Winter Storm Threat *Technical* Discussion. No Op Run PBP or Snow maps

[bncho]

On 12/30/2019 at 1:52 AM, psuhoffman said:

Hudson Bay Ridge

16 Storms

This was the single biggest factor able to equalize a crap pattern.  A lot of our "fluke" snows in otherwise bad patterns came because of this feature.  Basically a ridge near Hudson Bay is perfectly located to force a storm under us even without much else right.  Actually if other features are lined up right a hudson ridge would probably suppress a storm way to our south.  We would want the block much further north normally.  But in an otherwise crap pattern that feature has saved us often.  THis is the composite of those events.  

Seeing a ridge centered near Hudson Bay can indicate we have a shot...even if the pattern is otherwise crap

In PSU's snow climo classroom he mentioned some insightful things about the Hudson High pattern, good read above^^^

[winter_warlock]

7 hours ago, CAPE said:

And other rational, smart people who choose to join in. But I'm good talking to myself lol.

As long as ur not arguing with ur self ur good lol

[CAPE]

0z EPS- The primary energy ejecting from the SW does pop a low along the Gulf coast and moves off the NC coast. It gets some precip into the MA on the mean. Cold looks marginal but interior areas at elevation might be in a good spot should precip make it there. Just beyond that it looks mild with a temporary ridge over the east. Then we shall see about the potential around the 20th or so.

 

[psuhoffman]

3 minutes ago, CAPE said:

0z EPS- The primary energy ejecting from the SW does pop a low along the Gulf coast and moves off the NC coast. It gets some precip into the MA on the mean. Cold looks marginal but interior areas at elevation might be in a good spot should precip make it there. Just beyond that it looks mild with a temporary ridge over the east. Then we shall see about the potential around the 20th or so.

 

Oz guidance across the board didn’t eject enough energy and trended more suppressive with the Atlantic look. Bad combo. Result is this. We need x to be where y is and stronger but that’s redundant because for it to be where y is it would have to be stronger. 
 

[Terpeast]

7 minutes ago, psuhoffman said:

Oz guidance across the board didn’t eject enough energy and trended more suppressive with the Atlantic look. Bad combo. Result is this. We need x to be where y is and stronger but that’s redundant because for it to be where y is it would have to be stronger. 
 

Disappointed, but not surprised. The red flag yesterday and even the day before was that guidance was trending weaker with the undercutting energy beneath the hudson bay ridge. 

[psuhoffman]

All the guidance has flipped places. The GEPS is now the most favorable and the Euro stuff the least. 
 

[psuhoffman]

6 minutes ago, Terpeast said:

Disappointed, but not surprised. The red flag yesterday and even the day before was that guidance was trending weaker with the undercutting energy beneath the hudson bay ridge. 

We are still far enough out for that to adjust again. We need that Baja wave to eject stronger and the Atlantic flow to be slightly less suppressive. It wouldn’t take much, an adjustment well within a typical 150 hour error, but we’ve been so unlucky for so long that I think we juts assume nothing good will happen.  Which given our climo is usually right. Snow here isn’t a “fair” game. There are like 10 major variables and we need almost all of them to go right. There are way more losing combinations than winning ones so every threat is more likely to fail. I mean even in the rare cases when we get the flow to be cold enough then we have to worry the storm gets squashed or goes south of us!   But eventually if we keep playing we will roll the right combination and get lucky.  

 

[CAPE]

2 minutes ago, psuhoffman said:

Oz guidance across the board didn’t eject enough energy and trended more suppressive with the Atlantic look. Bad combo. Result is this. We need x to be where y is and stronger but that’s redundant because for it to be where y is it would have to be stronger. 
 

Recent cycles have  ejected significant energy and the outcome in those cases has been a low cutting west/ Miller B. 6z GFS does the latter, but the coastal gets going at our latitude. Still a range of possibilities imo. Timing with energy moving into/through the 50-50 region is also going to be a key factor in the outcome. Everything is on the move.

[psuhoffman]

1 minute ago, CAPE said:

Recent cycles have  ejected significant energy and the outcome in those cases has been a low cutting west/ Miller B. 6z GFS does the latter, but the coastal gets going at our latitude. Still a range of possibilities imo. Timing with energy moving into/through the 50-50 region is also going to be a key factor in the outcome. Everything is on the move.

I don’t think this particular threat is high probability SE of 95. You’re right that area is in a double bind. Any stronger wave will initially try to gain latitude in the Midwest because there is some ridging there. It will get blocked by the Atlantic flow eventually but without arctic air in place not sure what the “Win” scenario for SE of 95 is.  Even if things go the way we want it’s probably more a 95 NW threat. Even the snowier solutions were indicating that. 

[CAPE]

1 minute ago, psuhoffman said:

I don’t think this particular threat is high probability SE of 95. You’re right that area is in a double bind. Any stronger wave will initially try to gain latitude in the Midwest because there is some ridging there. It will get blocked by the Atlantic flow eventually but without arctic air in place not sure what the “Win” scenario for SE of 95 is.  Even if things go the way we want it’s probably more a 95 NW threat. Even the snowier solutions were indicating that. 

Agreed. Only chance here is something like the EPS has but in that case the low is weaker and there still isn't enough cold. Might be a rain snow mix/snow tv. Would need an ideal track and a more significant low.

[psuhoffman]

15 minutes ago, CAPE said:

Agreed. Only chance here is something like the EPS has but in that case the low is weaker and there still isn't enough cold. Might be a rain snow mix/snow tv. Would need an ideal track and a more significant low.

Yea for the lowlands to “win” in a thermal regime like this you’d need a true coastal track. The problem is the wave is de-amplifying as it hits the Atlantic flow.  So I don’t see how that scenario is on the table. Ideally you’d want a weak wave initially that amplifies on the coast but that’s not on the table. The win for areas NW of 95 is a stronger wave to the west that transfers just in time. Maxes dynamic cooling to take advantage of the marginal cold we have. The reason that could work is there isn’t some deep phased trough to our west this time. There is a split flow with the NS out the FCKN way for once and a cut off system traversing under the NS flow. So there isn’t that screaming SW wind ahead of the wave to destroy our mid level thermals. A marginal cold can work here but the issue for SE is 95 is that because of the flow deamplifying we need a stronger wave to our west to get anything and that will wreck the low level thermals for coastal areas. 

[Weather Will]

General comment:  the way non experts like myself learn is for these posts to be integrated into  the broader discussion. Having expert analysis is great only if it is easily accessible.  The ivory tower approach taken here has a chilling effect on the entire forum.

[psuhoffman]

7 minutes ago, Weather Will said:

General comment:  the way non experts like myself learn is for these posts to be integrated into  the broader discussion. Having expert analysis is great only if it is easily accessible.  The ivory tower approach taken here has a chilling effect on the entire forum.

I don’t think that’s the intent. CAPE can correct me if I’m wrong but genuine comments and questions are ok. But this thread is a place to actually analyze without 500 clown snow maps and bickering. This way those that want that kind of more “fun” relaxed but storm related banter have that thread and here we can do deeper analysis without wading through the BS. It’s a way to have both. 

[Weather Will]

1 minute ago, psuhoffman said:

I don’t think that’s the intent. CAPE can correct me if I’m wrong but genuine comments and questions are ok. But this thread is a place to actually analyze without 500 clown snow maps and bickering. This way those that want that kind of more “fun” relaxed but storm related banter have that thread and here we can do deeper analysis without wading through the BS. It’s a way to have both. 

I do appreciate that you are posting a lot of your analysis in both threads.  Maybe that is an  approach that everyone could take.