The -NAO block really starting to show up on modeling strong today. I believe this will cause some changes over the next two days in the outcomes the models show for the medium range
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Pattern December to Remember
- Thread starter SD
- Start date
pcbjr
Member
... but what will really happen? ...
Cary_Snow95
Member
No pics yet, but 6Z is by far the coldest yet l(so expect the next to not be as cold obviously) with it a whopping 8BN at Chicago, 7BN at NYC, 6 BN at RDU, 3BN at ATL, and 2BN at SAV for January 2-27! Wedges are raging during this run and Arctic dominates most of the E US.
The CMC Ensembles are exactly where we want them to be!
Meanwhile the EPS is still torchy
Imo I like the change around AK vs a straight up +EPO but the ridge axis is centered over the Aleutians, which often wants to torch us
Webberweather53
Meteorologist
EPS has been slower to the punch and most bearish about the -NAO overall amongst the 3 major model suites, I think it's probably wrong in that regard and the stronger -NAO (which has been a consistent trend in the medium-range that's propagated deeper into the runs) should yield a cooler pattern overall compared to what it's showing atm.
Even still, today's run once again ticked stronger w/ the -NAO in the 10-15, closer to what the GEFS has had. I think the EPS's slower than verified MJO forecasts are hurting it.
Webberweather53
Meteorologist
Polar vortex starts to take a beating late in the month on the GFS. I can see it tho w/ the semi favorable-looking wave-2 pattern in the troposphere
I can't put lipstick on a pig. That is horrible and if that look ends up verifying we'll still be a long way from anything good. That's an east based
-NAO, we want west based. That Aluetian ridge is an eye sore that's going to cause a -PNA on steriods. I can't spin that to anything good. Maybe some onset ice in a CAD event but the cold isn't even in southeast Canada or New England to provide us a legit CAD storm. I know we've been talking very late Dec or early Jan for anything good but if that Aluetian ridge ends up that strong in that location in late December that early January timeframe will quickly go to mid January. But that's just my opinion ?
For entertainment these are from the 6Z CFS/expect the next few runs to not be as cold, of course, since this one was by far the coldest and extreme and they typically jump wildly from one run to the next:
Anyone seen the 12Z CFS? Doesn’t WxBell already have it by now?
iGRXY
Member
You are getting way too upended by the 360 he EPS. Especially when it’s MJO progression is slow which is a bias. Expect the continued -NAO begin to squash any SER.
Stephenb888
Member
Not gonna happen so don’t worry about it.
The CFS progression IMO follows basically what the ensembles show, at first a eastern ridge response to the -PNA then early jan everything undercuts the block and we get a very nice look, 
To my untrained eye there it's raising heights in the NAO region but it's east based. The ridge in AK, which is too far west, is trending stronger and lowering heights on the west coast even more. To me that looks like the wrong trends for the SE. Sure the more blocking up there will lead to colder weather in North America but it looks like it'll go to the wrong areas. You would do well in New Mexico. What am I missing there? I'm just taking it verbatim and realize it's probably wrong since it's too slow with the MJO, but if it were right I see that the end of December or 1st week of Jan flip may be in trouble.
I certainly hope it's not even close to being correct.
Even so, the 12Z EPS maintains the colder 12/19-22 in much of the country including the SE with its wedge. It is still warm late, but it could be too slow to break down the SER and even if not, MJO climo and many CFS runs have been suggesting that the E US, especially MW to NE will get much colder a few days later.
At first the CFS torches us like the EPS then all the -EPO derived cold moves across conus under the -NAO 
