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.

[Scarlet Pimpernel]

Just now, 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. 

Yeah, I was going to post this the other day but I appreciate this thread.  General discussion on what the overall pattern looks like, and how/if some threat could actually materialize.  Without the whining, etc., with every model run.  I take it that if an actual event threat materializes, that will be discussed more in the regular medium range (and potentially eventual storm specific thread).

OK, on topic:  It does appear that next weekend's possibility is looking pretty slim right now.  I know most guidance has been advertising a general warmup sometime just after next weekend, but it's unclear (to me) how entrenched that gets.  I've only followed the guidance (500-mb mainly) in a cursory way, trying to see how things evolve as we get into the last week or so of this month.  It seems to me that the warmup doesn't look "extreme" and we kind of end up after that in a sort of changeable look with potential favorable situations for some decent snow chances.  I am still hopeful from various things I've seen in here (various indices, extended Euro guidance, etc.) that we're not done yet.  I still believe that we don't escape February with zero snow; not a HECS system, but I think a SECS to a MECS level event surely must be on the table.  Similarly for the first part of March.

[Blizzard of 93]

9 minutes ago, Weather Will said:

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

People can read more & post less. They can read & learn without sifting through emotional whiny banter that changes every 6 hours…

It is ok to just read & not interject mindless posts that offer no value.

These posts in here are gold & are the reason that I joined this forum 12 years ago. My learning continues because of the good posters on here & across the various regional forums.

[ravensrule]

1 minute ago, Blizzard of 93 said:

People can read more & post less. They can read & learn without sifting through emotional whiny banter that changes every 6 hours…

It is ok to just read & not interject mindless posts that offer no value.

Excuse me, my posts involve A LOT of thought. I just didn’t say what kind of thoughts. 

[Paleocene]

20 minutes ago, Blizzard of 93 said:

People can read more & post less. They can read & learn without sifting through emotional whiny banter that changes every 6 hours…

It is ok to just read & not interject mindless posts that offer no value.

These posts in here are gold & are the reason that I joined this forum 12 years ago. My learning continues because of the good posters on here & across the various regional forums.

Agreed wholeheartedly. I don't want to look at snow maps, surface maps, or snow means for threats D6+ out. A long range pattern analysis thread is helpful for figuring out whether or not I need to pay attention. Speaking for myself I feel like I've learned a lot about how to read/track threats that are more real, i.e. inside 72 hours. I feel like I "get" thermals at different layers, low positions, wind direction, even the 500mb charts to understand phasing, ULLs, etc. But the big picture pattern/teleconnections are still a partial mystery to me. So having one place here to read about that really helps.

[Maestrobjwa]

1 hour 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 appreciate this thread--helps to cut through some of the noise. I've purposely stayed off of this site the last few days for the very reason of not wanting said noise leading up to a possible threat. But I did start to miss the great analysis here, so I caved and came back, lol This page is easier to read...and I hope I can ask some novice technical questions in here on things I don't always understand!

[Miss Pixee]

I agree some of the technical climate discussion whizzes past me. What if there's an informational thread with graphic samples and explanations of basic terms used here? Like FOLKS. I can't find that mentioned anywhere but on this forum.

Miller B vs Miller A look

MECS, SECS, HECS (I forget what SECS is).

Prime hi/lo locations for large snowstorms in mid atlantic

Clippers vs coastal formations

I think a quick reference guide/thread would help. It could even be added to over time. I usually don't mind banter but when everything turns into banter its annoying and distracting. When all the colorful maps are posted some of us non weather heads would understand better what to ignore (or pay attention to) on various runs. Just my two cents.

[CAPE]

3 hours ago, psuhoffman said:

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. 

12z GFS pretty much does it. A significant and sharp shortwave, coastal low, facilitated by the Central Canada/Hudson ridge and well timed 50-50 with surface HP where we need it. Just like the old days where this setup could snow in the MA.

[Terpeast]

 

12z gfs just showed us the win scenario we all need, including the lowlands. 

First, we need a lead shortwave (over MN/IA at 132 hr) to reinforce cold air just before the main wave (over AZ/NM) arrives. 

