Typeing3 wrote: ↑Sun Sep 20, 2020 11:26 am
Generally, yes. Unfortunately QBO data (from what I can find), only goes back to around 1950. ENSO and solar data go much further back than that.
The problem we get when using parameters such as moderate nina/+QBO/low solar, we're left with only a couple analogue years. As Monty mentioned, it just isn't enough data to help us when trying to draw any conclusions.
Weak Nina/+qbo/low solar isnt the be all to end all though. Looking at the list I posted earlier, the vast majority of moderate and strong Nina's are cooler than normal with above average snowfall.
Yup I was noticing the same thing. Not enough data to draw any definitive conclusions. What we can say is that a Nina/+QBO/Low solar combo will likely produce at least a decent winter but also has potential to be 2008/2009 epic. Time will tell. But my fingers are crossed for an epic winter
NOAA composite plots have data back to 1948. Since then we've had five moderate nina winters - '49-50, '70-71, '84-85, '95-96 and '11-12. These are the temp and 500mb height anomalies we get from an average of these five winter seasons.
Temp anomaly:
WPn9EVHIJb.png
500mb height anomaly:
K6s3GjVzLx.png
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Typeing3 wrote: ↑Sun Sep 20, 2020 11:05 pm
NOAA composite plots have data back to 1948. Since then we've had five moderate nina winters - '49-50, '70-71, '84-85, '95-96 and '11-12. These are the temp and 500mb height anomalies we get from an average of these five winter seasons.
Temp anomaly:
WPn9EVHIJb.png
500mb height anomaly:
K6s3GjVzLx.png
I’d be tempted to remove 49-50 from the data set as it was such an extreme outlier
North end of Shawnigan Lake. Southern Vancouver island. 500ft
There has been discussion on as to whether a weak Nina is better for cold and snow in the PNW versus moderate-strong events.
Just thought I'd mention that 07/08 was a strong Nina and while we didn't see any sustained cold, we did see numerous low elevation snow events. Abbotsford recorded 103.4 cm that winter. The QBO was also negative. I'd be interested to know what the outcome of that winter would have been during a positive phase of the QBO.
This is just one example but it does show that we can still get a snowy winter even with a strong Nina.
AbbyJr wrote: ↑Fri Sep 25, 2020 1:13 pm
There has been discussion on as to whether a weak Nina is better for cold and snow in the PNW versus moderate-strong events.
Just thought I'd mention that 07/08 was a strong Nina and while we didn't see any sustained cold, we did see numerous low elevation snow events. Abbotsford recorded 103.4 cm that winter. The QBO was also negative. I'd be interested to know what the outcome of that winter would have been during a positive phase of the QBO.
This is just one example but it does show that we can still get a snowy winter even with a strong Nina.
It can happen, but statistically strong La Ninas are less snowy on average than weak or moderate La Ninas.
For Abbotsford, weak and moderate La Ninas average near 70 cm, while strong La Ninas average near 45 cm. Neutral years also average near 70 cm.
The average for all years including El Ninos was 55 cm (1981-2010).
Abby_wx wrote: ↑Fri Sep 25, 2020 5:22 pm
It can happen, but statistically strong La Ninas are less snowy on average than weak or moderate La Ninas.
For Abbotsford, weak and moderate La Ninas average near 70 cm, while strong La Ninas average near 45 cm. Neutral years also average near 70 cm.
The average for all years including El Ninos was 55 cm (1981-2010).
Phil on the American forums told me that he doesn't think there is any evidence to suggest the Nina intensity has anything to do with cold and snow in the PNW. Rather, its external factors apart from ENSO. He gave examples of some of the better PNW winters that were El Nino but said that it doesn't prove that El Nino favours colder and snowier winters here. Its just that external factors can overcome a less favourable ENSO.
That said, even if Nina intensity was a factor, this upcoming Nina will likely end up moderate at most. So we should still be good to go to get our December 1996 and January 1954 redux we have all been patiently awaiting.
Abby_wx wrote: ↑Fri Sep 25, 2020 6:53 pm
Yes, it could be merely coincidental that strong La Ninas have historically been associated with lower snowfall.
Wouldn't surprise me. Either way, there is really not enough data to come to a definitive conclusion. That said, I do think we are in good shape for at least a decent winter. Likely at least normal snowfall if not above normal.
