This evenings model runs are still coming out, however, like we assumed earlier, they are changing once again. So here we are only 24 hours out from this event, and yet we still continue to see the changes in the models. Why? As we stated earlier this afternoon, the surface low will be strengthening as it moves off to the northeast. The models are having a hard time with how deep the surface low will develop. Right now, as the low moves by Iowa, it is at 987mb and continues to drop as it moves off to the northeast. As it moves off to the northeast, colder air gets sucked in on the northwest side of the low.
This afternoon, the 18z run of the high resolution WRF had moderate to heavy snowfall totals across northeast Iowa. This model run was very bullish and was hard to buy into.
As expected, this evenings 00z WRF run has backed off and has become more reasonable and believable. Instead of the 2″-8″ that the 18z WRF was forecasting, the newest 00z WRF has 2″-4″. What is a common theme is where the snow will fall. The best chance for snow will look to stay east of I-35, with the greatest chance across northeast Iowa.
What is developing is this evenings 00z NAM model run is now further west than the 18z model run. However, it is more aggressive with snowfall totals than it previously was at the 18z run.
We will have to see what the 00z GFS and ECMWF come out with, however, things are still foggy 24 hours out. Right now we will refrain from buying into these moderate snowfall totals, but we just wanted to show what the models are outputting as if things line up correctly, we could be looking at a decent amount of snow Sunday night into Monday. Continue to check back here for all of the very latest details as tomorrow morning we will hopefully have a clearer answer as to what we expect to happen.