January Medium/Long Range Disco Thread

[WinterWxLuvr]

7 minutes ago, CAPE said:

Yeah they look close. I just think there are probably enough subtleties than cant be detected by comparing past h5 composites to a current projected mean. I would have to be convinced that the current Pacific state is not more hostile than say back in Feb 2010, despite the similar h5 looks.

As I said in a discussion we had the other day, I am willing to consider the possibility that what used to be our "money looks" for snow events here may not work as well anymore. Maybe a  -EPO becomes the new -AO.

I’d rather see a -EPO than anything else if I only get to pick one.

[psuhoffman]

7 minutes ago, CAPE said:

Yeah they look close. I just think there are probably enough subtleties than cant be detected by comparing past h5 composites to a current projected mean. I would have to be convinced that the current Pacific state is not more hostile than say back in Feb 2010, despite the similar h5 looks.

As I said in a discussion we had the other day, I am willing to consider the possibility that what used to be our "money looks" for snow events here may not work as well anymore. Maybe a  -EPO becomes the new -AO.

I don’t disagree but that’s not a trade I want to make. Im a snow fan not a cold fan. And a -epo will never be as effective at promoting a favorable storm track for snow.  I think 2014 and 2015 gave a false impression of what a typical epo ridge pattern is.  We’ve had quite a few great EPO ridge patterns since and none produced that result. This example from 2018 is way more indicative of a “normal” result in an epo ridge pattern. A lot of rain with a lot of snow to our northwest.

 I could pull out several more epo ridge patterns from the last 5 years that produced some cold into the US but no snow for us. 
 

ETA:  you actually can do “better” in a EPO driven pattern then the typically more favored parts of our region, sometimes getting clipped by late developing progressive waves or follow up systems.  So for the eastern shore maybe it’s not as bad a trade lol. 

[WinterWxLuvr]

The euro and gfs are miles apart on Sunday. Really interesting 

[WinterWxLuvr]

On pivotal which is the gfs para?

[psuhoffman]

7 minutes ago, WinterWxLuvr said:

I’d rather see a -EPO than anything else if I only get to pick one.

Since 2015 I’ve had 9 warning level snowfalls. Not a single one was EPO driven (and we’ve had several beautiful epo ridges in that period). 7 were AO/NAO driven and 2 were PNA driven. Historically the numbers are similar. The EPO has never had much correlation to our snowfall. 2014-15 was an anomaly. 

[chris21]

52 minutes ago, PivotPoint said:

 

Lesson learned from this year: stable and early in the season blocking can screw us... badly. The issue here for winter weather this season is simple. Our source region had no time to build up cold and the PAC has a mean trough look. Pretty simple actually. There’s other side dishes in there but the meat and potatoes is there is no cold within 2000 miles to our N/NW. -5, -10 temp anomalies in central Canada have people saying “that’s cold enough for snow”. Well, yes. For them though, not for us. By the time that airmass were to reach us it would be modified and mixed to the degree that it would not support snow down here in the mid Atlantic. The only way to help fox our source region this late in the game would be a SSWE, or perhaps an EPO ridge and +NAO combo that allows cold to build back up for 4-5 weeks, then we hope for a cold March. It’s becoming pretty clear to me that any major snow chances might be a real outside chance (again) this year. I think we’ll probably luck into some times front that has some trailing energy to allow enough cold drainage for snow, but there’s a real chance that NOVA/DC metro gets blanked. Even if it does snow I bet we have surface temp galore problems not having any juice behind an artic high or even a modified front. Not feeling warm and fuzzy about our chances through foreseeable future. Maybe mid feb-March will produce.

Im going with this guy over psu, HM, and Webb.

[SnowDreamer]

4 minutes ago, WinterWxLuvr said:

On pivotal which is the gfs para?

V16

[aldie 22]

I'll take 31 degrees at all levels and tons of moisture and take my chances and I don't care who is driving the car

[CAPE]

8 minutes ago, psuhoffman said:

I don’t disagree but that’s not a trade I want to make. Im a snow fan not a cold fan. And a -epo will never be as effective at promoting a favorable storm track for snow.  I think 2014 and 2015 gave a false impression of what a typical epo ridge pattern is.  We’ve had quite a few great EPO ridge patterns since and none produced that result. This example from 2018 is way more indicative of a “normal” result in an epo ridge pattern. A lot of rain with a lot of snow to our northwest.

