Bob Chill

FV3 is the perfect track/evolution for the d9-10 deal. I'll be hugging the 12z run unless the euro ups the ante.

GFS is going that way too. I'd much prefer that in the long range versus worrying about a cut to the west or phased rainer. We're still in shotgun spread mode so I'm not overthinking anything. The 10k foot view is a pure southern stream shortwave is going to traverse the country into the deep south. That's on all guidance. Where it goes from there won't be known for probably 5 days

Not somuch what it shows verbatim QPF wise but the track/transfer happens entirely to our south. That's a pretty good solution. It's not all that cold leading in so any slp track that approaches to our west pretty much kills any chance at snow. I don't trust the solution but it shows how it can work here.

12z ICON is a perfect track/evolution for the 5th event. Best case scenario.

There's been a theme last 3-4 years or so where pattern flips (good or bad) in the long range wash out or never even materialize. We thought winter was over multiple times in 2013-14 but it kept on coming. 2014-15 was the opposite where a good pattern kept getting pushed back until it finally came in Feb. When the flip to a +EPO first showed up it was pretty drastic and now it's getting tuned down as time rolls forward. Would not be surprised at all if the worst of it never materializes and the -AO and/or NAO comes back nicely by mid Dec. If it does then the calls for a solid winter in the east start looking pretty good imho.

EPS still looks pretty ugly but shifted the AK trough a little further west and not tucked so close to the coast. Starting to see a slight kink in the isobars along the west coast of Canada. If that trend keeps up NA will be spared from a complete onslaught of pac air. Get some help from the Atl and it could very well be just a run of the mill relaxation that we're hoping for.

Ens are backing off on the depth of the "potential" crap pac pattern down the line. Scand ridge poking into GL now showing on GEFS/GEPS/EPS and the AK vortex is slowly shifting towards more of a trough and further west than previous runs. Still not a great look but a bit better already compared to the more dire recent runs.

NS cuts both ways with setups like this. Remember when I mentioned the pattern is also good for a southern slider? We may need some sort of tug from the ns to be in the game or it will miss south. These types of fine details are usually never worked out until the med/short range. Just something to keep an eye on. I don't get too invested on any storm until 5-6 days out at the earliest unless it's a Jan 16 type of deal. Ensembles still have large spread and any one of the solutions has equal odds.

This panel is a good visual. The ns vort helps raise heights in front of the ss vort and screws up the mid levels. And before someone comes in to tell me not to take a d10 op seriously... I'm not... Just pointing out something to keep an eye on as the whole thing evolves. Obviously there's no way in hell an op is going to nail anything in the northern stream this far out.

Not a fan of the northern stream vort on the 18z F3 with the d10 potential. I wonder if that's behind a number of ens members with a good track and mostly or all rain. Obviously it's way to far out to worry about something like that now but it's something to watch as the days go by. Seems like there's 3 camps with the possible storm. Southern sliders have no northern stream interaction and suppressed flow. Rainers or west tracks have northern stream influence. The good solutions either have hp over the top or a perfect track between the 2 hps with limited or no northern stream interaction.

I can easily see how the storm on the 5th could work in our area. Not very likely but I wouldn't be surprised if more confluence starts showing up and the track moves east over the next few days. Move the departing 50/50 south just 150 miles or so on this panel and it's snowing here...

Yep, it's what we want to see. We can pretty much expect a relaxation of some sort in Dec and that's totally fine and completely normal. But the strength of the +EPO on the EPS and recent GEFS runs is something we really need to avoid. If a deep bn height anomaly sets up in the EPO region it's more likely than not to have some staying power. That's troubling because of what it does to north america as a whole. It takes time to recover back to a winter pattern even after the bad pattern starts to relax. Luckily it's so far out in time that we don't need to worry about it yet. Any trend away from the blue ball is a welcome sight.

I agree. I also think the 12z gfs showing the strong hp draped over the top is suspect as well. GEFS is similar to what the EPS showed last night with a departing high off the coast and another hp to the west. This looks very similar to the 0z EPS with a wave running the gauntlet:

GEFS took a nice step in how we can avoid a terrible pac setup. The Scand ridge pushing into the NAO region will help both the east coast not flip to warm and also help prevent a burly AK trough/vortex. GEFS backed off quite a bit on the strength of the +EPO building over AK. Look at the isobars along the pac coast of Canada. Much better than the trough axis further east like the EPS and recent GEFS runs have shown. If ensembles continue to trend in that direction we can breath a small sigh of relief...

The potential centered around the 8th-9th isn't going to be handled well at all. No confluence or hp over the top. That could easily change going forward but for now ens guidance is showing a wave running the gauntlet between a departing hp off the coast and a fresh hp dropping into the plains. If that's how things develop then the precip shield is going to be fast moving and narrow. Not something that any model is going to handle well until the lead time is far shorter. I can see how it can work out but there is plenty of reason to question everything for now. ETA: the type of event is similar to many that we saw in 2013-14 with progressive flow and waves running boundaries. If anyone remembers tracking those events then they'll understand how tricky they were leading in. We didn't have much confidence in many of those events until they were inside of 5 days and even then they were prone to plenty of swings and wobbles.

The window checks off some boxes. -AO/NAO are relaxing, active southern stream, solid cold airmass, and pattern is prob flipping to warm. That's a pretty typical combo to get a coastal in our area. All we can hope for is it to hold together as the leads close. Would be kinda funny if it ends up a southern slider. Upper air pattern evolution fits that possibility as well.

Yea, it's not a textbook case but it's really just splitting hairs. For our area we just need to avoid strong or east based Nino's. I'd take my chances of with any other nino versus strong or east based.

Control run is sweet but multiple good ones this run. Long ways to go but at least we have something to track/discuss.

Some very nice tracks in the mix. The flush hits look nice on the panels. Sometimes the gefs memebers have snow but a totally unrealistic way of getting it. There are some really good evolutions in the mix. Nice seeing the southern ones mixed into the spread as well...

Yea, was just going to post that 18z ens members upped the ante again. It's a tricky setup with high pressure to the west instead of north but it's a reinforcing shot so the antecedent airmass will prob be decent. If we can score even an advisory level event before things potentially make a turn for the worse it will make it a lot easier to deal with a crappy pattern. I like seeing the gefs and eps slowly warming up to the idea as the days go by. We'll prob get a nice op run in the next day or 2.... or 0z tonight.

I'm still not sold its going to happen in the first place so I won't put the cart before the horse and even begin to guess how long a strong +EPO that hasn't formed yet will last. Hypothetically it could last a week or a month or most of winter. Until it becomes a fixture in real time I'm assuming (like everyone else) that it's either not going happen as shown or be pretty short lived. Our area doesn't typically get going for winter wx until after Christmas in the vast majority of years so I won't get concerned about a dud until mid Jan at the earliest.

Like I said earlier today. It can only get better from the current LR look. EPS isn't an ambiguous or washed out mean... it's crappy with a clear message for now.

Yea, it's really bad. Basically a complete evacuation of cold air across the continent... especially western Canada. A pac onslaught of epic proportions. If it were to happen like that it would take a lot of work before winter returns.

It's a good thing that TT doesn't have EPS d11-15. It's quite hideous. I'd prefer to be staring at a SE ridge honestly.

Like the GEFS, EPS is warming up to the idea of something d10-13. Far from a strong signal but a step in the right direction.