raindancewx

This winter should feature some good snow storms pretty far south. I think there are three mechanisms for that given what we've seen to date: 1) Exceptional dry air briefly overtakes an area, leading to very cold mornings...and then very wet subtropical/tropical air ends up on top of it. That 22F / -10 dew point air we had on Halloween Morning is probably going to combine with the subtropical jet at some point. We sort of had a version of it already here in late November, with the 20F / 12F dew-point morning turning into a 30F / 25F snow storm. 2) The Blue Norther of mid-November 2019 broke a lot of records from the legendary Blue Norther of 1911. I think its possible that setup returns one more time, but encounters more moisture from the subtropical jet. 3) We've had extended cloudy periods already in the SW this cold-season. If that continues in Dec/Jan, it will be eventually become very cold here, and that really puts the kibosh on any warm ups spreading to the east/north out of the Southwest. The cloudy periods are actually not great for valleys, we stay above freezing without the radiational cooling, but the mountains are only above freezing during the peak of the afternoon sun, so the cloudiness preserves the snow and cold higher up, which probably helps storms stay dynamic/cold as they pass through the Southwest.

I haven't really looked, but it seems like the PDO is a stronger correlation for the EPO than ENSO itself, even though the PDO is tied to ENSO. I think of the PDO/North Pacific as a dog on a leash, with ENSO as the master. At any given moment the dog may be ahead, behind, left or right of the ENSO signal, but never too far away from it, in terms of time. It's early days yet, but the warm Nino 4 = warm US December signal is holding up so far. There are signs the middle of the US will turn colder, but I'm fairly happy with my idea to warm up he green area on the correlation map from my raw winter forecast blend by 2F in light of Nino 4 coming in around 29.3C or so in December, not 28.6C as my analogs had. Somewhat different so far from last year. Composite on the left is the 12 warmest Nino 4 years since 1950.

So far, the December SOI has been slightly positive, but it's not at the level of last year yet. 2019 335 1012.31 1007.80 4.10 2019 336 1012.38 1007.35 6.80 2019 337 1012.67 1007.20 9.08 2019 338 1012.06 1009.10 -3.95 2019 339 1012.70 1010.55 -8.15 2019 340 1014.24 1009.75 4.00 +1.98 Dec 1-6 2019 2018 335 1014.01 1009.05 6.43 2018 336 1014.79 1008.40 13.86 2018 337 1014.10 1008.80 8.20 2018 338 1013.56 1009.35 2.54 2018 339 1012.80 1007.45 8.46 2018 340 1011.07 1006.20 5.97 +7.57 Dec 1-6 2018

I've been playing around with predictive variables for El Nino winter precipitation for Albuquerque. I've settled on a good blend. The average error in the hind-cast for precipitation is only 0.34 inches, with 93% of years within 0.80 inches (+/-). Forecast blend is for 2.10" in Albuquerque for Dec 2019-Feb 2020, give or take 0.8". That kind of makes sense in the wake of six days in November with over 0.10" precipitation. Five of those were over 0.20". Long-term average for precipitation in winter is about 1.30", so the confidence is pretty high that the city will be at least somewhat above average, without hitting record precipitation (3.46") in winter either.

SOI has dropped some again after starting off pretty positive in December. Should be a big storm around 12/14 or 12/15 over the SW. New European ENSO plume from 12/1 should also be available publicly soon. I remain convinced that the +9 SOI last December is responsible for the warm-east/cold-west February look in 2019. If the SOI doesn't pop, a more canonical El Nino February is likely. 17 out of 18 years with an SOI over 8 in December see a warm February in at least parts of the South, all the way back to 1931. 5 Dec 2019 1012.70 1010.55 -8.15 -6.53 -8.09 4 Dec 2019 1012.06 1009.10 -3.95 -7.41 -8.12 3 Dec 2019 1012.67 1007.20 9.08 -8.42 -8.21 2 Dec 2019 1012.38 1007.35 6.80 -9.07 -8.48 1 Dec 2019 1012.31 1007.80 4.10 -9.40 -8.74

Here is monthly SST anomalies in Nino 3.4, through November 2019, using the stable 1951-2010 base I prefer. If you notice, the US roasted in Aug-Sept when El Nino conditions broke by this standard. Once they returned in October, ferocious cold returned to the pattern immediately - it's part of why I tend to look at 27.0C in the Oct-Feb as the 'on' switch for tropical forcing from Nino 3.4

If you weight the four Nino zones equally, Sept-Nov, these are the top matches. It's probably not the right approach since Nino 4 and Nino 3 make up Nino 3.4, and all the other zones are much bigger than Nino 1.2 Year Sept Oct Nov Sept Oct Nov Sept Oct Nov Sept Oct Nov Blend 2019 29.34 29.52 29.46 26.76 27.22 27.23 24.64 25.14 25.42 20.03 20.27 21.43 0.00 1977 28.95 29.04 29.02 27.12 27.35 27.19 24.87 25.25 25.30 19.61 20.54 21.19 3.23 1990 28.98 29.15 29.20 26.94 26.93 26.81 25.02 24.84 24.90 20.24 20.31 21.00 3.76 2003 28.94 29.12 29.07 26.99 27.14 27.04 25.05 25.38 25.75 20.28 21.25 21.94 4.41 2012 28.97 29.07 29.00 27.10 26.98 26.86 25.24 25.00 25.08 20.79 20.65 21.24 4.64 1968 28.57 28.69 29.10 26.72 26.75 27.20 24.82 24.96 25.15 21.05 20.87 21.56 4.88 2004 29.45 29.46 29.45 27.53 27.44 27.36 25.35 25.52 25.73 20.46 21.16 22.37 4.96 Left to right, the data is Nino 4, then 3.4, then 3, then 1.2. The blend of the years above is a warm East cold NW look for December, which I don't really buy. Here are the top Nino 4 matches - blended this is essentially what the CFS/Canadian had for December 2019 1994 2004 2002 2006 1987 2018 Here are the top Nino 3.4 matches - its literally the exact opposite look of the CFS/Canadian, as well as last year. 2019 2003 1951 1977 2014 1968 1969 My winter forecast had a cold middle of the US in December, with the coasts warm, and the '0' line around the mountains - Appalachians and Rockies. We'll see.

I saw. My analog blend of 1953-54 (x2), 1983-84 (x2), 1992-93, 1995-96, 2009-10 (x3), 2018-19 had Boston at 8.5 inches in December, and about 40 in total. So I don't see any big issues for what I had yet. CPC has ONI at +0.3C now for SON. They raised October as I expected, from this - 2019 8 26.91 26.91 0.00 2019 9 26.77 26.80 -0.03 2019 10 27.19 26.75 0.44 To this - 2019 8 26.91 26.91 0.00 2019 9 26.77 26.80 -0.03 2019 10 27.22 26.75 0.46 2019 11 27.23 26.75 0.48 Not much. Keep in mind, long-term averages for Oct-Feb in Nino 3.4 temps are 26.5C - so this borderline event in ONI sense is warmer than several events considered El Ninos historically. 1977 9 27.11 26.51 0.60 1977 10 27.34 26.48 0.86 1977 11 27.18 26.46 0.72 1969 9 27.15 26.34 0.81 1969 10 27.34 26.33 1.01 1969 11 27.11 26.35 0.76 1968 9 26.72 26.34 0.38 1968 10 26.75 26.33 0.42 1968 11 27.20 26.35 0.85 1958 9 26.40 26.15 0.25 1958 10 26.45 26.03 0.41 1958 11 26.75 26.10 0.65 1953 9 27.00 26.14 0.85 1953 10 26.87 26.01 0.86 1953 11 26.88 26.06 0.82 1951 9 27.22 26.14 1.08 1951 10 27.20 26.01 1.19 1951 11 27.25 26.06 1.19 In more recent times, we're pretty close to 2004, 2006, 2014. 2014 9 27.01 26.80 0.21 2014 10 27.16 26.75 0.40 2014 11 27.46 26.75 0.71 2006 9 27.32 26.80 0.52 2006 10 27.42 26.75 0.66 2006 11 27.70 26.75 0.95 2004 9 27.52 26.80 0.72 2004 10 27.44 26.75 0.68 2004 11 27.36 26.75 0.61

Official measurement for Boston is 2.3" through 12/2.

I should say, I don't actually expect the tropical forcing map I posted to verify for December - it's just what you get from blending the years that match. I think my blend of 1953 (x2), 1983 (x2), 1992, 1995, 2009 (x3), 2018 should hold fairly well. November behaved, with the warm West look, and a colder East. I did warm up the raw blend 2F because my blend is too cold in Nino 4 - around 28.6C and it's close to a degree above that. Anyway, snow pack is good here too: PDO still looks somewhat negative to me with the warmth east of Japan and NOT by Alaska & Canada on the immediate coast. SOI has been going positive past couple days - have to watch that. First time we've had two positive days above +4 in six weeks I think.

SOI has popped positive... Date Tahiti (hPa) Darwin (hPa) Daily Contribution 30 day Av. SOI 90 day Av. SOI 2 Dec 2019 1012.38 1007.35 6.80 -9.07 -8.48 1 Dec 2019 1012.31 1007.80 4.10 -9.40 -8.74 QBO is still positive. Looks like 2002 more than 1995 now. 1995 8.38 8.01 8.79 11.79 14.92 15.62 11.74 9.53 6.98 3.43 -0.77 -4.57 2002 4.64 8.00 9.32 14.03 14.16 13.26 10.05 10.60 8.90 7.66 4.46 -0.50 2019 9.02 9.25 11.82 13.36 14.59 14.36 10.96 9.97 8.25 7.27 5.07 -999.00 Solar activity for the six months to Nov 2019, was the lowest six month average (0.8/month) in any six-month period since Jun-Nov 1823 according to the SILSO data. The 12-month average to November 2019 was down to 3.8, lower than the 5.5 in the period ending November 2008. PDO still looks slightly negative in November. Warmth east of Japan shouldn't be there in a warm PDO, and the ring of warmth right along the Western North American coast isn't there, the warmth is in the 'east of Japan' area and it fades toward Alaska & Canada. Compared to last November, I'd say the PDO is more negative this year, and it was -0.05 in Nov 2018. Nino 1.2 has popped positive, right in time for Christmas, as our Peruvian friends have been observing for hundreds of years. The reading for Nino 3.4 is probably going to be about 27.25C on the monthly data, which I would consider an El Nino reading, given the 1951-2010 November average SST in Nino 3.4 is 26.5C. CPC uses 26.75C as their baseline (it is the 1986-2015 average) in November. So it's real close either way. The little cold pocket of water that has been showing up below Nino 3.4 does seem to be surfacing as the warmth to the east surfaces, so this is becoming less of a Modoki El Nino by the day at this point for now. 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 13NOV2019 20.9-0.6 25.6 0.6 27.4 0.8 29.6 0.9 20NOV2019 21.7-0.1 25.6 0.6 27.4 0.7 29.5 1.0 27NOV2019 22.5 0.4 25.4 0.4 27.0 0.4 29.3 0.8

Nov 1991: 1.93" precip in Albuquerque. Nov 2019: 1.99" precip in Albuquerque. (1991 was the record for Nov here for the past 100 years). I think because the IOD is enhancing the response you'd get from the subtropical jet-stream for an El Nino this weak, 1991 is probably a good precipitation analog nationally. Not really convinced for temperatures. The models depicting a positive SOI for December may not be too wrong - it looks neutral to positive for most of the next ten days on the European, although their might be one big drop in a a couple days which would support a big storm in the SW mid-month, and then maybe a pattern change nationally. The Canadian may actually be trying to do 1965, 2018 for its forecasts because of the SOI pattern. SOI Sept Oct Nov 1965 -13.5 -11.0 -16.7 2018 -8.5 +2.6 +0.6 Blend -11.0 -4.2 -8.1 2019 -12.7 -5.2 -9.5

