Thursday, November 1, 2012

Strong Storm System Correlates With LRC in Mid-Nov.

The latest runs (yes, plural) of the GFS model are showing a strong storm system making landfall on the West Coast in mid-November, when winds at the 500mb level (commonly used to identify areas of high/low pressure) surpass 80 knots- a benchmark for the 'strong' storm system line, in my opinion. Usually, such long range forecasts are worth next to nothing to me. But here's the thing:

I believe this forecast.

This is the 500mb map from August 21st of this year. Note how there is also a strong low pressure system in the Ohio Valley and another one just off the West Coast. Also observe the presence of a high pressure system (shown by arcing lines in the Rockies) out West. If we compare this to the November 9th forecast, we see a striking similarity. The forecast also holds a disturbance in the Northeast and a strong system on the West Coast. Adding to the similarities is the presence of a ridge in the Central US. This is what we call the Lezak Recurring Cycle, and those of you who have followed me for a while know what I am talking about. Here's the low down of the LRC:

•A 40-60 day pattern that sets up every year in the fall.
•This pattern continues thru winter, and is never the same from year to year.
•Every 40-60 days, a 'cycle', or repetition, occurs.
•Because the LRC involves disturbances and ridges, each cycle means that the same piece of energy or high pressure system would come around again 40-60 days later, in the general same area.

The LRC is hard at work. Now, we can apply the LRC to the rest of winter and see what'll happen. I'll have more details on this tomorrow.



Anonymous said...

could this improve california overall precip for this winter?

Josh Herman said...

So you're seeing an 80-81 day cycle?

I put some effort into studying your forecast but I do not see the pattern. From what I can tell, dates prior to the comparison do not correlate. It's hard pressed to correlate them going forward as well.

Can you provide more clues to what you're seeing?