ORH_wxman

That is interesting. The rare tropical volcano that contributes to warming rather than cooling. That’s the way to do it though…inject a bunch of water vapor and little to no sulfur.

I don't even think the GEPS would be that bad...they are definitely a warmer look but they still have a big NAO block so we'd have chances. Obviously we'd prefer the GEFS/EPS to verify, but I wouldn't be bridge-jumping either if the GEPS was closer to reality. GEPS almost reminds me of late Dec 2002/early Jan 2003 pattern which was very good for the interior.

No doubt a lot of similarities between the modeled pattern and Dec 2010 (and early Jan 2011).

Yes. There's probably multiple reasons for it....first, we're just entering winter so everyone is impatient. Second, I'll bet a large part of it is there are no snowstorms on the operational runs. That gets a lot weenies anxious, even though it shouldn't. Snowstorms occur from shortwaves.....good luck having models find a shortwave in the flow 10+ days out. Third....there is definitely Tip's psychology aspect to it. Some probably doom and gloom so they can either be "right" or "happy"....if they are wrong, it's cold and snowy and they won't care that they were wrong. But if they're right, they get to troll everyone and pat themselves on the back for calling the bust well in advance.

Here is the progression in 3 charts....first one is Dec 6, 2nd is Dec 9, and last one is Dec 13

The pattern change is going to go through multiple stages....when the block is first forming, we get the torch with a likely cutter or warmer type system going to our northwest (Dec 5-7) which actually feeds back into the block.....2nd, we get the initial cold push which still has higher heights in the south. This is what Tip was commenting on earlier with "Velocity" issue. This would be like in the Dec 8-12 time frame. We can get a system in this type of flow, but usually clippers and SWFEs. Then finally, you get the higher heights in the south retrograding into the western plains and Rockies (post 12/12....heading toward mid-month) which is what Scooter was talking about above....that's more of a big dog look. That's a very good pattern for larger snow events for us. Hopefully it sets up and hopefully we cash in.

Not in Dec '69. Feb '69 maybe. Dec '69 was huge in far western New England....but it was merely just very good over interior spots like from ORH to CON.

Only in the Vatican is 12 days of AOB average temps after record warmth the first 10 days of the month is considered no pattern change.

I haven't kept up in recent months, but back in the first weeks after the eruption, I recall reading that it didn't eject enough mass sulfates up into the stratosphere to really be anything close to something like a Pinatubo when it comes to climate impacts. I'm guessing that is still the case....a lot of the material probably stayed under water and/or settled back to the earth as much of it never got high enough to get into the stratosphere.

KCON

No pattern change to see here

Here's a good visual....you can see early on how there are still above normal heights in the south while we are BN..... Then you will note how late in the period at the end, the heights are below normal across all of the east including the southeast with the ridging pushed back toward western plains and rockies.

I think the velocity issue will probably be present early on in the blocking pattern because it is still fighting the SE ridge a little, but it seems to really relax after the first week of the pattern or so....at least it's implied by the models. We retro some of the ridging back toward the Rockies and that really loosens the gradient between Quebec and the SE US. We'll see if it plays out that way....but regardless, we'll still likely see threats either way....but if we're fishing for the Big Dog, we'd obviously want to see that relaxation in the south.

Yes we can see the posts.

That's a good thing in that it keeps us in the game when the PAC goes kind of ugly...then ideally, you'd have the PAC go more favorable as the block finally breaks down (ala January 2011 when kept the fun going all month into early Feb after the block broke down during the 1/12/11 event)

The flow does get a bit zonal on ensemble guidance for a few days but the biggest effect is out in the plains. We keep colder due to huge NAO block and the plains mini-ridge looks like it retrogrades back toward the Rockies after a few days. As long as we have that block, we’re fair game for something.

For your ‘hood, it was prob 1945. For northern part of SNE N of the pike, could be 1970. ORH is actually 1992 but that’s a bit deceptive since it’s almost all from that one storm.

Orientation of the block would have to change pretty dramatically to set up a semi-perma ridge over the east that links up with the NAO block. We get the eastern ridge temporarily as the block is just starting to set up shop, but it quickly goes away because that block is oriented from like Iceland back into Davis strait which isn’t the way to blow up an eastern ridge. It forces PV lobes underneath when it’s oriented like that. It’s possible the orientation changes but that’s pretty doubtful considering the consistency and cross-guidance agreement.

12/6-7 kind of looks like that. That’ll send many into a bit of a tirade I’m sure regardless of how good it looks going forward.

Here’s the progression. You can see the initial cold dump west…but those low heights get forced under the NAO block as it migrates eastward. When we have a +NAO, it often will just swing up into Baffin/Davis Strait and keep us in a perpetual ridge situation….but not here. Dec 5th Dec 8th Dec 12th:

I’m not really getting “PV into the western US while we stay warm” vibes from this look…but whatever urgent panic floats your boat is fine, just at least support it with something. The initial cold dumps west…no disputing that, but it doesn’t maintain that look.

Even in 2010, the pattern flipped around 12/5….but we then whiffed on a snow chance a day or two later and then we had a torching cutter on 12/12/10 within that favorable pattern. The retro storm on 12/21-22 was our first accumulating snow in the pattern and it was only a big deal on the Cape. Boxing Day finally happened a few days later.

Yes I know it would be. That’s why we’re posting it so that you can re-adjust your expectations. Sometimes we get a snow event right at the beginning of the pattern change, but sometimes we don’t and we have to wait a week-plus.

There’s a pretty reasonable chance we don’t get any snow events through 12/13. That’s like a week (maybe not even) into the pattern change. I’d be surprised though if we made it to 12/20 without one.

Some people should prob log off for about a week and then check back in. There’s very likely going to be no threat to track until at least that point.