406 FXUS63 KDMX 130858 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 258 AM CST Sun Feb 13 2022 .SHORT TERM.../Today through Monday/ Issued at 257 AM CST Sun Feb 13 2022 Forecast Impacts for the week: ...Little Improvement in Temps Today ...Warming into Midweek ...Midweek Storm Chances then More of the Same Confidence Short Term: Medium to High Short wave over Nebraska at 04z continues to track to the east southeast this morning and should be in north central Missouri by 12z. Attendant H850 warm air advection which has been driving the heavier snow band and more broadly occurring light snow will move east and southeast of the region by 15z. High pressure will replace the system for today with some sunshine along with increasing cold air advection aloft; especially over the east and northeast through the morning hours. On the back side of the high, another Clipper is already making its way into Saskatchewan this morning and will quickly dive southeast into northeast Iowa by Monday 12z. Similar to the system that is just exiting the area this morning, limited amounts of moisture will accompany the strong lift which is mostly focused into Minnesota tonight. The far northeast may be grazed by a dusting of light snow with little if any impacts into the morning travel period on Monday. Highs today will be chilly again with afternoon readings in the teens northeast to the 20s elsewhere while tonight our lows will drop to the single digits northeast to the lower to mid teens central and south. Monday will see milder air begin to return overall, with H850 temperatures in the upper teens to lower 20s central areas to the lower to mid 30s and in the upper 30s to lower 40s in the southwest. Following the system tonight into early tomorrow, there is really no Arctic push to bring temperatures back down to sub-zero levels for quite some time. && .LONG TERM.../Monday Night through Saturday/ Issued at 257 AM CST Sun Feb 13 2022 Confidence: Medium The forecast consensus is improving for the workweek on several fronts. Little if any change is anticipated for Monday night through Tuesday night. After we rid the area of the last lobe of Arctic cold, building heights at H500 and persistent downslope conditions will replace the deeper northwest flow that we've seen for quite some time. Meanwhile, the models are still on track to take the current strong H500 system in the Gulf of Alaska and slam it into the PACNW by 12z Monday; then beginning to dig the wave as it begins to shear, into the southwest US by 06z Wednesday when it cuts off as a closed low. In the short term, this evolution will develop a classic southwest upper level flow pattern with thermal ridge at H850 extending northeast into Iowa by Tuesday and early Wednesday. We'll benefit with milder temperatures and continued snowmelt. Lows Monday night will still be cold with single digits to mid teens in the central sections. In the south, mid to upper teens and lower 20s will be common. Tuesday strong warm air advection will push H850 temperatures into the 4 to 6C range across the area as low pressure in the northern stream tracks across southern Canada. With plenty of sunshine, highs will reach the upper 30s to near 40 northeast while closer to the metro, lower 50s will be common. In the south, lower to mid 50s can be expected. The warm conditions hold on into Tuesday night as well prior to the arrival of the midweek system. Tonights view of the evolution continues to fall more into place. Going back to the H500 pattern, there is a distinct H500 wave in the northern stream which will track faster across the Northern Plains than the southwest system. Similar to the last split event that eventually kept most if not all of the precipitation south of Iowa, the leading northern stream wave will likely push a shallow front into eastern and southeast Iowa by Wednesday afternoon as increasing thetae advection arrives to be isentropically lifted above the boundary into portions of central and southern Iowa. Lows Tuesday night will remain in the 20s northwest with a range of 30s to mid 40s in the southeast. The precipitation is expected to begin in the mid to late morning hours as the cooler air slides southeast. With the shallow cold layer in place, rain and possibly a mix of some light freezing precipitation is expected Thursday morning in the southeast third of the area. Timing will be critical as to what and how much falls as either sleet or possibly some light freezing rain/rain. Little rise in temperature is anticipated Thursday as colder air then displaces the warmer airmass from the day prior. As for the differences between the Euro/GFS; there is better consistency today with the GFS resembling more the operational Euro. The GEFs now lends support with a solution generally southeast of Iowa as well, as it has slightly shifted the axis of heavier snow southeast into southeast Iowa/northeast Missouri. In either case, we may be just close enough to see some light snow accumulation in our far southeast with most outside our forecast area once again. For now, the trends support mainly minor impacts to our area for this upcoming event. The exception might be how much freezing rain/sleet falls with the initial changeover to snow later Wednesday and this will continue to be evaluated. With the colder air arriving Wednesday into Wednesday night, overnight lows will drop to the single digits north to the lower teens south. Beyond the midweek storm, little change in the previous forecasts is evident. A quickly exiting area of high pressure and colder conditions Thursday will give way to west northwest flow aloft. This will initiate a quickly warming trend into Friday as a fast moving Clipper tracks across North Dakota and southern Canada. H850 temperatures will rise to around 0C Friday yielding afternoon highs with decent mixing in the 35 to 50 range over our area. We repeat the cold front passage into Friday night with a cooler Canadian High settling into the upper Great Lakes on Saturday. Dry, but tolerable temperatures returning to the 20s northeast to the lower to mid 40s southwest to begin the weekend. && .AVIATION.../For the 06Z TAFS through 06Z Sunday night/ Issued at 1152 PM CST Sat Feb 12 2022 Light snow with periods of reduced visibilities continue through through the start of the TAF period, mainly across KFOD, KMCW and KALO terminals. MVFR/IFR conditions due to cigs and visibilities are expected to continue until 09z to 12z from north to south. KDSM and KOTM will see periods of light snow through the early morning as well, hovering around MVFR til 12z. Ceilings improve by the mid to late morning from north to south with clearing skies. Winds start out from the north through the morning, shifting southerly by Sunday evening as they remain light between 5 to 15 knots. Mid level clouds return ahead of the next clipper system slated to arrive through the end of the period, where portions of northeast Iowa will be the main concern for MVFR Sunday night. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...REV LONG TERM...REV AVIATION...Bury/REV