• Member Statistics

    16,122
    Total Members
    7,904
    Most Online
    Weatherlvr
    Newest Member
    Weatherlvr
    Joined

Recommended Posts

Looks like three days of pretty -SOI readings are likely 10/26 to 10/28. This is the middle of the period - some pretty high pressure by Darwin and pretty low pressure by Tahiti.

Image

 

Share this post


Link to post
Share on other sites

The October SOI reading in 2007 was about +6. I think we'll be in that area by the end of the month given where are now and how the SOI looks the rest of the month. Nothing like the +20 in October 2010 though. That said, 2007 got a lot more 'connected' after October between the SOI and the SST readings.

Date Tahiti (hPa) Darwin (hPa) Daily Contribution 30 day Av. SOI 90 day Av. SOI
25 Oct 2020 1011.65 1009.80 -6.71 6.96 7.51
24 Oct 2020 1012.72 1009.65 1.16 7.74 7.60
23 Oct 2020 1013.92 1009.60 9.22 8.18 7.65

The forecast of a +NAO in at least early November, as well as the recent SOI crash favors at least some storms in New Mexico, unlike the mid-Sept to late-Oct period that went precipitation free. The map favors dryness on the West Coast, and only NM is heavily favored to be wet, so I have to assume cut off lows or the subtropical jet stream are in play here?

Image

Share this post


Link to post
Share on other sites

Nice and snowy today in the Southwest! Check out Red River, the same spot that beat their 1906-2014 record for earliest snow on record in early September (July-June basis).

Image

For those who saw my winter forecast from October 10th on the prior page, I had the dry spell that started 9/10 ending around 10/24 in Albuquerque based on the dry spells at the same time in the analog package. Not bad.

               Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA
 30SEP2020     20.1-0.5     23.8-1.1     25.6-1.1     27.9-0.7
 07OCT2020     19.5-1.2     23.4-1.5     25.5-1.2     27.8-0.8
 14OCT2020     19.6-1.2     23.6-1.3     25.3-1.4     27.8-0.9
 21OCT2020     19.9-1.1     23.8-1.2     25.3-1.4     27.8-0.8
 03OCT2007     18.3-2.3     23.2-1.7     25.4-1.3     27.9-0.7
 10OCT2007     18.8-1.9     23.3-1.6     24.9-1.8     27.7-1.0
 17OCT2007     18.6-2.2     23.5-1.4     25.3-1.4     27.9-0.7
 24OCT2007     19.2-1.8     23.5-1.4     25.3-1.4     27.8-0.8

Still looks like 2007 to me. Around two weeks behind though.

2007-v-2020-Subsurface-10-26-2020

  • Like 1

Share this post


Link to post
Share on other sites

image.thumb.png.a574cbc4d230965e4011189f93a1ce78.png

Noticeable deepening the cold pool has taken place over the course of past couple of months thanks to the Nina standing wave. Looks to be some weakening over the next week or so in the standing wave, but the trade surge currently east of the dateline and propagating westward should help in cooling Nino 4 a bit more.

wkxzteq_anm.gif

Share this post


Link to post
Share on other sites
33 minutes ago, andyhb said:

image.thumb.png.a574cbc4d230965e4011189f93a1ce78.png

Noticeable deepening the cold pool has taken place over the course of past couple of months thanks to the Nina standing wave. Looks to be some weakening over the next week or so in the standing wave, but the trade surge currently east of the dateline and propagating westward should help in cooling Nino 4 a bit more.

wkxzteq_anm.gif

I don't think region 4 is going to cool much more.

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, 40/70 Benchmark said:

I don't think region 4 is going to cool much more.

Based on? The -1˚C contour there is clearly spreading west with time. A progression similar to 2007-08 would follow that kind of idea.

Share this post


Link to post
Share on other sites

Nino 4 should get pretty cold. I don't think it will be as cold as 2010 or even 2007, my issue has always been it would take a while. It's definitely cooling slower than 2010 or most strong La Ninas. The CFS depiction for November is almost dead on to November 1954, which turned into a cold West winter after an extended very hot Summer and Fall, kind of like 2007. I'd imagine for that era it also had very low sea ice. The late hurricane activity of 2020 is also similar to 1954.

I know I've said for years now that Nino 4 is directly correlated to eastern warmth/coolness in December, but if we believe the CFS for November, other factors are over-riding that correlation. A cooler Nino 4 should lead to a colder Northern Plains. The CFS says very hot there. 2007 was a year that ignored the cold East via cold Nino 4 correlation - so if  we're going to ignore the Nino 4 in November, the pattern will likely ignore it in December too. The CFS also had Montana very hot in October, which is a horrible bust, but that doesn't mean it will be wrong in November.

