Hoosier

And the 12z HRRR and 15z RAP. A farther north and more robust frontogenesis band, ala NAM. Sorry for the image overload lol

Notice the difference

The model differences show up as early as tomorrow and into Tuesday morning with the handling of the fronto band of precip. The GFS basically fades it away entirely as time goes on, while the NAM does not. Usually I'm going to lean on the NAM handling of a more mesocale feature like that, and the HRRR/RAP look more like the NAM as well. Curious what RC thinks about that.

Quite a run for our backyards.

A few of the 00z GEFS members are, well, insane. Vast majority are not like that though.

The weenie fronto band

I mean, wow

Hard to believe there is even a possibility of largely being missed to the south on April 20 of all times. I know it is possible but it's almost one of those you gotta see it to believe it things. At least convection down south is not a potential source of error with this system... sometimes that screws with the mass fields and results in a southeastward track.

Ha, just beat my post.

Our South Bend guy should enjoy the NAM.

One thing I like for mby is that good rates look to linger into early evening. So even if accumulations struggle more than anticipated in early-mid afternoon, there should be a few hour window (I'll say around 6 pm and later is when we'll see the diminishing effects of the sun angle) where it accumulates more efficiently.

00z HRRR is slower with the cold front than 18z. This would probably lead to our system tracking farther north. How much stock you want to put in the extended range of the HRRR is up to you though.

I'm about as bullish as I can be on a 3-6" type hit in the middle of April. I think the max band will be heavier than that but it would likely require quicker deepening to bring it in here. This should easily be the most interesting wx event around here in the past several weeks, and the overall rarity of doing this with the trees leafing out as they are adds an element of intrigue.

Here comes the baby steppin northwest GFS.

At the end of the NAM you can see what appears to me to be some lake enhanced/effect snow around Chicago and northwest IN (maybe going on before then but harder to pick out?). One would expect some of that in this setup with delta T getting into at least the mid teens and sufficient inversion heights. The issue is that it's countered by the warmer temps near the shore courtesy of the onshore flow. So while it may not actually result in higher snow amounts, it's possible that it could help smooth things out a bit so that total snow amounts don't drop as much closer to shore.

NAM went big in MI. Still snowing at the end of the run from around Chicago eastward.

Still a little early to say for sure, but based on how the 18z NAM is coming in so far, I don't think there will be a major southeast shift on this run.

They should be at this point since most models are really targeting the IWX cwa.

IWX tried to find some humor in it all. Even managed to work in a reference to the Edmund Fitzgerald song.

Looking back at that 1961 event, I am pretty sure the leafout was not as far along as now. It's interesting to note the reports in Storm Data from back then, which mention drifting snow with even some 10 foot drifts. That is crazy for mid-April in Indiana.

It's almost hard to put into words how rare the UKMET would be for Indianapolis. Indianapolis has had a total of 7 calendar day snows of 1"+ after 4/15, with the biggest being 2.5". This model is currently a southern outlier though and I wouldn't put a ton of stock in it at this point.

This is a major key to this event and helps to reinforce confidence that we are on the verge of seeing a pretty anomalous outcome. Here are the progged GFS 925 mb temps... and I would point out that other models are even a little colder. If 925 mb was barely below freezing, it would be very problematic this late in the season. But this is solidly below freezing at only a couple thousand feet up, which will enable precip type to be snow and help knock surface temps back toward freezing in the main band of precip.

Could argue that the farther southeast it goes, the more historic it gets. In any case, I think we are locking in on an event of that magnitude for somebody. A reasonably safe bet would be that the final outcome ends up somewhere in between the current NAM and UKMET runs.

We are among the best in handling vaccinations for sure. There were plenty of mistakes earlier on though.

This is sort of a pick your poison thing, but from a snow side, it does appear that some areas will drop below freezing while it is still snowing, especially as we get toward Tuesday evening and certainly after. This would help make the snow not quite as wet/heavy as earlier on, thus reducing the weight. On the other hand, dropping below freezing means more hours spent below freezing and increases the chances for hard freezes. I expect temps to be AOA freezing here for virtually the entire snow event, as onshore flow keeps things a bit warmer. Then a drop well below freezing as flow turns more offshore, so I may get the worst of both worlds lol