susqushawn

Bit of a tangent here ...The CPC methodology for calculating the PNA index may be subject to flaws. This week ahead is a case in point. It projects a +PNA despite an unmistakable trough modeled out west. It was pointed out to me that the CPC formula for + phase looks for above normal heights from Hawaii to the intermountain west, and below normal heights over the Alleutians and SE Conus. The week ahead is an anomaly as it does indeed have below normal heights in the SE but obviously not resultant from a west coast ridge, rather, a stagnant rex block. I suspect that's the main anomaly "fooling" the formula into believing we have a notable +PNA, when from a sensible wx standpoint it's the complete opposite. If this was winter the CPC projection would be under greater scrutiny. That would be an exciting +PNA projection in DJF but sensibly it couldn't be farther from reality.

A raging Pac jet tickling the coast certainly doesn't aid in sustaining a +PNA, been a common theme the past several winters. Ridge rolls over or lops off. Chill that thing out a bit and hope springs eternal

I analyzed pna nao cycles earlier in the season, it was something like 10-12% of the time did we have a +PNA/-NAO couplet the past 10 winters or so

Possible debris signature on CC S of Baltimore

oh you know just your typical retrograde of an Atlantic low hundreds of miles before phasing with northern stream energy, stall/loop, bring some flakes then off it goes. no biggie lol. nice to see HP anchored in E Canada that long, of course it's only the op...

Euro sniffed out the upcoming stronger pass in phase 4 before the gefs which was in the COD before adjusting

An eps projection for comparison. That sea of okhotsk trough had been a staple

Brief couplet

Colin