Terpeast

So I wanted to share a couple thoughts. I grew up in this area and have lived here up until 2010, and it’s really not common to get sig snows in December… even at all. December is not a snowy month here. We’re normally lucky to even get a couple of inches. I feel that the 6”+ers we got here since 2002 and the 2009 HECS had us spoiled and raised our expectations for snow in Decembers. Even I get caught up in the model drama sometimes, but not getting much, if any, snow in December is the norm as far as I can remember… and that has always been the case here. Onto January!

Seems to be a decadal oscillation. It’s been pos for a while now https://www.cpc.ncep.noaa.gov/data/teledoc/tnh_ts.shtml

Yep, there’s that. At least it won’t be 70 degrees on xmas day.

Yep. Digging further west.

OH valley ridge slightly weaker and trough “bridge” starting to appear north of MN & MI. GFS still appears to be digging into its own camp. (At 48h)

That’s what I’m thinking/hoping will happen. That little lead frontrunner wave across the gulf shore might get going and suck some energy out of it.

Possible that both camps are not wrong. Could turn out to be an inland/cutter low with a transfer to a coastal.

The op gfs actually looks like a tick towards euro with the double barrel low look. Gefs appears to be the last hold out.

Haven’t even looked, but the model wars continue for at least another day or two.

See how the butterfly effect in Alaska makes a huge difference? It’s almost as if a polar bear farts in a certain direction…

SLP position actually further east vs 18z

One thing for sure… I don’t envy the NWS forecasters in the eastern 1/3 of the US.

Looks like ICON, but slightly east

0z GFS I notice the Alaska s/w is holding back behind the UL. Most obvious change to me. Don’t know where that’s going but may help with more separation?

Too bad it’s the icon. Or is it?

And latest euro shears it out and digs deeper with a stronger UL over w canada. Goose is cooked on this run.

Feature to watch is the s/w riding over the alaska block (circled yellow) If it stays strong and sharp, then we get a good solution per gfs. If it flattens and shears out like the 12z euro, we lose the storm. Butterfly effect.

That was an out-to-sea scenario, and then it turned north at the last minute. I remember Doug Hill saying "okay, I'm a little suspicious, this seems to be moving north not east..." We're not going to do the reverse unless there's a redevelopment scenario.

Yeah, skewed mean is probably the best explanation. That's why we have to be careful "blending" models together.

Curious. If NBM is a "blend" of models, and most models are going cutter, how can this be?

Unless the GFS digs in and scores the coup of the century, this may be the best case scenario... cutter with redevelopment over CAD with a small thump to dry slot. I'll take it if it the models compromise to that scenario.

That has to be a shift of at least 1,000 miles

Maybe we're just used to losing storms modeled 7 days out so we're not that surprised.

The fact that WPC favors the Euro over GFS over the first 3 days of the model runs gives me pause. What if the Euro is correct on handling the ULL in W Canada for the first 72 hours from now.

Here’s how WPC is weighting models for their forecast blend: “The WPC fronts/pressures was primarily based on a 40% ECMWF/20% GFS/20% CMC/20% ECENS blend for Monday and Tuesday, and then the proportion of the ECENS and GEFS means were increased going through the remainder of the week to account for the increasing model uncertainty. Future forecast updates will provide additional clarity on the eventual East Coast storm evolution and potential impacts.” This was after the 0z suite. https://www.wpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=pmdepd