And the main wave is strong enough to maintain a miller A with sufficient gulf feed:

We don’t want them to phase too early else it will cut, and we also don’t want zero interaction between the two streams either.

 

•  

[CAPE]

2 hours 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. 

Correct. All are welcome, just want it free of complaining and emotional breakdowns after every run that has an undesirable outcome. Drama free, and no random posts of maps without explanation. No snow maps until guidance agrees on a storm.

[CAPE]

11 minutes ago, Terpeast said:

 

 

12z gfs just showed us the win scenario we all need, including the lowlands. 

First, we need a lead shortwave (over MN/IA at 132 hr) to reinforce cold air just before the main wave (over AZ/NM) arrives. 

And the main wave is strong enough to maintain a miller A with sufficient gulf feed:

We don’t want them to phase too early else it will cut, and we also don’t want zero interaction between the two streams either.

 

•  

So much of what ultimately occurs hinges on wave timing. Its always the case but especially with a busy NS and lacking a true NAO block. It all works out pretty nicely on this run.

[Climate175]

For those with more knowledge, did the GFS and ICON at 12z show a type of Miller A situation? 

[Scarlet Pimpernel]

8 minutes ago, Climate175 said:

For those with more knowledge, did the GFS and ICON at 12z show a type of Miller A situation? 

Just from my cursory look at both, it looks more Miller A-like to me.  Primary low forms in the southeast and runs along the coast.  Your typical Miller B would run a primary into TN/KY, and then a secondary forms off OBX or there about that takes over (in our more ideal situations for snow here from Miller Bs).

[CAPE]

GEFS looks similar with the NS energy from the Midwest moving southeastward to reinforce the confluence.

[SnowenOutThere]

3 minutes ago, Climate175 said:

For those with more knowledge, did the GFS and ICON at 12z show a type of Miller A situation? 

Its primarily a miller A solution IMO. Looking at the H5 map of vorticity (which approximates upper air diffluence and consequently lift in the lower levels) we can see that the main energy of the system on the GFS is over the Gulf

 

Looking at the surface pressure map around 12 hours later we can see that there is a nudge of pressure going up the Ohio valley (due to the H5 amplifying the surface across the East coast) which does indicate a bit of a miller B/C depiction.

However, the real meat of the storm is in Georgia after tracking across the Gulf states. This is really just a miller A but without enough blocking in place to prevent the H5 diffluence from promoting some surface cyclogenesis in the Ohio valley. In order to prevent this storm from cutting we just need the NS to promote enough confluence to prevent the 925/850 low from going up the valley like what happened on Jan 25th. Generally we want either more confluence or the wave to eject from the SW earlier while we still have that cold air push. 

[SomeguyfromTakomaPark]

This is annoying having to read 2 threads now….cant u guys just post in the main thread and put the posters u dont wanna read on ignore?

[NVAwx]

1 hour ago, Miss Pixee said:

I agree some of the technical climate discussion whizzes past me. What if there's an informational thread with graphic samples and explanations of basic terms used here? Like FOLKS. I can't find that mentioned anywhere but on this forum.

Miller B vs Miller A look

MECS, SECS, HECS (I forget what SECS is).

Prime hi/lo locations for large snowstorms in mid atlantic

Clippers vs coastal formations

I think a quick reference guide/thread would help. It could even be added to over time. I usually don't mind banter but when everything turns into banter its annoying and distracting. When all the colorful maps are posted some of us non weather heads would understand better what to ignore (or pay attention to) on various runs. Just my two cents.

A good one from CTP: https://www.weather.gov/ctp/SnowStormTypes

Miller A's are classic.

Miller B's are trickier and can shaft many of us, but tend to produce well for areas NE of Baltimore. 

 

 

 https://en.wikipedia.org/wiki/Miller_classification

https://www.13newsnow.com/article/weather/severe-weather/noreasters-different-types-miller-a-miller-b-snowstorm-blizzard-winter-weather/291-945f5b59-6569-4dc9-b3a8-40b8921efade