A while back I decided to begin finding the frequency of the PNA and AO as I had been for the 500mb in the CONUS. Now I need to verify the PNA/AO frequency can be used to capture past weather conditions in order to project future weather conditions. I will attempt such in this post, using the PNA.
I correlate the frequency (recurring patterns) of the PNA. Recently the high frequency has been ~37 days and the low frequency has been ~70 days. See image below.
The frequency is transient and pulses slowly back and forth (animation) Starting from a point in time; Aug-1. I want to verify the high frequency of this past cycle, 6/25-8/1, to two cycles ago 5/23-6/25. Knowing the average high frequency we can project forward. 5/23-6/25 should resemble what was to come 6/25-8/1.
With this comparison it seems the trough axis shifted a bit west, but overall it's not a bust. I want to verify the low frequency also. The low frequency as of this writing is ~70 days. The frequency is transient, and after analyzing the frequencies of a cycle previous, 3/14-5/23, I feel the need to shorten the range by ~5 days going back another cycle.
The low frequency PNA from 3/19-5/23 did OK projecting the time frame of the next low frequency cycle 5/23-8/1. Certainly not a bust.
If there are any questions, comments, or suggestions on the material presented please let me know. Click on the images for a larger view. Thanks for reading!