My basic idea for December for New Mexico & Colorado & West Texas is that the storminess of November dies off somewhat, but we still finish wetter than average, with temperatures probably not that far from average either way, despite impressive cold at times later in the month. In recent El Ninos, the US temperature pattern for Oct 16-Oct 31 has tended to become the December temperature pattern nationally, but shifted somewhat East. We had near to record cold in that period this year. My objective high temperature & precipitation matches for the July-November period include six very cold Decembers locally, including the record and near record cold of 1943, 1952, 1953, 1992. Only 1939 was warmer than normal, and that was the weakest of the ten objective matches. Objective matches for the subsurface in the Tropical Pacific, years with a big warm up Sept to Oct, and then a cool off in Oct to Nov also support somewhat cold temps in the SW. Additionally, if you blend all years when Nino 4 is above 29.3C (there aren't too many of them) in Fall/Dec, the composite looks a lot like the map below. The top SOI matches for Sept-Nov also look like the map below. Years with positive NAO readings in December. I do expect the pattern in early November to repeat at some point later in the winter - probably January, but its worth remembering most of the severe cold was destroyed pretty quickly. It's obviously amplified, but the very warm coast/colder middle thing repeated last Nov 1-15 in January. It's just it came in much more severely, even though it was similar spatially.

The 10/31 forecast from the Canadian for November, as well as the 11/30 forecast for December both look like a blend of 1965 & 2018 on that model. The Canadian forecast from 11.30.18 for December 2018 was actually pretty bad, unlike the winter forecast. The subsurface data for November came in for 100-180W, top 300m. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt Best blend I could find was this - 100-180W Sept Oct Nov 1986 0.65 0.95 0.52 1986 0.65 0.95 0.52 1991 0.60 1.41 1.22 1991 0.60 1.41 1.22 1991 0.60 1.41 1.22 1991 0.60 1.41 1.22 1998 -2.15 -2.35 -2.33 2005 -0.33 -0.14 -0.57 2005 -0.33 -0.14 -0.57 Blend 0.10 0.55 0.27 2019 0.00 0.70 0.26 Crazily enough...it looks identical to last year? So I am skeptical. I tried to respect the subsurface features though - big warm up in October and then the big cool down in November.

The Canadian Model has the El Nino for winter now. I don't think this is right, but it has the "Nino 4 warm" pattern, with the US roasting in December, except the SW. Interestingly, it has the NE somewhat cooler. I think there will be more cold in the middle of the US than shown, a lot of snow pack is coming to the middle of the US and western Canada from what I can see. 11.30 run for Dec 10.31 run for Dec The winter look is a drier 2004. Last year, the November idea for Dec-Feb wasn't completely wrong, for what its worth.

For the 2010s (2010-11 to 2019-20), snow frequency has really improved quite a bit over the 2000s decade. We're pretty likely to get several more snowy months by May so this graphic will have to updated when the eight month cold season is over, instead of just 1/4 over. If we finish the season above 13.5" snow - a coin-flip at this point - that 6.9" for the decade would match or exceed the 7.34" for the 2000s but without the heavy concentration of snow this decade in December 2006. We're already at four Oct-May periods with over 7 inches of snow in the 2010s (2011-12, 2014-15, 2015-16 2018-19), the 2000s had two (2000-01, 2006-07). We'll likely have a fifth in 2019-20 too. Statistically, the seasons with at least two inches of snow in Albuquerque are far more likely to be snowy or even very snowy. None of the years with over two inches of snow in November have had under 5.5" for Oct-May. Years with at least two inches of snow in Albuquerque average 10.6 days with accumulating snow - all others are only 8.1. So we likely still have around 8-9 snowy days left here. We're about due for a season in the high-teens for snow here and it's ~4x more likely than usual now, although still less likely to happen than to happen.

We're at 3.9" officially in Albuquerque for November 2019, and a lot of the front range cities are well above average too. In years with at least two inches of November snow in Albuquerque, we average another 10 inches of snow from Dec-May. Historically 3:1 to see above average snow here after at least two inches in November. It's a pretty reliable indicator statistically. If we get to 13 inches or more, that's typically bad for the NE in El Ninos. Nino 3.4 has been over 27.0C since late Sept, with the subsurface warm and the SOI negative. So I consider this an El Nino.

