raindancewx

I post Southwest stuff because your precipitation patterns are correlated to ours in El Ninos, especially for snowfall. Once we hit our averages last February I was pretty much certain you guys wouldn't get to yours. The AMO cooling was actually a reference to the NE anyway - you guys have been pretty dry. Fall doesn't really indicate temperature patterns too well in winter, but it's usually not terrible for precip patterns.

The negative PDO in winter correlates to a warm Southeast and a cold Northwest - with the NAO forcing a more winter styled pattern in October when it was negative, that was exactly what we saw in October with the PDO negative. Saying "the PDO has been positive since 2014" completely misses the point. The trend is down. Look at the transition by Nov-Apr: 2012-13: -0.40 2013-14: +0.38 2014-15: +2.07 2015-16: +1.70 2016-17: +1.07 2017-18: +0.30 2018-19: +0.51 2019-20: Since 1931, there are no Nov-Apr periods above +0.5 after the PDO is 0 to -1 in October. It will probably be right around 0 or somewhat negative. A cold Nino 1.2 in October also strongly favors that the PDO values in Fall will fall from winter/spring. So far, the cold in November is exactly where you'd expect it to be based on a strong negative SOI in September. Look at the green areas on the SOI map and the places in the US that are cold. I'd imagine once all the warm lows and moisture come out from our storms this week in the Southwest, quite a bit of the cold will burn off, but we'll see. I don't think the models have that built in yet. We're still not that different from last year this Fall - the PDO went negative for a brief moment last year too after all, although not to -0.45.

As long as the waters away from the coast are much warmer than next to the coast, it is just a warm version of the negative PDO. It's not like October was that different but it was -0.45 on the JISAO index. I'm not disputing that the waters along the West Canada coast are still somewhat warm, but relatively speaking, they're colder than the waters south of Alaska.

El Nino with a -PDO November. Indian Ocean is kind of nuts compared to last year too. In real +PDO years, you have the warm ring around the cold waters.

There is a tropical storm in the East Pacific moving North ahead of the system, so I think a pretty widespread precip event is likely. My analogs had several years with a big storm around 11/20 in the SW, so that looks right, at least for now. For NM & Southern Colorado it's probably a rain event initially, even 8,000-9,000 feet up initially, but it would go over to snow later, down to pretty low elevations by Friday. My analogs implied around 0.25"-0.50" for NM with the system - wouldn't be shocked if it came in higher given the dying tropical system plus the other sources for moisture.

This is why I went somewhat colder in the East than last year. Although I don't think this extent of the cold is quite right, I think it will be less cold and less warm on each end. All the modeling had the warm core of the El Nino around 120W last year, this year, it's shown around 180W. I think my idea from late Sept/early Oct is still about right in the tropics -

The new Jamstec is similarly cold for the US for winter as in the last run. It has really exaggerated the differences in the SSTs from the West Tropical Pacific and the East Tropical Pacific. I'd call it an El Nino. The West also trended much wetter. The temperature, sst and precip maps look a lot like my forecast now, although I don't expect the cold to penetrate as deep into the Southeast. The warm West/New England look strikes me as about right though.

From what I remember, if Boston had actually gotten 3-6" or whatever it was last November at the official site, instead of nearly nothing, I would have been within 2-4" of what I had forecast for Boston. If you think it's 40" instead of 27", I'm just low instead of high by a few inches last year, so it doesn't really matter to me. Looking at the forecasts of others, I do think it would be prudent to find predictive variables that are objectively known ahead of winter for precip/temps/snow, other than say, ENSO or the PDO or whatever. Something like a precip pattern in Summer. You guys really live or die with the teleconnection indexes - AO, NAO, PNA, EPO - etc. You can probably predict...most of them correctly in any winter, but all is a tall order. My stuff is designed to be something like 1/3 data mining, 1/3 statistics, 1/3 global patterns. I find that there are like a 100 ways to match on any blend of ocean/atmospheric/solar variables, but it's much harder to have those match and get your weather to match day and date for an extended period - so that's what I try to do. Matching the highs/precip patterns for a long-time with the oceans/solar stuff seems to be a way to lock onto the MJO signal for a few months if nothing else.

Right is for a -4 to -12 SOI Sept-Nov with a 0 to -1 Oct PDO. Left is El Nino winter + an Oct PDO of 0 to -1.

