Stormchaserchuck1

I posted this in the La Nina thread, but long range GFS ensembles are showing a very favorable pattern for westward moving tropical systems starting the last week of August. The N. American pattern evolution would favor more GOM or FL hurricane hits, as that central Canada ridge moves east with a -PNA. The central-N. Atlantic ridge of 594dm is strong on the mean. If we see African waves progress, they would likely move more westward under that ridge at this time.

That 60W/20N is a big climo spot. Storms that pass NE re-curve >90% of the time. CV Storms that pass SW of it re-curve vs hit land 60/40. Models do have a -EPO developing when the storm is getting close to the EC, and that favors more of a troughy pattern, so I would right now probably favor a turn out to sea, but if it tracks so far south as to the Caribbean first, it could stay clear of the EC trough, but I don't see the pattern as favorable for SE US or NE, US hits.

LR GEFS is flexing a ridge east of Japan again, near that warm pool region. The US pattern in evolution would favor more GOM or FL hurricane hits, as that central Canada ridge moves east with a -PNA. central-N. Atlantic ridge is strong on the mean. If we see African waves progress, they would likely move more westward at this time.

I actually thought that Winter 22-23 would be cooler than it was. It was one of those years where the subsurface wasn't accurate.. nothing is perfect, but over a larger amount of data, it does work better than the surface, and even the PDO.

We'll see.. if it's La Nina this year, that will make 4/5 years with La Nina (which is the most consecutive going back to 1948). 86-88 was at the peak of +PDO phase so I'll give you that We have also had 7 +NAO bouts so far this year, where for the last 4 years, it was 2-3. That could possibly signal a phase shift.. The NAO is looking not so positive for August and possibly September though.

It's been because of a +WPO/+EPO though, which isn't necessarily an El Nino indicator.. although maybe for east-based events.. 5 of the last 6 Winters have been +WPO. This is a cold weather anomaly over the Bering Strait region.

22-23 would probably be #2 on his list

In other news, the North Pacific High near the Aleutian islands looks to be strong for the next 15 days on models.. Will continue to strengthen the -PDO. Not coincidentally, this is occurring while the central-ENSO-subsurface is in "Moderate La Nina" range

The western subsurface is building warm anomalies, and the 90-day SOI is -9. I mean, it is possible, but the trends for the following year usually start to post clues around this time. That Nino 4 is still warm-Neutral kind of puts Winter potential Kelvin waves into play. Remember, most ENSO events peak only a few months from now, and El Nino to Neutral isn't usually followed up by a La Nina (it may still be Weak Nina, but the "swing" after a Strong El Nino usually sets the tone in the 1st year). Maybe I'm rushing the warming train (El Nino probabilities a few years from now)..

Yeah.. probably won't be a La Nina next year.

99-00 is probably your best match, but you aren't going to find anything that fits all of that. A lot of recent analogs are closer to your guidelines than older ones..

98-99 was also very warm across the CONUS Dec-July [97-98], which matches that this year is #1 in that regard..

October has a slight opposite correlation to the Winter's NAO (and it's the only month of the year where this is true), so it may be a backwards way of doing things, but if we are looking at a +NAO Winter, I'd watch for a -NAO October, or maybe before.. -NAO in October could connect up with a -PNA, or even if it's not a strong NAO signal, I think the -PNA would be amplified by the tendency.. These -wind bursts may strengthen the central-ENSO-subsurface which is already in Moderate La Nina range, just further amplifying the -PNA signal in the coming months..

I did it before and published my work on easternuswx, but I don't have those filed saved anymore. Here is what you are looking at though, if you want to do an analysis yourself (it would take a few hours). The +SSTA area I give 1.00 weight to, and the -SSTA area I give 0.65 weight to. It looks something like this: Because the northern area has more volatility. I made the total dataset, SSTs and NAO even, by multiplying the total historical absolute number of both, and dividing it by each other. Here is what 8-5-2024 looks like:

Latest daily AAO: -4.2561 -4.6111 -4.2231 -4.0094 -4.0707 It looks like it's suppose to stay <-3 until Aug 15th: Based around the Winter solstice (Dec 21), here is the Dec-Jan correlation to July-Aug AAO.. there is a signal there, not coincidentally at the North Pole Makes me like the +NAO vs -AO/-EPO Winter potential

Western ENSO subsurface around 120E is holding +2 to +3 anomalies.. 1 strong Kelvin wave could wipe out that central-ENSO-subsurface cold pool (which is -5c to -6 currently!) in the Fall. It will be interesting to see what happens.. Right now I am leaning toward a warm progression in ENSO after about November. This La Nina looks like it's likely peaking here as subsurface effects in the next few months. I could be wrong though, it's not always a linear movement.

It's going to be hard to sustain a La Nina next year if the SOI never goes strongly positive for this event.. From 2020-2023, we had 37 consecutive months of +SOI! Then the Strong El Nino hit last year, and it seems to have changed the SOI phase a bit.

PDO will continue to be <-2 likely through the Fall.. hard to get that wild card -EPO for the Winter that I've been talking about when PDO is so negative.. we would need to see a new N. Pacific pattern start in Sept-Oct imo to carry through that "less extreme version of 13-14" possibility for the Winter. But I think +NAO probabilities does heighten that chance a little (neutral or neg EPO/WPO for the Winter). I like the 21-22 analog as the mix between the two versions of forecast possibly.

Hey @40/70 Benchmark (Ray?), I just looked at this yesterday. The reading for May - Aug 5 right now (63% of the way through) is about +0.50, making it a 50% chance of having the DJFM NAO -0.04 to +1.04. Meaning, we have just as good of a chance of seeing a strong Winter NAO of +1 over 4-months, as Neutral. The August 5th reading is +1.00, so it's looking like the index will continue to increase at least through this month, and possibly going into the final month, September. I would guess right now it finishes May-Sept around +0.70, making it a 50% chance that the DJFM NAO is +0.16 to +1.24! (Since inception, that 0.54 SD, is 9 wins, 9 loses, right at the original assessment in 2005.) Also remember, that means there are equal chances of the NAO going >+1.24 as < +0.16.

Yeah, the American part of the measurements looks like +PNA. I think it's useful to give more weight to the Pacific though as the leading area, since you can have all kinds of patterns (AO, NAO) alter the N. American temps, or even local topographical effects. I find using the Pacific more useful when integrated with ENSO, PDO, etc.. but yeah the shortened wavelengths of July really shortened up and gave American a more +PNA look.

Looks like -PNA/+NAO Euro seasonal actually did very good about the hot Summer in the NE this year from this range. They were pretty far off about a cooler Winter last year in the east.. it has a heavy ENSO bias

Weird..

Wonder if you've seen the CPC's DJF forecast. Looks pretty good for you.

Yeah the July number.. I think that means it peaks at >+20 in the next few months. QBO phases aren't always as strong as that.. This makes the ENSO state more sensitive, as a Stronger La Nina will connect in the stratosphere with -10mb conditions in the cold season, likely leading to a +AO. Having a La Nina/+QBO or El Nino/-QBO is about 75% for 10mb anomaly Nov-Mar, which is a pretty high correlation. Having a stronger QBO tightens that up a bit. but a weak La Nina or the subsurface moderating could weaken the signal

My thing with a +NAO is, it has been connecting with a N. Pacific ridge in the northern latitudes, more since 2013 and even more since 2019. If that RNA ridge expands over Alaska, you can get some good precip combos in the interior NE as storms run inland (+nao) and hit some pretty strong temp gradients (-epo). 21-22 is one example of the N. Pacific ridge extending north.