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Tropical Season 2017

40/70 Benchmark

By 40/70 Benchmark,
in New England

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weatherwiz

weatherwiz

Posted
Posted

Was just working on a post and I noticed that according to this the PNA is slightly negative.  However, looking at the upper air pattern which is currently in place that is anything reflective of this state.  Is it b/c the PNA signal is rather weak right now?  What is the driver than behind the current upper air configuration? 

pna.sprd2.gif

 

 

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Typhoon Tip

Typhoon Tip

Posted
Posted
50 minutes ago, weatherwiz said:

Was just working on a post and I noticed that according to this the PNA is slightly negative.  However, looking at the upper air pattern which is currently in place that is anything reflective of this state.  Is it b/c the PNA signal is rather weak right now?  What is the driver than behind the current upper air configuration? 

 

 

 

 

The entire domain space of the PNA is truly massive.  It's on the order of 4 X's the size of the EPO or NAO ...  If you go to the CDC, they give you the lat/lon bounded regions... The PNA covers almost 1/5th of the Earth's surface area.

Where I'm going with that description is that with such a large area, the North American region that occupies the total (being a comparatively small fraction compared to that whole) can take on flow orientations that don't always look like what the total derivatives are indicating the index actually may be at that time.

We think of -PNA(+PNA) as a trough(ridge) in the west and a ridge(trough) in the east ...and that will 'tend' to be true most of the times. But sometimes, particularly when there is a regime change sweeping east through the Pacific... the PNA may begin calculating out to a negative(positive) PNA before the trough(ridge) sets up out west.

In fact, the present idea in many guidance/means for a trough in the west could in fact be just such a "lag" in the N/A realization of the pattern forcing.  

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weatherwiz

weatherwiz

Posted
Posted
3 minutes ago, Typhoon Tip said:

 

The entire domain space of the PNA is truly massive.  It's on the order of 4 X's the size of the EPO or NAO ...  If you go to the CDC, they give you the lat/lon bounded regions... The PNA covers almost 1/5th of the Earth's surface area.

Where I'm going with that description is that with such a large area, the North American region that occupies the total (being a comparatively small fraction compared to that whole) can take on flow orientations that don't always look like what the total derivatives are indicating the index actually may be at that time.

We think of -PNA(+PNA) as a trough(ridge) in the west and a ridge(trough) in the east ...and that will 'tend' to be true most of the times. But sometimes, particularly when there is a regime change sweeping east through the Pacific... the PNA may begin calculating out to a negative(positive) PNA before the trough(ridge) sets up out west.

In fact, the present idea in many guidance/means for a trough in the west could in fact be just such a "lag" in the N/A realization of the pattern forcing.  

Thanks for the information!  This was quite informative.  In the meantime, I looked back at what I posted and then took a harder look into the current upper air look and the forecast and I think in my head I was thinking of +PNA becoming established but obviously that isn't the case.  I sort of classified the PNA as "neutral" in my post and then explained with ridging building into the GoA this is an indicator of a more -PNA state and the amplification of a trough across the west further strengthens this case which is even further strengthened by building heights in the east.  It would be really awesome if someone who was super smart could break down the PNA into different regions and such...sort of similar to what RaleighWx did several years back with regards to the NAO.  Like you said, the PNA region is so massive that you have to look at it more than just positive and negative.  If the index can be broken down further you might be able to gather a stronger correlation to certain patterns and this includes exploring orientations of the troughs/ridges  

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Typhoon Tip

Typhoon Tip

Posted
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4 minutes ago, weatherwiz said:

Thanks for the information!  This was quite informative.  In the meantime, I looked back at what I posted and then took a harder look into the current upper air look and the forecast and I think in my head I was thinking of +PNA becoming established but obviously that isn't the case.  I sort of classified the PNA as "neutral" in my post and then explained with ridging building into the GoA this is an indicator of a more -PNA state and the amplification of a trough across the west further strengthens this case which is even further strengthened by building heights in the east.  It would be really awesome if someone who was super smart could break down the PNA into different regions and such...sort of similar to what RaleighWx did several years back with regards to the NAO.  Like you said, the PNA region is so massive that you have to look at it more than just positive and negative.  If the index can be broken down further you might be able to gather a stronger correlation to certain patterns and this includes exploring orientations of the troughs/ridges  

Well yeah... I mean we have this local vernacular over the "west" and "east" biased NAO constructs, and frankly I like that level of awareness... It shows a willingness, and a correct one at that...to qualify matters.

Anyway, I don't see why there isn't a "N/A PNA" sort of distinction - one that differs from the "PNAP" ...which is the Perennial North American Pattern, consisting of a flat ridge in the west and a shallow trough in the east.  That should be the torque budget base-line canvas in the absolute absence of a any forcing - which is obviously impossible.  But the point is, not to confuse the two.  The PNAP neutral is the flat ridge/shallow trough rest state, where as a +PNA N/A (SAY) would be any state of more positive standard deviation heights in the west...and so forth, regardless of whether the whole PNA domain is calculating in positive vs negative mode. 

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Paragon

Paragon

Posted
Posted
2 hours ago, ORH_wxman said:

Edouard should never be mentioned in here...too much PTSD from that storm.

