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SNE "Tropical" Season Discussion 2021


WxWatcher007
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10 hours ago, MJO812 said:

NAO is going negative 

 

Will this impact the storm?

In theory ... a -NAO either materializing or already in place, particularly if the negative characteristic is over the western aspects of the NAO domain space ( D. Straight as a general theme ), that provides a block that prevents TC from moving toward that region.

That supplies/connotes a continued west motion.  There are other modulating factors on cyclone track of course. But that is one of the main larger scaffolding.   You also need a solid, non- perforated subtropical ridge N to buffer it along... Lower shear... all that too.

The problem with the present NAO: ...as far as I can tell, the GEFs automation for determining the index at CPC are reporting a "faux" -NAO over the next 10 days.  The reason I surmise its artificial ( or 'fake' for lack of better word ..) value, is because looking at all individual ensemble members ( all 33 ), their individual orientation of the flow does not look like -NAO.   By convention... that look should feature top heavy heights over arcing the higher latitudes, with the polar westerlies either pinching off underneath, or, doing very large undulate curvature around - which this latter form probably wouldn't be the case at this time of year, not with lower hemispheric gradient still associated to seasonal climatology... etc.  Anyway, neither appears to be setting up in those members. 

Instead, focus on the 576 DM height contour at hour 168:  http://www.meteo.psu.edu/fxg1/ENSHGT_0z/ensloopnew.html

... roughly the nadir of the projected -NAO.  That contour is displaced anomalously far N... from roughly lake Superior over SE Canada, out across the Maritime of Canada to S of Greenland - and it's orientation is nearly west to east, i.e., not curved around any "island" of positive anomaly or undercutting - neither version.  So why the negative... ?

The CPC calculates the index using the geopotential heights.  The anomalies of that one metric is what ultimately determines the positive or negative result of the calculation  ( if you really want a popsicle headache, you can crack open a statistical-math text and read about Eigenvectors and EOFS, "empirical orthogonal functions.. ) 

Anyway, my hunch is that the heights overall being unsually high as they cut through the southern limb of the NAO's total domain may be lowering the results of those calculations, when in reality ... the construct detailing of the flow is not very -NAO instructive, ...not in the typical sense.   So faux ( or fake ) in this sense is kind of sloppy ...because the math is what it is.  But the negative values appear to be  materializing out of a calculation, that is really kind of failing to truly characterize a -NAO.  it's not forcing a jet S along the E seaboard, ...instead, we are just getting this weird inconsistently, pallid weakness there as a result of "not really" -NAO.

 

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29 minutes ago, CoastalWx said:

Lol. I don’t know much about it or what they tweaked. I just know the European op has been terrible with tropicals. 

The tweak is specifically to address the tropics.

Taken from FB:

"Apparently the Euro will be getting a big upgrade in a few weeks, and this update is specifically designed to fix some of the errors that have popped up in recent years in the tropics since the update they made in 2018, which was designed to increase the model’s accuracy with mesoscale features up at Europe’s latitude. Anywho, this new Euro designed to be more like the old Euro with tropical systems is now running parallel to current Euro. And wouldn’t you know it? It shows a violent capture with the upper level low and pinwheels a major hurricane into southeast New England next weekend".

 

More details:

"Cycle upgrade 47r3 will bring improvements to the assimilation and observations usage and a significantly improved physical basis for moist processes, necessary to facilitate further development of the Integrated Forecasting System (IFS) and future application at convection-permitting resolutions.

The upgrade will bring more accurate upper air fields, particularly tropical winds, as well as precipitation in convective regimes. Several new convection-related products will be available and systematic errors are reduced for wind gusts and visibility for fog and precipitation".
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Having said all that to MJO ...

The 00z runs      ...yuck. 

Sort of abolished the elephant in the room, yesterday, that was a continuing along a trend to build features into an orientation that might offer pornographic hope to blue-balled storm enthusiasts...   These 00z runs were proved yesterday was just another tease.

It seems to me that two aspect swooped in ( and it is true in all guidance - which is interesting... It's not like just the Euro or GFS ..etc) and broke that trend continuity -

The substropical ridge helping to guide SAM west over the short to early mid range, came in modeled weaker by just oh so crucial amount, that it starts initiating polar track jumps in small increments earlier on the track guidance comparing previous runs.  And it's not a lot, but is still definitive and crucially so.  By the time Sam gets west of 70 W, ...it's outside the climate 'key slot' ... This slopes off chances of TCs making far enough W at steep angle.  That's A...       B,  the entire manifold of the synoptic construct from 100W to 70 W has changed all at once.  The U/A/cut off is now more of a long wave trough like right on 70 W.   That, in its self, ends it on a dime - no further consideration.  None. Over. 

Both those are suspect in the objective sense.

