Winter 20-21 Discussion

[ThomasRodriguez]

This is such a great thread with so much to learn about weather monitoring! I am new to weather chasing, mostly for aerial photography and I often follow websites like climacell.co. This thread has given me so many more options to explore. Thanks to each and everyone who has posted the sources of the weather monitoring websites.

[40/70 Benchmark]

5 hours ago, ThomasRodriguez said:

This is such a great thread with so much to learn about weather monitoring! I am new to weather chasing, mostly for aerial photography and I often follow websites like climacell.co. This thread has given me so many more options to explore. Thanks to each and everyone who has posted the sources of the weather monitoring websites.

It really is in an incredible resource with some gifted minds. I am humbled by the exchange of information each and every season. The fact that someone like myself, who has been math and science deficient my whole life, can compose a coherent winter outlook is largely a credit to these forums.

[40/70 Benchmark]

4 minutes ago, 40/70 Benchmark said:

https://easternmassweather.blogspot.com/2020/11/winter-outlook-2020-2021-mixed-type-la.html

 

Here is my winter outlook, if you are looking for something to pass the time, while a team of molasses molecules counts the NV ballots.

The abridged version is linked....there are also options for more technical discussion of the telconnections if so desired.

Most wintery period looks to be December, and potentially another bout in March, but it may very well just result in a cold spring...as last season did.

 

[raindancewx]

This is pretty close to my thought process, although I dislike half of his years. https://www.youtube.com/watch?v=MXg0srzblgk&ab_channel=EricWilhelm

He likes 2016-17 as the main analog. I think a de-amplified 2016-17 is sort of the right idea (less extreme warmth East, less extreme wetness West). He mentions a pretty high likelihood of a top five warmest ever winter for his area (Youngstown OH).

His blend is:

2016-17 (x4)

2010-11 (x2)

2007-08

1998-99 (x2)

1995-96

1988-89

1983-84

If you were to just do a QBO/ENSO blend, at this point I'd say a 2010/2016 blend is appropriate, and maybe you throw in 1961 to get some more Gulf Hurricane activity in there like this year. That's a 2C SST drop off in Nino 3.4 overall as a blend, which is at least ballpark for this year (I still think its 27.1C to 25.5C for the actual winter, but could be colder). The blend below looks like what I have, but colder in the East/Southeast.

Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct
1961	-5.47	-0.62	0.54	2.82	6.88	7.96	6.69	5.60	6.02	7.59
2010	-16.02	-16.98	-19.68	-23.57	-26.28	-25.05	-9.84	1.45	6.58	10.83
2016	9.34	6.77	3.16	0.64	2.37	3.86	6.25	10.07	10.48	12.83
Blend	-4.05	-3.61	-5.33	-6.70	-5.68	-4.41	1.03	5.71	7.69	10.42
2020	-2.51	-3.20	-4.36	-5.03	-4.86	-2.78	0.34	4.78	7.95	10.80

 

[michsnowfreak]

10 hours ago, raindancewx said:

This is pretty close to my thought process, although I dislike half of his years. https://www.youtube.com/watch?v=MXg0srzblgk&ab_channel=EricWilhelm

He likes 2016-17 as the main analog. I think a de-amplified 2016-17 is sort of the right idea (less extreme warmth East, less extreme wetness West). He mentions a pretty high likelihood of a top five warmest ever winter for his area (Youngstown OH).

His blend is:

2016-17 (x4)

2010-11 (x2)

2007-08

1998-99 (x2)

1995-96

1988-89

1983-84

If you were to just do a QBO/ENSO blend, at this point I'd say a 2010/2016 blend is appropriate, and maybe you throw in 1961 to get some more Gulf Hurricane activity in there like this year. That's a 2C SST drop off in Nino 3.4 overall as a blend, which is at least ballpark for this year (I still think its 27.1C to 25.5C for the actual winter, but could be colder). The blend below looks like what I have, but colder in the East/Southeast.

Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct
1961	-5.47	-0.62	0.54	2.82	6.88	7.96	6.69	5.60	6.02	7.59
2010	-16.02	-16.98	-19.68	-23.57	-26.28	-25.05	-9.84	1.45	6.58	10.83
2016	9.34	6.77	3.16	0.64	2.37	3.86	6.25	10.07	10.48	12.83
Blend	-4.05	-3.61	-5.33	-6.70	-5.68	-4.41	1.03	5.71	7.69	10.42
2020	-2.51	-3.20	-4.36	-5.03	-4.86	-2.78	0.34	4.78	7.95	10.80

 

He actually said a 25% chance of a top 5 warmest winter for his area, and a 15% chance of average temps.  He's really harping on 2016-17. I actually think that a deamplified 2016-17 would be a decent winter here. Throw away the insane February torch and it really wasn't bad.

[40/70 Benchmark]

3 hours ago, michsnowfreak said:

He actually said a 25% chance of a top 5 warmest winter for his area, and a 15% chance of average temps.  He's really harping on 2016-17. I actually think that a deamplified 2016-17 would be a decent winter here. Throw away the insane February torch and it really wasn't bad.

I would take 2016-2017 and run. I had that as a secondary analog.

[michsnowfreak]

4 hours ago, 40/70 Benchmark said:

I would take 2016-2017 and run. I had that as a secondary analog.

Thanks to a few good lake squalls, i ended up with snowfall right around avg (DTW finished with 38" so about 5" below avg). it was not as bad as some people make it out to be. I hate when people do "take away" posts but im going to do it anyway. Take away the 2nd half of Feb inferno and it wasn't that bad.

 

BTW I read your outlook. very well thought out. Its leave raking, outdoor Christmas decorating Indian summer weather right now, but I've been on the "mild Nov  wintry Dec train" for a while now. Just a gut instinct/Nino climo but your outlook is similar thinking. People put way too much in week 5 or month 2 or whatever on the models. An active, mild winter here can produce lots of snow, just not the nonstop frozen tundra snowpack I like lol.

[raindancewx]

Weatherbell stuck to their warmed up blend of 1973-74, 1988-89, 2010-10 (x2).

The Joe D'aleo Pioneer Model has a lot of years I like as analogs:

https://www.weatherbell.com/winter-2020-update

I've seen a lot of people saying you can't really get a strong or moderate La Nina look with the North Pacific so warm. You really can if you blend in a year with a very strong La Nina with a year that had a very warm North Pacific. I think blending in 2019-20, 2012-13 in at a low weight with a strong La Nina does a pretty good job warming up the north Pacific a lot without diminishing La Nina strength too much. That's what I did in my outlook anyway.

I didn't use all of these years in my outlook, but at this point I think the 10 best analogs for winter are probably 1954, 1961, 1973, 1988, 1995, 2003, 2007, 2012, 2016, 2019. This will be a good year for seeing which factors matters most. 

My general sense is the warm North Pacific, with low sea ice and a pretty strong La Nina means you'll get (sporadic) very strong troughs/cold dumps into the West, but because a lot of extra moisture sources exist (Arctic Ocean, East Pacific at mid-latitudes), you'll see more snow and wetter Western storms. In the Southwest, we're usually dry in La Ninas because storms run out of moisture by the time they get here if the storm track has to crash over mountains, through cold water and a ridge. I don't think that's the case this year. You had an almost identical SOI crash that preceded the late October snow storm here to 2007, but the system this year had far more moisture. To me, that's likely to keep happening with a warmer North Pacific / Arctic.

 

[Orangeburgwx]

As I South Carolina resident, anytime I see 72/73 being used I get a bit of anxiety. Got nailed by an ice storm that January, then the Motherlode of all Southeast wintersless than a month later

Sent from my LGL322DL using Tapatalk

[chubbs]

How much for Philly? This plot suggests that any relationship between October sea ice and subsequent Philly snow is complicated. In any case, can say that very low Oct sea ice, below 4.5 million sq km,  doesn't help. Not good with this years October sea ice area a record low of 4.08 million sq km.  

[Kingfil]

Will next year be a shift towards El Nino, or do we stay in the La Nina regime?

[raindancewx]

The cold-ENSO winters following two El Ninos usually do not lead to multiple-La Ninas in a row. I lean toward a Neutral that flashes cold and warm at times for next year but it is pretty early for that. My guess is Nino 4 will be pretty cold early next year, but warming steadily. The other zones will probably warm initially, but might reverse cooler later on.