 I could pull out several more epo ridge patterns from the last 5 years that produced some cold into the US but no snow for us. 
 

ETA:  you actually can do “better” in a EPO driven pattern then the typically more favored parts of our region, sometimes getting clipped by late developing progressive waves or follow up systems.  So for the eastern shore maybe it’s not as bad a trade lol. 

Its more of a crapshoot for sure. There is a high risk of cutters/inland runners with storms that amplify without NA help. I would need at least some timely -NAO episodes for it to work out here most of the time. The one big snow/slop storm in 2014 did not go so well here.

eta- remember, the context with which I brought it up was possible "new normal" going forward, lol. So the historical stuff would become less useful.

[psuhoffman]

6 minutes ago, WinterWxLuvr said:

The euro and gfs are miles apart on Sunday. Really interesting 

On the surface. But overall they aren’t as different as it seems. It’s a critical tipping point where there is enough space to amplify and get precip from that SW pass. GFS and Euro are barely on either side of that threshold. A minor shift in the mid and upper levels by either flips it’s surface solution. 

[WinterWxLuvr]

2 minutes ago, psuhoffman said:

Since 2015 I’ve had 9 warning level snowfalls. Not a single one was EPO driven (and we’ve had several beautiful epo ridges in that period). 7 were AO/NAO driven and 2 were PNA driven. Historically the numbers are similar. The EPO has never had much correlation to our snowfall. 2014-15 was an anomaly. 

Doesn’t the EPO help produce the PNA? And also, you’re saying that in every one of those warning level snows the EPO was positive?

And all of us aren’t looking for just warning level snow. Some of us are looking for cold and throw  in the occasional clipper and light 1-3” snows. Personally I hate a warning level snow only to be followed two days later with temps in the 50’s.

My screen name is Winter weather lover, not occasional 10” snow lover.

[poolz1]

Increasing CAD continues on the 12z gfs....31/32 aint gonna cut it for an icy scenario but a few more changes like this and a sneaky, brief icing event could unfold. Notice the steady push further south into SVA and NC. Dews in the mid/upper 20s showing up along the MD line.

 

[Maestrobjwa]

56 minutes ago, psuhoffman said:

Your second point is interesting. The one biggest change is the enhanced pac jet. But that seems to be a new normal since it’s existed for quite a while now regardless of enso state.  But perhaps that has made that look less supportive then it once was. And your point about outdated analogs is true. But that also kind of feeds my point which summed up is “we better hope that look still works because it’s responsible for A LOT of our best snowstorms and it’s not like we’re picking up new ways to snow to replace it in this warmer climate base state”. 

 

41 minutes ago, CAPE said:

Yeah they look close. I just think there are probably enough subtleties than cant be detected by comparing past h5 composites to a current projected mean. I would have to be convinced that the current Pacific state is not more hostile than say back in Feb 2010, despite the similar h5 looks.

As I said in a discussion we had the other day, I am willing to consider the possibility that what used to be our "money looks" for snow events here may not work as well anymore. Maybe a  -EPO becomes the new -AO.

This here...is why I'm a tad anxious about how things turn out this winter--because it could have implications for the future. Could we not say that by the end of this winter we'll know if our snow climo is more damaged? Because I mean...if we get money looks and they don't work as well...that is foreboding. Because then you couldn't say "try again next year", because the over climo would be more hostile. So this winter is gonna be very important for our future snow prospects...and that's a tad nerve-wracking. Our snow future could be riding on what we see this year, couldn't it?

[psuhoffman]

8 minutes ago, WinterWxLuvr said:

Doesn’t the EPO help produce the PNA? And also, you’re saying that in every one of those warning level snows the EPO was positive?

And all of us aren’t looking for just warning level snow. Some of us are looking for cold and throw  in the occasional clipper and light 1-3” snows. Personally I hate a warning level snow only to be followed two days later with temps in the 50’s.

