Tuesday 24 September 2013

1990-91 exhibiting incredible similarities to upcoming winter

The more I look at the winter of 1990-91, the better it looks as an analog for this upcoming winter. First thing to note is that it matches very well with our current QBO state. It is one of two years(the other one being 85-86) within 3.50 of our current 30mb QBO anomaly that also has a neutral ENSO state.

2013 30mb QBO numbers from Feb to Sept: -4.13 -0.23 3.12 8.36 14.25 17.89 21.01 21.36
1990 for the same time period: -6.78 -5.74 1.21 5.68 13.06 17.40 19.26 19.32


The Dec-Feb SST pattern also matches up very well with forecast SST setup from the ECMWF/CFSv2. Note the warmest ENSO anomalies are in nino 3 and 4 with very warm water east of japan. Cool water is positioned off the west coast which is where we are trending this year given expected troughiness.

1990-91 SST setup:
 Reduced: 90% of original size [ 565 x 436 ] - Click to view full image
Attached Image

Euro DEC forecast looks fairly similar with the exception of a warmer north atlantic setup. Would expect more blocking and higher heights near the canadian maritimes with this years setup. Wave breaking also favourd south of iceland.
 Reduced: 79% of original size [ 641 x 438 ] - Click to view full image
Attached Image

500mb heights that winter have more of a positive NAO look with a SE ridge and a -WPO/strong aleutians ridge.
 Reduced: 90% of original size [ 565 x 436 ] - Click to view full image
Attached Image

Another interesting note about that winter is the spike positive in the PDO in late summer and early fall only to see the index drop considerably during winter.
Jul to feb PDO: 0.27 0.11 0.38 -0.69 -1.69 -2.23 -2.02 -1.19 

2 comments: