raindancewx

Just for kicks:

+WPO La Nina: 1988-89, 1998-99, 2000-01, 2005-06, 2007-08, 2008-09, 2016-17, 2017-18, 2020-21, 2022-23

-WPO La Nina:  1950-51, 1954-55, 1955-56, 1956-57, 1964-65, 1970-71, 1971-72, 1973-74, 1974-75, 1975-76, 1983-84, 1984-85, 1995-96, 1999-00, 2010-11, 2011-12, 2021-22.

-WPO & La Nina, recent progression

+WPO, La Nina, recent progression

January-February tends to be much hotter with the +WPO look in the East. Western typical La Nina cold is stronger with the WPO (+WPO is a strong Western cold signal for Feb-Apr centered on NV).

Old Mexico has been seeing a severe heat wave this month in the central/southern part of the country. Similar timing and magnitude May 1998. Part of why I've been saying that is a good match to global weather. A lot of the highland climates that have monthly highs peak out around ~80F over a 30 year period have had daily highs in the upper 80s and low 90s. This is directly tied to the absence of the monsoon that normally develops in April-May.

I look at Pachuca as it is higher up than Mexico City. May is normally 78 / 52 (ish) for the high and low. This month has been 88 / 58 so far (+8). Still pretty tolerable for a place that is at 20N, but it is crazy warm for 8,000 feet above sea level. Temperatures on 90%-95% of days are between 30 and 90 in the highlands, so hitting 91 or 92 in Pachuca counts as a pretty major heat wave when it happens multiple times in a week or month. May to date looks like it is +7F or hotter for about the SE 1/3 of MX month to date.

The monsoon seems to begin when high elevation sites in the SW US see higher daily/monthly temps than the high elevation sites of Central/Northern MX. Right now, we're still running about 10F colder than the highlands of Central MX - which is unusual and not a good sign for the monsoon. Normally, ABQ would be 80/50 in May with Pachuca 78/52 and the monsoon rapidly creeping north late month.

We should hit 90F here in a few days. That's a bit early, but close to the long-term average. Not really a cold/warm signal like in some of the recent La Nina emerging years, when Albuquerque hit 90F around May 5 or as late as June 5.

I use solar activity the way I include all variables. I match on 7-10 factors that have occurred in the past that have predictive power in winter. I try to get the blend to match within 5% of what is supposed to happen. Not the individual years necessarily.

One thing I've been testing recently is if there are any timing tendencies from solar conditions. It does seem like there is some tendency for which part of the country has front loaded or back loaded winters by solar trajectory (rising / waning sunspots). 

I do think we're likely to see the WPO go negative for at least some portion of the cold season this year, which would allow for at least some major cold shots in the East with any kind of meaningful NAO block. -WPO is actually a really strong cold signal for the US in the Plains in the Fall. Might be necessary just to knock that part of the US back into annual variation norms given how warm the past winter was.

This is the closest I've come so far to re-creating what the Canadian has for the winter. It's too cold in the Atlantic, but I'd give it a B+/A- as a match globally. It's not a particularly interesting winter, but it does seem to have some resemblance to how the Spring has gone. The La Nina will be coldest to the east though Sept/Oct before rapidly moving West if this is the right idea.

The past winter had a) El Nino conditions b) Russia seeing colder than usual conditions c) extreme warmth over Canada. If you look for a similar trifecta and roll it forward, the matches are pretty interesting,

The only similar El Nino to La Nina transition with the same global pattern in winter is 1997-98. You can make a weak case for 2009-10 but the warmth/cold are in the wrong spots. 1986-87, 2002-03 are kind of similar but avoid going to a La Nina and 1952-53, 1979-80 (if you count them as El Ninos are OK matches too if you warm them up a degree or two globally.

Here is 1997-98 (x4), with 2009-10, warmed up one degree (F). You can see the warmth shows up at about the same magnitude in a lot of the right places, since it never left Russia (southeastern Europe, west Africa, eastern Canada etc - all similar warmth to 2023-24.

