Dec/Jan Medium/Long Range Disco

[psuhoffman]

1 hour ago, WEATHER53 said:

So to recap the Christmas change did not happen, 28th/29thv the same , early Jan iffy, maybe 1/7 good..

instead of random 36 panel examples, does anyone have any graphics showing clippers underneath of us and/or cold high pressure over or east of Hudson Bay?  Organized low pressure from Atlanta are helpful also.  Phase job transfers are not helpful 

Pattern the last 7 days 

pattern the next 7

One of those gives us a much better chance of snow. And rolls forward only an even better chance.  Snowfall on your yard is an awful way to determine whether there’s been a pattern change since even a better pattern can fall to produce snow. An awful pattern might yield a 5% chance of snow and a good one a 50% chance.  Both might end up with the same ground truth, no snow, but that doesn’t make them the same. 

1 hour ago, TSG said:

Not sure I understand the macro comment. Typo? meant micro? I am certainly on your side when it comes to it being more difficult for us to see snow now than in the past. I've been called out multiple times for supporting it. I don't think this specific case can be attributed to that much if at all though.

The SW flow at the surface up to ~900mb starts on the 30th/31st when that shortwave is still exiting Canada, not when it digs into the South and starts coming East on the 1st/2nd. There is NOTHING to resist that flow. No sign of a high pressure to our North anywhere. This is such a classic way for us to fail it's making my head spin that people are acting like it would normally work 10+ years ago. There's a friggin GLL (Great Lakes Low).... what I learned to be our #1 enemy for snowfall around here. IMO this setup sucks and would still suck if it was in the distant past.. And if we weren't all so traumatized from years of low snow I think more would be calling it for what it is.

If you do have a specific example of where this worked previously I'll happily eat crow, but thinking back on past seasons this just seems like a stinker of an opportunity top to bottom.

 

 

A couple weeks ago we got snow when a SW flow and 60 degree temps ahead of it!  The SW flow isn’t the problem other than at the start. The problem on that run was there was no cold even behind the SW flow!  

[WEATHER53]

5 minutes ago, psuhoffman said:

Pattern the last 7 days 

pattern the next 7

One of those gives us a much better chance of snow. And rolls forward only an even better chance.  Snowfall on your yard is an awful way to determine whether there’s been a pattern change since even a better pattern can fall to produce snow. An awful pattern might yield a 5% chance of snow and a good one a 50% chance.  Both might end up with the same ground truth, no snow, but that doesn’t make them the same. 

A couple weeks ago we got snow when a SW flow and 60 degree temps ahead of it!  The SW flow isn’t the problem other than at the start. The problem on that run was there was no cold even behind the SW flow!  

Thanks PSU. That is a better look but it’s not the first better look that has been presented over last 2+ weeks .  So now we just need the example to materialize and I hope so. 
Anybody  get a snowblower from Santa?

[frd]

I believe this raises the bar for cold and stormy weather here,  while enhancing cold air intrusions after Jan 20 th.

Robust agreement here. 

 

 

 

   

[fujiwara79]

17 minutes ago, psuhoffman said:

Most yes. There seem to be 3 groups.

once an issue becomes politicized, facts, logic and evidence don't sway people, unfortunately.   on any particular topic, 30% of the population believes in some crazy nonsensical things....and it's not always the same group of people.

lots of random talks with Uber drivers make me think it's higher than 30%....but I like to have some faith in humanity  

[frd]

Check this out

-NAO and then the SWWE

Long duration - AO and - NAO upcoming  

 

 

[Ji]

Thanks PSU. That is a better look but it’s not the first better look that has been presented over last 2+ weeks .  So now we just need the example to materialize and I hope so. 
Anybody  get a snowblower from Santa?

Looks the same to me. It’s going to take a while to change our source region(Canada to cooler)

[TSG]

39 minutes ago, psuhoffman said:

A couple weeks ago we got snow when a SW flow and 60 degree temps ahead of it!  

oh come on PSU... we both know that was not a comparable setup. First, positively (Jan 3rd) vs negatively (Dec 11) tilted troughs. Second, the storm on the 11th had another piece of energy over the GL pressing that cold into the backside which gave us a couple hrs of changover, instead of the 0-15 mins we're used to with cold chasing precip. There is no such mechanism available for the storm on the 3rd, at least not as currently depicted.

