January Medium/Long Range Disco Thread

[aldie 22]

Lol classic day in the Mid Atlantic forum

[cbmclean]

2 minutes ago, WxUSAF said:

Apparently that beautiful H5 look on the week 3 map gives us a +8F temp departure!? lol that’s pretty amazing

Where are you able to see that data?

[Ralph Wiggum]

8 minutes ago, psuhoffman said:

Before anyone jumps off a bridge I do NOT take snowfall maps at range seriously....just was posting that for a LOL more then anything else.  Of course...come March if we had a west based NAO block all winter and DC doesn't get ANY snow...we can bump this post.  

Yeah, those maps had my area over 56" in a 3 week period last winter. We ended with 0. So yeah, grain of salt on the snowfall maps. 

[jaydreb]

1 minute ago, leesburg 04 said:

Lol classic day in the Mid Atlantic forum

Talk of SSW - check

3 week maps - check

Despair over lack of digital snow - check

Judah Cohen - check

Lack of cold air - check

Reminiscing about historic patterns - check

 

[WxUSAF]

1 minute ago, cbmclean said:

Where are you able to see that data?

Saw it posted on another forum

[CAPE]

1 minute ago, psuhoffman said:

It's worth noting...the snowfall does NOT align with the H5 look at all...frankly the pattern to the snowfall mean matches a +NAO look more with the greatest +Snowfall anomalies from the upper midwest through Ontario and Quebec.  Those are places that usually are warm (for them) and dry in a west based NAO blocking pattern.  That said...I will take the H5 look over anything else 100 times out of 100 on a long range prog.  Guidance is way more likely to get the large scale longwave pattern correct then any of the synoptic and meso scale details that dictate snowfall.  But again...doesn't mean its not worth pointing out the oddity.  Let's hope its just an oddity.  

Cold and dry, warm and wet. That we can do!

Ofc we all know these super LR tools are large scale, general idea stuff, and have low resolution. Given that, I like it.

[psuhoffman]

3 minutes ago, cbmclean said:

Where are you able to see that data?

This H5

 

equals these temps lol

[aldie 22]

So apparently based on the conversation there is no such thing as a good look in the long range anymore...thanks for keeping it real fellas lol 

[CAPE]

3 minutes ago, leesburg 04 said:

So apparently based on the conversation there is no such thing as a good look in the long range anymore...thanks for keeping it real fellas lol 

Everything was fine until PSU showed up trying to be all logical and stuff.

[aldie 22]

2 minutes ago, CAPE said:

Everything was fine until PSU showed up trying to be all logical and stuff.

The more you know the less you enjoy 

[WVclimo]

Maritime polar air masses crossing the country. Really need a ridge out west to shunt that for awhile and tap into the cP and cA stuff up north.    

Would be a loaded pattern if we get any PNA assistance with that kind of blocking.

[BristowWx]

1 minute ago, CAPE said:

Everything was fine until PSU showed up trying to be all logical and stuff.

If that really happens..that pattern and +8...it’s truly the end of days...the end

[CAPE]

Just now, leesburg 04 said:

The more you know the less you enjoy 

I remember as a kid watching those fat flakes falling and knowing I had to resist looking at it or it would stop.

[psuhoffman]

16 minutes ago, WxUSAF said:

Apparently that beautiful H5 look on the week 3 map gives us a +8F temp departure!? lol that’s pretty amazing

Yea there is a huge disconnect between the h5 and the temps/mslp/precip anomalies/snowfall. Those details all look like a +NAO pattern as I said above.   I doubt it goes down that way. But...if we do manage that h5 look and torch with a storm track through the lakes right through it...I think it’s time to be a bit alarmed at what our winter climo might be now. 

[cbmclean]

1 minute ago, BristowWx said:

If that really happens..that pattern and +8...it’s truly the end of days...the end

All humor aside, what is the mechanism of what is going on?  I see a big gulf of Alaska vortex.  Does that also flood our source regions with mild pacific air as well?  Is that the cause of this monstrosity?