PDO in October 2019 went the most negative it has been in six years. https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO There are no cases of the PDO topping +0.5 from Nov-Apr after a reading of 0 to -1 in October for the 1931-2018 period. PDO was -0.45 in October 2019. El Nino October PDO Nov-Apr 1951 -0.32 -1.02 1963 -0.52 -0.88 1965 -0.36 -0.44 1968 -0.34 -0.81 1977 -0.61 0.50 2004 -0.11 0.47 2006 -0.05 -0.04 Similar SOI matches (-4 to -12 SOI in Sept-Nov) with a similar October PDO - Year Oct SOI SON 1932 -0.29 -5.7 1944 -0.40 -4.0 1946 -0.36 -9.0 1951 -0.32 -10.7 1963 -0.52 -9.9 1977 -0.61 -12.0 1990 -0.69 -4.5 2004 -0.11 -4.6 2006 -0.05 -7.2

Just for fun, since it is pretty rare - El Nino. PDO in October of 0.00 to -1.00 on the JISAO index (it was -0.45). https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO El Nino October Nov-Apr 1951 -0.32 -1.02 1963 -0.52 -0.88 1965 -0.36 -0.44 1968 -0.34 -0.81 1977 -0.61 0.50 2004 -0.11 0.47 2006 -0.05 -0.04 Some very cold winters in the Southwest in that mix. 1963-64 is the coldest winter in 120+ years in New Mexico. 1965 is right behind it. 2006 is very cold too. 2004 and 2006 are also extremely wet. If you look at all October PDO values, 1931-2018, that were 0 to -1, November to April PDO values finish between +0.5 and -1.78. There are no strongly positive PDO cases. The years right around -0.45 in October tend to see the PDO stay between -0.5 and 0.0 for Nov-Apr. Overall, 18/24 cases of the PDO between 0 and -1 in Oct saw the PDO stay below average from Nov-Apr after an October value of -1 to 0. The Neutral/Negative PDO + El Nino composite is a cold West composite - we'll have to see what happens.

I had the right idea here - the PDO came in at the most negative level observed in six years in October: -0.45 on the JISAO / Nate Mantua method. Some bounce back maybe in November, but I don't think it is too too dramatic. Much warmer anomalies away from the coast then on it - that's the signal if the waters east of Japan are warm too.

Nate Mantua sent out the PDO data for October 2019: https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO So...lowest PDO value since 2013 in any month. -PDO is strongly correlated to a cold NW/warm SE in winter if it continues. 2019-01-01T00:00:00Z 0.66 2019-02-01T00:00:00Z 0.46 2019-03-01T00:00:00Z 0.37 2019-04-01T00:00:00Z 1.07 2019-05-01T00:00:00Z 1.03 2019-06-01T00:00:00Z 1.09 2019-07-01T00:00:00Z 1.03 2019-08-01T00:00:00Z 0.38 2019-09-01T00:00:00Z 0.41 2019-10-01T00:00:00Z -0.45 2013** -0.13 -0.43 -0.63 -0.16 0.08 -0.78 -1.25 -1.04 -0.48 -0.87 -0.11 -0.41 2014** 0.30 0.38 0.97 1.13 1.80 0.82 0.70 0.67 1.08 1.49 1.72 2.51 2015** 2.45 2.30 2.00 1.44 1.20 1.54 1.84 1.56 1.94 1.47 0.86 1.01 2016** 1.53 1.75 2.40 2.62 2.35 2.03 1.25 0.52 0.45 0.56 1.88 1.17 2017** 0.77 0.70 0.74 1.12 0.88 0.79 0.10 0.09 0.32 0.05 0.15 0.50 2018** 0.70 0.37 -0.05 0.11 0.11 -0.04 0.11 0.18 0.09 0.26 -0.05 0.52

Your percentage listed for Boston is 80-27/80. Comparing the error to the theoretical total (80") doesn't make any sense. If I told you your kid was going to be 8 feet tall and the kid ended up 3 feet tall would you call that a 60% error? That's what you did. It's closer to a three fold error. I had 35" in my blend last year, and even that is a 30% error for Boston if you use real math. You picked average snow this year, so mathematically you don't have to worry anyway, it's more or less impossible to be as wrong as last year for Boston, so in that sense at least I'm sure you have a much better forecast. I don't really care what people forecast, but if you are going to grade yourself, you need to do (expected-actual)/(actual). You did (expected-actual)/(expected) which doesn't mean anything.