We'll see how it goes, but a strong subtropical high in southern Asia with a strong jet running West to East, with any cold diffusing into Northern Europe seems to be the look.

Probably a fairly cold winter for the Northwest US / Northwest Canada, which we already seem to be seeing anyway. As the El Nino fades away the cold that has been getting trapped in the Great Basin will shift to the Northwest more consistently, and the pattern for May will become the occasional dump of Arctic air into the West.

All that being said, if the Atlantic gets hyperactive, I would expect all of the major features shown above by North America to be displaced  by 2-4 'hours' clockwise, that seems to be the main effect of the hyperactivity. If the purple blob is at 1 o-clock and not 11, then presumably the heights end up over TX and the SW, not the NE.

As much as I enjoy seeing the Northern Lights in the deserts, it's not a great omen for global electronic and communication infrastructure.

We're currently in a period of very high solar activity, with Uncle Sam issuing a warning for a level four solar storm impacting the Earth. I'm expecting to see the Northern Lights again locally when skies clear over the next few nights.

1998/1999/2000 all had pretty high solar activity, with 1998 following a big El Nino. I don't really like any of the more recent La Ninas except for maybe 2011 or 2022 as similar to this event. 1988 also had subsurface La Nina conditions when the surface showed El Nino in Spring, with high solar, like this year. Not really a fan of any of the other La Ninas from 1960 to 1990, although something like 1970 or 1971 may not be terrible.

Early arriving 90F temps locally in a developing La Nina tends to signal a cooler winter in the Southwest. Usually due to one or two severe cold snaps. Currently no support for hitting 90F anytime soon. Year to date, we've yet to hit 85F even actually. I generally look for pre-May 10 as very early - as the average first 90F high here is May 25.

The 100-180W subsurface for Feb/Mar/Apr came in at -0.16/-0.54/-0.80. Subsurface El Nino conditions were last March (remember the blizzard warnings in San Diego county?) through January 2024.

Here is a similar blend - it's actually a decent match to the May 1 Canadian for DJF 2024-25 SSTs.

It's a decent-ish match to what the Canadian shows for US temps in May too. ACE would be around 140 - that's about the lowest realistic number I could see for the Atlantic. I've been expecting 175-225. No method to that. Just my gut. Low ACE La Nina years are also correlated to colder La Ninas in the Southwest with brief periods of severe cold.

----------------------------

1998: -0.38 / -0.61 / -1.06

2022:  0.12 / -0.47 / -0.34

-----------------------------

Blend: -0.13 / -0.54 /  0.70

2024: -0.16 / -0.54 / -0.80

More bullshit Spring weather today. Mid-40s for highs, low elevation rain, graupel, thunder, no snow in town. Even at 5,600 feet I saw some accumulating snow today just outside town. Mountains look amazing with the strength of the April sun, rainbows, and then a fresh coat of heavy snow.

Canadian has a fall peak for a pretty healthy La Nina. It weakens the event east-west, which means a pretty active March is already likely next year. 

Snowfall distribution has been fairly interesting so far for the cold season. The fluky snow in the South looks like it will hold. Have to see if the late season Nor'easter verifies. Couple more big storms for the West too through 4/15 before I can really analyze if the snow outlook was good.

March has eaten away at some of the snowfall deficits nationally. It's been a very snowy month for most of the West, although shifted somewhat north of March 1973 unfortunately. Late March 1973 had the big snows by WI as well if I remember right. Taos Powderhorn (11,000 feet up) locally went from ~40" at the start of March, which is pretty low, to 74" the other day for snow pack. So it's been a good month for the West. That site tends to peak around 60 inches in March.

We're nearing the end of that fabulous period in the Rockies I call "bullshit Spring". It runs from 2/15-4/15. High elevation zones often get smoked with heavy snow, high wind and frequent rapid temperature changes.