[Eskimo Joe]

Welp

 

 

[psuhoffman]

1 hour ago, CAPE said:

Was just going to mention this. For all the hand wringing about a crappy Pacific/-PNA/ 'disappearing' Aleutian low, it looks to be more brief than expected. Nino forcing ultimately overwhelms any temporary MJO modulation/NPAC jet retraction.

 

56 minutes ago, WxUSAF said:

That plus a SSW will favor a trough east of the Rockies at some time lag after it happens. So if it happens around the 7th, the SSW would start helping that pattern around the 15-20th.

It was really just Chuck and Webb. Everyone else agreed it was likely a very temporary issue. 

[DarkSharkWX]

Welp
 
 

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[CAPE]

1 minute ago, psuhoffman said:

 

It was really just Chuck and Webb. Everyone else agreed it was likely a very temporary issue. 

Everyone else as in our regulars here? WW was in a bit of a panic about -PNA until I reassured him, and then there is always EJ..

[WxUSAF]

It’s an interesting argument on Twitter and I’m not sure how if this is really a disagreement or just confusion. But it seems 12z eps was a pretty huge outlier from a long trend. So either way I’d wait for some confirmation before jumping off a cliff. 

[CAPE]

3 minutes ago, WxUSAF said:

It’s an interesting argument on Twitter and I’m not sure how if this is really a disagreement or just confusion. But it seems 12z eps was a pretty huge outlier from a long trend. So either way I’d wait for some confirmation before jumping off a cliff. 

Check out the GEPS

[cbmclean]

3 minutes ago, CAPE said:

Check out the GEPS

I like the -NAO, but not a fan of the +EPO or -PNA.  is this a "good" look?

[Eskimo Joe]

7 minutes ago, CAPE said:

Check out the GEPS

Unless I'm missing something, that looks pretty rancid in Canada. Just Pacific puke in our source region.

[NorthArlington101]

18z GFS had a pretty different look for Friday and looks to be doing something different for the 2nd too. Chaotic stuff.

[WxUSAF]

6 minutes ago, cbmclean said:

I like the -NAO, but not a fan of the +EPO or -PNA.  is this a "good" look?

The point is that the -PNA is already on its way out as a ridge builds in and the +EPO heads toward an Aleutian low.

[CAPE]

5 minutes ago, Eskimo Joe said:

Unless I'm missing something, that looks pretty rancid in Canada. Just Pacific puke in our source region.

Yeah you're missing something. Not a surprise. 

[CAPE]

3 minutes ago, WxUSAF said:

The point is that the -PNA is already on its way out as a ridge builds in and the +EPO heads toward an Aleutian low.

And as is that's a cold look across most of the US.

[BristowWx]

8 minutes ago, Eskimo Joe said:

Unless I'm missing something, that looks pretty rancid in Canada. Just Pacific puke in our source region.

Thanks Subtropics!  Remember that guy. Tried to block him twice.  Double block.  Never been done before.  

[Heisy]

Welp
 
 

Yea hopefully just a blip run, that would suck. Weeklies look good for SSW but they’re last night


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[Terpeast]

9 minutes ago, Eskimo Joe said:

Unless I'm missing something, that looks pretty rancid in Canada. Just Pacific puke in our source region.

It’s not that bad. Not a terrible look at all once Canada gets a chance to cool down until then

[CAPE]

17 minutes ago, NorthArlington101 said:

18z GFS had a pretty different look for Friday and looks to be doing something different for the 2nd too. Chaotic stuff.

The 4-5th window is realistically the first chance for something other than rain for the MA lowlands.

[pazzo83]

8 hours ago, WesternFringe said:

Never said it didn’t bother me, so please don’t put words in my mouth.  I think it is perfectly relevant to distinguish between weather depicted at Day 8 on a model (with very little skill after Day 5) and weather that has actually occurred.  

