Earlier this morning, we showed you the morning run of the high resolution model, also known as the WRF (graphic included above). This morning, the WRF was showing very little snowfall totals, ranging from 1″ to 2″ with isolated 3″ totals along the Mississippi river.
Now this afternoons run, has increased snowfall totals, and not just by a little, but by a lot. It isn’t just the WRF that has picked up on this increased, it is also the GFS and NAM. However, at this time, the WRF is the most bullish with these snowfall totals. Before we continue, we want to stress that the following is just the raw model outputs.
Why the flip? Well the biggest reason is the low pressure that will be moving to the northeast across northeast Missouri Sunday night, will be strengthening as it moves to the northeast. Because of this, it is hard to determine just how strong the low will develop as it moves by to our southeast. The stronger the low becomes, the more cold air it will pull in on the northwest side of the low, allowing the changeover from rain to snow as shown in the graphic above.
As you can see from the graphic above, the latest 18z WRF has an area of heavy snowfall across northeast Iowa. This is because the latest WRF has the low deepening enough, that cold air will transition the rain over to snow earlier.
Above is the latest 18z GFS run. As you can see, it also shows snowfall on the range of 3″ to 5″ east of interstate 35.
There is still a lot that will need to be watched so do not take this article as a forecast. If this low does deepen enough, it is a possibility that eastern Iowa may see some moderate snowfall totals, especially northeast Iowa. We will continue to watch all the latest model trends and will continue to bring you all the very latest updates right here at iowachase.com and on our Facebook and Twitter pages.