Both those are entirely reasonable and likely to occur in the abject subjective sense - LOL.   sorry, but this method has merit - it just f'n does.

No but in the objective sense, "continuity breaks" are always suspect until more runs come out and give substance by accumulative confidence. Duh, but also, the sampling of the subtropical ridge out there over the lower Sargasso Sea ...mm.  Okay - we'll see. 

The other aspect that is obvious is that this whole ordeal is still playing out deep in the mid range or even early extended, so there's modulation time in the runs.

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17 minutes ago, 40/70 Benchmark said:

The tweak is specifically to address the tropics.

Taken from FB:

"Apparently the Euro will be getting a big upgrade in a few weeks, and this update is specifically designed to fix some of the errors that have popped up in recent years in the tropics since the update they made in 2018, which was designed to increase the model’s accuracy with mesoscale features up at Europe’s latitude. Anywho, this new Euro designed to be more like the old Euro with tropical systems is now running parallel to current Euro. And wouldn’t you know it? It shows a violent capture with the upper level low and pinwheels a major hurricane into southeast New England next weekend".

 

More details:

"Cycle upgrade 47r3 will bring improvements to the assimilation and observations usage and a significantly improved physical basis for moist processes, necessary to facilitate further development of the Integrated Forecasting System (IFS) and future application at convection-permitting resolutions.

The upgrade will bring more accurate upper air fields, particularly tropical winds, as well as precipitation in convective regimes. Several new convection-related products will be available and systematic errors are reduced for wind gusts and visibility for fog and precipitation".

Btw, I didn't throw this post a like merely because it implicates a funner more appealingly dramatic PARA solution.  LOL. 

Seriously, we've been palpably observing so egregiously bad - and consistent to the point of predictive ass vomit - performance coming out of the Euro products suites in the tropics...for years, that it baffled explanation.  Yeah, okay - just since 2018 .. .BULLSHIT by the way.  They're partially marketing the reader there, because I remember back before then, it had a stingy genesis tendency - it did well "after" the cyclones materialized, but never had to absorb the guilt of false spin ups.   Ha ha, for that fetish we could always rely upon the Canadian 'cumulus cloud --> cat 5' in 20 minutes ...

Jokes aside, Johnny-come-lately shows up and it's, "okay, other models, here's what we're going to do with what you worked so hard and risked your reputation and succeeded in seeing.."    Ha.

It always pissed me off and it definitely predated 2018 ...sorry, it does. 

But, whatever. ECMWF is directly and non ambiguously stating that they are addressing the problem and as such, it would be really really awesome if that model stops finally hangin' it's ass over the Atlantic punch bowl and ruining the parties -

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1 minute ago, Typhoon Tip said:

I didn't throw this post a like - btw - merely because it implicates a funner more appealingly dramatic PARA solution.  LOL. 

Seriously, we've been palpably observing so egregiously bad - and consistent to the point of predictive ass vomit - performance coming out of the Euro products suites in the tropics...for years.  Yeah, okay - just since 2018 .. .BULLSHIT by the way.  They're partially marketing the reader there, because I remember back before then, it had a stingy genesis tendency - it did well "after" the cyclones materialized, but never had to absorb the guilt of false spin ups.   Ha ha, for that fetish we could always rely upon the Canadian 'cumulus cloud --> cat 5' in 20 minutes ...

Jokes aside, Johnny-come-lately shows up and it's, "okay, other models, here's what we're going to do with what you worked so hard and risked your reputation and succeeded in seeing.."    Ha.

It always pissed me off and it definitely predate 2018 ...sorry, it does. 

But, whatever. ECMWF is directly and non ambiguously stating that they are addressing the problem and as such, it would be really really awesome if that model stops finally hangin' it's ass over the Atlantic punch bowl and ruining the parties -

Yea, I figured as much.

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5 hours ago, 40/70 Benchmark said:

The tweak is specifically to address the tropics.

Taken from FB:

"Apparently the Euro will be getting a big upgrade in a few weeks, and this update is specifically designed to fix some of the errors that have popped up in recent years in the tropics since the update they made in 2018, which was designed to increase the model’s accuracy with mesoscale features up at Europe’s latitude. Anywho, this new Euro designed to be more like the old Euro with tropical systems is now running parallel to current Euro. And wouldn’t you know it? It shows a violent capture with the upper level low and pinwheels a major hurricane into southeast New England next weekend".

 

More details:

"Cycle upgrade 47r3 will bring improvements to the assimilation and observations usage and a significantly improved physical basis for moist processes, necessary to facilitate further development of the Integrated Forecasting System (IFS) and future application at convection-permitting resolutions.

The upgrade will bring more accurate upper air fields, particularly tropical winds, as well as precipitation in convective regimes. Several new convection-related products will be available and systematic errors are reduced for wind gusts and visibility for fog and precipitation".

Tossed 

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