raindancewx

We're heading into a pretty severe heat wave locally for late August. I've never really found much predictive in local June data for the upcoming winter. Wet Junes can be active in Oct/Nov, which ties in well with my idea for the cold season. But June doesn't matter for Dec-Feb. July was a bit warm but fairly average for temps/precip. August has the least temperature variation in absolute terms over the past 100 years. So when it is unusually hot or cold for the month I pay attention. Hottest La Nina Augusts (Mean High): 1938, 1973, 1983, 1995, 2011, 2020 Hottest Augusts, with similar July 2024 (93.5F): 1973, 1983, 1995, 2011, 2020 Hottest Augusts, with similar June 2024 (92.5F): 2011, 2020 Need to see how August/September plays out locally. But I suspect this will go down as both a pretty hot Summer locally, and a pretty wet Summer. Unusual to get both in one year. 2010 had a completely different distribution of heat, but it was wet/hot. 2011 and 2020 both had major cold shots in September. September 2020 was a major preview of the late winter cold shot that destroyed Texas. My highs/lows for Sept 2020 - average high for Sept 9 is 84 or so. 2020-09-07 96 66 81.0 7.8 0 16 0.00 0.0 0 2020-09-08 80 42 61.0 -11.9 4 0 0.19 0.0 0 2020-09-09 47 40 43.5 -29.1 21 0 0.37 0.0 0 2020-09-10 55 42 48.5 -23.8 16 0 T 0.0 0 The first repeat showed up again October 2020 with the MJO cycle repeating. The airport had 4.4" of snow, although most of the city away from the airport had 5-10". All fell during a period when average highs are ~65F, and following multiple days in the 70s/80s. 2020-10-22 80 47 63.5 7.6 1 0 0.00 0.0 0 2020-10-23 73 46 59.5 4.1 5 0 0.00 0.0 0 2020-10-24 77 40 58.5 3.5 6 0 0.00 0.0 0 2020-10-25 73 38 55.5 0.9 9 0 0.00 0.0 0 2020-10-26 39 19 29.0 -25.2 36 0 0.16 2.9 0 2020-10-27 34 19 26.5 -27.3 38 0 0.06 1.3 4 2020-10-28 46 27 36.5 -16.9 28 0 0.02 0.2 1 December 2011 was also extremely cold locally. 2011-12-06 30 9 19.5 -18.8 45 0 T T 0 2011-12-05 27 14 20.5 -18.1 44 0 0.02 1.0 1 2011-12-07 38 17 27.5 -10.6 37 0 0.00 0.0 0 2011-12-25 36 17 26.5 -9.3 38 0 0.00 0.0 0 2011-12-24 38 18 28.0 -7.9 37 0 0.00 0.0 0 2011-12-04 37 26 31.5 -7.4 33 0 T 0.2 T 2011-12-03 39 26 32.5 -6.7 32 0 0.10 0.7 1 2011-12-23 36 23 29.5 -6.4 35 0 T 0.1 1 2011-12-26 43 16 29.5 -6.3 35 0 0.00 0.0 0 2011-12-11 42 20 31.0 -6.2 34 0 0.00 0.0 0 2011-12-08 45 19 32.0 -5.9 33 0 0.00 0.0 0 2011-12-10 42 22 32.0 -5.4 33 0 0.00 0.0 0 2011-12-12 36 28 32.0 -5.0 33 0 0.24 T 0 2011-12-02 40 30 35.0 -4.5 30 0 0.03 0.2 0 2011-12-20 38 26 32.0 -4.0 33 0 0.00 0.0 1 2011-12-21 41 23 32.0 -4.0 33 0 0.00 0.0 0 2011-12-22 41 24 32.5 -3.4 32 0 0.01 0.7 0 2011-12-09 45 24 34.5 -3.1 30 0 0.00 0.0 0

The tropical Atlantic isn't really that warm right now, and seems to be cooling relative to averages. Waters by Indonesia aren't super warm either. Tropical Indian Ocean / Nino 4 are pretty warm - but I can't imagine the RONI thing will be of any use if the non-Nino global tropical oceans are moving toward neutral. Warmest oceans v. average temps right now are far North Atlantic, Med, and then by Japan. Beaches off NC are warmer than anywhere off West Africa by SSTs. All the bullshit about this being some kind of incredible hot Summer for the entire country has magically vanished in recent days and weeks. I wonder why. Actually been pretty cool for a while in the middle third of the US. My guess is we're already seeing the dominant and recessive patterns for the winter. Pattern one is dominant heat West/East thirds of the continental US with cold waves of varying severity and duration in the middle third of the US. We've seen this in July/Aug at times. Pattern two is weaker cold in the Northern Plains and Northwest, with the rest of the US warm (see May/June). If September reverts to one of those two patterns, I think it's likely we continue to see those two patterns dominant in the cold season. CFS currently has average temps, perhaps implying weak cold, in the Northern Plains for September. A blend of the two gives a pretty conventional La Nina look, but the magic is figuring out if the cold in the Central US or the Northern Plains / NW is dominant. Actually think there is a decent case for highs off the NW / NE coasts to be stronger than normal, which would flood the Central US with frequent cold snaps in between warm rebounds, while the rest of the US is mostly warm all winter.

