so_whats_happening

Im honestly unsure about this but looking at how things progressed with the early December warming I would presume at 10mb we would want it more over Eurasia versus Kamchatka/ North Pacific. I included 10mb and 50mb animations. Here was the 500mb during that time frame as well of course we don't get to see the moving parts unless we do a daily gif but you kinda get the gist.

TAO through the 19th every 2 days. 

Edit: Don't mind the hiccup around the 3rd from about the 2nd-4th there were a few buoys missing from the data.

7 hours ago, GaWx said:

Wow, as @griteaterjust said, this run has by far the weakest SPV/strongest concentration of members with major SSWs of any run for Jan 2-13 with the mean dipping to a mere +3 on Jan 7th vs a climo mean of +33!! The lowest of any day prior to this run was +11 to +12:

 

It’s impossible to count but I bet there are 40+ just for 1/2-9, easily the most yet. I see ~22 that are extreme (sub -15), by a good margin the highest yet.

By far one of the stronger signals I have seen thus far. Lets see if the models are a little too aggressive at first or if this is the right idea.

Btw SOI has been rather positive over the last 2 weeks. 30 day is now above -4 and 90 day is about -8.

https://www.longpaddock.qld.gov.au/soi/

6 hours ago, 40/70 Benchmark said:

I am so sick of the PV kicking to the other side of the globe....can't we get it to near Hudson Bay just once...ugh.

I mean...

6 hours ago, Maestrobjwa said:

What mechanism is causing that? (Does it have to do with things just being more difficult overall?)

It is actually a fairly typical Wave 1 response on the SPV typically you have two location of ridging (AK/ Europe) and two locations of troughing in a split  (Canada/ Russia Siberia region) with displacements you typically get a ridging pattern like we see near Alaska sometimes we get an erroneous one like last winter across Europe to northern Asia.

Last year was well connected to the 500mb pattern.

Latest TAO and CPC subsurface look. TAO im back to doing every 2 days.

Edit: I just noticed the bad data around the 1st to about the 4th on TAO. Looks like some buoys were down during that period giving it a funky look.

Since the MJO forecasts have weakened considerably we also have weakened the potential WWB event as we head to mid to late month. There is still a little something there but nothing to tip the bucket more as of now. We can definitely see the area around 1+2 may fall even further coming up here. Last I saw was around 1.3 on OISST will have to check with the update later on.

17 minutes ago, griteater said:

Nino 3.4 at +1.89 today (as of 12/6)

Yea sounds about right with how things are looking right now. Im not sure this will have much impact in December maybe the last week we may see a slight warming? Similar progression to the last one but definitely weaker.

1 hour ago, GaWx said:

I absolutely have been saving a bunch of the Euro Weeklies SPV progs. I was the one repeatedly mentioning the can kicking that went on between the Nov 1 and 19th runs. Remember? After that, they suddenly got much more bullish about a weak SPV.

 In recent days, I’ve noticed not as weak of an SPV in early to mid Dec as in runs from a few days ago and in late Nov. We have to make sure this won’t turn out to be a mirage just like with all model progs for anything.

 Today’s isn’t as weak as the three prior runs of 45+% of members with major SSWs. Today it is ~38%. Also, the # of members with a sub -10 is only ~18%. That was way up at ~30% a couple of days ago.

Cool the only reason I asked was to see if the model was overthinking the weakening, which sounds about right given past warming events models go too quick with it. I personally would like to see a strong pass in Phase 5-6-7 to really hammer the SPV but I know it would be a very unwelcomed thing.

53 minutes ago, GaWx said:

1. The Nov +PNA means that for only the second time since 1950, there was a +PNA in all of June-Nov. The only other time was 2021. But 2009 was a very close call. I consider +0.25+ a +PNA month.

2. The Nov -NAO means that for only the 3rd time since 1950, there was a -NAO in all of June-Nov. The only other years were 2012 and 2010. I consider -0.25- a -NAO month.

Last year was awfully close to that time frame for PNA, it collapsed toward the end of October. Good it is at least holding up a bit.

1 minute ago, Terpeast said:

Judging from the gradients near the dateline, forcing should strengthen around the dateline and then drift a bit east after Dec 17 or so

Potentially that time frame has been changing over the last few days. Couple days ago it showed a strong advance to 3.4 but has backed off. I get the feeling we may in fact have a stronger MJO wave through 6/7 than what is currently modeled but will have to wait probably another week to get a better grasp. Until then I expect the cold to not really filter into the east until the last week of December and that may be generous.

BTW PDO updated yesterday down to -1.79 for November from -2.97 in September. Truly rare territory here even 72-73 warmed the PDO to near neutral for this time period. The only years that managed to be close to this low during an El Nino were 94-95 and 04-05 in the last ~70 years.

To get back on topic a bit here is the upcoming look at the WWB there is certainly something there.

27 minutes ago, GaWx said:

 

Again I even gave you a little heart because I read through your discussion I see what you are trying to say. Until we get to the cooler phases which do not happen until the end of the month we will feel the effects of warmth from the warmer phases and even when that happens the dirty work is done and December should still average above outside of the far NE and probably PAC NW. I still do not know what you are trying to refute here from what I said. Phase 7 all amplitudes, including low ones, still offers a warm look in the east for December. Phase 8 has a more neutral tendency which could offer some cool SE look but would just bring averages instead of say +3 to a more +1 to +2 state. 

As we carry over to January Phase 8 and 1 show a much colder signal, stronger amplitude would favor a slightly warmer scenario but still cold.