The models have Neutral to near-El Nino conditions by late next year.

The transitions after two El Ninos that went to a La Nina/near La Nina are these:

1929-30, 1930-31 --> two cold Neutrals for 1931-32, 1932-33

1957-58, 1958-59 --> two neutrals in 1959-60, 1960-61

1968-69, 1969-70  --> two La Ninas in 1970-71 and 1971-72

1976-77, 1977-78 --> two neutrals in 1978-79 and 1979-80

1986-87, 1987-88  --> a big La Nina in 1988-89, and then a neutral in 1989-90

2014-15, 2015-16  --> I consider 2016-17 a La Nina, but it is really a Neutral strictly speaking, and 2017-18 was a La Nina

[raindancewx]

Love those big SOI crashes! Check out 11/3-11/5 and the corresponding Western snow 11/13-11/15. Snow anomalies from my winter outlook are very much on target.

Don't think California is actually in for a particularly dry winter, but we'll see how that goes. Don't think it is super wet though either.

 

[raindancewx]

The local weather service likes 2016-17, 2010-11, 2007-08 as analogs for the winter.

https://www.weather.gov/media/abq/Briefings/202021WinterOutlook.pdf

 

[raindancewx]

The UKMet November update is warmer than last month for the winter. Looks like most of their recent November outlooks for winter have been bad for the US though.

If that colder look in Western Canada verifies though, someone in the US should at least see impressive cold snaps if nothing else. The look is pretty dry along the Mexican border, but it would only be slightly dry where I am, which is more or less what my analogs had too. I would say the SE tended meaningfully drier on the new run in addition to the warmer look overall for the US.

On their probabilistic outlook, Texas is most favored to be drier than average, with the NW & Ohio Valley most likely wet. Only California to Montana has a better than 20% shot of being colder than average on the new run, a smaller area than before.

[griteater]

Posted my winter outlook here: https://www.americanwx.com/bb/topic/54042-griteaters-winter-outlook-20-21/

 

[40/70 Benchmark]

On 11/10/2020 at 8:49 PM, raindancewx said:

The local weather service likes 2016-17, 2010-11, 2007-08 as analogs for the winter.

https://www.weather.gov/media/abq/Briefings/202021WinterOutlook.pdf

 

I would be happy with either of those.

[raindancewx]

A quick look at each Nov 1-15 from 1950-2019 shows that the current spatial look to November is fairly rare in that period. I only found six good matches nationally - 1964, 1975, 1978, 1987, 2011, and 2015. You're looking for something like this, but ideally warmer than 2011 was. The best match may be 1964 overall. 

Here is a look at the unweighted six year blended highs - 1964, 1975, 1978, 1987, 2011, 2015 for ten US cities 11/1-11/15:

Boston: 59.9F v.  (55.2+65.3+56.1+54.6+60.1+60.9)/6 --> 58.7F

Richmond: 69.8F v. (70.2+72.9+68.7+66.6+65.0+66.1)/6 --> 68.3F

Jacksonville: 78.7F v. (75.2+76.6+74.9+74.7+72.7+81.1)/6 --> 75.9F

Detroit: 61.9F v. (64.0+61.3+58.7+55.3+59.4+60.9)/6 --> 59.9F

Chicago: 62.9F v. (64.0+61.3+58.7+55.3+59.4+60.9)/6 --> 59.9F

St. Louis: 67.3F v. (71.7+65.3+65.9+65.1+65.6+65.7)/6 --> 66.6F

Billings: 51.0F v. (50.0+58.2+42.5+56.5+45.1+51.0)/6 --> 50.6F

Albuquerque: 63.0F v. (61.1+66.7+63.7+61.9+56.9+58.7)/6 --> 61.5F

San Diego: 72.7F v. (70.3+70.9+69.3+70.3+67.9+73.1)/6 --> 70.3F

Seattle: 52.7F v. (48.3+53.7+50.3+56.5+51.2+52.3)/6 --> 52.1F 

The blend has a cold West look to December as a composite. The ten city average "error" for the Nov 1-15 blend is about 1.6 degrees. I find blends that close over a large area of the US usually hold for a little bit - but we'll see.