It's not perfect, especially in the middle period, but people not including 2018-19 as an analog to this winter are a bit nuts to me. Oct/Nov will probably be ~0.2C different in Nino 3.4? Close to a rounding error. I think the pretty similar to last year honestly, just shifted somewhat east - that's the certainly the impression from the Fall. Here is 2018 (10/01-10/15, 10/16-10/31, 11/01-11/11): Here is 2019 (10/01-10/15, 10/16-10/31, 11/01-11/11):

Take it or leave it but - 1) When you evaluate your forecasts, you should use (observed-forecast)/(observed) as your metric. You somehow have last year's call for 80"+ as only a 60-something percent error, when Boston only had 27". The math should be (80-27)/(27), i.e. your forecast was around +200% (triple) observed. Observed is the anchor, not the forecast. 2) I suspect December will be a lot warmer than you have in the North/East. Nino 4 is around 1.0C warmer than your composite. Even years with a lot of blocking aren't that cold in December when Nino 4 is that warm. My composite in my forecast had Nino 4 too cold too, so I mentioned I expected the East and North to be 2-3F warmer than depicted by the raw analogs. 3) It does amuse me that despite pretty different background states in some ways, you essentially forecast the same thing nationally two years in a row. Doesn't mean your wrong this time, just amuses me. 4) A lot of your very cold analogs for the East had much higher solar than this year: 1958, 1969, 1989, 2014. I think 1958 and 1989 are literally around 255 sunspots/month and 200 sunspots/month for July-June. This July-June is probably...3? Maybe 4? If you take out those four years, the cold signal is gone in December for the East.

My winter analogs included several years that featured snows in the Southwest around November 20th, way back when I did my winter forecast in early October. I weighted the years 1953 (x2), 1983 (x2), 1992, 1995, 2009 (x3), 2018. So assumed it was close to 50/50 we'd get snow here around 11/20. Looks promising so far on the models. https://www.scribd.com/document/429712619/Winter-2019-20-Outlook The Raw Snow Data: 2018 6 (Dec 2, Dec 26, Dec 27, Jan 1, Feb 19, Feb 22) 2009 11 (Oct 29, Dec 8, Dec 23, Jan 22, Jan 23, Feb 3, Feb 4, Feb 7, Mar 11, Mar 20, Mar 24) 1995 7 (Dec 17, Dec 18, Dec 31, Jan 1, Feb 1, Feb 2, Mar 6) 1992 13 (Nov 4, Nov 20, Nov 21, Dec 4, Dec 5, Dec 12, Dec 15, Dec 16, Dec 19, Jan 13, Feb 15, Feb 28, Mar 1) 1983 7 (Nov 19, Nov 26, Dec 25, Jan 14, Jan 16, Mar 18, Apr 26) 1953 9 (Nov 18, Nov 19, Nov 20, Nov 21, Dec 5, Dec 11, Jan 12, Jan 13, Jan 20) Snow Windows Albuquerque: Nov 18-21 Dec 2-5 Dec 15-19 Dec 25-Jan 1 Jan 12-16 Feb 1-4 Mar 18-20 The SOI support is there too. Over a 10 point drop from 11/8 to 11/10. Should put a big system in the SW US or Mexico around 11/20 12 Nov 2019 1011.94 1010.50 -9.17 -5.76 -8.39 11 Nov 2019 1011.42 1010.05 -9.61 -5.18 -8.48 10 Nov 2019 1011.08 1010.50 -14.64 -4.71 -8.51 9 Nov 2019 1011.85 1010.70 -11.01 -4.37 -8.38 8 Nov 2019 1013.13 1010.25 -0.00 -4.38 -8.23 7 Nov 2019 1013.77 1008.40 15.84 -4.69 -8.01

The AMO has cooled off a lot again from September to October. Back to the level of warmth seen entering last winter in the Atlantic. If the AMO is really going to be around 0.00 from Nov-Apr in a lot of winters now, that's definitely a good sign for the Southwest for precipitation. Nov-Apr values tend to lower toward 0 from October. My over/under for the true AMO flip is about 2024 - we'll see how that goes. It could be as early as now or as late as 2030 though. My analogs had Boston getting about half an inch of snow in November this year. The winter blend had a cold West October, warm West November, with the East relatively opposite. Looks promising so far. The cold in Albuquerque in November has been stronger than I expected so far. We've had 11 days with lows of 32F or less since 10/1 here - a top five frequency figure in the last 90 years or so.

With the temperature down to 34F at 6 pm and low dew points, Albuquerque should be up to 11 nights of 32F or less since October 1 on 11/11. Tied with 1991 for fourth most since 1931 (10/1-11/11 lows of 32F or less).

