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!

OSNW3 Trend Comparison to the Jeremy Nelson LRC Based Long Range Forecast

I wanted to analyze the OSNW3 long range numbers for February in conjunction to Jeremy Nelson's forecast for southeastern WI. Jeremy is a meteorologist at WISN12 in Milwaukee who uses LRC techniques to long range forecast. His "February forecast and beyond" can be found at this link.

I will highlight some pieces of the forecast.

1. "The pattern looks to stay busy with a chance of snow around February 4-5 and 7-8 [...] some of the storm systems will have more moisture to work with" - February 1-7 Section (Black)

2. "Following each snow chance a quick hit of cold air will sweep across southeastern Wisconsin. More below zero lows are likely this month. Temperatures should moderate and possibly move above average late in week two of February [...] The average/above average temperatures should last 1-3 days" - February 8-15 Section (Orange)

3. "The middle of the month should see the return of one of the biggest precipitation producers for southeast Wisconsin [...] As this feature returns around February 14-17 another storm system is possible impacting our area" - February 16-28 Section (Blue)

4. "Closing out the month a moderation in temperatures is possible around February 20-22 before another surge of cold air around Feb 23-25. A couple chances for snow showers also possible the final week of February" - February 16-28 Section (Red)

The image below is a snap shot of the Milwaukee, WI trend from the OSNW3|WxClimate website for February. I highlighted the points mentioned above in the image. For Jeremy's entire forecast be sure to click the blog link above. Click here for more information on the image below, which will provide an interactive experience for the Brewer's home opener Jeremy mentions in his forecast as well.



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