Nino-4-November1934-1954-2005-2008-2016-as-Nov-2020

My winter analogs had a hot West / cold East look for November, but the cold and heat would be pushed West of where they are shown on the CFS currently. The CFS will likely change some, but probably not dramatically by 10/31.

Share this post


Link to post
Share on other sites

Another one for me.

Date Tahiti (hPa) Darwin (hPa) Daily Contribution 30 day Av. SOI 90 day Av. SOI
28 Oct 2020 1012.31 1011.65 -14.38 5.06 7.45
27 Oct 2020 1011.80 1009.45 -3.48 5.83 7.41
26 Oct 2020 1011.35 1008.90 -2.84 6.33 7.44
25 Oct 2020 1011.65 1009.80 -6.71 6.96 7.51
24 Oct 2020 1012.72 1009.65 1.16 7.74 7.60
23 Oct 2020 1013.92 1009.60 9.22 8.18 7.65

Share this post


Link to post
Share on other sites
19 hours ago, 40/70 Benchmark said:

The mean of the ECMWF Nino 4 ENSO plume is about -1.3.. I don't see it getting lower than that.

Is this an indication for a east based La Nina?

Share this post


Link to post
Share on other sites

By the way, for classifying ENSO strength in terms of SSTs, I've always liked how it is done by Jan Null - https://ggweather.com/enso/oni.htm

So, in order for the La Nina to be classified as Strong, 3 consecutive tri-monthly ONI readings would have to be -1.5 or lower....e.g. SON / OND / NDJ would each have to be -1.5 or lower (or OND / NDJ / DJF)

Share this post


Link to post
Share on other sites
11 hours ago, sebastiaan1973 said:

Is this an indication for a east based La Nina?

It looks fairly basin wide to me - cold at 3 and 3.4...but I’m not fully up to speed on the classification of CP, EP or basin wide events when using the 4 usual ENSO regions. Perhaps someone here can point to, or give, a definition.

Share this post


Link to post
Share on other sites
2 minutes ago, Catacol said:

It looks fairly basin wide to me - cold at 3 and 3.4...but I’m not fully up to speed on the classification of CP, EP or basin wide events when using the 4 usual ENSO regions. Perhaps someone here can point to, or give, a definition.

In the paper from Zhang et al., they categorized Ninas as Central Pacific when the max cool anomaly stayed along 160W from late summer thru winter, whereas the East Pacific and Mixed Ninas started with the max cool anomaly along 110 to 120W before migrating west during the winter - https://link.springer.com/article/10.1007%2Fs00382-014-2155-z

The current Nina aligns more with the East Pacific or Mixed versions

5DNFg6W.gif

 

  • Thanks 1

Share this post


Link to post
Share on other sites

CPC is starting to fix the MJO site. It now has a rotation in November through phases 8-1 in early November on most models. That's somewhat similar to 2016.

The CFS is starting to move the heat core in November away from Montana, and into the West/SW, which probably makes a lot of sense if we're going to spend some time in MJO phases 3-6 in November. I would think we could be back into phases 4-5-6 by Nov 20th? My forecast assumed 3-6 would be where the MJO would 'want to be' most of the cold season.

Locally, Albuquerque has never finished Oct-May with above average snowfall in a year when November had a high of 61F or hotter. Long-term average is about 57.3F. So I am curious to see how warm it is in November, since we're ~45% of the way to our 1931-2019 snowfall average already. The most recent Weatherbell winter outlook uses 1973, 1988, 2010 (x2) as the November and winter blend - that's a cold West, hot East look - opposite what the CFS shows. Real curious to see what happens. It seems like a lot of the stronger La Ninas do go cold in the West in November, but the weaker ones don't typically. CPC has a pretty big cold dump into the West week two of November.

Image

The late October snow here, even though it has melted already probably cooled off the ground and made it harder to be super hot here in November. So I wouldn't be shocked if November came in a bit lower than the ~60F my analogs had here.

Oct-2020-snowstorm

 

 

 

Share this post


Link to post
Share on other sites

The CFS has gone to my main winter analog for November: 2007. I would expect the CFS is too warm everywhere, but probably correct spatially for November 2020.

Image

Tropical Tidbits currently has these as the top SST matches globally: 1967, 1988, 2010, 2011, 2017. Weatherbell had a cold West look for November (1973, 1988, 2010, 2010) - will be curious to see if the warm West verifies of if they see something the models don't. I think we'll have some cold in the West in November but generally a warm month. The issue is 1973/1988/2010 are all way too cold/strong compared to where the current La Nina is, especially in Nino 4 where those years are near 27.0C, and this year is still near 28.0C.

