After starting off very cold this morning with the air temperatures ranging from -5°F to -25°F, and wind chills a few degrees cooler, things will feel much warmer by Saturday. There has been a lot of talk around Sunday and Tuesday. If you haven’t heard yet, these two days are when our next weather makers will move through.
Starting off with our first system, a trough will begin to dig into the southwest and will lift off to the northeast, and will begin to approach the state as early as Saturday afternoon. Snow will begin after 5pm across southwest/southern Iowa and will then continue to track off to the east/northeast. The models have been fairly consistent on this system over the past few days so we are feeling pretty confident that the majority of the snow will stay south of interstate 80. Most of the moisture will also stay to the south of Iowa, so because of this, only light snowfall accumulations will be expected. Snowfall accumulations will range from 1″ to 4″ with the higher end of that range near the Iowa/Missouri border. The snow will then begin to pull out of the state by Sunday afternoon and then we will get a brief break on Monday before the second system arrives on Monday afternoon.
This second system is going to bring mixed bag of precipitation including rain, ice, and snow. Because of this mixture, we are going to have to keep a very close eye on this system. Precipitation will begin late Monday, mainly after 10pm. At midnight, which is pictured above, snow will be across the northern portion of the state, with an icy mix across the south.
By 6am Tuesday, as pictured above, the models are depicting that the icy mix across the southern half of the state will transition over to rain. This is because warmer air will begin to pull into the state behind a warm front. Highs on Tuesday across the southern half of the state will be in the upper 30’s.
As the low continues to slide off to the east, it will begin to pull colder air back in on the northwest side of it, which will transition everyone back over to all snow. Eventually this system will then pull out of the state by early Wednesday morning.
Looking at the meteogram for Des Moines, the models are showing the potential for a light glazing of ice accumulations, under a tenth of an inch. While this is minor, it will still be enough ice to make things slick.
Right now, it is going to be hard to determine snowfall accumulations so I am half hesitant to even show the map above. This is because the track of this system is going to have a big impact on totals. When you have to deal with the rain/snow line, it is more complicated than when dealing with all snow. Right now, the greatest snowfall accumulations look to be across northern Iowa and this is because they will stay all snow, unlike southern Iowa which will see more rain/ice than snow.
One last item of concern will be the blustery winds expected on Tuesday into Wednesday. Winds will be gusting 30mph to potentially 35mph, as shown in the image above, which will blow around the snow, and with any ice accumulations, that will not be good combination.
There is still a lot to be worked out over the coming days, so right now, just take this forecast as an advanced warning knowing that things will still change with Tuesday’s system. We will continue to keep an eye on the forecast all weekend and will bring you all the very latest updates on our Facebook and Twitter pages, and as well as right here at iowachase.com.