SnowGoose69

Its been too amped in a short sample size so far the last 6-8 weeks...it almost always does better than the EPS but it was way too amped on the wave forecast in mid december

If you scroll through the 12Z GEPS/GEFS it seems already at 360-380 its reshuffling out west and the low is retrograding back towards the Aleutians with slight building in heights over W Canada and the block in E Canada lifting north...its like if you can just run it to 480 hours we'd be right back to an eastern trof.

DT has torn into those calculations for years...he's shown how the -NAO stats can be wrong at times where you might technically have higher Greenland heights and lower Azore heights but its not really a -NAO, or certainly not one which impacts us in any positive manner for snow or cold

I am still suspect of any long duration -PNA pattern happening...depends largely on what the dynamics behind the change are but if its strictly based on the MJO going 4-5 I am far from sold it happens.

If indeed we are gonna torch or go mild for a time around 1/8 onward it makes sense we could see a big event just prior to that as the 12Z Op shows...1/5-1/7 might be where something goes down

It seems we no longer can get overrunning events with trofiness in the west. Events like December 84/90 January 89/December 08 just do not happen anymore....it seems everything just wants to super amp or undergo massive phases in those good overrunning type setups so you just get way too much mid level torching vs long duration overrunning to start. Many people mention how the coastal low track like January 87 has sort of vanished which is why people in CNY/CPA have struggled somewhat the last 10-15 years but the weaker/moderate SWFE seems to have sort of vanished too

I'll personally have this forum shutdown if this happens lol

You can see that on the 12Z Op run...snow verbatim nearby or overhead in what is really a 2009-2010 type air mass.

Meanwhile plenty of cold air exists in the hemisphere...Beijing just got to -6...their previous coldest ever temp in December was -1

It may end before that....it would have to be thread the needle or fortunate timing but there are chances for something to happen the final 10 days of the month

Underrated fact, the last few days the GFS is kind of getting owned by the CMC/Euro/ICON beyond 72 hours...we have legit not seen that since maybe the 2017-2018 winter on any consistent basis...probably something to do with more southern stream influence

If its from like 120-180 it can be a problem in this part of the country as very strong winds from that direction over 40-45 are less common, especially once just inland so the tree roots are not often as adjusted. Strong winds between 270-060 usually do least damage...once outside of that even without leaves you'll usually see more damage begin, especially with wet ground. I know in NJ we saw that in 85 with Gloria, we probably were gusting stronger from 340-020 but when we went 230-250 stuff started going down all over the place despite the speeds being less

Unfortunately that wave may complete its cycle before we really see things reshuffle enough to get legit cold air in place and the pattern setup as we want. Could be into the COD or even weakly into 3-4 by the time we reach 1/2-1/5 which is when I think we might have the Pac/Canada setup well. It could be partially why though we saw things turn better overall in the post 12/20 period after ensembles abandoned ship for 2-3 days last week,

It almost had to, GFS was on an island not really digging behind the storm whereas every other model was

The airmass is gonna be puke as a whole, at least at 276. But as you saw if you follow the Op run to 384 it gets colder as you more or less develop a -NAO/AO by that time

It may be correct as far as legit cold because even if the pattern flipped to a December 89 setup on 12/26 it would probably take Canada 10-15 days to cool off

At the time the 94-95 winter NAO average I think was the most positive on record...since the I think we have beaten it 1 or 2 times. The real killer in 1994 was the stratosphere was frigid...it was noted by some mets at the time in Oct/Nov that we might be in major trouble for the winter as it was just crazy how cold it was.

I was all over that one on the old forum. Never believed for a minute snow wasn’t going to happen once that low closed off. I was surprised how badly all the models missed it other than the GFS

Funny thing is we saw this often last winter the other way around. GEFS tried making pattern favorable for us at a couple of points consistently D12-16 but Op runs mysteriously kept showing raging SERs and torches and sure enough those verified better strangely enough. We were talking about this in the NYC forum yesterday, its somewhat odd. I'd have to really dig in last year and now to see if ensembles were being skewed by 15-20% of members going severe one way

It comes down to us not having a stupidly -PNA. You can usually survive to about as bad as -1.25 or so from BOS south but if you consistently go below that your NAO could be -4 and it probably won't matter much

As long as the PNA is not like -1.5 or worse and or the EPO is not raging positive you can usually do okay with a lousy or so-so Pacific and a -AO/NAO

In the absence of a pronounced and persistent SE ridge you won't see something 2015 like. 97 maybe, Dec 97 relative to 2015 and some other recent Decembers was not THAT warm. Something more like a December 99/14/18 is more likely in this pattern. One of the interesting things myself and a couple other Mets discussed in recent days is how the Op GFS/GEFS are doing the inverse of what they did last winter. Last winter we so often saw the GEFS look sort of decent days 7-12 yet the Op runs were torches. This last few days we see the reverse often, semi ugly GEFS runs but Op runs that have shown periodic colder shots and chances. Last winter more often than not those Op runs verified closer to reality. Its possible that in this regime we are in enough ensemble members are being fooled to skew the mean too far one direction.

Yeah I have my doubts how much the MJO really matters when ENSO is in a moderate or strong regime. It most definitely caused Dec 2015 to act like a Nina vs a Nino....in reality it acted like a February La Nina pattern, not so much a December one, but regardless a raging SER is unheard of in a mod or strong Nino December. I am not sure if the MJO wave now or even 10 days from now is strong enough to really be causing the regime we will be in. To me it looks more or less like your usual mod-strong Nino December where nobody is really cold but the Carolinas to FL average the coldest

If anything happens it’s going to be with that second system but it’s going to have to work out perfectly.

I am too lazy to dig that far but isn't phase 7 in Dec during Ninos quite a bit better than it is in neutral or Nina?