12/1/11

Are We In For One Troublesome Forecastable Winter?

Written by: William R. Deedler, Weather Historian 12/01/2011

In answer to the question of the headline: "Well, I really would hope not but analogue data indicating the interactions of the main jet streams involving strong wind maxs, does make one wonder".

Straight up: 
As we can see by the projected analogue winter jet streams, the problem readily shows up in the northern Pacific. Not only is this where a couple of jets are likely to phase/not phase this winter but also where observational data is scant. Much of the surface and aloft data is lost over the Pacific once it leaves Eurasia (including Japan) but thank our heavens above (no pun intended, well maybe a little) in the advancement of technology for satellite data (and upgrades). 

A big boom to forecasting came in the 1970s when satellite advancement really began to take off from its infancy in the 1960s. I recall at the WSFO at Detroit Metro Airport (at the time) what a ground breaking product this was and this was especially true for the local WSFO/WSO's in the Great Lakes what with: winter ice coverage and Lake Effect snows, synoptic rain and snow systems and severe weather. One could hardly wait at times for a recent picture to come out of the satellite machine (LOL) which currently is just another standard but important tool for forecasting!  Then, fairly quickly at the WSFO's, the micro-scale satellite interest expanded to a macro-scale interest over the US and points west, south and east with the Pacific Ocean, Gulf of Mexico and the Atlantic all having important watchable satellite data.

Back to the subject at hand:
As it is said, a picture is worth a thousand words and referring back to a few of the map pictures from my projected analogue jet stream and storm tracks in my Outlook, depicts nicely what we are up against.


The interaction of the Pacific and Polar/Arctic jets along with phasing location and timing; will have large repercussions on the downstream subsequent weather development this winter across the States. Of course, to a large extent, this happens most winters depending on the ENSO cycle, etc, etc as discussed in the Outlook. However, with the analogue data from this particular set of winters chosen, I feel tends to zero in on the perspective trouble spots and likely outcome. In addition, throw in at times the sub-tropical Pacific jet nosing in its beak for good measure and the complexity only grows. And to top it all off; the surface and aloft weather data you receive from many of these locations is very limited (if non-existent) and again, why satellite is such a valuable tool.
Analyzing the aloft data from the analogues, gives a valuable clue as to where the dominant storm tracks and subsequent forecast problems will likely arise. And, one eye on recent weather maps (surface and aloft) and the other on our analogue map projections reveals we are in the right place. 

Latest data from extended models is hinting at another dive of cold Pacific and Polar air over the western and central US next week; and possibly Arctic orientation air diving in the same location after that. Of course, this is too far out to get any sort of a grasp of its reality but December is beginning to show more of a mixed weather pattern as winter evolves (and the way analogues suggested).



December:
Along with write ups and updates on notable weather affecting Southeast Lower Michigan and the Great Lakes and posting my well received Christmases Past article;  I'll explore another troublesome area of forecasting...the ever elusive NAO/AO.

                                                                          Happy Holidays and may you have a
                                                                          prosperous and healthy New Year!
Making weather fun while we all learn  
Bill Deedler -SEMI_WeatherHistorian