[CAPE]

4 minutes ago, WVclimo said:

Maritime polar air masses crossing the country. Really need a ridge out west to shunt that for awhile and tap into the cP and cA stuff up north.    

Would be a loaded pattern if we get any PNA assistance with that kind of blocking.

Climo plus some EPO/PNA help at the right time, in conjunction with a persistent -AO/NAO should get it done. If that happens and we still fail, we really do suck and need to move to NNE.

[BristowWx]

Just now, cbmclean said:

All humor aside, what is the mechanism of what is going on?  I see a big gulf of Alaska vortex.  Does that also flood our source regions with mild pacific air as well?  Is that the cause of this monstrosity?

The real cold air is on the other side of the globe...and yes our source region has been flooded with warm pac diarrhea..Atlantic blocking can only do so much at our latitude.  

[psuhoffman]

5 minutes ago, WVclimo said:

Maritime polar air masses crossing the country. Really need a ridge out west to shunt that for awhile and tap into the cP and cA stuff up north.    

Would be a loaded pattern if we get any PNA assistance with that kind of blocking.

Except do you know how many snowstorms we’ve had with that look?  We shouldn’t need a PNA ridge and a perfect west based block! Historically a west based block mid winter with a mediocre pac is just fine. I could show you the h5 from our snowiest period ever in 2010. The pac was garbage.   I mean at some point all this “well that one thing isn’t totally perfect and that other thing was only 3 standard deviations not 4...” makes us sound like the people in the southeast that have to wait  years to hope once every blue moon 25 things line up exactly perfectly to have a chance at snow.  

[cbmclean]

3 minutes ago, psuhoffman said:

I think it’s time to be a bit alarmed at what our winter climo might be now. 

I think that that is completely reasonable, but even if it were to occur I think there is a chance that something more complex than simply a warmer base state may be involved.  I mean, it's not as if the who NH is warm.  Incredibly almost the entirety of Russia, from the Finish border to the Pacific is well below normal.  SOMETHING seems to be keeping the cold air completely shifted to Eurasia, which to me is a different situation than there just not being any cold.

[WxUSAF]

1 minute ago, psuhoffman said:

Yea there is a huge disconnect between the h5 and the temps/mslp/precip anomalies/snowfall. Those details all look like a +NAO pattern as I said above.   I doubt it goes down that way. But...if we do manage that h5 look and torch with a storm track through the lakes right through it...I think it’s time to be a bit alarmed at what our winter climo might be now. 

@tombo82685 was talking about that "NAO" block on twitter a bit.  Specifically, high/AN heights in Greenland/Baffin vs. a true ridge in that area.  Mostly what those weeklies maps show is high heights.  Now that might mean there's a ridge there at times, but AN heights alone don't act as a "block".  

Here's the 18z GEFS showing a true NAO ridge:

 

Now toward the end of the run is just AN heights through the Baffin Straight:

 

Now to some degree, that's probably just the ensemble mean smoothing things out.  A real NAO ridge will pulse and vary as waves break, etc, so that could be what ends up in the means at long range.  

[cbmclean]

Just now, psuhoffman said:

makes us sound like the people in the southeast that have to wait  years to hope once every blue moon 25 things line up exactly perfectly to have a chance at snow.

Take it from a lifelong North Carolinian; he's right.

[SnowGoose69]

30 minutes ago, BristowWx said:

Wonder if that’s ever happened. Sustained west based NAO block all winter and no snow.  Wouldn’t that be a kick in the pillbox

81-82 here in NY.   I don't know if it was west based but it was negative most of the winter and the winter had very little snow.

[cbmclean]

1 minute ago, WxUSAF said:

Mostly what those weeklies maps show is high heights.  Now that might mean there's a ridge there at times, but AN heights alone don't act as a "block".  

So what is the difference between "high heights", a 'ridge" and a "block"?  I am not a met or even a serious weenie but I have a pretty strong math/science background so feel free to include technical details in a response (if you fee like it; I know red tags often have better things to do then respond to novice requests).