If you use absolute value to score past 100 years for how they match to the observed highs from July-Nov in Albuquerque, you get this as your expected blend for December, ranked by how good the match is: 1960 1943 2011 1982 2018 1953 1983 1997 1948 1959 Believe it or not, that blend actually has the core of cold in November by the Mississippi river, like this November. 1943, the second strongest objective match in 100 years, is actually the coldest December in the last 100 years for a lot of the Southwest. None of those Decembers are warm in the Southwest, but most are very cold (1943, 1953, 1960, 1982, 1997, 2011). If soil moisture means anything, the record moisture in November in Arizona and New Mexico should prevent significant heating for a while. (This map doesn't even include today - I'm running over 4x average precip in Nov now, literally 1.99" v. an average of 0.46"). Big wildcard is if the SOI really does go positive in December like the CFS has been showing for a week. The dry central/eastern US did warm up a lot in the last week.

The CFS is still showing a +SOI look for December. Part of me thinks some kind of reigning in of the subtropical jet stream is due. November 2019 has just topped 1991 to become the wettest November in over 100 years in Albuquerque - and it happened in essentially two weeks.

I had 7.5 inches of snow in my backyard with the Nov 27-28 storm. The airport had 3.9". The general totals city wide seem to have been 4-8 inches. Mountain snow pack is in excellent shape as of this morning.

You guys make assumptions all the time about the NAO, PNA, EPO, WPO, etc being in the correct phase when only 30 years in a given phase exist. Bit inconsistent there?

SOI is -9.8 for the past 30-days, -9.3 for the past 90 days, and -10 for November to date. I've got 7.5 inches of snow in my backyard, with near record precipitation for November (1.65") through 11 am 11/28. A lot of that near record precipitation is snow...which is certainly more of an El Nino thing than a Neutral thing here - PDO still looks somewhat negative to me for November - you can have warm waters on the NW North America coast if they are relatively cold compared to waters off to their West and have a -PDO month. It's a relational calculation, not absolute like ENSO, where warm is El Nino, cold is La Nina. Subsurface still looks warm to me. The little cold pocket is going to get its ass kicked in the coming weeks. The warm waters continue to surface by Peru as we transition out of the Modoki El Nino to a basin wide event.

I use all the El Ninos since 1930 - close to 30 now. It's not that small. The weeklies have been over +0.5C for two months now, each week. The government declaring an El Nino is always a lagging indicator. The Jamstec news blurb has been calling this an El Nino Modoki for months, if you really want some kind of official statement, as if it matters. The SOI is going to be around -9 for the past 90 days too, which basically doesn't happen in non-El Ninos. http://www.jamstec.go.jp/aplinfo/sintexf/e/seasonal/outlook.html These are your drivers - ENSO forecast: As predicted earlier, the El Niño Modoki-like state is observed now. The SINTEX-F predicts the El Niño Modoki-like state will persist at least until early winter. We need to be careful of its impact, as it may be different from that of the canonical El Niño. Then, the model predicts that the tropical Pacific will return to a neutral-state from late winter through year 2020. Indian Ocean forecast: The positive Indian Ocean Dipole is now fully established reaching a level similar to that of the extremely strong events of 1994 and 1997. The model predicts that the positive Indian Ocean Dipole will persist in late autumn, and then decay in winter. We may observe co-occurrence of a positive Indian Ocean Dipole and an El Niño Modoki-like state in autumn and winter; this is as we observed in 1994 and 2018.

Yes. I keep saying it, in El Ninos, we're strongly negatively correlated. If I get to my seasonal total in an El Nino, it's very rare for the Boston to DC corridor to all hit theirs.

I'm up to eight inches now. Airport is about 0.40" that fell as snow, likely well over four inches now, maybe five or more already. Oct-May average is 9.6". Would be very hard to not have a snowier than average total in Albuquerque. This isn't really early for snow here, it's about an average date for first snow, just a lot.