LoveSN+

NAM is very warm aloft late in the run. Interesting solution.

It could be something with the microphysics scheme within the model itself as well. Not really sure what is going on. I do agree about your previous post though, i.e., this run is much more impressive than other guidance currently.

Look down at South Carolina. The modeled reflectivity never spits out snow, but if you look at the actual snow accumulation field, there is >10 inches. Something is most definitely wrong.

Something is wrong with the FV3 snowfall accumulation algorithm. Only weenies are believing this map.

Most people guaranteed frozen precip from the WAA part of this system at the onset.

Lots of run to run variability recently. Seems like the models are backing off the ridging in the 6-10 day range.

A real question: Have either of these models displayed skill? It seems like the ICON, anecdotally, does not perform well.

Windshield wiper effect.

No one mentioned the storm went poof on 12z run.

Are you allowed to share?

When does the November update for the Euro come in? Should be in the next few days, yes?

Not sure exactly how his calculation is done; I'm sure it's probably in his paper. But here is a link to Eurasia snow cover for Oct from 1967-2017. 2018 is not updated yet. https://www.ncdc.noaa.gov/snow-and-ice/extent/snow-cover/eurasia/10

Looks like SAI was middle of the pack.

When was the last time Dec was an epic month up here?

Not sure how good the canSIPS is, but has a nice look for winter in the recently updated run. Looks really great for Feb and Mar, with a stout -NAO block.

Definitely showing up on ensembles as well, both GEFS and EPS.

Props to you for sticking to your guns. I was just curious about your thinking!

I guess you are disregarding what I provided. What leads you to believe there is no impetus?

Yes, you are correct about Judah's outlooks. Just be on the lookout. I'm sure we can all be happy about the chances of a weakened vortex.

Judah is picking up on what I'm talking about, but this is in no way related to SAI and he never mentioned it was either.

Vertical wave activity flux is predicted to have a large uptick in the next week or two, with models beginning to show the possibility for a strong Scandinavian block, reinforced by consistent wave breaking in the North Atlantic. Obviously this is predicted, but model skill in terms of the stratosphere has been shown to be more accurate at longer lead times compared to tropospheric forecasts. However, there is little to no correlation between stratospheric vortex disruption and cold air in the US. Most of the correlation lies in Siberia. Just something to monitor, no guarantees.

Beyond the analogs, the prospects of a stratospheric vortex disruption are becoming more likely in the next few weeks. This could allow for some cold air to filter in during Dec.

North American snow, mainly in Canada, is above normal as well. Glad that Judah sticks to his guns, but you have to think with the past few winters there may be more going on than just how much/how fast snow builds up in Siberia in October.