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Model Mezzanine, the 2nd installment


Typhoon Tip

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there's extensive wave contention issues out over the open Pacific.  looking over the last couple cycle's worth of GFS operational runs re the full latitude synoptic evolution at 500mb shows a cornucopia of waves the model's are charged with handling, and their interactions (correctly modeling) is paramount to determinism down stream post relay over N/A. 

 

Firstly, timing and variance therein are going to be more prone to error given to the "flatness" of the flow over all.  There is a tendency to "buckle" the flow, but it is still doing it in a narrow enough corridor (everywhere) to fit squarely inside the latitudes above HA and below Alaska. 

 

The wave dynamics that would (presumably) go on to produce the mid-week most important trough amplitude in the east, was as of 00z's initialization...just leaving Japan's sector.  It's flat and wide open, with a lot of normalized jet velocity arcing its underbelly... As this massive impulse translates quickly across the Basin, another trough ...having smaller spatial dimensions but a bit more actual streak energy, plays catch-up.  This latter feature really amplifies by the time it gets near the longitudes of HA, at the expense of the beloved lead ..which per course -work has been getting negatively influenced (destructive wave interference) do to wave physics.   

 

Par for the tenor of this winter, that destructive interference be seen in model guidance that's preceding an event by 4 to 10 days between Coasts... 

 

But, that 'damping' of the lead mechanics then means that what finally squirts through the western building ridge has had some power stolen from it.  

 

I am noticing the static heights over the SE in between successive waves is not appreciably high; nor are the intramural wind velocities very far above 35 knts.  That means (for me) that as waves propagate E of the MV through the TV and Gulf interface regions .. .they are not getting absorbed by howling winds (shear) and thus dimming their cyclogen capacities... So that is good for storm seeking.  That leaves it up to the maelstrom over the Pacific to deliver the goods...

 

The last couple of runs of most guidance I have seen show that delivery to be shredding ... most likely do to the wave-spacing issues about between HA and Alaska as discussed above.  

 

The implicit argument here is that the Pacific flow isn't necessarily being correctly handled, and could correct either way(s).  Should the second impulse become dominant, than the lead washes out more entirely, and that opens even more uncertainty downstream over mid latitudes/N/A.   If it trends weaker...the leads then comes through the ridge stronger and has more to conserve as it tanks in latitude over eastern America and there you go...  

 

One thing: the general canvas is still supporting more amplitude...I am not sure how that helps (or not) all these affairs, but that is a monster +PNA era at this point, so waves of any strength coming through the west would get a huge steroid injection off of large-scale amplification-feedbacks.

You're late

Cue the next five paragraph soliloquy from Tip about the tenor of this season.

 

At 168 even though it looks good at the surface, it looks like at least three different shortwaves embedded in the longwave trough. Am I seeing that right? (looking at freebie maps)

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