4 minutes ago, bluewave said:

But that isn’t what I said. MJO 8 is still warm during an El Niño but we see improvement with phases 2 and 3 in January. As for the weak SPV this month during the El Niño, all the cold is currently over in Eurasia. So it isn’t doing us any good. Hopefully, we see changes on that front during the winters 2nd half should blocking persist. 
 

 

This about as classic of a wave 1 response (SPV displacement) as you get. The lack of strong CWB in the Atlantic is hurting the potential of wave 2 pattern popping up at this moment.

2 minutes ago, GaWx said:

I’ve posted many examples of weak left side MJO during El Niño showing that this combo during winter is often cold in the E US, especially SE US-Mid Atlantic. And that’s not necessarily even requiring a weak SPV.

I have seen but im not sure what you are getting at, care to explain further? Why it applies to my post about December? For January it doesn't make too much of a difference whether it is strong or weak in phase 8 and 1 the results are a cooler pattern.

7 hours ago, GaWx said:

 Dec 4th Euro Weeklies look similarly impressive with numerous EPS members (~45%, which is similar to prior two days) with major SSWs 12/28-1/18. A year ago (~12/31/22) the SPV was in stark contrast near a record high strength!

 Strongest SSWs:

~27% <-10 vs 25% prior run

8% <-20 vs 5% prior run

7% <-25 vs 3% prior run

5% <-30 vs 0% prior run
 

I sure hope you have been saving these to see verification. See whether or not it is trying to dive too quick or if there is clustering in a specific time frame.

Looking at MJO influence in a warm Enso the strong amplitudes tend to have slightest bit warmer look into the east during phase 8 for December but not major torch level.

Either way lets not get too hung up on it as this still looks to probably only be in maybe the last week of December and we still have some lag with MJO putting in work on the areas sensible weather.

Until then we see a relatively warm east and even SE which is about as expected as the sun rising in the east.

38 minutes ago, griteater said:

Sometimes I feel like the Pacific Jet is the Rodney Dangerfield of weather forecasting.  We actually need an extended jet to get +PNA patterns.  -PNA is the opposite...it is associated with the Pac Jet being in a weakened state where it is retracted back to the W Pacific (red and blue contours on the image are the height anomalies),

Of course, there are other flavors.  If the jet extension runs poleward, then that does favor low pressure in AK...but the point is, the Pac Jet strengthening and extending shouldn't be binned as a bad thing in all cases for the eastern U.S.

Bouts of warmth here in mid-Dec has been pretty well expected.  I think the bigger questions come late Dec into early Jan

 

 

 

 

Source: https://www.weather.gov/media/sti/nggps/Presentations 2017/08 NGGPS17_PImeeting_Bosart.pdf

If we can get cyclonic wave breaking occur im sure many will be happy with the results to come.

Unfortunately been a minute since i have seen how the Pacific has gone so cant say for sure where we are but if the pattern we have is an indication i would say we are still in the anticyclonic wave break pattern for now.

Oh and as always thanks for the link

In order to do this Oct (1.72), Nov (2.02) (probably revised up a bit as the other months have had revisions slightly warmer than initially posted), Dec would have to attain a monthly mean of 2-2.1 (closer to 2.1 for rounding purposes) for the anomalies. If this does not occur and hits at 1.9 instead we cap at a 1.9 trimonthly. The next potential would then be kicked to January and that is anybody's guess at this point because a lot will depend on how things hold up this month. Overall though the difference of a trimonthly at 1.8 (currently seen) to 2 is not really all that different.

If we go by Eric Webb( or is it Webber) you need an ONI trimonthly of over 2C so essentially 2.1 would attain that Super call and in order to do that December would need to come in at nearly 2.4 with upticking Nov numbers to 2.1 so we could round it up to 2.1. https://www.webberweather.com/ensemble-oceanic-nino-index.html

Im not so sure that happens especially with the chance of this WWB being a bit weaker than the last and not until the 15th -20th when it starts to make some impact on temps. Again if we end December at 2.1 we could attain the 2 mark and then it would be a try again in January but fools gold to know what will happen in January at this point.

Oh boy a lot of big Denver snow forecasts. Would think this would be further south into NM region with the STJ increase.

21 minutes ago, so_whats_happening said:

Looks like we stepped into warm phases briefly in early January and mid to late March that year. Tried to set it up in about 20 day increments.

December as a whole seemed to feature a -WPO pattern which is usually pretty good for the eastern US with Greenland blocking. We swung low amplitude that December through 4-5-6.

http://www.bom.gov.au/climate/mjo/

9 minutes ago, George001 said:

I don’t understand how unfavorable MJO states are inherently a Nina pattern, and also why is a Nina pattern inherently bad? The MEI averaged -1.9 for Dec 2010-Jan 2011, and the trimonthly ONI for NDJ was -1.6. That was a well coupled strong La Niña, yet it was still a very cold and snowy winter in New England. Historically, Ninos (especially stronger ones and ones with significant nino 4 warming) are mild in December, and Ninas are colder and snowier. Ninos tend to be more backloaded. 

Looks like we stepped into warm phases briefly in early January and mid to late March that year. Tried to set it up in about 20 day increments.

Also here are years in reference around similar dates. I can only do monthly before 1989 as TAO does not support the timeframe before that.

Gonna throw some fuel on the fire lol

DCA _NYC _BOS __ ORD _ATL _IAH ____ DEN _PHX _SEA

+1.6      +1       +.3       +2.1     +1.4    +1.2         +2.2     +1.8    +.5

DCA _NYC _BOS __ ORD _DTW _BUF ____ DEN _ SEA _ BTV

18       26      41         28      35      84           36       7       87

Edit: Want to change Den --> 40" and Buf --> 78" Hope that is ok on 12/9 ~18z