[raindancewx]

This is what I get looking at non-El Nino Decembers following a November with a very positive NAO (top 1/3 +NAO for 1950-2019):

[LibertyBell]

1999 and 2007 are reappearing analogs.  I've seen some extreme temp records in the SW (Phoenix, for example) that were previously held on the same dates in 1999.  

[40/70 Benchmark]

22 hours ago, LibertyBell said:

1999 and 2007 are reappearing analogs.  I've seen some extreme temp records in the SW (Phoenix, for example) that were previously held on the same dates in 1999.  

2/4 of my mixed la nina composite.

1970, 1999, 2007 and 2010.

I incorporated 2010 very little for various reasons. 2007 is best.

[raindancewx]

My July-June snow anomaly map looks OK so far. Canada border with Idaho/WA to NW NM/Western Colorado, Midwest, and Northern New England were favored zones.

[LibertyBell]

On 11/20/2020 at 9:52 PM, 40/70 Benchmark said:

2/4 of my mixed la nina composite.

1970, 1999, 2007 and 2010.

I incorporated 2010 very little for various reasons. 2007 is best.

Are there any that you are putting more weight in above the rest, Ray?

I have them listed as follows:

1) 2007

2) 1970

3) 1999

and 2010 a very distant fourth lol.  Also wondering if you considered 2005-06?

 

[40/70 Benchmark]

3 hours ago, LibertyBell said:

Are there any that you are putting more weight in above the rest, Ray?

I have them listed as follows:

1) 2007

2) 1970

3) 1999

and 2010 a very distant fourth lol.  Also wondering if you considered 2005-06?

 

I would give more weight to a modified Dec 1970, but 1999-2000 the rest of the way.

2005-2006 was actually very east based....not mixed type. Nina much weaker...it actually had more going for it leading in. ACE was of course off the charts. Not sure why it was so mild...solar?

[LibertyBell]

16 minutes ago, 40/70 Benchmark said:

I would give more weight to a modified Dec 1970, but 1999-2000 the rest of the way.

2005-2006 was actually very east based....not mixed type. Nina much weaker...it actually had more going for it leading in. ACE was of course off the charts. Not sure why it was so mild...solar?

1999 is catching up quick....I see a lot of records both in the east and west that were previously set in 1999.  I just have caution with it because of the 11 yr cycle.  By the way, this is far out there, but what do you see for next summer?  2021 is part of the 11 yr cycle of hot summers but if we have a developing el nino next year it might be like some of the 11 year cycle summers that had a developing el nino which have a week or two of heat but mild besides that (then again there's 2002 which was pretty hot throughout; it's not part of the 11 yr cycle of extremely hot summers but shows that you can have a hot eastern summer even during a developing el nino.)  I've also seen 1975-76 being tossed out there....what do you think of that comparison?

The funny thing about 2005-06 was that the second half of winter should have been more wintry.....March was pretty cold but we didn't get much snow.  Most of the snow we got that winter was concentrated in two storms, the one in December and the other one in February.  As you mentioned previously, in la ninas, December tends to be an indicator for how the winter will go.  It doesn't even have to be the beginning of December, but if you have a decent snow event sometime during the month it usually means good things for the rest of winter.

 

 

[40/70 Benchmark]

2 hours ago, LibertyBell said:

1999 is catching up quick....I see a lot of records both in the east and west that were previously set in 1999.  I just have caution with it because of the 11 yr cycle.  By the way, this is far out there, but what do you see for next summer?  2021 is part of the 11 yr cycle of hot summers but if we have a developing el nino next year it might be like some of the 11 year cycle summers that had a developing el nino which have a week or two of heat but mild besides that (then again there's 2002 which was pretty hot throughout; it's not part of the 11 yr cycle of extremely hot summers but shows that you can have a hot eastern summer even during a developing el nino.)  I've also seen 1975-76 being tossed out there....what do you think of that comparison?

