Storms have been coming hot and heavy the past two weeks and the next few days promise to be very active. Heavy rain will fall on many parts of my viewing area and some areas could even see some wet snow before it's all said and done.
Between the 2 storms rainfall in my area could easily exceed 2" in spots, especially near and east of the Mississippi. The latest EURO has this for rainfall totals the next 4 days.
The GFS has this for the same time frame.
This next graphic shows how much rain has occurred the past 2 weeks. Add on what's to come and rivers and streams (where the heaviest rains set up) could exceed flood stage in spots. The greatest concerns extend from southeast Iowa into Missouri and Illinois. Something to keep and eye on in coming days.
Regarding the snowfall potential, models have been back and forth on this issue with the second storm late Tuesday night or Wednesday. Sunday's trends have shifted the snow potential further east than in previous runs eliminating eastern Iowa as a target. Additionally, if the more southerly track holds rainfall will be reduced in my local area with this secondary piece of energy.
The biggest factors in this situation are the marginal cold air and final track of the storm. A degree or two could make the difference between several inches of sloppy snow and nothing more than a cold wind driven rain. Initially rain will be the primary form of precipitation. As the storm deepens dynamic cooling could drop temperatures enough for a mix or even a change-over to snow. The million dollar question is where?
The latest GFS shows this for total snowfall.
The EURO is further southeast and lower on amounts. Both solutions do show some snow in and around the Chicago metroplex by Wednesday night.
The latest NAM (which is an outlier) shows 2 areas of accumulating snow. One that even nails EC Iowa.
Interestingly enough, the Weather Prediction Center as of this posting was more in line with the NAM showing about a 30 to 40% chance of an inch of snow where the NAM does centered on eastern Iowa, NW Illinois and SE Wisconsin. Most likely it will end up further east like the EURO and GFS are showing.
The bottom line is this is a very difficult (if not impossible) snow forecast. There are way too many variables that are marginal, especially this late in the year. In most areas this will largely be a rain event but I sure won't be shocked if in some part of the central Midwest a narrow band of heavy wet snow develops. Later forecasts will confirm or deny that potential. If it does snow in your part of the Midwest it will be gone within 24 hours. Time will tell. Roll weather...TS