Stormchaserchuck1

The N. Pacific pattern will continue to correlate with the -200m subsurface. That will be the case until/unless the subsurface max moderates to ~-2c.

The pattern from the last few days of July, through the 1st week of August is one where temps bust warmer than forecasted. 18z GEFS has a very strong +EPO during this time, it may even snow in northern Alaska. That is hot, hot down here. I know I'm sort of saying the same thing in the last few posts, but the +epo may last through Aug 10th, which is very atypical..

There was a Southern Hemisphere Stratosphere warming over the last few weeks.. It usually lags with -AAO conditions, that could cause the mid-latitudes to cool. Kind of an A+B+C formula there, and over the tropics it's a little more inversely correlated, but that's what I could come up with..

Even in the 91-20 base period, we had more La Nina's than El Nino's.. I don't know why the difference

Maybe it's the 91-20 base period? They used to use 1950-1995 or 1950-2010 averages.

592-593dm ridge July 28-29, could make a run at 100.

ENSO subsurface is a very good tool. We have technologies that measure the ocean thermocline, and that increases the likelihood of given patterns. CPC has been doing extremely well on their monthly and seasonal forecasts over the past 1-2 years. But yeah, the neutralization of the climate is making consistency a top forecasting method these days. It's my opinion that classic methods are already taken into account, and factored into Oil prices, etc..

I'm not sure. This is what 1995's PDO looked like right now

Well this is what it looks like right now Nino 4 minus Nino 3 is a pretty high reading. That warmth near the Philippines will likely not cool in time for the Winter.. Since year 2000, Nino 4 (warm) minus Nino 1.2 (cool) has been in a league of its own.

I wouldn't be surprised if it was a near average to above snowfall season in the interior Northeast and Great Lakes.. +NAO actually has a higher +precip correlation than temps north of 40N. Especially if we are drier through the Fall.. since 2003, these dry periods have gone really wet after we started to approach drought conditions. It's happened about 20/20 times. I was saying this could also make the SE, US more prone to a Hurricane hit this year vs previous years. Coming up in late July will be our 6th moderate to strong +NAO period this year.. and I think we had like 2-3 in all of the past 4 years combined. I say that's important because it's changing the N. Atlantic SSTs to +nao roll-forwards. +NAO's favor storm tracks that go up through the Appalachians or Ohio Valley in the wintertime, Add a -PNA to that, and we could actually get some big storms riding up through the Midwest. The key I think will be if we tend toward +EPO or -EPO. +EPO is a big rainstorm pattern. -EPO will give some of you guys snow. Both are possible in La Nina, but there is a pretty strong correlation with -pdo and +epo.

If the ENSO subsurface weakens to Neutral in the Fall, it's not far off, although we have a -PDO and so far, +NAO N. Atlantic SST predictor index for the Winter, so I wouldn't use it..

Sometimes you have to be aware of a small sample size. I remember in the early 2000s, everyone would get excited about a Weak La Nina, because the historical map was cold. The meteorology is, X event correlates to Y. The stronger X is, the stronger Y, and the weaker X is, the weaker Y. But in the early 2000s, a small sample size showed we have a high likelihood of -NAO and I think some +PNA with Weak-Nina's, based on like 10 examples. (for map below "Weak Nina" is -0.5 to -1.0 DJF ONI). Then roll forward to the 2000s, and with more data added, the -PNA skew of the map evens out.. this is why I say beware of analogs behind sun phases, because a small sample, when there are so many things happening, could give a false result. It's more important to know the mechanism behind what it is. 2005+ Weak La Nina's (DJF ONI -0.5 to -1.0): Combined the two maps now looks like a La Nina, but it didn't in the early 2000s, leading to a lot of excitement over Weak La Nina's back then. I think I posted something earlier in this thread, where 13 Moderate/Strong ENSO events had a combined +100dm PNA/yr, and 8 Weak ENSO events had a combined +50dm PNA/yr. That's right where it should be, Now (but not 20 years ago).

Hot pattern returns last few days of July and into the 1st week of August, per 00z GFS ensembles.. +EPO/+NAO building after about July 27.. could get really hot.

CPC has been way more aggressive on La Nina call, and they are doing really good right now with monthly and seasonal forecasts, but Gawx is right, the surface is not really cooling and the SOI is deeply negative. https://www.longpaddock.qld.gov.au/soi/

There is a reason we only averaged 9 NS/yr in the Atlantic for the longest time. Add to it the fact that Africa has been super hot: And we don't have a lot of tropical convection right now. Some have suggested that the MJO becomes favorable in a few weeks, but there is a little bit of a model split. Atlantic SSTs and ENSO certainly still support a way above average season.

I'm starting to think the event may play out as more of an east-based event unless the Hadley Cells over the PDO region stretch it west. Last years El Nino started east-based then moved into record Nino 4 SSTs by the Fall, but the total event acted very east-based through the Winter. There may be a lag in effect lately. Some of those brutal warm Winters like 98-99 and 99-00 started west-based, vs progressing that way. I'd have to do the research to see if there is something to that..

69F here, it's actually a bit cool outside. Strong +EPO patterns often flip after a 7-12 day phase, this is what's happened the last few days.