 

Share this post


Link to post
Share on other sites

Image

The new Canadian trended the north Pacific warmer and the La Nina somewhat warmer too. Atlantic actually trended a lot colder too, with the Indian Ocean warmer.

Share this post


Link to post
Share on other sites

Ugh. Was really hoping this Nina would help kill the "Blob" of warm anomalies further north. It has been mucking up the flow over North America and thus the Plains/Midwest spring tornado seasons for the better part of the last decade.

Share this post


Link to post
Share on other sites

Solar activity rose to 14.4 sunspots for October 2020 - highest since June 2018. The 12-month average is now above the year ending October 2009, at 4.2 sunspots/month v. 3.5 sunspots / month. That isn't a big difference, but it is 20% higher. The six months ending October 2020 were 5.8 sunspots/month, compared to 4.9 for the six months ending October 2009 too.

Image

Oceanic-heat content for October for 100-180W fell to -1.08. That's somewhat colder than October 2016 and October 2017, but not much.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

Closest simple blend to match 2020 trends for Aug, Sept, Oct is 1999, 2007, 2016, 2016. Not the type of winter most of you will want if that blend holds. Would be a very warm November too.

Year Aug Sept Oct
2016 -0.71 -0.71 -0.92
2016 -0.71 -0.71 -0.92
1999 -1.21 -1.27 -1.07
2007 -0.68 -1.03 -1.19
Blend -0.83 -0.93 -1.03
2020E -0.81 -0.87 -1.08


 

Share this post


Link to post
Share on other sites
On 11/1/2020 at 11:45 AM, raindancewx said:

Solar activity rose to 14.4 sunspots for October 2020 - highest since June 2018. The 12-month average is now above the year ending October 2009, at 4.2 sunspots/month v. 3.5 sunspots / month. That isn't a big difference, but it is 20% higher. The six months ending October 2020 were 5.8 sunspots/month, compared to 4.9 for the six months ending October 2009 too.

Image

Oceanic-heat content for October for 100-180W fell to -1.08. That's somewhat colder than October 2016 and October 2017, but not much.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

Closest simple blend to match 2020 trends for Aug, Sept, Oct is 1999, 2007, 2016, 2016. Not the type of winter most of you will want if that blend holds. Would be a very warm November too.

Year Aug Sept Oct
2016 -0.71 -0.71 -0.92
2016 -0.71 -0.71 -0.92
1999 -1.21 -1.27 -1.07
2007 -0.68 -1.03 -1.19
Blend -0.83 -0.93 -1.03
2020E -0.81 -0.87 -1.08


 

Only one I would hate is 1999.

Share this post


Link to post
Share on other sites
                Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA
 30SEP2020     20.1-0.5     23.8-1.1     25.6-1.1     27.9-0.7
 07OCT2020     19.5-1.2     23.4-1.5     25.5-1.2     27.8-0.8
 14OCT2020     19.6-1.2     23.6-1.3     25.3-1.4     27.8-0.9
 21OCT2020     19.9-1.1     23.8-1.2     25.3-1.4     27.8-0.8
 28OCT2020     20.0-1.1     23.5-1.5     24.9-1.7     27.9-0.7

Nino 4 and 1.2 warmed a bit this week. Big drop in Nino 3 and 3.4 though. The current La Nina is now stronger/colder in Nino 3.4 than 2007 at this point, but warmer elsewhere. I was expecting Nino 3.4 to come in around 25.55C since the monthly data usually runs above the weekly data, but it looks lower than that now. This week the data is about half way between 1995 and 2007 in the eastern zones, but now much stronger/colder than 1995 in Nino 3.4. The slow cooling in Nino 4 is a feature of both years. Nino 4 was already dropping below 27.0C in 2010 and a lot of older La Ninas by this point (November). 

 31OCT2007     19.7-1.5     23.2-1.8     25.2-1.5     27.8-0.8
 25OCT1995     20.3-0.7     24.0-0.9     25.6-1.1     27.9-0.8

Pretty healthy La Nina in Nino 3.4 though - will likely be in "strong" territory in Nov-Dec before weakening.

