hlcater

Talk in the storm thread reminded me that I should update that the damage total is now up to 11 billion in NOAA's final 2020 analysis. https://cbs2iowa.com/news/local/derecho-damage-adjusted-to-11-billion

the derecho transcends any and all big dogs. That event sits in a league of its own and may never be surpassed.

Yea I was thinking that this storm was our best shot out of the past several years to make a run at that stat but to even be in contention, the wave needs to not shear out so quickly. Too bad that the trend tonight has been the opposite of that.

It came from a local news station, we've seen unofficial totals since that have flirted with 12" however. This storm would likely be a slam dunk in this regard if the confluence out ahead of the wave werent so damn strong.

Things are more or less the same here tonight as well. What changes though are that he odds of a truly historic snowfall(12+) for CR/IC itself are rapidly dwindling. Shame really, this storm had a shot to challenge CR's 40 year 12"er drought, but trends tonight are definitely in the wrong direction for doing so. My thoughts that someone sees 15" from this havent changed, just looking incredibly unlikely to be CR and decently unlikely to be IC.

It’s rather significantly drier in eastern Iowa. IC, for example fell from 14” to 9.5”. CR flirts with the northern edge. Crummy run for this area relative to everything else.

RAP is still a huge crush job for those west of the MS river. Will finish with a widespread 12+.

00z consensus has tended to be slightly drier and a tick south so far. Especially with eastward extent.

Think I'm gonna make a first call of 8-10" for IC. Though the QPF outputs are tantalizing and open the door for some really impressive totals if only ratios and banding cooperate. Still think someone somewhere in S IA exceeds 15".

Euro looks like it upped QPF in general from the 12z.

If we start trending towards 20" somewhere, I might just have to go find it.

With storms like this, I really do think that's a risk worth taking. I'd rather overwarn because that way you're afforded some wiggle room if that band shifts 40-50 miles north. It's one thing to warn something and bust completely, but I'd argue it's another to be liberal with watches in a high ceiling scenario to avoid conflicting messaging by issuing separate watches at separate times. I'd agree most of the time, but when real threats are on the table, it's best to be liberal.

It's just an interesting choice thats all. I'm sure its a confidence thing, as the watches as posted are really only for the areas that are consistently modeled to receive 10-12" or more. I can see some benefits for doing that, such as getting the word out earlier for those most likely to receive high end impacts, but the issue I see with that is conflicting messaging by issuing watches on the fringes later on. It would seem logical to just issue two watches with different criteria, especially when the ceiling is so high. I mean this isn't a 5-7" storm with no wind. Some areas could feasibly see north of 14" especially if convective elements and banding play out, in addition to wind concerns that flirt with blizzard criteria. Their reasoning is probably confidence based as stated, but imo, with this storm that may not be the best approach. Best to just get the word out, you can always modify the watches later on.

and the para. Essentially in lock step with the operational.

Exhibit A: The 18z GFS. Absolute crush job for essentially the entire DVN CWA. Chicago folks do well too.

Left out CR too for some reason. I'll almost certainly be in IC for this one, but models are showing a big hit in CR too, especially those that are on the northern end of the spectrum.

Regional GEM has continued to come north and is a total weenie run for CR/IC and much of Iowa really. Mixing concerns in the far south of LOT's CWA.

How’s the mean look?

Oh my god why are you making claims based on the NAM and RGEM when you have literally the rest of guidance suggesting otherwise. Sure they could be right, but neither of them are especially good and are both operating outside of 60hrs. A met should really know better than to go all in on 2 garbage models that are towards the end of their operational range to boot.

Euro is a bit wetter in Iowa. Precip shield is also a bit more tilted than 00z. I’d love if the low would die a bit slower.

Man this is looking like a heck of a storm out here. Could even be 12-15” in the max band. Not sure that’s CR/IC but probably just south of us as we are starting to reach a pretty tight track consensus. That said, gusts to 40-45 mph seem likely for most of the event, and combined with heavy snow, should allow blizzard criteria to be met for many in Iowa/perhaps N IL as well. Assuming watches will be hoisted in the afternoon package? Looking more and more like the highest impact winter event in DVN’s CWA since 11/25/18.

would you mind posting NE too? I'm just curious what this is doing in the plains.

I also think, subjectively, that in the end the shearing doesnt begin to have real detrimental effects until at Chicago's longitude or east of there. I also think there's an impressive QPF bomb (yielding 15" or more??) somewhere, but models still differ on where that is, exactly. Wave starts to feel it between F66 and F72, but you would think the degradation of the precip shield itself would delay that by several hours, which by then would be over/east of Chicago.

Not quite the fridge material that the 18z run was. But much like the UK and Canadian, it peaks in Nebraska. Still solid through chicago however.

Easily the most aggressive model with the shearing of the wave right now. No other model is really even close.