Anti-1976 looks OK for August at this point.

I suspect the extreme rain event for the East, in this time frame (August) is a useful signal for the winter. But I haven't looked at it yet.

May-July looks a bit like a blend of 1999, 2020, 2022 globally at 500 mb.

Canadian has a lot of the US by the Mississippi river cold for the next three months. Nice end to the Summer for a lot of that part of the country. Canada is shown pretty cold for the winter too. La Nina depicted much weaker than before. Just about dead in February, which is how 2016-17 went. WPO looks fairly negative at times which would prevent Central/Western Canada from getting flooded with 50 degree Pacific air in the winter.

I have a fairly coherent analog group that's been working pretty well. Anyone else?

I'm hoping one of these years ends up like 2013-14. Traditional Nino 3.4 measures get to 26.2C / -0.3C or whatever. But RONI is much lower, but it ends up acting like a Neutral even though the relative basis implies it's a Nina. If you all got 2-3x snow out of that kind of outcome I think everyone on here would permanently lose interest in the relative measures.

Anti 1976-77 and 1986-87 (flip of a -QBO, Weak/Mod El Nino, with low solar, +PDO, -AMO conditions)

This is probably a good winter for flipping conditions from anti-logs. Just flip a weak El Nino, with a -QBO, low-solar, and very +PDO, -AMO conditions. 1976: Weak El Nino, -QBO, Solar Min, PDO+ (+1.5), -AMO 1986: Weak El Nino, -QBO, Solar Min, PDO+ (+1.8), -AMO Anti 1976, 1986 blend (-7 to +7 scale) As a sanity check, you can see it is already working to some extent. June had the non-flipped 1976 and 1986 work as a better match, which makes sense to me as the QBO / ENSO state just flipped in July really. Anti 1976-77 and 1986-87 isn't a very cold winter, but it's probably one of the coldest Feb-Apr periods on record for the US.

I'd like to see you change the color scheme by the North Pole. I doubt it is all below average? Otherwise this is a very useful product if you can update it easily. There are a lot of datasets for doing SST maps like this one. I would also add the baseline used. It looks like 1991-2020 to me but I can't prove it. I would also add in the total (spatially weighted) SST warmth v. the baseline period as an index. Maybe the tropical warmth (23N-23S) too v. a baseline. I like the rectangular maps and automatically de-weight the lower/higher latitudes because the Earth is spherical. But a spherical representation would probably also do well.

CPC has the US pretty cold in the 6-10 and 8-14 period. It's already been pretty cold in the interior of the continent. We're close to trending behind the very late La Nina development of 2017-18 at this point. My guess is we'll eventually see SSTs at the surface drop off like a rock for a brief period, and then a flat lining and reversal will start shortly thereafter. We'll hit the La Nina SST thresholds for several months, but not the duration for an official La Nina - that's my guess. All the bitching I see in the news lately has been about how hot it has been. But it really seems like a strange month to complain about it in the US. At best parts of the US will be very warm and parts will be very cold. La Nina typically coincides with the Atlantic acting like it is an El Nino (a big warm stripe by the equator). We have a big cold stripe in the Atlantic at the equator. So I'm still fairly skeptical of a huge season. A relatively low number of storms that are very powerful, and a normal number of weak short-lived storms is at least as likely as a hyperactive season (that would see many powerful and weak storms).

Dead on match for the high ACE years so far in June (not). I'm sure the season will have active periods but I'm still pretty skeptical of 200+ ACE.

The composite above for the ACE seasons is completely wrong. Some of the ESRL sites have winters tied to the final year of the monthly period, others have the winter tied to the start. This is the actual composite of the recent highest ACE years. The idea is much higher than normal pressure over the SW and West. Cold drains into the East.

Here is a look at the Summer MJO composites for precipitation v. observations globally in June. The map is closest to the MJO 5-6 composite. MJO 4 is generally pretty active in the Atlantic but the huge dry spot in the Indian Ocean is very much anti-MJO 4.

Atlantic ACE got to about 36 with Beryl. Nothing on the horizon for a little while. SE ridge?

The warm tongue east of Japan has actually weakened a lot over the past week or so. At the surface the eastern part of the La Nina has weakened too. July has actually started very cold for a lot of the US. Not really surprising, a big portion of Western Canada was pretty cold in June. I basically agree with what the Canadian showed for Aug-Oct - a lot of powerful cold shots should come in for the next few months, for how early it is. Also, the warmest area of the global oceans now is well north of the Equator. It's by the Philippines-SE China, rather than by Indonesia. I doubt we'll see the pronounced response to phases 4-5-6 if that area of the ocean remains so much warmer than the spots by the equator. You have areas of 30-32C SST warmth as far as like 30N in the Pacific, none of the waters by the equator are that warm by Indonesia.

