Dec/Jan Medium/Long Range Disco

[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. 

[pazzo83]

4 hours ago, NorthArlington101 said:

partially?

I've been looking to see if you can run Google's GraphCast model with snow accums but I can't find it. Have found a site that shows rough MSLP + precip

those models are pure neural network models that don't incorporate any hard-coded equations like traditional weather models, right?

[WesternFringe]

3 minutes ago, pazzo83 said:

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...

So a model that factors in historical data is outputting what would not have been expected in the past? Thanks for the insight.

Abd btw, the model isn't even showing anywhere close to what we were disagreeing about 2 runs ago at hr 192 anyways, so you are way late.

[MDScienceTeacher]

1 hour ago, fujiwara79 said:

you don't need to search too hard.  the answer is staring you in the face.  Underwater volcanos!  

Yes.  Volcanic activity (large and small scale) can lead to significant exothermic processes.  Definitely enough to have an impact on world wide climate.  I dont think people realize just how much energy it takes to skew the earths natural Glacial-Interglacial Cycles, things like volcanic activity, sun spots and astroid strikes are all capable of changing the earths weather patterns.

But honestly, we are probably just in a slump and we will wind up getting a 50 inch season sometime very soon.

[NorthArlington101]

those models are pure neural network models that don't incorporate any hard-coded equations like traditional weather models, right?

I bet someone here knows more than me, but that’s my understanding. It’s trained off historical weather data and tries to use that to predict the weather going forward. Conceptually that seems like a great application of that kind of learning to me.

[psuhoffman]

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)

In 2010 Canada was way above normal. Quite often in a Nino Canada is torched. We survive by roughing under the NS flow (split flow) and just cold enough with a good track. Warm the whole equation and it might not work. 
 

But guidance has always said this next week would have temp issues. from 14 days ago. 

And 7

Im still disappointed even with a perfect setup we couldn’t overcome those temps on that one run. But guidance has said temps were still an issue. 

1 hour ago, TSG said:

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.

On the 6z run the trough wasn’t just negative it cut off completely to our southeast!  No idea what you’re talking about. 

[pazzo83]

3 minutes ago, WesternFringe said:

So a model that factors in historical data is outputting what would not have been expected in the past? Thanks for the insight.

Abd btw, the model isn't even showing anywhere close to what we were disagreeing about 2 runs ago at hr 192 anyways, so you are way late.

again - you are missing the point.  the fact that it was a model output at any point is the concern.

[snowfan]

5 minutes ago, clskinsfan said:

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

I believe he’s referring to those west of the Allegheny front.