Jump to content
  • Member Statistics

    17,703
    Total Members
    7,904
    Most Online
    Szaquli
    Newest Member
    Szaquli
    Joined

As WAR expands, do our snow chances increase? First wave may produce a middling event-solid advisory and possible low end warning for MLK Weekend


weathafella
 Share

Recommended Posts

10 minutes ago, dendrite said:

Kinda had to. It’s finally seeing the synoptics. 

I suggest your analysis late last night was pretty spot on.   

When the 500 mb isotachs have less "kink" inflection, the low is pancaked.  This NAM run is both a tick more inflected, and also just has a stronger core wind max and PV field in the core.  These two factors are the "finally seeing" identifiers.  So this incrementally moved toward the consensus, albeit only a small move. This will probably do this on every cycle through tomorrow night ...at which time it then suddenly has a run that has 24" falling in 3 hours -LOL

It makes sense when we're running a wave space through a compression that's so extreme it's sort of on the edge of total suppression. But this is a strong wave space, so if the compression gives it any window and the cyclone response becomes a rather abrupt correction/emergence

 

  • Like 1
Link to comment
Share on other sites

Left is 72 hours from 00z last night.     Right is 60 hours from 12z this morning. 

Same interval demoing a clear trend...  

image.png.59c8e86d8f81719fcff9ac99284495de.png

 

The NAM prooobably does this incrementally catching up routine for the next 6 or 8 cycles. 

  • Like 1
Link to comment
Share on other sites

It’s still doing the same thing with the vorticity as it did yesterday…just less so. I’m not worried about it unless other models start going that direction, but I bet the NAM eventually caves way more than the rest of the consensus. 

Link to comment
Share on other sites

I think I saw dendrite talking about this shortwave energy in one of the pages I was catching up on from overnight/this morning but maybe the NAM is being a bit too aggressive with it...too much influence from convection (though convection doesn't look like a big deal). But I guess there are two ways to look a this:

1) The NAM is totally off its rocker

2) It's a feasible reality and something that shouldn't be discounted, especially at this range. 

We all know the NAM isn't the greatest synoptically, however, it's not like it's presented output here is something that is outlandish or unlikely. It basically just continues indicating there is alot of spread. I'd be nervous putting snow maps out right now, especially if on the aggressive side. 

image.thumb.png.74fd77854c04d519839c27d285889a67.png

Link to comment
Share on other sites

Just now, weatherwiz said:

I think I saw dendrite talking about this shortwave energy in one of the pages I was catching up on from overnight/this morning but maybe the NAM is being a bit too aggressive with it...too much influence from convection (though convection doesn't look like a big deal). But I guess there are two ways to look a this:

1) The NAM is totally off its rocker

2) It's a feasible reality and something that shouldn't be discounted, especially at this range. 

We all know the NAM isn't the greatest synoptically, however, it's not like it's presented output here is something that is outlandish or unlikely. It basically just continues indicating there is alot of spread. I'd be nervous putting snow maps out right now, especially if on the aggressive side. 

image.thumb.png.74fd77854c04d519839c27d285889a67.png

NAM isn’t going to be correct. I’d prob not be putting out 6-10 totals yet but at least telling people that a decent snowfall is a very distinct possibility for Sunday afternoon/night. Even the 3k NAM is a lot more organized than the 12k. 

  • Like 1
Link to comment
Share on other sites

Just now, ORH_wxman said:

NAM isn’t going to be correct. I’d prob not be putting out 6-10 totals yet but at least telling people that a decent snowfall is a very distinct possibility for Sunday afternoon/night. Even the 3k NAM is a lot more organized than the 12k. 

I'm expecting the NAM not to be correct as well, however, sometimes I think we get a little too aggressive with quickly discounting the NAM. We have all been burned at times in the past discounting the NAM too quickly. Agreed on telling people that a decent snowfall is a distinct possibility but I would be very nervous offering ranges right now. Regarding the 3km vs. 12km...it's wild how much those models can differ and it's something which seems to have gotten worse lately. 

We've have seen before where we have strong support from global models, even inside 66-78 hours and then once we got inside the 60 hour mark we started seeing big shifts and quickly. 

  • Like 2
Link to comment
Share on other sites

Just now, weatherwiz said:

I'm expecting the NAM not to be correct as well, however, sometimes I think we get a little too aggressive with quickly discounting the NAM. We have all been burned at times in the past discounting the NAM too quickly. Agreed on telling people that a decent snowfall is a distinct possibility but I would be very nervous offering ranges right now. Regarding the 3km vs. 12km...it's wild how much those models can differ and it's something which seems to have gotten worse lately. 

We've have seen before where we have strong support from global models, even inside 66-78 hours and then once we got inside the 60 hour mark we started seeing big shifts and quickly. 

the model trend on the NAM has been pretty clear

  • Like 1
Link to comment
Share on other sites

Just now, weatherwiz said:

I'm expecting the NAM not to be correct as well, however, sometimes I think we get a little too aggressive with quickly discounting the NAM. We have all been burned at times in the past discounting the NAM too quickly. Agreed on telling people that a decent snowfall is a distinct possibility but I would be very nervous offering ranges right now. Regarding the 3km vs. 12km...it's wild how much those models can differ and it's something which seems to have gotten worse lately. 

We've have seen before where we have strong support from global models, even inside 66-78 hours and then once we got inside the 60 hour mark we started seeing big shifts and quickly. 

The thing is….it’s the NAM that’s slowly caving right now and not the other way around. I do expect the western outliers (Canadian suite) to start drifting east but I’m not expecting a wholesale shift SE to where most of SNE is getting just scraped by this thing. 

Link to comment
Share on other sites

14 minutes ago, ORH_wxman said:

NAM isn’t going to be correct. I’d prob not be putting out 6-10 totals yet but at least telling people that a decent snowfall is a very distinct possibility for Sunday afternoon/night. Even the 3k NAM is a lot more organized than the 12k. 

It's times like these I wish CPC still had the 'Model Diagnostic Discussion' product.  

I found that very useful back in the day.   Every so often, a guidance would go astray.  Invariably, you go read the discussion, which disseminated pretty soon after the model release actually ..., and it would read like this: 

"WV IMAGERY SUGGESTS THE NAM INITIALIZED BETWEEN 10 AND 15 KTS TOO LOW WITH THE WIND MAX VELOCITIES ASSOCIATED WITH THE WAVE SPACE SET TO IMPACT THE UPPER MA AND NE REGIONS ... RECOMMEND NOT USING IT IN LIEU OF ..." 

...x y z that do not appear to contain this error...etc.   something like that. 

This smacks as missing something in the grid but who knows -

  • Like 2
Link to comment
Share on other sites

1 minute ago, JC-CT said:

the model trend on the NAM has been pretty clear

 

Just now, ORH_wxman said:

The thing is….it’s the NAM that’s slowly caving right now and not the other way around. I do expect the western outliers (Canadian suite) to start drifting east but I’m not expecting a wholesale shift SE to where most of SNE is getting just scraped by this thing. 

It is that trend which is leading me to believe the NAM is not going to be correct but like I mentioned, we have seem several events over the past few years where we saw the NAM starting to cave towards other guidance and then all of a sudden other guidance started caving in the other direction. The direction I am leaning in right now is majority receive several inches of snow...that's how I felt yesterday morning when I posted in the main thread that I think this surprises...but I want to keep an open mind right now and understand we have seen some wild shifts inside 48-72 hours in recent years. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...