Winter Storm Monday into Tuesday

Heavy snow is expected to break out ahead of a developing area of low pressure and area of warm air advection. The snow will begin Monday morning for most places. I wide swath of 6-10" from Sioux City to Minneapolis is expected. Areas near the Mississippi River will battle warm air surging north from the Gulf of Mexico on Monday, hense the heavier snow west. Higher terrain will amplify snow total in southwest Minnesota, where over a foot of snow is possible. Many of the short term models do indicate numerous areas on banding, so a large gradient in final snow totals is expected. One city could maybe have 8" but 30 miles to the east or west might end up with 3". It will depend exactly where each band sets up. Unfortunately it can be tough to forecast such events, but the most likely amounts are plotted above. Thanks for stopping by at Midwest Weather. Check out the tabs above for more weather information, especially the computer snow output page! 

Heavy Snow Monday into Tuesday across the Midwest

Heavy snow is expected to break out ahead of a developing area of low pressure and area of warm air advection. The snow will begin Monday morning for most places. I wide swath of 6-10" from Sioux City to Minneapolis is expected. Areas near the Mississippi River will battle warm air surging north from the Gulf of Mexico on Monday, hense the heavier snow west. Higher terrain will amplify snow total in southwest Minnesota, where over a foot of snow is possible. A FULL UPDATE will be posted later this evening, including an official Midwest Weather snow map.

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Band of Heavy Snow to Coat Major Midwest Cities

A developing storm system will bring widespread heavy snow to the Midwest Friday into Saturday ahead of the coldest air of the season. The heaviest of snow looks to fall south of I-90 and north of I-80 on Friday. Models did come together in recent runs, HOWEVER, the european model has trended south in the last few hours. It is one of the more reliable models and could be on to something. With that said, the map to your left puts weight on prior runs as well as recent ones, a blend of models. For many areas across parts of Northern Iowa and Southern Wisconsin, this will has the potential to be the heaviest snow since the 2013-2014 season, depending exactly where the heavy band sets up! Winter storm watches have already been issued for the northern half of Iowa east through the WI/IL border. Most of these will kick over to winter storm warnings by the late afternoon or Friday morning time period. Otherwise, winter weather advisories will be issue just outside the band of heavier snow.

The timing of the snow has a larger role than usual. With it being so warm in recent weeks, and months for that matter, ground temperatures are rather high. A large portion of the snow will come at night which only amplifies the efficiency of snow accumulation on the surface. It will take a bit to accumulate on pavement, but the temperature and snow rate should overcome the warmer pavement temperatures relatively quickly.

Regarding timing, the storm looks to really ramp up by Friday afternoon. After about 12:00, a band of heavier snow will begin to train over central Iowa through Southern Wisconsin and Lower Michigan. Most of the snow will fall Friday evening into Saturday morning across these areas. This sets up a couple snowy college football games, such as the Northwestern @ Wisconsin games on Saturday. Otherwise, the map should give a general idea when the snow will begin to coast grassy surfaces!

Behind the system winds kick up out of the northwest and usher in cold air from Canada, here is a look at low temperatures for your Sunday. Very cold!...especially with fresh snow cover, off the 12z GFS model. It could be short lived however, as a surge of warm air is possible around Turkey Day! Maybe 15-25 degrees above average!

The Transition to Winter to Bring Accumulating Snow

A major pattern change is in the works for the end of the week. This change in weather will make things feel like mid-December across the Midwest and will be a shock to system for many. The surge of cold air will also bring the threat for accumulating snow in a narrow band over parts of Iowa to lower Michigan. Models are beginning to come together this afternoon, but still some uncertainties to work out in the next 24 hours or. The storm system has yet to come on shore the Pacific Northwest, where it can be better sampled in the weather balloon networks and ground reports. Once this happens, the model discrepancies will generally become filtered out. With that said, we will not publish a full snow map at this time, but rather give a more general forecast. As the system emerges out of the Plains it is expected to strengthen and drop several inches of snow on the back side by Friday evening. The heaviest of snow looks to fall from North Central Iowa to the WI/IL border to central Michigan. A half foot of snow will be possible in these areas, with more possible in SE Wisconsin and Lower Michigan as the storm ramps up and lake enhancement aids in the snow development. Be sure to check back for updates, our full snow map and forecast will be posted by this evening our early tomorrow afternoon. In the meantime, check out our social media platforms on the right hand side of the page.

Snow, Cold, Winter, Oh My

A pattern change is ongoing across the entire United States this week. A trough in the west will push east in the coming days and cold air funneling in from the north will bring the contrast in temperatures needed for atmospheric lift and precipitation. A wave of low pressure will develop along this boundary and move through the southern Great Lakes by the early weekend. On the cold side of the system a band accumulating snow will set up on the backside of the track of low pressure. We have plotted where "plowable snow" will set up according to three major numerical weather models, or 3"+ of snow. Some models takes the system up through lower Michigan and deepen the surface pressure. This could drop heavy snow over Lower Michigan and ramp up lake effect snows on the back side of the cyclone as it pulls away Saturday and Sunday. The potential exists for nearly a half foot of snow in areas such as Chicago through Grand Rapids, Michigan, with 2-5" as our best estimate over Iowa. With it being 4-5 days out there are a few discrepancies and issues in the forecast:

*The timing...warm ground and pavement temperatures would limit accumulations if the snow comes during the day, accumulates more efficiently at night
*The track...where the low pressure goes will determine the general area of snow
*Phasing...if this storm cuts north as it passes east of the Mississippi River heavier snow could fall

Either way, the storm will bring in northwest winds by Saturday and Sunday which will usher in much colder temperatures across the Midwest by the weekend and beyond. Low temperatures for Sunday morning are plotted below, off the ECMWF model. Notice the lows will be ~10 degrees cooler in areas with fresh snowfall, due to radiational cooling. Keep it here to Midwest Weather for updates throughout the week.

First Midwest Winter Storm?

Models, trends and the atmospheric set-up are look increasingly favorable for accumulating snow across the heart of the Midwest. A band of snow will develop along a line of frontogenesis, or an area where the difference in temperature across two points is increasing. These bands of precipitation can be tough to pin down exact locations, because they can be so narrow and not fully reliant on the track of low pressure. With the said, models are starting to finally agree on the location of such an event. The darker shade of blue is the location currently thought by numerical weather models to have the best chance of moderate snow accumulations. Either way, cold air will funnel in behind the system and bring the coldest temperatures of the season to much of the eastern half of the country by the weekend. A very similar situation set up last November, Post from Last Year, almost a carbon copy! That storm, like many sections of temperature gradient induced snows, trended north with time. This and prior model runs is why we included areas such and Minneapolis to Green Bay in the potential for accumulation. Now the real question, how much are we talking? Well, model runs in recent days have been impressive, but it looks like a general 3-5" with isolated amounts of 6+"  where possible banding could set up. The higher amounts look to develop east of the Mississippi River, lesser amounts west. This will need to be watched closely in the coming days, as we look to pin down the exact location of moderate snow. The pattern looks to kick over to cold and stormy beyond 5 days through the end of the month. You can always watch the snow models come in yourself on our Computer Snow Output page. Keep it here for updates throughout the week and our first snow map of the season when the event gets closer.

**Next update scheduled by Tuesday, 2pm CDT**