593 FXUS63 KDLH 022359 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 559 PM CST Sat Feb 2 2019 .SHORT TERM...(This evening through Sunday) Issued at 321 PM CST Sat Feb 2 2019 Widespread fog and areas of freezing drizzle are the main forecast concerns during the short term. A weak shortwave trough will move through the region tonight and Sunday. A warm front was found over southeast South Dakota, southern Minnesota, and southern Wisconsin this afternoon and is expected to lift northward into central Minnesota and northwest Wisconsin tonight. North of the front, isentropic forcing for ascent has led to the development of stratus from near the Twin Cities into northwest and east-central Wisconsin. The stratus will spread across the remainder of the forecast area this evening. The moisture advection over the cold snow pack should produce widespread fog tonight and areas of freezing drizzle in northwest Wisconsin. Model soundings suggest the stratus layer will be too shallow for freezing drizzle west of the I-35 corridor. Have issued a Winter Weather Advisory for the freezing drizzle potential over Bayfield, Ashland, Iron, Sawyer, and Price counties from 9 PM tonight until 10 AM Sunday morning. The highest confidence in freezing drizzle with accumulation greater than one- hundredth of an inch is found over those areas. With the recently departed Arctic airmass, we have likely drawn a considerable amount of heat out of the ground across the region. Especially under roads, sidewalks, and parking lots which were mainly clear of snow during the Arctic blast. Temperatures will likely remain below freezing across the Northland and the deep reservoir of cold ground should overcome any warm air advection to allow the drizzle to freeze to surfaces. The shortwave trough will scoot eastward out of the region Sunday. As near-surface winds veer west and southwesterly, slightly drier air should raise visibility while the stratus lingers overhead. Think the best time for the freezing drizzle will end by late Sunday morning. Don’t think the Sunday night/Monday system will quite reach my western areas before 00Z. Squeezed the range for my max temps Sunday by adding a few degrees to the colder side over Koochiching County and trimming a few degrees from my warmer areas over northwest Wisconsin. Look for highs from around 20 degrees north-central Minnesota to the low and middle 30s in northwest Wisconsin. .LONG TERM...(Sunday night through Saturday) Issued at 321 PM CST Sat Feb 2 2019 A digging upper level trof will move into the eastern Dakotas Sunday night. Meanwhile, an area low pressure will move into west central Wisconsin. There area some minor timing differences with the onset of precipitation and its overall coverage, with the NAM being the slowest. Used a blend for Sunday night. The precipitation will be a winter mix over the southern two thirds of the forecast area, with snow over the northern third early, then transition to snow from northwest to southeast over the northern half of the area late. On Monday, the trof becomes baggy as it progresses through the region, while the surface low reaches the eastern Great Lakes. After some wintry mix in the morning in northwest Wisconsin, a conversion to all snow is expected by afternoon as much colder air arrives. All snow elsewhere. The models continue to waffle on position of QPF/snow axis, but have trended farther north. If this trend continues, will likely need headlines. As the system continues to pull away Monday night, lingered some pops from the Arrowhead into northwest Wisconsin in the evening, then just along the higher terrain of the South Shore of Lake Superior as the surface flow turns northwest, binging on some lake effect potential. The ice has shifted over western Lake Superior which brings any amounts into question, depending on the ice location. High pressure covers the area Tuesday morning. In the afternoon, the next round of precipitation is forecast to begin as pieces of energy in a fast west southwest flow aloft move into the region. This scenario continues through Wednesday night as the parade of vorticity maxes passes overhead. The upper flow becomes southwest on Thursday as the next upper level trof approaches from the west. Model differences become quite large with the handling of the associated surface low, and how it affects the region through Friday. Used a blend to resolve some of the differences. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 544 PM CST Sat Feb 2 2019 A warm front draped across northwest Wisconsin this evening will bring deteriorating conditions across the region. Initial LIFR/IFR conditions at KDLH and KHYR, to settle to LIFR for both visibilities and ceilings through approximately 15z, with a gradual improvement to IFR after that. KBRD and KHIB should also deteriorate to LIFR ceilings with IFR visibilities, and INL to have VFR visibilities and IFR ceilings. Conditions are expected to gradually improve after 15z, but most locations will keep at least MVFR ceilings, even as visibilities return to VFR. && .PRELIMINARY POINT TEMPS/POPS... DLH 19 26 13 15 / 20 10 90 90 INL 11 20 1 3 / 10 20 90 90 BRD 18 28 13 14 / 10 10 90 80 HYR 26 32 22 22 / 50 20 90 90 ASX 22 28 19 19 / 50 20 90 90 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Winter Weather Advisory from 9 PM this evening to 10 AM CST Sunday for WIZ002>004-008-009. MN...None. LS...None. && $$ SHORT TERM...Huyck LONG TERM...GSF AVIATION...LE