Make no mistake about it, we are entering into an energetic period of weather in the Midwest that will be marked by 2 potent storm systems in the next 5 days. As it stands now, models are in good agreement on the evolution of the first disturbance. They are still struggling on the details of the second.
Due to perceived problems with the U.S. based GFS model, I have relied heavily on the EURO EPS ensembles to base this outlook on.
Storm 1 is due to arrive late Saturday bringing a slug of moisture and precipitation that will linger into Sunday morning. The track will be across eastern Iowa assuring nothing more than a rain event. The surface map at noon Sunday.
The EPS mean shows much of Iowa picking up 1/2 to 1.00" of rain Saturday night and Sunday morning.
Following a 24 hour break a second storm is likely to rapidly develop on Monday. This has the ear marks of a major storm. All one needs to do is look at the energy wrapping into a 500mb closed low on Tuesday. Dynamic to say the least.
At the surface the EPS shows a deepening 988mb surface low near Chicago Tuesday morning.
As it kicks northeast the pressure dips to 982mb over the northern Great Lakes.
The 2 systems combined on the EPS mean show much of the Midwest with 1-2" of total precipitation.
The operational run of the EURO has some 3" to 3.5" totals from NE Iowa into Minnesota and Wisconsin.
With such a strong system there is the potential of dynamic cooling which could change the rain to snow in some areas. This is a low confidence scenario but the operational EURO shows some accumulations Monday night or early Tuesday northwest of the surface low.
Here's another perspective that's further north. Again, snow of this magnitude is far from certain at this point.
The tight pressure gradient will also produce some gusty winds. The EURO shows a 48 mph 10 meter gust near Iowa City. Many places in the 40-45 mph range.
Needless to say we are in the early stages of this complex event but there are strong signals a stormy period is coming to the Midwest starting Saturday. For now the devil is in the details. More to come. Roll weather...TS