Fall and Winter 2019-20 Predictions and Discussion

[Phil]

Here are my thoughts going forward.

 

- Much greater -AO/-NAO than last winter

- North Pacific blocking regime we have seen this fall should continue to be dominant, though it will shift more over Western Canada at times, especially mid January on

- eastern 1/3 of the country will be much colder Jan-Mar this winter

- November should see cold centered over the central part of the country

- Early December to early January is best window for major cold/snow events in PNW

- Highly elevated chance of top tier cold across the entire US, due to persistent and strong high latitude blocking, weak jet

- Precipitation is highly unpredictable, but the west coast should see extended dry periods punctuated by heavy rain/snow events and strong storms

- First half of winter should tend more -PNA, second half more +PNA

- This will be an anomalously snowy winter for many regions

- Overall, it would not surprise me if 2019-20 is a top 5 coldest winter for the past 50+ years in the US

- That being said, extreme swings in temperature will be common, especially for the middle of the country and southern sections

Interesting. Will be interesting to watch this one unfold given the change to elements the background state relative to recent years.

 

FWIW I largely agree, though I’m more bearish on December in the West this year.

[BLI snowman]

Late January is still really, really due out here.

[Deweydog]

Late January is still really, really due out here.

Cool it with the MLK stuff, dude. Not cool.

[BLI snowman]

Cool it with the MLK stuff, dude. Not cool.

 

Australia Day.

[snow_wizard]

Here are my thoughts going forward.

 

- Much greater -AO/-NAO than last winter

- North Pacific blocking regime we have seen this fall should continue to be dominant, though it will shift more over Western Canada at times, especially mid January on

- eastern 1/3 of the country will be much colder Jan-Mar this winter

- November should see cold centered over the central part of the country

- Early December to early January is best window for major cold/snow events in PNW

- Highly elevated chance of top tier cold across the entire US, due to persistent and strong high latitude blocking, weak jet

- Precipitation is highly unpredictable, but the west coast should see extended dry periods punctuated by heavy rain/snow events and strong storms

- First half of winter should tend more -PNA, second half more +PNA

- This will be an anomalously snowy winter for many regions

- Overall, it would not surprise me if 2019-20 is a top 5 coldest winter for the past 50+ years in the US

- That being said, extreme swings in temperature will be common, especially for the middle of the country and southern sections

 

I agree with most of this.  Good work!

 

I think there is a somewhat realistic shot at this being a top 10% cold winter for the NW based on what we have been seeing and solar.

[snow_wizard]

I considered years like 85-86, 71-72 specifically, but ultimately I think we will diverge from those paths. 77-78 may be an possible anolog. My primaries are 2004-05, 2012-13, 1969-70. I really like the 1969-70 analog. That would be a wetter year. 

 

My secondary analogs would probably be 1959-60, 1980-81, 1977-78, 1985-86.

 

I'm not a huge believer in considering solar.

 

I think Pete Parsons at the Oregon Department of Agriculture has some good analogs, I would say I used somewhat similar methodology.

 

Why are you choosing mostly Nino years?  I think your forecast is extremely pessimistic and has little chance of verifying, but we'll see.

[snow_wizard]

Was solar activity measured the same way back then as it is now? I have no clue, just curious.

 

Yes....they have standardized everything.  They only counted spots prior to the 1950s or so.  The fluxes, AP, and other metrics are much newer.  From spots alone it appears this is the quietest the sun has been in about 200 years.

[GHweatherChris]

Yes....they have standardized everything. They only counted spots prior to the 1950s or so. The fluxes, AP, and other metrics are much newer. From spots alone it appears this is the quietest the sun has been in about 200 years.

What evidence is there that sunspots were observed 200 years ago?

[Deweydog]

I was heading west on Highway 14 this evening and the solar seemed pretty D**n strong to me. Sunglasses and visor were deployed out of necessity.

[Phil]

Why are you choosing mostly Nino years? I think your forecast is extremely pessimistic and has little chance of verifying, but we'll see.

Because the system state is closer to that of an El Niño that a La Niña? There should be no La Niña analogs used this winter, period.

[snow_wizard]

What evidence is there that sunspots were observed 200 years ago?

 

The graphs are available online.  They actually go back more than 200 years.

[snow_wizard]

Because the system state is closer to that of an El Niño that a La Niña? There should be no La Niña analogs used this winter, period.

 

Warm neutral seems reasonable.  Historically a very good ENSO state for us.  It's really a stretch to call this Ninoish.  Right now the MJO is in Nina territory.  This is classic neutral.  As I pointed out before the all important OLR 160W to 160E is actually Ninaish right now and has been for a while.  We have serious mixed signals.

[Phil]

Warm neutral seems reasonable. Historically a very good ENSO state for us. It's really a stretch to call this Ninoish. Right now the MJO is in Nina territory. This is classic neutral. As I pointed out before the all important OLR 160W to 160E is actually Ninaish right now and has been for a while. We have serious mixed signals.

Except it’s not..

 

The strongest positive OLR anomalies have been located over the Maritime continent, with the lowest OLR anomalies over the WHEM/EPAC. The reason there have been so many positive OLR anomalies from 100E to 150W this autumn is because the Walker Circulation has been much weaker than normal, which has reduced uplift over the IPWP domain. This is partially due to the super +IOD (which may have climaxed..we’ll have to see).

 

Again, it’s about the *spatial distribution* of the anomalies, relatively speaking. Not their values..it matters where they are occurring relative to one another and where the gradients are.

[Front Ranger]

Wxstatman is gonna have a ton of write-ups to do after this fall/winter.

[Guest CulverJosh]

Kyle Dittmer has real data as it pertains to sunspots and La Nina...PNW weather

[snow_wizard]

Wxstatman is gonna have a ton of write-ups to do after this fall/winter.

 

I think you're right.

[Front Ranger]

After several record-breaking cold air masses across the West the past 6 weeks, now it's the East's turn: https://www.washingtonpost.com/weather/2019/11/08/hundreds-records-could-fall-next-weeks-impressively-cold-snap/

[Phil]

After several record-breaking cold air masses across the West the past 6 weeks, now it's the East's turn: https://www.washingtonpost.com/weather/2019/11/08/hundreds-records-could-fall-next-weeks-impressively-cold-snap/

It was chilly this morning (21*F @ IAD was the coldest this early since the 19*F in 1976) but unless we can decouple next week, it’ll be tough to beat the numbers Nov 2014 eventually put up.

 

We suck at early season cold more than most places, so I’m always bearish until the winter solstice.

[Front Ranger]

It was chilly this morning (21*F @ IAD was the coldest this early since the 19*F in 1976) but unless we can decouple next week, it’ll be tough to beat the numbers Nov 2014 eventually put up.

 

We suck at early season cold more than most places, so I’m always bearish until the winter solstice.

 

I didn't realize that was so impressive in your area. Definitely one of the most anomalous cold air masses in recent decades, and affected a huge area.

[Phil]

[Deweydog]

[Jesse]

[Phil]