Several of those winters were pretty warm in Minneapolis. Couple cold ones, but that five year period is held up by two or three cold winters of the five.

Warmest Minneapolis winters since 1870, following winter in () 1 2023-2024 29.9 0 2 1877-1878 29.0 0 (16) 3 1930-1931 26.9 0 (22.5) 4 2001-2002 26.8 0 (13.1) 5 2011-2012 26.3 0 (19.8) 6 1881-1882 26.1 0 (9.3) 7 1997-1998 25.9 0 (21.6) 8 1986-1987 25.8 0 (16.4) 9 2016-2017 24.3 0 (17.1) 10 2015-2016 24.2 0 (24.3) 11 1982-1983 24.0 0 (14.3) 5 warm / 5 cold against 1870-2023 median (16F) for DJF. 6/10 cold against 1991-2020 median (~19F) Non-El Nino winters since 1980 following near-record Plains winter heat - fairly standard La Nina.

In terms of actual SSTs for Nino 3.4, these are the years within 0.20C (+/-) the 27.89C observed in June 2024. 27.69-28.09 1951, 1958, 1965, 1968, 1969, 1977, 1980, 1993, 1994, 2004, 2005, 2006, 2009, 2012, 2014, 2016, 2017, 2018. Some of the late forming La Ninas like 2005 and 2017 get pretty cold in Nino 3.4 for where they are in June. But you can see most of the years (12 of 18) go to El Nino from similar SSTs. 1980 (27.94C), 1993 (28.08C), 2005 (27.77C), 2012 (27.75C), 2016 (27.69C), 2017 (28.06C) are the non-El Nino winters of the bunch. June 2013 actually looks a lot like SSTs if you just eyeball It. Of course it's a non-La Nina. Just a cold Neutral. I'm assuming the RONI crowd doesn't consider it a La Nina because it's kind of a good winter for the East. The Indian Ocean is warmer and the Atlantic is warmer. But the Atlantic has the right shape with cold SSTs by Africa/NW Europe. Tropical Tidbits has 2007 & 2013 as top SST matches globally since 2000. I think if you warmed up oceans by 0.1C globally that's probably about the right idea. Thee seasonal models seem to be trying to go to something like this for the winter now. This makes sense to me intuitively, the Plains likely won't see record warmth two years in a row. At some point I'll run the winters after the hottest winters in Minneapolis out of curiosity.

I mentioned a while ago that the upper level high over Mexico had to move or get destroyed as a condition of the hurricane season ramping up. Check out May v. June 2024.

CPC still has ONI / RONI in non-La Nina status for Apr-June by the way. Not sure even on the RONI scale we'll be there in May-July. For June CPC still has +0.16C for Nino 3.4 on the ONI basis. One thing I dislike about RONI is if we have a particularly active hurricane season, the tropical oceans would likely cool right? That would screw up the sliding scale nature of the baseline, which makes it unreliable. Beryl is forecast to be around in some capacity through Sunday. Every day with at least 100 kt sustained winds adds at least 4 ACE. We have a shot at nearing 40 ACE by Monday morning in the Atlantic - definitely a bit nuts.

You were never going to have a big Aleutian low last year with the PDO near -3 to -1 the whole time. The north pacific stuff is tied much more to the PDO than ENSO. The ENSO stuff has direct control over the subtropical jet which was very strong last year.

Presumably the entire plume will shift warmer with the Euro miss for June. Subsurface heat content also weakened a lot (i.e. it warmed) in June from 100-180W. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt 1999 and 2007 seem to have had similar June thinning of the subsurface. 1999 by itself is a good match - that's a fairly cold / wet Summer here, which is kind of the right feel for how things are trending with a late start to the heat and a lot of rain. Lot of Caribbean hurricanes in those years. Apr May June 1999 -0.91, -0.81, -0.52 (x3) 2007 -0.59, -0.58, -0.18 (x1) -------------------------------- Blend -0.83, -0.75, -0.44 2024 -0.81, -0.80, -0.46

La Ninas / El Nino function as an evaporation v. precipitation constant locally. We seem well on our way to an exceptionally wet Summer that is only somewhat warm (+1 or +2). When we get 'too much rain' in the Summer in La Nina, a very dry winter almost always follows. Given the hurricane season, the trend toward an east-based La Nina instead of a Modoki, the -PDO, and the potential for the -WPO to flip, I'm actually getting a lot more bullish on winter for the East. If we finish with a wet Summer and an active hurricane season, I'd bet at least on an exceptionally dry winter here, even if it isn't blazing hot. At 180+ ACE or more I'd be pretty tempted to put a +7F over the entire western half of North America with cold draining into the East. At 120-180 ACE it's more of a tough call. Beryl alone could jack up ACE to 30-40 before it dissipates, 1/4-1/3 of a normal season, and it is only July. But we could also do the 2007 thing where we have two huge systems, and a bunch of weak ones that hit Central America. Too early to know.