Seeking an Auto Discovery Cycle Duration - Part 4

The patterns are cycling but the season they recur in is likely the missing feedback in the Trend. I am seeking to eliminate this seasonal hiccup. An accurate dominant harmonic correlation must be integrated into the formula. The short-term ISO may allow the trend to latch onto seasonal change and produce a more accurate projection. Testing out a new formula to calculate a dominant harmonic correlation, a recent analysis produced a short-term ISO of 18 days. This number led me to potential analogs at specific harmonics.

~18, 36, 54, 72

Correlations




The primary and second harmonic were the most dominant as there wasn't regional consistency in positive correlation past 40 days (see above images). I chose the second harmonic. Give or take a couple days, 36 days away from mid March was early/mid February. I knew that back on Feb 20 (see tweet below) the atmospheric setup produced a severe weather event that had recurred on two separate occasions in the long-term cycle.

Primary harmonic ~18. Seeing good correlation in the 2nd harmonic. Could this be recurring at the end of March? #ISO pic.twitter.com/pEXlv49uyQ
— Josh Herman (@OSNW3) March 17, 2014

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The SPC had nothing in their D4-8 forecasts on Mar 20 or Mar 22. They did in the D3 on Mar 25 though. Very good.

Just saying. See image. The potential power of knowing the #ISO and the recurring #Rossby it produces. @OSNW3 pic.twitter.com/awCkrgH7bG

— Josh Herman (@OSNW3) March 25, 2014

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The above observation is over a week old and the dominant ISO components have evolved. Below is the Mar 26 run. More to come.

Correlations


If there are any questions, comments, or suggestions on the material presented please let me know. Thanks for reading! More to come.

Seeking an Auto Discovery Cycle Duration - Part 3

I am putting the 500mb sounding correlations to use and seeking the recurring weather pattern. There is talk about severe weather approaching. The SPC probabilistic outlook for 2/20-21 is below. This feature has occurred before.



I want to track this feature back in time through the ISO. I start by seeking the dominant components in the correlations. The listed correlations are the greatest positive correl from the short and long term ISO components. Short-term is on the left, long-term is on the right. Give or take a day or two on each side, I see a consistent short-term component of 20-21 days in the FEB correls. I utilize standing wave harmonics and pin point a long-term component of 60-63 days. I see a consistent long-term component of ~50 days in the DEC correls.

FEB Correlations


DEC Correlations


Observations and Forecasts


Starting with the forecast date of 2/20/14 I subtract ~60 days and find 12/21/13, I then subtract ~50 days from 12/21/13 and find 10/31/13. Simply put, from within the correlations we are seeing the movement of ISO components in relation to the recurring Rossby Wave Train and cyclic weather patterns. If there is interest in the data it can be found here. Another step closer.

Click for FEB observations
500-Millibar Height Contour Map 20140220
Storm Prediction Center Storm Reports 20140220

If there are any questions, comments, or suggestions on the material presented please let me know. Thanks for reading!

Seeking an Auto Discovery Cycle Duration - Part 2

Stemming from seeking an auto discovery cycle duration I started running the sounding correlations on a daily basis. They now begin from the current day and loop 10-80 days backward in time.

When I first began correlating the soundings I started the sample period on 10/1/13. I recall ~15 days being the short-term component from those runs - a consensus on positive correlation from all stations. Beginning from the current day the short-term 10-20 day ISO still holds the top positive correlation, but now ~20 days has the consistent positive correlation. It seems to me that the short-term cycle of the ISO stands out as the dominant component this season.



I am very interested to see what happens to this correlation as the days move along. Should I expect the wave to continue on or will it roll back towards ~15? Am I seeing a seasonal ISO in the 70-80 day range? I should loop to 90 or beyond to get a better glimpse? It's a work in progress, but I think we are very close to finding an index to aid in calculating a daily cycle duration based on a primary harmonic. More to come.

If there are any questions, comments, or suggestions on the material presented please let me know. Thanks for reading!