Some nice rains fell on parts of the central Midwest Tuesday night. Here's a view of the rain swaths from the Midwest Climate Center.
As you can see my area was split with the majority of the rain falling northwest of a line from Janesville, Wisc. to Ottumwa, Iowa. Little if any fell from the Quad Cities southeast.
From the looks of things this has primed the pump for a more significant rain event that will get underway Thursday lasting into early Saturday. Here's the surface features Saturday showing a healthy 995mb surface low tracking through central Iowa Saturday morning.
It's working on some deep moisture with PWAT's (precipitable water vapor) of 2.3" in Missouri, 2" into SE Iowa.
That level of moisture in early October is 3.7 standard deviations above normal-more than 3 times the norm in the bullseye below.
Throw in a vigorous upper air disturbance, and a stout low level jet max and a significant precipitation event is likely somewhere, especially Thursday night through Friday night. Here's the 500mb jet forecast Saturday showing the energy (a closed low) advancing across the Midwest.
As far as total rainfall is concerned, there's high confidence that some heavy rain will fall in the central Midwest but less with regards to the location. There has been a trend for models to shift further south and west with the higher totals. The NAM which had over 5" totals in eastern Iowa last night is down to amounts closer to an inch Wednesday night. Here's the comparison. First the old 0z run
Now the new 0z run. That's troubling!
The GFS remains more consistent with widespread amounts of 1-2", still some 3" totals.
Here's a tighter view.
The EURO is pretty much in the same camp as the GFS. Here's it regional perspective.
The Iowa based perspective.
There's some details to work out but we should have a pretty good handle on the final outcome later Thursday. One thing's for sure, the majority of the rain in the Midwest falls Thursday night through Friday night. That's the latest and greatest for now. Roll weather...TS