My screen name is Winter weather lover, not occasional 10” snow lover.

The EPO was positive in most yes and in the others it was neutral or only weakly negative. It wasn’t driving the bus.  An epo ridge usually promotes a trough too far west for us.
 

And a full latitude PNA/extremely east based EPO ridge absent a block is a cold dry look. Once in a while you can get a crazy storm like March 93 from that kind of ridiculous full hemisphere wave but I’ve shown in the past (when someone was throwing around that analog) how that was a huge anomaly and most of the time with a similar look we just get a short arctic blast then warm up.  

An exception would be what we had in 2014, an extremely positively tilted east EPO ridge that poked all the way into the AO domain. Then we can suppress the SE ridge and get progressive waves. 2015 worked because the TPV got displaced into Quebec. That works too. But those are really rare anomalies that I can’t find that many examples of historically. 
 

My point is the EPO alone doesn’t work. We need other factors. And yes an epo ridge with a -NAO can work...but actually a +EPO -NAO correlates to snow even more so obviously the EPO want the determinant. 
 

You’re point about 1-3” snows could be valid. I’ve not done much study on that. That’s not really my thing. 
 

 

[psuhoffman]

20 minutes ago, CAPE said:

Its more of a crapshoot for sure. There is a high risk of cutters/inland runners with storms that amplify without NA help. I would need at least some timely -NAO episodes for it to work out here most of the time. The one big snow/slop storm in 2014 did not go so well here.

eta- remember, the context with which I brought it up was possible "new normal" going forward, lol. So the historical stuff would become less useful.

Yea I think we’re making slightly different points. I’m saying I hope that isn’t true because of an EPO is the best way to get snow in the new normal...the new normal is going to suck. 

[WinterWxLuvr]

Is this pattern really too much to ask for lol

[psuhoffman]

 

[CAPE]

4 minutes ago, psuhoffman said:

Yea I think we’re making slightly different points. I’m saying I hope that isn’t true because of an EPO is the best way to get snow in the new normal...the new normal is going to suck. 

But that premise is based on the past/current normal, which would no longer exist.

In all seriousness, the advertised pattern on the extended tools includes an EPO ridge, and that may be exactly what we need to flush the puke and get some decent cold- which is where this whole discussion started this morning. No we don't want winters dominated by an EPO blocking ridge with a +AO/NAO, and a WAR.

[psuhoffman]

1 minute ago, WinterWxLuvr said:

Is this pattern really too much to ask for lol

Lol that’s super rare.  Typically a ridge into AK and you get a trough dumped further west then that.  Most of the time to get that wavelength spacing to work requires a -NAO also. 

[psuhoffman]

Just now, CAPE said:

But that premise is based on the past/current normal, which would no longer exist.

In all seriousness, the advertised pattern on the extended tools includes an EPO ridge, and that may be exactly what we need to flush the puke and get some decent cold- which is where this whole discussion started this morning. No we don't want winters dominated by an EPO blocking ridge with a +AO/NAO, and a WAR.

Maybe. But sometimes with a -NAO a EPO ridge dumps the cold into the west unless it’s an east based EpO that extremes into Canada. If it’s a central pac EPO ridge into AK that’s actually a bad sign. It’s one of the few NAO killers. 

[CAPE]

2 minutes ago, psuhoffman said:

Maybe. But sometimes with a -NAO a EPO ridge dumps the cold into the west unless it’s an east based EpO that extremes into Canada. If it’s a central pac EPO ridge into AK that’s actually a bad sign. It’s one of the few NAO killers. 

Well, we were told it was meteorologically impossible anyway.  I cant remember who that was lol.

[Vice-Regent]

4 minutes ago, CAPE said:

Well, we were told it was meteorologically impossible anyway.  I cant remember who that was lol.

It is now impossible because the land-ocean contrast has increased too much. Stuff can still dig in that far south but not as far east. It's complicated.