 

I think highest impact scenario on Jose is probably equivalent to a powerful nor' easter for the eastern half of SNE and a moderate one for western half. We'd prob need it to actually track voer the Cape to get that and that's about on the western edge of realistic solutions right now. Prob will end up SE of that though.

Will, do you think Jose will be the best chance we'll get this year or do you think the pattern going forward, with abundant blocking setting up, will offer something better in the long term?

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Paragon

Paragon

Posted
Posted

About Jose, looks like it tracks further southwest in its track early on, so it looks like the 18z GFS trended west of 12z.  Could get tropical force gusts to the Jersey shore and NYC.  This still has room to trend further west, especially with how much it went SW early on in the 18z track forecast.

Interesting that it's forecast to be stronger now too, and interesting intensity forecast put out by the NHC.

FORECAST POSITIONS AND MAX WINDS

INIT  15/2100Z 27.1N  70.3W   65 KT  75 MPH
 12H  16/0600Z 27.8N  71.4W   75 KT  85 MPH
 24H  16/1800Z 28.8N  72.2W   80 KT  90 MPH
 36H  17/0600Z 29.9N  72.4W   80 KT  90 MPH
 48H  17/1800Z 31.4N  72.2W   75 KT  85 MPH
 72H  18/1800Z 33.9N  72.2W   70 KT  80 MPH
 96H  19/1800Z 36.7N  71.6W   65 KT  75 MPH
120H  20/1800Z 40.0N  69.5W   55 KT  65 MPH

$$
Forecaster Blake

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Paragon

Paragon

Posted
Posted
1 minute ago, Ginx snewx said:

GEFS rots Jose south of LI, never making LF, huge coastal hit for erosion and overwash. Sends Next system into SE

in that location could be a significant amount of rain and wind too- my little rule of thumb for systems like these is if they make it to the latitude of ACY while still staying west of MTP, it's going to be a good rain and wind maker.

 

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SJonesWX

SJonesWX

Posted
Posted
7 hours ago, Typhoon Tip said:

That's because 99% of what people post about are indirect lies - that's why. 

What is really wanted has less to do with substantive analysis, and more pure dystopian thrill of being, if not in the rifle sites at all times, in the buck-shot possibilities for impact, so they can satisfy a weird dependency on that sort of thing for triggering gaiety (for lack of better ending word there..). 

When a couple of respectable Mets, new sourcing, or ...memes emerge out there in the din of the electronic ether that happen to spurn a potential.. the posting tenor immediately redirects from analytic content to "how boring things are," - - even if the object in question, in this case 'Jose' is still on the maps and models.  Because they're not interested in much else other than the ambiance of a threat - it's just that simple. 

What's really on the mind? ... just how bummed out and frustrated they are that the end of the world isn't as nigh as they hoped..  

 

welcome to the forum, new here?

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Typhoon Tip

Typhoon Tip

Posted
Posted
2 minutes ago, SJonesWX said:

welcome to the forum, new here?

:lol:  ...although your sarcasm is miss-directed... I was in fact sarcastically taking a poke for him - I am already aware of such atmospheres...

oy -

Hi guys, how about the GFS 18z run (yes yes I know other's mentioned that run) showing almost the exact same thing with Jose, about 5 days later...  That's amazing...

PF would like the end of that run, too - heh. 

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LongBeachSurfFreak

LongBeachSurfFreak

Posted
Posted
4 minutes ago, Typhoon Tip said:

Looping canes are neh ...

this is one reasons in many why they tend to underwhelm.  but as you say, it's progged to move over the g-string -so

He has a small window of warm and light. If he capitalizes we'll see. I have been pushing the cold shelf waters in the NYC thread. Below normal YTD, due to the cold start to the month and plenty of upwhelling. We have seen shelf/shear combo crush storms that make Jose look like a baby... Good example at a similar time of year Gloria 85.

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Paragon

Paragon

Posted
Posted
8 hours ago, Typhoon Tip said:

That's because 99% of what people post about are indirect lies - that's why. 

What is really wanted has less to do with substantive analysis, and more pure dystopian thrill of being, if not in the rifle sites at all times, in the buck-shot possibilities for impact, so they can satisfy a weird dependency on that sort of thing for triggering gaiety (for lack of better ending word there..). 

When a couple of respectable Mets, new sourcing, or ...memes emerge out there in the din of the electronic ether that happen to spurn a potential.. the posting tenor immediately redirects from analytic content to "how boring things are," - - even if the object in question, in this case 'Jose' is still on the maps and models.  Because they're not interested in much else other than the ambiance of a threat - it's just that simple. 

What's really on the mind? ... just how bummed out and frustrated they are that the end of the world isn't as nigh as they hoped..  

 

it's because the "end of the world" (really just the end of the most recent version of humanity- the world will be fine, maybe even better after humanity is gone) gives their life some special meaning because they want some vast cataclysm to punctuate it.

 

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Paragon

Paragon

Posted
Posted
46 minutes ago, Typhoon Tip said:

:lol:  ...although your sarcasm is miss-directed... I was in fact sarcastically taking a poke for him - I am already aware of such atmospheres...

oy -

Hi guys, how about the GFS 18z run (yes yes I know other's mentioned that run) showing almost the exact same thing with Jose, about 5 days later...  That's amazing...

PF would like the end of that run, too - heh. 

there is another storm on deck and getting ready to hit a week from now too.

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