Image

Share this post


Link to post
Share on other sites
2 hours ago, raindancewx said:
                Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA
 30SEP2020     20.1-0.5     23.8-1.1     25.6-1.1     27.9-0.7
 07OCT2020     19.5-1.2     23.4-1.5     25.5-1.2     27.8-0.8
 14OCT2020     19.6-1.2     23.6-1.3     25.3-1.4     27.8-0.9
 21OCT2020     19.9-1.1     23.8-1.2     25.3-1.4     27.8-0.8
 28OCT2020     20.0-1.1     23.5-1.5     24.9-1.7     27.9-0.7

Nino 4 and 1.2 warmed a bit this week. Big drop in Nino 3 and 3.4 though. The current La Nina is now stronger/colder in Nino 3.4 than 2007 at this point, but warmer elsewhere. I was expecting Nino 3.4 to come in around 25.55C since the monthly data usually runs above the weekly data, but it looks lower than that now. This week the data is about half way between 1995 and 2007 in the eastern zones, but now much stronger/colder than 1995 in Nino 3.4. The slow cooling in Nino 4 is a feature of both years. Nino 4 was already dropping below 27.0C in 2010 and a lot of older La Ninas by this point (November). 

 31OCT2007     19.7-1.5     23.2-1.8     25.2-1.5     27.8-0.8
 25OCT1995     20.3-0.7     24.0-0.9     25.6-1.1     27.9-0.8

Pretty healthy La Nina in Nino 3.4 though - will likely be in "strong" territory in Nov-Dec before weakening.

Image

I think strong ONI peak is pretty questionable...weekly data, sure.

  • Like 1

Share this post


Link to post
Share on other sites
On 10/29/2020 at 4:09 PM, griteater said:

In the paper from Zhang et al., they categorized Ninas as Central Pacific when the max cool anomaly stayed along 160W from late summer thru winter, whereas the East Pacific and Mixed Ninas started with the max cool anomaly along 110 to 120W before migrating west during the winter - https://link.springer.com/article/10.1007%2Fs00382-014-2155-z

The current Nina aligns more with the East Pacific or Mixed versions

5DNFg6W.gif

 

I used that piece extensively in my outlook. I have this season as mixed, but a tad east of totally neutral.

  • Like 1

Share this post


Link to post
Share on other sites

Year

DJF

JFM

FMA

MAM

AMJ

MJJ

JJA

JAS

ASO

SON

OND

NDJ

2020 0.5 0.6 0.5 0.3 0.0 -0.2 -0.4 -0.6 -0.9

 

CPC lowered the September Nino 3.4 reading to 25.88C fro 25.96C initially. October was 25.48C - warmer than 2007 (25.32C) but still tracking close to it. 

Nino 4 came in at 27.97C in October - still pretty near the 1951-2010 average. But similar to October 2007 (27.91C). 

The reading in Nino 4 in October 2010 was already down to 27.15C. So the pattern is a lot closer in Nino 4 to October 2016 (28.32C)  still than 2010 despite how cold Nino 3.4 is.

Share this post


Link to post
Share on other sites

The latest plume from the European still has rapid weakening of the La Nina late winter. The cool down is supposed to continue longest in Nino 4 with the reversal (warming) starting slowest there. I think there is a pretty cold period in Nov-Dec for Nino 3.4 (now) before rapid weakening sets in, so i drew in my expectations - aggressive cooling early, aggressive warming late for Nino 3.4. In Nino 4, I like slower cooling initially, and then slower warming late. Those seem to be the biases for the plume in La Nina years from my recollection.

The biggest ever (1950-2019) drop off from September to DJF in Nino 3.4 is about 1.0C. So anything below 24.9C (-1.6C) for DJF just strikes me as very unlikely (<2% odds?). 

Image

 

  • Like 1

Share this post


Link to post
Share on other sites

The CFS look for next Summer is actually very similar in the Pacific to what the "cold ENSO" after two El Nino look is historically.

Those are 1929-30, 1930-31 El Ninos followed by 1931-32 (Summer 1932), and then more recently Summer 1960, 1971, 1979, 1989, 2017. Idea is Nino 4 is still pretty cool, and it occasionally bleeds into Nino 3.4

                                                                            June-Aug-2021

 

Share this post


Link to post
Share on other sites

This is what I get for closest match August-October in each Nino zone, with Nino 1.2 weighted least (x1), and Nino 3.4 (x3) most. Nino 3 and Nino 4 are in between at x2.

Top-Monthly-SST-Matches

The unweighted blend is a bit different.

1952, 1959,1961, 1962,1966, 1978,1985, 1995,2007, 2011

For October alone, the top years are very different using the weighting above -

Year Oct Oct Oct Oct Match
2020 20.24 23.85 25.48 27.97 0.00
2011 20.24 23.92 25.67 27.86 0.93
1999 20.15 23.60 25.48 27.79 0.95
1961 19.97 23.69 25.71 27.83 1.56
1970 19.88 23.71 25.60 27.59 1.76
2007 19.50 23.55 25.32 27.91 1.94
1956 19.82 23.91 25.75 27.64 2.01

The October blend looks what I had for winter.

Top-October-SST-Matches

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.