[psuhoffman]

@CAPE everyone is mad at that north Pac trough but we’ve had some epic snowfall regimes with that look. 1996, 2003, 2010. And that trough is keeping the central pac ridge suppressed. That ridge (remember my soul crushing post last December)is the single biggest snow hope destroyer there is. It can even destroy a -NAO!  We have occasionally overcome a pac ridge with a -NAO like feb 2006 but it was still a warm month and if they one storm hadn’t worked out we would have wasted a beautiful block because of that pac ridge.  My number one “want” is keep that central pac ridge away.  This look on the long range GEFS is getting dangerous.

Retrograde that WPO vortex anymore and that pac ridge is going to go ape and we will be fighting a SE ridge even with a block!  A perfect pac isn’t in the cards. Getting some huge stable PNA ridge just is unlikely with the current forcing. So imo a WPO vortex is by far the lesser of 2 evils v a central pac EPO ridge that dumps cold into the west while we ridge out!  I don’t care about cold it it’s on the other side of the country!!!

[Wonderdog]

14 minutes ago, psuhoffman said:

Lol that’s super rare.  Typically a ridge into AK and you get a trough dumped further west then that.  Most of the time to get that wavelength spacing to work requires a -NAO also. 

Is it correct to say we need that ridge further east running thru Idaho?

[frd]

12 minutes ago, psuhoffman said:

Lol that’s super rare.  Typically a ridge into AK and you get a trough dumped further west then that.  Most of the time to get that wavelength spacing to work requires a -NAO also. 

Do you still feel the Pac will improve in late Jan? I mean beyond periodic + PNA intervals. 

This area  is another area of various conflicting views from mets and pros. 

[psuhoffman]

7 minutes ago, CAPE said:

Well, we were told it was meteorologically impossible anyway.  I cant remember who that was lol.

I think there is some confusion with what an EPO is. An extremely east based EPO coupled with a PNA ridge centered along the western US into western Canada is a great thing. But that’s not a typical EPO and I doubt that’s in the cards. A typical EPO ridge extending from the central PAC into AK is too far west and dumps the cold into the western US. Those both fall into “EPO” but for our purposes are totally different patterns. One good one bad...both under one index. 

[Ji]

GGEM out of nowhere now has the coastal...but too warm

[psuhoffman]

3 minutes ago, Wonderdog said:

Is it correct to say we need that ridge further east running thru Idaho?

Now you’re getting really specific but yes ideal pna ridge axis is around Idaho 

[psuhoffman]

4 minutes ago, frd said:

Do you still feel the Pac will improve in late Jan? I mean beyond periodic + PNA intervals. 

This area  is another area of various conflicting views from mets and pros. 

I’m of the mind it doesn’t need to improve if we get a west based block. Actually is the N PAC trough vacates and we get a ridge there that’s a worse look with a -NAO. 

[CAPE]

2 minutes ago, psuhoffman said:

@CAPE everyone is mad at that north Pac trough but we’ve had some epic snowfall regimes with that look. 1996, 2003, 2010. And that trough is keeping the central pac ridge suppressed. That ridge (remember my soul crushing post last December)is the single biggest snow hope destroyer there is. It can even destroy a -NAO!  We have occasionally overcome a pac ridge with a -NAO like feb 2006 but it was still a warm month and if they one storm hadn’t worked out we would have wasted a beautiful block because of that pac ridge.  My number one “want” is keep that central pac ridge away.  This look on the long range GEFS is getting dangerous.

Retrograde that WPO vortex anymore and that pac ridge is going to go ape and we will be fighting a SE ridge even with a block!  A perfect pac isn’t in the cards. Getting some huge stable PNA ridge just is unlikely with the current forcing. So imo a WPO vortex is by far the lesser of 2 evils v a central pac EPO ridge that dumps cold into the west while we ridge out!  I don’t care about cold it it’s on the other side of the country!!!

That vortex needs to relax though. We aren't getting any cold now, other than briefly behind a storm, and it isn't even that cold. Need to strike some sort of balance, and flirting with a SE ridge is par for the course in a Nina. As long as we have legit blocking, a mean trough further west could still work. That vortex has been dumping energy out west and amplifying it, and we ridge out anyway with storms tracking NW.