week, then a welcome warm-up this weekend. On the synoptic scale a maturing low will be over the Upper Great Lakes Tuesday night, weakening and exiting to the northeast on Wednesday. This low will be responsible for bringing what will almost certainly be the coldest air of the season to the Upper Midwest as an arctic high then builds in from the west Wednesday into Thursday, which is expected to allow skies to finally clear out Wednesday night into Thursday and allow temperatures to plummet to near record-breaking values. Late in the week a mid/upper level longwave ridge builds from the Rockies into the Great Plains and Midwest, ushering in a surge of warmer air across the Great Plains and Midwest. The warm frontal zone on the leading edge of this warmer air will move across the Upper Midwest late Thursday which could result in a brief period of drizzle, but the main impact to sensible weather will be increasing temperatures. Temperatures will surge to the mid 20s to mid 30s on Saturday before a cold front arrives Saturday night into Sunday bringing in more seasonable temperatures into early next week. A potent mid-level shortwave trough will eject out of the southwest into the Great Plains Sunday into Monday, tracking towards the Upper Great Lakes. This mid-level shortwave and associated surface low could produce a broad area of precipitation Sunday night into Monday, with the best chance across central Minnesota and northern Wisconsin. The coldest wind chills of the season are likely to occur Wednesday with northwest winds 10-20 mph and temperatures 20 to 35 below zero resulting in wind chills around 40 to 60 below. At these extreme wind chills, frostbite can develop on exposed skin in as little as five minutes. Spending more than a few minutes outside on Wednesday without proper attire *will* result in frostbite. The "warmest" the wind chill will reach on Wednesday is 20 to 35 below zero, with the air temperature around 5 to 15 below zero. Cloudy skies in the morning will give way to sunshine from west to east during the afternoon. Wednesday night will be the coldest night of the season, with record lows possible. High pressure will be centered over the Midwest Wednesday night with mainly clear skies across northern Minnesota and northwest Wisconsin. These clear skies will allow for radiational cooling through the night, creating perfect conditions for temperatures to fall to record-breaking levels. Forecast lows have been lowered a few more degrees from the previous forecast, but locally colder temperatures are possible. With high pressure nearby, winds will be much less of an issue, but since at these temperatures just a 5 mph wind can result in much greater heat loss, wind chills of 30 to 50 below are expected on Thursday morning. In addition to the cold, lake effect snow will linger along the south shore through Wednesday, but amounts will be light. Enjoy the sunshine on Thursday morning because clouds return from west to east late in the day as the warm front builds in. Lows Thursday night 15 to 25 below zero, with little to no wind. Not as cold Friday with highs in the single digits to low teens ABOVE zero. Warmer Saturday with highs in the mid 20s to mid 30s, warmest in northwest Wisconsin. Southerly winds 5 to 10 mph. Cooler Sunday with highs mid teens to low 30s. An increasing chance for snowfall Sunday night into Monday, greatest along and south of Highway 2. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 531 PM CST Mon Jan 28 2019 Mostly VFR after snow comes to an end later this evening. Winds pick up as the cold arctic air mass arrives Tuesday morning. Could see IFR for the next several hours though believe snowfall intensity should start to decrease NW to SE this evening. A little difficult to decipher with KDLH's radar down. && .CLIMATE... Issued at 251 PM CST Mon Jan 28 2019 Record lows are possible this week. Below are records and current forecasts for select sites with a long history. Record Lows for Tuesday January 29... Duluth................-35 in 1951...Forecast...-21 International Falls...-41 in 1951...Forecast...-28 Brainerd..............-38 in 1965...Forecast...-25 Hibbing...............-34 in 1951...Forecast...-24 Ashland...............-35 in 1951...Forecast...-10 Record Lows for Wednesday January 30... Duluth................-25 in 1994...Forecast...-29 International Falls...-40 in 1950...Forecast...-36 Brainerd..............-40 in 1996...Forecast...-37 Hibbing...............-33 in 1951...Forecast...-33 Ashland...............-35 in 1950...Forecast...-19 Record Lows for Wednesday January 31... Duluth................-33 in 1982...Forecast...-32 International Falls...-35 in 1996...Forecast...-43 Brainerd..............-46 in 1996...Forecast...-40 Hibbing...............-41 in 1996...Forecast...-38 Ashland...............-33 in 1996...Forecast...-23 && .PRELIMINARY POINT TEMPS/POPS... DLH -24 -15 -32 -11 / 60 10 10 10 INL -31 -19 -40 -16 / 10 10 10 0 BRD -25 -19 -38 -15 / 10 0 0 0 HYR -19 -10 -30 -8 / 70 10 10 10 ASX -11 -7 -23 -5 / 70 40 50 40 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Wind Chill Warning from 9 PM this evening to 9 AM CST Thursday for WIZ001. Wind Chill Warning from 4 PM Tuesday to 9 AM CST Thursday for WIZ002>004-006>009. Wind Chill Advisory from midnight tonight to 4 PM CST Tuesday for WIZ002>004-006>009. MN...Wind Chill Warning from 9 PM this evening to 9 AM CST Thursday for MNZ010>012-018>021-025-026-033>038. LS...None. && $$ UPDATE...Wolfe SHORT TERM...Grochocinski LONG TERM...JJM AVIATION...Wolfe CLIMATE...JJM