I will have to respectfully disagree on this one.  When you say, “it shouldn’t be possible” it very well might not be.  There are plenty of times the experienced and knowledgable posters on here disagree with the surface depictions based off of the H5 in the Day 5-10 range.  But this time it is irrelevant that the event hasn’t occurred and is 8 days away?  C’mon, man!

i don't think you are quite grasping what he's saying.  all weather models are probabilistic models that factor in historical data, current observed data, and the understood mathematics that describe the atmosphere.  obviously it could be wrong because models are often wrong.  but let's look at the inputs again - unless you are arguing that one of those inputs was somehow corrupted for this particular model run, it is telling you that the most likely outcome is what is shown (with rain basically everywhere).  i think that is where the concern lies - it is outputting an outcome that is not what one would've expected in years past, meaning it is incorporating some sort of fundamental change in terms of those inputs.  I don't think the math has changed wildly (if only to improve model precision), so...

[NorthArlington101]

The 4-5th window is realistically the first chance for something other than rain for the MA lowlands.

For sure - should’ve clarified it’s really a big deal for the few folks out in far W MD and some of our WV folks. Rather dramatic run-to-run shift.

[jayyy]

Maybe not, but there is nearly unanimous consensus we would reach climo or climo+ on snowfall.  Most of the region will exit December 150%-200% of normal on precip.  That could continue, or we could just be normal or even slightly below for January and February and still finish the winter above normal on precip.  And no one really forecasted a materially BN winter temperature wise.
Either way, someone needs to start tracking cold air or even just seasonably cold air masses.  This year increasingly has the "one storm makes climo" look to it, which historically happens here when the pattern breaks down (the hoped for pattern arguably isn't even showing signs of setting up, and most likely won't before Feb).

I don’t see the fact that I have seen only 3” of snow on December 26th as an indication that we won’t reach climo by end of march. Even if we have seen a good amount of precip (thank you niño / STJ) We have been here many times before. Two things can be true at once. It can be harder to snow in marginal setups early on in winter, but also still snow a lot if we get a few flush hits.

Average annual snowfall isn’t all that high in our general area to begin with. People forget that climo for Baltimore and the surrounding area is like 20” (+ or minus a bit depending on your exact location) That’s really only one big and one or two moderate snowfalls. That’s it.

We’re 5 days into actual winter. We rarely get snow before December 15th, especially as of late. It rains in December in the mid Atlantic. That’s nothing new. I grew up in the Hudson valley in NY, which averages 2X more snow than my area in northern MD. Saw plenty of December snowfalls growing up, but also saw plenty of shutout Decembers too.

Backloaded niño winters are quite common, and the fact that we sometimes get one snowfall in December doesn’t mean the rest of the season is done for. My area saw 3” a few weeks ago. 4” in PSUs backyard. If I see 3” in December and then 20-30” between January - march, that’s a successful winter as far as climo is concerned. If 09-10 is what people are measuring this up to, that’s a foolish things to do.

I don’t see what you’re seeing - that we won’t see a workable pattern until February. Models have had a pretty decent signal for January 6-8th period for some days now. That hasn’t really changed.

I understand people’s pessimism and impatience, but I’m not seeing any signs that we’re now suddenly delayed until February. We can revisit this possibility if models truly do back away over the coming days (for Jan 2-8th) and weeks (for the rest of January into feb)

[WEATHER53]

1 hour ago, Ji said:

Looks the same to me. It’s going to take a while to change our source region(Canada to cooler)

SSW being examined above.  Was this not supposed to happen previously?

[jayyy]

EPS members for between now and the 10th. Take exact totals with a grain of salt, but I don’t understand the “models are now pushing things back to February” talk. It’s just not true. Plenty of members showing snow chances in the coming 2 weeks. We’ll revisit this if the possibility breaks down, but I don’t see the need for the premature debbing.


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[NorthArlington101]

For sure - should’ve clarified it’s really a big deal for the few folks out in far W MD and some of our WV folks. Rather dramatic run-to-run shift.

Butterfly effect ends up with a substantial winter storm for GA (by their standards) up into the Carolinas for the 3-4th. Wacky run

[clskinsfan]

7 minutes ago, NorthArlington101 said:

For sure - should’ve clarified it’s really a big deal for the few folks out in far W MD and some of our WV folks. Rather dramatic run-to-run shift.

Meh. It would just be white rain anyways. The following week we have some manageable temps at least.