Dec/Jan Medium/Long Range Disco

[TSG]

1 hour ago, psuhoffman said:

You are looking macro. Pull back and look at the hemisphere long wave pattern. 
 

Look where that NS energy originates a few days before. It comes down from near the Yukon and dives through Manitoba. This isn’t some cut off southern treat subtropical system. It’s a NS wave diving down from northwest Canada. And look at the flow.  

As it dives into the upper Midwest the flow into our source regions is still directly from the north.

Now as the wave digs to our west and turns east yes we have a southwest flow.  But one that’s true of any wave approaching from the west.  Anytime any wave is west of us we will have a southerly flow ahead of it.  So what are you saying we can only snow from some negative tilt capture scenario where a wave bongs south of us and pulls due north?  Good luck with that.  Second look at the larger flow.  Look where the air to our southwest originates.  The larger flow to our area is still straight from the arctic!  

after this the upper low is amplifying and tracks to our south. Even if we concede the initial surface track is such that it would start as rain in DC there is absolutely no excuse why it’s not snow once the surface low is 988 off the coast with an amplified NS upper low whose SW originated in northern Canada and a deform band puking heavy precip on us. 
 

Finally, yes there are minor imperfections here you can point to and try to say “but if this or that variable had been more perfect” but I did a case study it every 4” snowstorm at BWI going back to 1950 years ago. And almost all of them were flawed in some way. The ones that weren’t were the HECS storms. Yes if we want 20” we need it to be textbook. 50/50, cold high, block, perfect track in every way. But that’s not true of almost all the 4-8” type storms we’ve had over the last 75 years!  The reason they weren’t a HECS was whatever flaw it had. But one or two minor flaws wasn’t a reason we can’t get snow at all!  There are a ton of variances. Micro. Macro. We could go over like 10+ important variables that influence a snowstorm to some degree. If we need every single one to line up perfect we’re screwed!  I’m not saying we can’t snow if we get like every possible thing right. Of course we will still get a hecs if we get a 3 std dv block with a 50/50 and a 1045 arctic high over Montreal and a bonbinh 980 STJ system tracking up the east coast. I know that will still work. But that setup will happen once a decade. Are we F’d the rest of/ the time?  

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.

 

 

[WEATHER53]

Easiest answer is lay off the juice of 6+ days.  The guidance can’t guide. Most likely manner of changing pattern is a clipper cut south and off coast and pulls down cold air. That’s a day 5 and sooner style event. 

Right now Enso and ao/nao just are not predictive bellwethers of years gone by .

[WEATHER53]

1 hour ago, Ji said:

There isn’t much support for a Jan 2-3 storm right now anyway

Just a slight delay 

[Kevin Reilly]

27 minutes ago, Terpeast said:

Canadian ensembles see it, too... if not a day earlier. They mostly skipped the Jan 3 perfect track rainstorm though (suppressed SE)

That is a reasonable correction. 

[WEATHER53]

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 

[Scarlet Pimpernel]

10 minutes ago, WEATHER53 said:

Just a slight delay 

Made me think of "Major League" with..."JUUUUST a bit outside!" (JUUUUST a slight delay!)!! 

[Scarlet Pimpernel]

42 minutes ago, AlexD1990 said:

thank god, a voice of reason to stop the cliff jumping...

Since when did a voice of reason ever stop that from happening??? 

[jayyy]

73 and 98 are absent from the "good years" dataset for a reason, but you already knew that.  16 kinda makes the point does it not - pattern flipped cold in early Jan, big storm and pattern breaks down.  
We are delusional if we think 02-3 or 09-10 are still on the table.

No one thought this would be a 09-10 winter. Literally no one.

[NorthArlington101]

EPS looks solid enough for 12 days out re: the Jan. 8 shot.

[JenkinsJinkies]

58 minutes ago, AlexD1990 said:

thank god, a voice of reason to stop the cliff jumping...

Cliff jumping in earnest doesn't happen until all the denial runs out after a long shot rain event in a given early March.

[jayyy]

Oy gavault, as my grandmother used to say.

Some people in here just repeat the same shit over and over again, despite being 100% incorrect in what they’re saying.

That fact that some think models got this timeframe incorrect is mindblowing. CHECK 10-15 days ago on the EPS and GEFS. Compare it to right now. Pretty much 100% spot on. Who cares that the weeklies from November were 6-7 days off on the start of the pattern change? That doesn’t mean they weren’t right or that the “can is being kicked”.

This window (2nd-8th) has looked like the first serviceable window for quite some time now if you’re looking for a legitimate snow threat outside of the western highlands. The 29th idea has been DOA for a solid week plus. Those OP runs were rushing the progression of the pattern. Nothings changed. Most niño winters, including snowmaggedon in 2010, were backloaded. Nothings really changed. People are just impatient. Rightfully so, but let’s stop conflating the accuracy / consistency of the models with people’s inability to remain levelheaded about the weather.

[RIC_WX]

8 minutes ago, jayyy said:

No one thought this would be a 09-10 winter. Literally no one.

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).

