so_whats_happening

Man went for a warmer BOS than anticipated. Also the lack of a break in the warmth out west a bit of a surprise.

I believe a +EAMT should help in maintaining the ridge in the strat and maybe inject a bit of warming aloft. If this is the case I would watch a we go into the first two weeks of January what stirs up. Also hoping we can maintain the -NAO a bit longer to finally put the nail in the coffin.

You can have 2 scenarios that occur. We tend to want the top-down approach for SSWs but bottom up can still be impactful for us. The issue tends to be on top-down it can start to enhance the type of pattern we want (not always of course) with blocking and many times a very wintry time period. The bottom up approach tends to mean the troposphere is experiencing the perfect conditions but things can go awry and do not tend to last as long. Over the years watching while it is nice we do focus on the 10hPa layer I tend to think we should also be focusing on 50-100hPa layers in these displacement events to give us a better understanding of how patterns shake out. This was a wind reversal in the technical sense but was a large wave 1 process that took place with actually limited warming. I think the warming is very important in conjunction with wind reversals as sort of a 1-2 punch. The Atlantic just would not cooperate with us this go around hence the lack of a wave 2 response after the displacement. The Atlantic only just started working for us in allowing, in the last about 2 weeks, this -NAO pattern to set up. If we had the stout ridge from the wave 1 process still around from early in December we would have certainly entertained the idea of a split as we finish out the month. Also don't worry many of us are still trying to better understand the connection the processes have, even myself after many years of looking over the data.

Here is the latest subsurface from November to present. The wind anomalies have all but halted but things are primed if we get another solid weakening event of trades. Right now we are just maintaining the Nina SST profile. I will say it is fascinating to see how active the sun has been going into winter and us getting a pronounced -NAO periods showing up now multiple times.

Fun! Let us see if it shifts more west in time, as of this look Maine and Nova Scotia get the fun.

I do not have an issue with the idea of what RONI is to show, which is the impact we have seen from a warming world in response of increases with CO2 and others. My issue is say we get to a point where there is such a difference that is large enough to become an error in a way. An example would be if ONI reads -.5 but RONI reads it as moderate event so < -1 creating a difference of nearly 0.5 or more do we believe the RONI value to be more representative of the atmosphere or do we believe ONI has a better handle? I guess this is the million dollar question of course. I mean they even mention it towards the end themselvesThe cyclical aspect will be interesting to follow coming up here, AMO seems to be throwing some curveballs right now I would have liked to have seen just how much difference does continue to show and maybe was used more in conjunction with seeing differences and the impact on atmospheric events in comparison to ONI values. BOM must know something more than we do in now using RONI versus ONI values. @donsutherland1

These are two of the posts I wanted to bring over that sparked this conversation.

Lets give this a shot I am not sure if this will be able to be downloaded and opened. In the Excel sheet I created a decade by decade side by side of RONI and ONI from CPC and charted them out to get an idea of how things sort of coincided with each other (RONI, ONI). These are trimonthly readings dating back from 1950 to present, I'll let the data speak for itself but please excuse the X-axis in the charts. The numbers are just place filler for the data to the left and it would have been rather tedious and clogged up to have date and trimonthly with the charts. RONI vs. ONI.xlsx

I hate to even be abhorrent to the idea of a retrogression but this is not the first time models have shown a Scandi like ridging pattern and no actual retrogression took place. I do hope that it comes to fruition but I think the Nina background state is still causing issues overall. The flow is just too damn fast even with the -WPO in the tank. I think what this could at least open up for us in the east is the potential of more precip east of the rockies and then we play the game of can it happen with cold air still holding on enough to allow snowfall. We can't keep this dry train going.

Ill ask my work colleague as I am also interested if there is something out there. I don't see why there wouldn't be. I start vacation this weekend into the new year so I'll have free time to finally catch up on things online (thankfully). I know I keep saying this but I will set up the thread this weekend to chat about RONI. Im still surprised so many folks are caught off guard by this warm up and the potential of it being an extensive one at that, I wouldn't go as far as to say we are 'torching' but some areas especially in the southern plains and even lower midwest could hit record territory. Been beating this warm drum since about the beginning of the month. Even with the prospects of a deep -NAO coming up this does not cause any bit of a cooldown for much of the east after christmas into the new year, as should be expected. I would not be surprised to see temps get to average if not slightly below average a few times during the week before the end of the year but overall much of the cold that has been across the eastern 1/3rd of the country should take a solid beating on the monthly scale. The cold is locked in Alaska and NW Canada I do expect as we get into the new year and especially after the first week for us to push a more normal state temp wise and eventually that cold should dislodge and make a run into the CONUS. We should know the models have a hard time grasping these types of pattern evolving (the potential retrogression) just like they tend to rush a -NAO out much quicker than reality suggests.

Nice looks like the call for a trimonthly of ~ -0.6 was a good call. Should continue to rise from here slowly. Unfortunately I do not think this will be an 'official' La Nina based on ONI numbers but darn close like last year. Still liking my call of about the week of Christmas into the new year being the warm up time frame leaving the tail end of phase 8 into 1. Here is an updated subsurface from beginning of October to December 1st. Also @donsutherland1 I'm still working on chatting with you about RONI. I may just create a different thread and tag you instead of keeping it in this one, we will see. Hope to be done by this weekend. Work and life just taking precedence right now unfortunately.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA -1.4 -1.3 -1.6 -2.6 +.8 +1.2 +1.1 +2.1 +.6 DCA _ NYC _ BOS ___ ORD _ DTW _ BUF __ DEN _ SEA _ BTV 14" 23" 39" 42" 40" 91" 38" 4" 87" Sorry im late, time just flies by.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/

It is based on RMM phases not specific to La Nina or El Nino. Phase 8/1 doesn't become as conducive until we head into January and February for the east. I wouldn't expect blazing temps but I certainly wouldn't expect downright frigid outside of the colder period until about mid December/3rd week. Still feel pretty confident in the warming potential as we move into christmas week and the new year. Surely things can change and it will be interesting to see if it does but overall I would expect near normal through much of the east with above normal across the SE. The true test will be what happens with the December 2nd/3rd system and how that sets up. We will be able to see if the models are overzealous in either direction with respect to the SER or cold pressing into SE Canada.