Once 'bullshit Spring' ends the next item to look for is when heat arrives in the Southwest. La Ninas that see early heat in Albuquerque (90F by 5/10 or so) tend to be relatively cold winters in the Southwest with more frequent cold waves. Given the harmonic tendencies of recent months, I actually think May could be fairly cold here. We've actually not hit 70F yet here, even though late March average highs are about 65F. 

I was checking some observations in the highlands of Mexico the other day. Nino 1.2 has flipped negative v. averages. Typically the vacating of excess heat in that zone accompanies unusually dry air getting fairly close to the equator. I saw some dew points as far South as 15-20N in the teens (F) in recent days. Normal dew points are ~40(F) ish in that area of the world in March. 

The PDO continues to reverse from pretty negative despite the El Nino falling apart. That's worth watching. The +PDO La Ninas are an interesting bunch. 

+PDO tends to be cold East, La Nina tends to be cold North. It's the opposite of last winter where -PDO tends to be cold West, and El Nino tends to be cold South. Years like 1995-96 and 2017-18 are +PDO La Ninas. 

I see some indications that the WPO may flip pretty negative in the Fall. That's often accompanied by early Fall snows nationally, but we'll see how that goes.

The El Nino finished at ~28.4C in Nino 3.4 for Dec-Feb. The years most similar to that were 1957-58, 1972-73, 1982-83, 1991-92, 1997-98, 2009-10. The roll forward is very much a Modoki La Nina look if you throw out 1958 and 1992 which are not La Ninas. 

1973-74, 1983-84, and 2010-11 are actually pretty interesting winters with pretty severe cold shots at times in places you wouldn't expect given the overall patterns. I believe 1983-84 and 2010-11 had TX power grid destroying cold shots / Blue Northers.

We seem to be entering the March 1973 part of the pattern now. After 10 feet of snow in California's high terrain in two days earlier this month, I suspect our mountains will get 1-3 feet in 1-2 days with this storm. I don't think it's the last one either. I would prefer to have a stout cold high in Wyoming trapping a flow of moisture from Puerto Penasco, but trapping a strong storm with a lot of moisture and some cold for a long duration under a high isn't half bad. If any of you still need your snow fix, our mountains will get pasted with this setup even though it's not as good as the Casper v. Penasco setup. I'm a little surprised this didn't happen in December or January, but these types of regimes tend to accompany the transition from East based to Modoki setups. If you look, the thunderstorm activity has kind of died in the East Pacific in recent days / weeks.

It makes sense that it looks fairly cold in the East now. I would bite on this being a Modoki El Nino from now until it completely collapses into an East based La Nina in six weeks. 

It looks like I had the right general idea for temperature and precipitation profiles seasonally, but not monthly. Warmth was more impressive than I expected too. But I had the warmest part of the US as MO to MN and east, and that verified. No one was expected to be cold overall, which verified, but coolest spots South and West. Dry spots in an ocean of above average moisture were generally placed correctly too. I'll do a more in-depth update on snow once the March snows settle down late March into April.

I've always found it a bit silly to look for a 500 mb profile in ENSO that is typical, and to complain that anything that doesn't match that profile is atypical. It's much more common for ENSO events to go to a temperature profile that matches the typical / atypical idea in comparison to the 500 mb profile.

You essentially had the normal warm North / cool South look from this El Nino, regardless of how you got to it, plus maybe a bit more coolness for the Northwest with the -PDO. 

I'd be more willing to agree with your assessment if the subtropical jet had failed to be strong. But that actually is a direct physical response to ENSO, and it was there. The mid-lattitude stuff that people look for is essentially over fitting trend lines and history in a lot of ways.

Remember how I said there would be an incredibly powerful storm around March 1? Check out the blizzard over California the past two days. Welcome to March.