[DarkSharkWX]

eps looks good

[StormyClearweather]

Pretty wild for ~36 hours out. From the LWX discussion this afternoon. 

THE TWO 12Z DETERMINISTIC MODELS VARY GREATLY STARTING AFTER   12Z WEDNESDAY. THE 12Z GFS TAKES THE LOW PRESSURE E OFF OF CAPE   HATTERAS ON WEDNESDAY, WHEREAS THE 12Z ECMWF BRINGS IT TO ORF,   THEN OVER DELMARVA AND UP THE NJ SHORE. WHILE BOTH MODELS GIVE A   STEADY RAIN IN THE MORNING, IT IS WHAT HAPPENS AFTER 18Z THAT   WILL DETERMINE THE LEVEL OF IMPACT OF ADDITIONAL AFTERNOON AND   EVENING RAINS. WITH THE 12Z GFS BEING OFF CAPE HATTERAS, THE   AFTERNOON AND EVENING RAINS WOULD REMAIN LIGHT TO MODERATE AT   TIMES. HOWEVER, THE 12Z ECMWF GIVES MUCH HEAVIER RAINFALL   TOMORROW AFTERNOON AND EVENING, WITH TOTAL QPF AROUND 2-2.5   INCHES BY 06Z THURSDAY. IT SHOULD BE NOTED THAT THE 12Z HREF   24-HR QPF ENSEMBLE MAX IS IN THIS BALLPARK.

[RIC_WX]

10 minutes ago, jayyy said:

This window (2nd-8th) has looked like the first serviceable window for quite some time now if you’re looking for a legitimate snow threat outside of the western highlands. 

Its not snowing in the western highlands.  It hasn't snowed in the western highlands for a week.  It's no longer forecasted to snow in the western highlands before Friday or Saturday or Sunday or Monday.  In fact, it's the same temperature in the highlands as it is in the lowlands nearly this entire week, which lends itself to +15 or greater departures out here.

Go back and look at the models from December 10 / 15 / 20-/ 24th for the highlands and tell me the can hasn't been kicked.  It's kicked out of the medium range every time this season except for maybe the underperforming event December 18-19.  

I am sorry that ground truth is defeating the modeled predictions for more favorable conditions in the medium range.

[WxUSAF]

Solid ensemble agreement for the period around the 6/7th. Still a ways to go. I also like seeing signs that any “mild/relax” period will be pretty short lived. Can already see off/on hints of the trough undercutting the NAO and also reestablishing an aleutian low. 

[CAPE]

1 minute ago, WxUSAF said:

Solid ensemble agreement for the period around the 6/7th. Still a ways to go. I also like seeing signs that any “mild/relax” period will be pretty short lived. Can already see off/on hints of the trough undercutting the NAO and also reestablishing an aleutian low. 

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.

[psuhoffman]

2 hours ago, CAPE said:

I think most here do see it. You kinda beat this dead horse constantly though. Snow climo sucks worse than it used to, and it has never been great in the lowlands at our latitude. So we accept it and adjust expectations. Other options include relocating.

Most yes. There seem to be 3 groups. One that sees it and openly talks about it. One that sees it but would rather not bring it up. And one group that seems in denial (for whatever reason) and argues it’s all bad luck or cyclical and likes to find that one factor that’s not perfect to assign blame every time a marginal threat goes wrong. It’s that last group that my comments are directed at not the majority.  But your right it’s beating a dead horse at this point and there are likely to be better threats ahead with more cold to overcome the thermal disadvantages we face. 

[WxUSAF]

13 minutes 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.

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.

[Weather Will]

 

3 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.

The stratwarm has been the most annoying thing about this pattern change.  JB talked about it reloading.  Where was the first load?  I am skeptical that it will do anything.

[Weather Will]

I'm all in for the Jan. 6-10th, let's see if it trends in the right direction as we head towards the NY.

[fujiwara79]

3 hours ago, Kevin Reilly said:

I am searching and searching for the reasons why we are in this snow drought, but it is not just DC, to Baltimore, to Philadelphia this is happening it's happening in a lot of places over the past 2-4 years.

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

[TSG]

51 minutes ago, RIC_WX said:

Its not snowing in the western highlands.  It hasn't snowed in the western highlands for a week.  It's no longer forecasted to snow in the western highlands before Friday or Saturday or Sunday or Monday.  In fact, it's the same temperature in the highlands as it is in the lowlands nearly this entire week, which lends itself to +15 or greater departures out here.

Go back and look at the models from December 10 / 15 / 20-/ 24th for the highlands and tell me the can hasn't been kicked.  It's kicked out of the medium range every time this season except for maybe the underperforming event December 18-19.  

I am sorry that ground truth is defeating the modeled predictions for more favorable conditions in the medium range.

Yeah, no, the onus is not on everyone else in the room to go look and see if you're claims are true. That's your job. Bring some evidence to the show or expect that you'll be ignored.

the GFS looks pretty accurate to me for this period. What are you looking at?

Dec 19th 12z GFS, valid 00z Dec 27

12z GFS today, valid 00z Dec 27

[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.