837 FXUS63 KDMX 011134 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 534 AM CST Fri Mar 1 2019 .DISCUSSION.../Today through Thursday/ Issued at 350 AM CST Fri Mar 1 2019 As we head into March, there a few signs that the cold and snowy period which began on January 11th will subside as meteorological spring arrives. A shortwave was passing through the Plains early this morning with increasing isentropic lift. The system also had moderate to strong mid level q-convergence although the bulk of this forcing will just skim the northern portion of Iowa. The short term model output indicates snow spreading into northwest Iowa toward daybreak and moving east through the morning with much of the northern two or three tiers of the forecast area seeing snow by midday into the early afternoon. The southern limit of light snow appears to be close to Highway 30 although flurries south of this wouldn't be a surprise given some lift in the area. Measurable snowfall is expected north of Highway 20 with 2-3 inches right along the IA/MN border. The snow will taper off late this afternoon/early evening as the system pulls east with increasing north winds on the backside. While these winds will not be overly strong, some ground level blowing snow is likely overnight which may lead to some ice development on roadways in northern Iowa overnight. Heading into Saturday and Saturday night, the model suite is considerably farther south compared to this time yesterday with regards to the weekend system. The good news is that the bulk of forcing and associated precipitation will be south of the state. Some very light snow/flurries is expected Saturday afternoon in far western Iowa with some light snow across the far south into Saturday night/early Sunday. However, the remainder of the state will likely remain dry during this time as arctic ridging pushes into the state with very dry low level air keeping any snowfall from occurring. That being said, nothing has changed in regards to the very cold airmass which will slide into the state late Saturday into Sunday. Temperatures will be around 30 degrees below normal on Sunday into Monday with near record low readings. As has been advertised, wind chills early Sunday morning of 15 to 30 below will be common and by early Monday morning, even colder values of 20 to 35 below are expected. There will continue to be some concern from later Saturday into Sunday of near surface blowing snow as the increasing cold advection/winds will blow any loose snow along the ground and over roads. This would likely create slick roads/tire track glazing during this time. Monday through Wednesday appears dry with slowly moderating temperatures although readings will still be well below normal for early March. Both GFS and Euro indicate the potential for snow into Thursday as strong warm advection pushes into the state. Will continue to watch this system closely for its evolution and snowfall potential. && .AVIATION.../For the 12Z TAFS through 12Z Saturday morning/ Issued at 533 AM CST Fri Mar 1 2019 System will pass through the Midwest today with light snow across northern Iowa. This will produce MVFR to IFR conditions in the far north affecting KMCW the most. Farther south, conditions will remain VFR for the entire forecast period. Surface winds will be light from the southeast to south today, becoming northwest tonight with a slight increase. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...Cogil AVIATION...Cogil