I doubt the models really have the orientation of SSTs right for next winter. It could definitely be very warm out here for 2024-25. But truth be told, a lot of the Modoki La Ninas are pretty good for snow out here. The Modoki El Ninos and Modoki La Nina both tend to see one of the dominant ENSO signs fail more often than the east-based events. The El Nino signs here are ~70% cold / ~70% wet, and the La Nina signs here are ~70% warm / ~70% wet.

In Modoki El Ninos a lot of times the wet signal fails in winter (see: 1957-58, 2009-10, etc), and in Modoki La Ninas a lot times the warm signal fails (1974-75, 1984-85, 2000-01, 2020-21, 2022-23).

One other thing that's lost is that La Nina tends to amplify the temperature differentials in the mid-latitudes by enhancing dry air. So here in the desert, with drier air and more sunshine, we tend to have very cold nights in a lot of -PDO/La Nina setups. In El Nino, moist air is abundant and the mid-latitudes have lower temperature differential v. the tropics, so we tend to have a lot of warm nights and cold highs. The caveat to that is that enhanced snow and snow cover duration offsets the warm nights. The 2022-23 La Nina had something like 112 nights with lows that were freezing or colder from Oct-May. That's a pretty severe winter by lows for us - even though the highs were not cold.

Whether any of you believe me or not, there is a real tendency for the West to face incredible periods of severe cold in La Nina following years of low hurricane activity in the Atlantic. All of our record cold events, even in the Southwest are in La Nina. Look at February 2011, November 2000, January 1971, etc. La Nina climatology for the Southwest is persistent warmth, like 70 of 90 days that are +3 or more, with 20 or so days that are -5. The "harsh" La Ninas just have the 20, or 30 cold days at -10 or -20 v. means instead of -5. So you're really just trying to predict the harshness and duration of the brief cold periods.

Google is your friend.

https://tropical.atmos.colostate.edu/Realtime/index.php?arch&loc=northatlantic

Canadian is a bit different from the CFS. The absence of heights by Japan is a major change from the winter and should come with some colder systems and/or late Nor'easters for the East Coast.

Google is your friend.

https://psl.noaa.gov/data/correlation/wp.data

I'm not crazy for thinking the CFS has March 1973 right? I mean...that's an insane month for the West if it even comes to verifying. Top five for snow in the past 100 years I'd guess regionally. It does look like the North Pacific high pressure feature is off in terms of placement east/west, and maybe a touch north of 1973. But it really does look close to March 1973 to me. At this range, the CFS actually has skill for the next month too. It's done pretty well this winter actually.

Just for future reference - the area of the world that was coldest (v. local means) this winter was NE Russia. Looks very much like the WPO drove the winter pattern in Asia and North America as much as anything.

We're really starting to see the handiwork of the Super +WPO again.

I've been telling people for six months here, the closer we get to March, the crazier the weather gets. You can see we're almost there. Plenty of heat in TX. https://twitter.com/MattHinesTX/status/1762276038665457919/photo/1

3-9 feet of snow for California in two days, starting Thursday.

I've actually found a lot more predictive 'events' with La Nina than El Nino over the years.

A few examples:

Early heat waves in the West (ABQ first 90F high, where 1 is May 1, 31 is May 31, etc) in La Nina are highly correlated to cold winters in the Rockies/West for La Nina. This is from my outlook for 2022-23. I've always assumed this worked because it meant a coherent MJO wave in phase 4-5-6-7 was showing up around 5/1. At a standard 45 day MJO lag (more dark arts, i.e. counting), that turns to 6/15, 7/30, 9/15, 10/30, 12/15, 1/30, 3/15 which indicates that 4-5-6-7 will show up several times in winter, when it is a cold signal here. MJO 5 is generally cold here early on (Nov-Jan).

La Nina cold snaps in the West are also highly tied to ACE in the Atlantic -

In the absence of cold snaps in the West, the cold either isn't anywhere in America, or it is going to the East. But really for the East, the high ACE thing is more of a good snow year indicator than a cold indicator.