weatherwiz

Mow the snow too

Yeah I totally would not rule out a colder December yet. As you know, there certainly have been some cold December's in stronger EL Nino episodes. Those saying, "December will be warm b/c that's what climo says" are selling themselves short. I would not be at all surprised to see some blocking in December, maybe something along the lines of pesudo-blocking. Nothing thus far though I think is 100% convincing for a warm Dec.

No drinks near the laptop this time. Years ago I spilled a 40 on my laptop. I also spilled Red Bull and Jager on I think the same laptop. EDIT: Nevermind....I didn't spill those on laptops, I spilled them on a keyboard. I had desktop back then

Thanks! I forgot that was offered on TT I think I will take that

That signal for anomalous warmth the second half of next week is very real and I would say is quite high on the confidence level. When looking that far out and dealing with the potential for something rather anomalous, and in this case warmth, you want to look very closely what is going on across eastern Canada and the northwestern Atlantic northeast of Maine. In this case there doesn't seem to be any high to our northeast which would yield the potential for CAD and there is no high off to our north to dampen the rising heights. Looks pretty favorable for an anomalous S/SW llvl flow to become established well into eastern Canada as the week progresses.

However, I am assuming we are going to want to see this configuration change up. These +SVP anomalies across the U.S. can't be a good thing

tells me that period could be quite stormy...and hopefully we're on the colder side of the spectrum

I don't think that storm will really have an impact in that manner, but typhoons in the PAC (especially recurving Typhoons) can alter the downstream pattern significantly. @Ginx snewx and @Typhoon Tip can go into biblical details on this.

If we can maintain this massive warm pool driving the -PDO through winter I think that is going to bode very well for us. It doesn't even have to remain this intense...even if it were to weaken Obviously the PDO has been negative for quite some time and these warm anomalies have been a fixture for quite a while. This has helped to maintain very strong ridging just west of the Aleutians I was looking back at past EL Nino winter's which presented this 500mb height anomaly structure. The reasoning is as follows: The ridging west of Aleutian is yielding a persisting troughing feature within the Gulf of Alaska domain and we should continue to see this strengthened as the Aleutian Low strengthens (typical of a Nino). The Aleutian Low can make us and it can break us, but past years 1913-1914 1940-1941 1957-1958 (BIG FAVORITE OF MINE FOR AN ANALOG!!!!!) 1958-1959 1965-1966 1968-1969 1994-1995 (no please but also the Aleutian Low was rather south and we had a raging +AO) 2009-2010 all featured persisting troughing within the Northeast and also favored blocking (exception of 94-95). I am on board for some major blocking periods this winter. I mean look at those height anomalies spanning the Arctic across the hemisphere...things to me seem to be setting up nicely. While I do think Dec could be a typical EL Nino like month...I would not set this in stone yet.

A great place to really start is always the Pacific but the overall hemispheric pattern can provide a good signal...especially when its a ridge/trough pattern and everything is on the progressive side. You can get an idea of where your ridges/troughs will be 3-5+ days out. It's not always this clear cut but identifying where your troughs/ridges are can help.

Really interesting to see some potential for tropical activity within the next 10 days. This may be a long shot but there may be a system in the Gulf late weekend/early next week which could materialize into something and the GFS has been really hinting at a pretty power Caribbean storm later next week or next weekend. Now of course neither of these will have an impact on our sensible weather, but when looking at this from an atmospheric perspective and forcings...this could be a clue of how the pattern could evolve moving through the second half of the month.

In my endeavors regarding the IOD, I came across this. Not sure if anyone is familiar with this but this is a pretty sick site https://www.jamstec.go.jp/virtualearth/general/en/index.html#SINTEX/DJF2024/SINTEX_wind/SINTEX_wind/mean/all/orthographic=-221.21,34.27,773

Does anyone know off-hand if this is the best or preferred source for historical IOD data? https://psl.noaa.gov/gcos_wgsp/Timeseries/DMI/

Agreed, I think there's a pretty good chance we see multiple blocking periods emerge this winter. My top analogs in my winter outlook all featured winter's which featured more blocking than not. I think the only one of my years I heavily looked at was 1986-1987 (or maybe it was 1987-1988 I don't remember off hand) which didn't have much, if any, blocking. But like you said, moderate-to-strong EL Nino's tend to favor blocking and given how the QBO is already quite easterly my thinking is that will prevent the PV from becoming too strong as we ramp towards into winter.

I've posted this in the SNE ENSO thread, but I think this EL Nino is going to be more reflective of earlier EL Nino events (pre-1980) and alot of those seasonal models have been yielding that look. Not sure if the increase in the Modoki EL Nino is the leading contributor in how EL Nino's have behaved, but there has been a clear cut shift in the behavior of EL Nino since around 1980. This is going to be one of the more interesting EL Nino's (when you factor in PDO, tropical forcing, etc.) we have seen in a while.

IIRC correctly, they do quite well precipitation wise during EL Nino episodes. Ultimately though, I don't think there is a strong signal overall between ENSO phase and snowfall for the Sierra's. I think if you look at their top 10 snowiest seasons there is a heavy mix of EL Nino/La Nina. However, it is interesting to note that when they got whacked last winter it was during a pattern which resembled more of an EL Nino than the La Nina state we were in.

Also nice to see a severe threat emerge in the Lower Mississippi Valley region but its near 300 hours.

Second half of next week could be quite warm...meanwhile the Sierra's could see their first significant winter storm of the season.

That almost kind of looks like December/January of 1929.

Yeah it is borderline...I was thinking too that precip rates could influence p-type there and whether that little dry slot would influence as well. Another factor to consider too is the NAM may be a bit tool cold at the sfc there

If we are going to get any good chances in December it will come with a period where the PAC is rather favorable. I don't think we'll be getting Arctic support but that will change as winter progresses. That's a pretty decent look there...we may have to watch the N PAC for some potent storms which may help drive a brief, but favorable period.

Yeah this does kind of resemble a SWFE. I was just looking at some soundings on the 12z NAM and this is some textbook sleet stuff EDIT: best guess precip type says freezing rain but ehhh

There may be a heavier burst too of wintry precip...probably up near the MA/VT/NH border. I could see some spots, especially higher terrain getting a couple inches.

I wouldn't be surprised if the PNA is rather transitory through the winter...so when looking back at the DJF or DJFM average the overall index won't be overly strong or overly positive. I really wish these indices were also broken up into bi-weekly data as opposed to just a raw monthly value. I believe the CPC provides daily readings for NAO, AO, and PNA (maybe not PNA?). I don't have the mathematical mind to do such a thing...I suppose you can just take two weeks worth of data and get an average, but I don't think that would be an accurate method of going about it.

Going through this and comparing to the link I was using. I really wish I had come across this data source sooner. At the end of the day, I probably was incorrectly using the data source I used but the information on the link you provided is much more in-depth.