Jan-March 2014 is another example of the ENSO subsurface dictating the pattern. We had a Kelvin wave, or "Weak El Nino" in the subsurface, while the surface was Neutral, to neg Neutral. Gave us that +PNA/-EPO And the net effect of an El-Nino subsurface, or strong Kelvin wave is cold anomalies across the eastern 2/3 of CONUS. (it actually seems to be a stronger indicator when you do relative value of subsurface minus surface) On easternuswx, I made an index about this, going back to 1979, and found it correlated up to +40% vs Nino 3.4. Now it's harder to make custom timeseries, there are error messages on the CDC site (problems with ftp). If someone knows how to do it, let me know, and if I have time, I'll run a subsurface total dataset again going back to 1979.

Greenland has seen the strongest negative H5 anomaly in the N. Hemisphere in about 3-4 years, this Summer. Some people and climate models might latch onto that and say, there is a chance. The thing is though, there is a strong correlation to Summer SSTs in the N. Atlantic with the following Winter's NAO, and that deep trough had made the predictive area move into a SST range that has a +NAO likelihood for the Winter. I have tested that NAO formula out real time since 2005, and it's 9-9, within the standard deviation of 0.54. Right now the NAO-predictor index is running about +0.35, making the 50% odds that the NAO runs -0.19 to +0.89 for DJFM. But the index runs out to September, and what we have seen lately is warming, so it may finish >+0.50 for the year, giving us like a 75% chance that it will be a +NAO Winter.

I think that what we are seeing is a "global stabilization", and the data for Nino 4 shows a gradual, linear increase year-to-year. This makes things like the RONI have more weight, because it is considering the relative-index correlation to ENSO. No negative anomalies here north of 50S since 2015: Ultimately, the continued warm conditions on the surface are probably making it likely that Nino 4 doesn't see a dip into La Nina range this year. The "shut down" of global extremes has made the Tropical Pacific, closer to the America's, hold all the weight, on the opposite side of Pacific Ocean High pressure systems. This has made Nino 3 have more variance than Nino 4, since about year 2000. Since the surface is holding warm waters, partially associated with a neutral SOI, it's hard to imagine the La Nina does eventually make it far west. Climate models were showing a west-based Nina this past Winter, but Nino 3 seems to be the core area now. This is another reason I like to use the subsurface. We have seen this central-subsurface region organized since mid-February this year. And, ta-da, the N. Pacific pattern has been this strongly correlated to the central-ENSO subsurface: With it being a hot Summer this year and likely a Weak La Nina ONI peak, I can see 1995 being an analog for some. The thing to note is, the subsurface in 1995 was deeply negative during the Summer, and moderated to Neutral for the Winter: This led to a hot Summer (like this year), and an active Hurricane season. But there are actually warm anomalies in the subsurface that following Winter. There is no automatic that the subsurface won't moderate in the Fall like it did in 1995, but unless it does, 95-96 is not a good analog in my opinion.

The +EPO has been especially strong in this Dec-July period. A lot of time though, the EPO "evens out" in the time after a strong phase, so there is some hope I think for -EPO periods this Winter, or maybe beyond. -PDO usually continues +epo though, at least through the Fall..

The top 30 analogs to US-based warmth that we have seen Dec-July (which I think this year is #1 all time), are very warm into the following March. December is the one month that is near average in that roll-forward, but every other month goes like +2 to +5.

Actually, we had -PNA conditions during last years El Nino, so I could argue that it's been La Nina conditions for 8 years in a row.. although the STJ was strong last year, and global precipitable water spiked. This is just an amazing map, because it features 14 months, over a 7-year-consecutive period. Going back to 1948, we've never seen an anomaly greater.. #2 was +95dm over the -NAO region 1964-1969, and I think that was just for a 1-month period. The pattern starts right after the N. Hemisphere's coldest day of the year (Jan 27th), which I don't think is a coincidence. It's my personal opinion that the wave hit in 2013. I was personally observing the sun shining brighter and hotter way before the 2015+ period even came to be. So again, this is just personal conjecture but I think the 14-16 +PDO and El Nino was an opposite wave to what was happening. I would say sun spikes if I didn't know better, but we have definitely seen something a major change/pattern take place, after 2013 (you say Dec 2015.) It's especially seen in the Pacific. I think a secondary wave came in 2018-2019, and since then the -NAO has been correlation with -PNA and +EPO, and +PNA/+NAO and -EPO. It will be interesting to see if that eases up or changes in the next few years.. ENSO climatology/roll forward says we have a good shot at +PNA 2026-2028.

Looks like they are holding onto a +EPO again. To clarify, +EPO pattern (cold anomaly over Alaska) is different from the global warming trend. It's the top index-pattern for warmth across the US. The +EPO correlation to -PDO has been strong over the last few years. The -PDO has its highest correlation in the Fall, so if this forecast hold, we can very well expect a warmer to much warmer than average Sept-Nov.

The Winter following a Super El Nino (peak ONI 2.0 or greater): Actually makes some sense, because El Nino's are associated with global warming, that takes some time to offset, although that is a -PNA map so again, the reversal post-ENSO is a pretty strong signal.