911 FXUS63 KFSD 282353 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 553 PM CST Mon Jan 28 2019 .SHORT TERM...(This evening through Tuesday) Issued at 346 PM CST Mon Jan 28 2019 A temperature roller-coaster is expected this week, as we see record setting cold heading into mid-week, followed by a return to above normal readings by Saturday. Arctic airmass has settled over the region. While winds continue to gradually decrease today, windy conditions persist with gusts to 30 to 40 mph seen across the southern half of the forecast area. This evening winds will decrease further, and will average 10 to 15 mph across the board by midnight. Band of low to mid stratus continues to stream across our western border near an area of very weak convergence, with some isolated to scattered flurries being reported in this deck. Went ahead and added flurries to the forecast into tonight as this feature lingers across south central SD then expands into the Missouri Valley on the nose of a jet max. Light snow or flurries should end by daybreak Tuesday, with little to no accumulation expected. Temperatures will slowly fall this evening and overnight, with lows expected in the to range from around zero near the Missouri River, to -13 in the Buffalo Ridge area in southwest Minnesota. While winds do decrease this evening and overnight, we will still see wind chills drop well into advisory criteria areas north of I90 and the Iowa Great Lakes where -20 wind chills are ongoing. Did bump up the start up time in our northwest to now. A reinforcing shot of colder air arrives as early as Tuesday morning with breezy northwest winds quickly increasing to 15 to 25 mph with gusts to 35 mph. Temperatures will remain steady or drop through the day, and as a result, wind chills really start to reach dangerous levels. Wind chill warnings remain posted for the north around daybreak and the south by afternoon. Expect values in the -35 to -45F range during the daytime. Air temperatures will fall into the teens below zero for much of the forecast area by sunset. With the gusty winds and recent snowpack, will also issue a winter weather advisory for southwest Minnesota and the HWY 14 corridor of east central SD from mid morning Tuesday through sunset Tuesday. As we have seen today, areas where snow recent fell have been reporting blowing snow and reduced visibilities to around 1 mile. While no additional snow is expected, low visibility will be enough of a concern in open areas with the strong gusts to warrant an advisory. Winds decrease by sunset, so will end Winter Wx Advisory at 00z. .LONG TERM...(Tuesday night through Monday) Issued at 346 PM CST Mon Jan 28 2019 The coldest temperatures so far this winter arrives Tuesday night into Wednesday morning and should set daily low temperature records across the board. While the readings will not quite reach all time record cold, we should see the coldest airmass since January 2010. Expect lows to reach as cold as -35F in east central SD and southwest MN, with the warmest areas near the Missouri River "only" dropping into the upper teens below zero. While winds will be decreasing overnight, wind chills will still be extremely dangerous for the entire forecast area at around -40 to -60 F by daybreak Wednesday. Wind chill warnings will be in effect Tuesday night and Wednesday morning, transitioning back to advisories through Thursday morning in the southern half, while the north remains in Warnings during that time. Much of the area will remain well below zero for air temperatures (not wind chill) through the day Wednesday, followed by lows in the -5 to -30 F range Wednesday night. Southwest MN will again see the coldest of these conditions. As previously mentioned, the roller coaster of temperatures swings back towards a warming trend for the second half of the week. By Saturday, temperatures are expected to be back above freezing, possibly even reaching the 40s for areas with little to no snowpack in our south. Winds turn more southerly Thursday into Saturday, but the general pattern remains dry during this period. Early next week looks like the next significant chance for precipitation. Models agree with breaking down the ridge in favor of a wave, but the timing, track and intensity of this feature is much less certain. This also highlights the uncertainty of the precipitation type for this evening. Temperatures do look to trend cooler again early next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 540 PM CST Mon Jan 28 2019 A few light snow showers/flurries will continue to move from northwest to southeast this evening. Brief MVFR/IFR conditions are possible at times due to passing snow showers and patchy blowing snow. Otherwise, VFR conditions are expected through the period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Wind Chill Warning from 3 PM Tuesday to noon CST Wednesday for SDZ050-057>071. Wind Chill Advisory from 6 AM to 3 PM CST Tuesday for SDZ050- 057>071. Wind Chill Advisory from noon Wednesday to 9 AM CST Thursday for SDZ050-057>071. Winter Weather Advisory from 9 AM to 6 PM CST Tuesday for SDZ039- 040-055-056. Wind Chill Warning from 6 AM Tuesday to 9 AM CST Thursday for SDZ038>040-052>056. Wind Chill Advisory until 6 AM CST Tuesday for SDZ040. Wind Chill Advisory from midnight tonight to 6 AM CST Tuesday for SDZ038-039-052>056. MN...Winter Weather Advisory from 9 AM to 6 PM CST Tuesday for MNZ071- 072-080-081-089-090-097-098. Wind Chill Warning from 6 AM Tuesday to 9 AM CST Thursday for MNZ071-072-080-081-089-090-097-098. Wind Chill Advisory until 6 AM CST Tuesday for MNZ071-072-080- 081-089-090-097. Wind Chill Advisory from midnight tonight to 6 AM CST Tuesday for MNZ098. IA...Wind Chill Warning from 3 PM Tuesday to noon CST Wednesday for IAZ012-020>022-031-032. Wind Chill Advisory from 6 AM to 3 PM CST Tuesday for IAZ012- 020>022-031-032. Wind Chill Advisory from noon Wednesday to 9 AM CST Thursday for IAZ012-020>022-031-032. Wind Chill Warning from 6 AM Tuesday to 9 AM CST Thursday for IAZ001>003-013-014. Wind Chill Advisory until 6 AM CST Tuesday for IAZ002-003-013- 014. Wind Chill Advisory from midnight tonight to 6 AM CST Tuesday for IAZ001. NE...Wind Chill Warning from 3 PM Tuesday to noon CST Wednesday for NEZ013-014. Wind Chill Advisory from 6 AM to 3 PM CST Tuesday for NEZ013-014. Wind Chill Advisory from noon Wednesday to 9 AM CST Thursday for NEZ013-014. && $$ SHORT TERM... LONG TERM... AVIATION...05