The funny thing about 2005-06 was that the second half of winter should have been more wintry.....March was pretty cold but we didn't get much snow.  Most of the snow we got that winter was concentrated in two storms, the one in December and the other one in February.  As you mentioned previously, in la ninas, December tends to be an indicator for how the winter will go.  It doesn't even have to be the beginning of December, but if you have a decent snow event sometime during the month it usually means good things for the rest of winter.

 

 

I don't really concern myself with summer outlooks.

True RE 2005-2006 wastedMarch potential. I actually used the 2005-2006 analog for the 2017-2018 season, citing the forecasted bookend nature of the winter, with an exotically mild stretch in between. Both were ep la nina seasons. Difference is we capitalized on the March potential in 2018.

I don't think 1975-1976 is a bad sensible weather analog, but it did not meet my analog criteria.

[raindancewx]

My issue with the 1970s La Ninas, almost all of which were cold here and/or snowy here, is you have a much colder North Atlantic and North Pacific, and generally low ACE values. 1970 and 1975 are both very low ACE years particularly for a La Nina. Atlantic ACE is loosely correlated with the AMO so that makes sense. Outside the NW US, it really does seem like the Atlantic drives patterns in La Nina winters, unlike in El Ninos where the Pacific matters far more.

I'm not a huge fan of 1999 either. I'm actually pretty curious to see how November finishes because it's pretty tough right now to get a good spatial match for it.

The six years I mentioned as good matches through 11/15 are really not all good matches anymore. 1978 turned very cold by this point in the Northern & Western US as an example. Here is the same analysis but six days later. Here is a look at the unweighted six year blended highs - 1964, 1975, 1978, 1987, 2011, 2015 for ten US cities 11/1-11/21:

Boston: 58.0F v. (54.0+63.9+54.5+53.8+59.0+58.6)/6 --> 57.3F

Richmond: 67.2F v. (69.3+72.6+67.0+64.6+64.1+65.8)/6 --> 67.2F

Jacksonville: 76.7 (76.4+76.3+75.2+73.2+74.0+80.2)/6 --> 75.9F

Detroit: 58.7F (58.0+61.1+54.1+53.2+57.0+59.5)/6 --> 57.2F

Chicago: 60.0F (58.3+62.0+55.8+54.4+54.5+57.9)/6 --> 57.2F

St. Louis: 65.7F (63.4+64.7+60.0+61.0+62.8+63.5)/6 --> 62.6F

Billings: 50.8F (46.4+51.2+33.7+54.0+42.0+48.3)/6 -->45.9F

Albuquerque: 64.8F (57.1+63.4+62.0+60.0+57.7+57.6)/6 --> 59.6F

San Diego: 73.3F (68.1+69.7+68.9+71.0+66.6+73.5)/6 --> 69.6F

Seattle: 52.7F (46.5+52.0+48.2+55.8+49.4+51.4)/6 --> 50.6F

The ten city average error jumped from 1.6 degrees to 2.2 degrees - pretty big increase for such a short period.

[raindancewx]

Eyeballing past years, I'd say the top snowfall matches to Sept 1-Nov 20 2020 are 1946, 1947, and 1985, with 1996 and 2011 the best matches of the past 30 years. Those are some pretty good snow years out here, except for 1946.

[raindancewx]

One year I've been looking at a lot lately in 1959. The NW Pacific is cold that year, but you have a very warm NE Pacific with a pretty cold ENSO event. If you blend in years to warm up the NW Pacific with 1959 it's not that hard to get a map resembling the oceans today but less extreme.

More importantly though, early December 1959 is dead on to the CPC forecast.

That map has issues for the La Nina intensity, and the far northern oceans are different. But the MJO / tropical zones are are in the correct spots, the little SE to NW warm zone from India to Australia west of a cool patch south of Indonesia is there, the cold ENSO and cold tropical Atlantic are there. The warm patch into the NE Pacific is too far SW, but the real issue is that cold spot in the NE Atlantic. If you try factor in the northern oceans, this probably a bit better with 2011 in there to fix the north Atlantic in particular (it has the same cold blotch by Greenland as 2020), while 2008 fixes the NW Pacific.

[StormchaserChuck!]

On 11/7/2020 at 4:29 PM, Kingfil said:

Will next year be a shift towards El Nino, or do we stay in the La Nina regime?

El Nino or warm-neutral