Any sense on temperature or precipitation anomalies by month? I.e. what you expect to be the most extreme periods? My stuff implied some pretty powerful cold for a while, but also some early/late winter warm ups.

Models had shown Nino 4 cooling. It has a bit. If that continues, a colder December is possible nationally. https://www.cpc.ncep.noaa.gov/data/indices/wksst8110.for Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 25SEP2019 20.0-0.5 24.8-0.1 27.2 0.5 29.7 1.1 02OCT2019 20.0-0.6 25.1 0.3 27.2 0.5 29.7 1.0 09OCT2019 19.7-1.0 24.8-0.1 27.1 0.4 29.5 0.9 16OCT2019 20.6-0.2 25.3 0.4 27.5 0.8 29.7 1.1 23OCT2019 19.7-1.3 25.0 0.1 27.3 0.6 29.7 1.0 30OCT2019 20.8-0.4 25.4 0.5 27.4 0.7 29.6 0.9 06NOV2019 20.7-0.6 25.2 0.3 27.2 0.5 29.3 0.7 26SEP2018 20.2-0.3 25.5 0.6 27.3 0.6 29.3 0.6 03OCT2018 21.3 0.7 25.6 0.7 27.4 0.7 29.5 0.8 10OCT2018 21.1 0.4 25.6 0.7 27.3 0.6 29.5 0.9 17OCT2018 21.1 0.3 25.9 1.0 27.6 0.9 29.6 0.9 24OCT2018 21.3 0.3 25.9 1.0 27.7 1.1 29.8 1.1 31OCT2018 21.4 0.2 25.9 0.9 27.8 1.2 29.8 1.1 07NOV2018 22.1 0.8 25.8 0.9 27.4 0.8 29.5 0.9

This is going to verify...in Mexico, and no it isn't relatively common because of the elevation.

In Albuquerque, Nino 3.4 temps / solar conditions / Nino 3.4 temps in the prior winter are pretty predictive for highs in Oct-May. Once October is in you, you can anchor the data to what was observed then too. Last year it was a strong match in all non-March months. This year, I have a decent match for the sun, and ONI (ONI will probably be around 27.1C) and a good match for October. But I don't have a good way of getting ONIp and the sun to work together. But so far, the blend is holding in November. Will be curious to see how it goes.

Good luck. My map wasn't that different from yours - although I never include March. I just think the cold is shifted counterclockwise a bit from what you have, out of the South and a little deeper into the West with the PDO near Neutral. The PDO tends to not go positive Nov-Apr if Nino 1.2 is near 20.0C in October, or colder. Also went somewhat warmer in the Lakes because they were warmed up a lot in July-Sept - you can kind of see in November that the cold has had some trouble crossing west-east across the Lakes in full force as a result. My sense for this winter is that for various reasons, even though a lot of cold air is around, it will have trouble locking into a set of locations for any extended period. So the waves of severe cold in the West (Oct), and now East (Nov) are both part of the pattern, as are the corresponding warm responses (Denver had record cold at times in October...and then it was near 80F there yesterday, the South had incredible heat in early October and incredible cold now, etc). The coldest spot will be in between the movement of the cold waves I think. If you were to go by Oct/Nov, I'd say Missouri and Kansas is that spot, edge of the cold West in October, well into the cold in November so far. I think the mechanism for the cold moving around is probably some combination of the PDO fluctuating a lot or the blocking/tropical forcing changing a lot throughout the winter. Nino 4 is still very warm which favors a warm North in December, but it is forecast to cool off as the heat drains/expands East toward Peru later in the winter. December 2013 but 2F warmer in most spots (to account for Nino 4) seems about right for the East to me.

Latest European run has Nino 4 cooling, Nino 3.4 and 3 warming through November, then cooling, and then Nino 1.2 warming into January before cooling after. It's kind of a "warmth drains East" look. The dashed line tends to verify at the extreme end of the sea surface temperature plume in most months, so I think it's fairly safe that November and December at least see Nino 3.4 above El Nino thresholds. There isn't much warmth below the surface after that though, so some cooling is likely. This event probably won't count as an El Nino by CPC, but it probably is going to count by the Jamstec definition (165E-140W) definition. By my older thresholds (1951-2010), it will probably count, since 26.5C is the average for me I use for Oct-Feb anomalies, while CPC is higher in Fall. The SOI response, right around -8 for the past 90-days, is also consistent with a weak El Nino Modoki setup.