[frd]

3 minutes ago, WxUSAF said:

@tombo82685 was talking about that "NAO" block on twitter a bit.  Specifically, high/AN heights in Greenland/Baffin vs. a true ridge in that area.  Mostly what those weeklies maps show is high heights.  Now that might mean there's a ridge there at times, but AN heights alone don't act as a "block".  

 

Seems like conflicting views and opinions, even from various well respected mets regarding the - NAO/block/ AN heights near and around Greenland. Some say what tombo stated, others are gung-ho about real storminess and snow prospects in the East.                     

[WxUSAF]

2 minutes ago, cbmclean said:

So what is the difference between "high heights", a 'ridge" and a "block"?  I am not a met or even a serious weenie but I have a pretty strong math/science background so feel free to include technical details in a response (if you fee like it; I know red tags often have better things to do then respond to novice requests).

Basically, anticyclonic flow over a region is a ridge.  When it's oriented in a way (east-west across Greenland and Baffin is ideal of a NAO for us) to disrupt the zonal flow it's a "block".  @CoastalWx is talking about this in SNE also I see.  

[psuhoffman]

7 minutes ago, WxUSAF said:

@tombo82685 was talking about that "NAO" block on twitter a bit.  Specifically, high/AN heights in Greenland/Baffin vs. a true ridge in that area.  Mostly what those weeklies maps show is high heights.  Now that might mean there's a ridge there at times, but AN heights alone don't act as a "block".  

Here's the 18z GEFS showing a true NAO ridge:

 

Now toward the end of the run is just AN heights through the Baffin Straight:

 

Now to some degree, that's probably just the ensemble mean smoothing things out.  A real NAO ridge will pulse and vary as waves break, etc, so that could be what ends up in the means at long range.  

I think it’s just smoothing. I’ve never actually seen a strong ridge signature on the height lines past day 12 or so.  It’s been the same on ensembles as you pointed out but when I look at the individual members most have a true ridge or even closed Rex block. Take the euro weekly control for instance. These are just a sampling. It pulses and wanes obviously. But looks like real blocking to me most of the run. 

[cbmclean]

OK, so atmospheric physics questions: how is it physically possible for a region to have a sustained period of below normal 500 MB heights yet also have above normal temps over the same period?

As I have mentioned elsewhere I do not have a strong background in meteorology or any serious model chops but I have read a fair bit and have seen it stated over and over in explanations that the geopotential height can be considered as a proxy for the average temperature for the parcel of air between the surface and the height level.  So cooler parcels mean lower heights, and vice versa.  How can we have low geopotential heights for a long period of time yet have warm temperatures in that parcel of air?

[WxUSAF]

Just now, frd said:

Seems like conflicting views and opinions, even from various well respected mets regarding the - NAO/block/ AN heights near and around Greenland. Some say what tombo stated, others are gung-ho about real storminess and snow prospects in the East.                     

I think it's probably a situation where both are somewhat correct.  In a smoothed ensemble mean, you often don't see sharp ridges or troughs due to orientation, timing, and other differences between each member.  So even if all the members have a nice NAO ridge around a given time +/-, when you average them all together, it may just look like what you see in the long range ensemble mean or weeklies product.  

As @Ji said earlier, we actually haven't had a true NAO ridge yet.  That can has definitely been kicked a bit, although it does seem like a real one will develop as we start January.

[psuhoffman]

8 minutes ago, SnowGoose69 said:

81-82 here in NY.   I don't know if it was west based but it was negative most of the winter and the winter had very little snow.

Yea but 82 was very snowy in the mid Atlantic which is more common with a west based NAO block. Sometimes that can favor further southwest then NYC. 

[WVclimo]

10 minutes ago, SnowGoose69 said:

81-82 here in NY.   I don't know if it was west based but it was negative most of the winter and the winter had very little snow.

That was an above-average snowfall season at DCA-BWI-IAD.  A really nice winter in western Md. too  I measured 45” in the valley near CBE.