January 2017 Discussion & Observations

[Rjay]

1 minute ago, Allsnow said:

Yep. The pattern looks great on the eps for the end of week threat 

Looks great for overrunning snows.  The SE ridge is a big help to us in this case.  But any storm that gets too strong too fast will pump heights and the coast could have issues.

[PB GFI]

1 hour ago, Isotherm said:

 

Agree. Going to be difficult to force a protracted -NAM with these background conditions, for now at least:

 

The period is 12 to 15 days long , not 5 . The ridge is a garbage low height ridge day 13 to 15 and the old day 13 to 15 day ridge 3 days ago has now supressed the heights in the new day 10 thru 12 .

 

Trough in Japan 

Trough in Europe 

-AO 

-NAO

Means mutes SE ridge / doesnt have to kill it , we dont want too .

Thats our barroclinic zone .

 

All due respect I know you are strat focused  above and I believe you are missing a 2 week 4 way stable pattern.

 

The 5 day pattern is already being taken apart in the ensembles. 

 

 

[PB GFI]

3 hours ago, CIK62 said:

Why are so many members so excited about the next 15?   This shows that the 500mb. THK is lower right now than at any time in the next 2-weeks.

You realize the Canadian skill scores behind the 

EPS

Euro

UKMET 

GFS para

GFS

 

Can you get the EPS in Coney Island ? 

 

[mikemost]

10 minutes ago, PB GFI said:

You realize the Canadian skill scores behind the 

EPS

Euro

UKMET 

GFS para

GFS

 

Can you get the EPS in Coney Island ? 

 

While we're on the H5 topic. Here's another one for cfskid. Verification since 12/1. Courtesy of Superstorm93.

[PB GFI]

The answer to why are people excited is the EPS .

 

[Isotherm]

1 hour ago, PB GFI said:

 

The period is 12 to 15 days long , not 5 . The ridge is a garbage low height ridge day 13 to 15 and the old day 13 to 15 day ridge 3 days ago has now supressed the heights in the new day 10 thru 12 .

 

Trough in Japan 

Trough in Europe 

-AO 

-NAO

Means mutes SE ridge / doesnt have to kill it , we dont want too .

Thats our barroclinic zone .

 

All due respect I know you are strat focused  above and I believe you are missing a 2 week 4 way stable pattern.

 

The 5 day pattern is already being taken apart in the ensembles. 

 

 

 

I've been on board for a favorable pattern for a week (the Jan 5th-12th). We'll see what happens thereafter. The problem is that even if we were to operate under the assumption that the long term -NAO is genuine, the SE ridge would still be an issue as the poleward ridge retrogrades into the WPO domain space and low heights flood Western Canada/W US. This will force a SE-ridge, albeit not a blowtorch pattern, which I never said. I don't think January will be a blowtorch month.

And with all due respect as well, you must admit that December turned out much warmer than you thought. +0.5 to +2 across most of the Eastern US and below normal snowfall at the coastal sites.. This winter has been progressing pretty much as expected from my standpoint so far. I will happily admit that I was incorrect in short-changing this pattern if we're cold and snowy through late month. That's a bust I'd like to have rather than the reverse.

 

[PB GFI]

44 minutes ago, Isotherm said:

 

I've been on board for a favorable pattern for a week (the Jan 5th-12th). We'll see what happens thereafter. The problem is that even if we were to operate under the assumption that the long term -NAO is genuine, the SE ridge would still be an issue as the poleward ridge retrogrades into the WPO domain space and low heights flood Western Canada/W US. This will force a SE-ridge, albeit not a blowtorch pattern, which I never said. I don't think January will be a blowtorch month.

And with all due respect as well, you must admit that December turned out much warmer than you thought. +0.5 to +2 across most of the Eastern US and below normal snowfall at the coastal sites.. This winter has been progressing pretty much as expected from my standpoint so far. I will happily admit that I was incorrect in short-changing this pattern if we're cold and snowy through late month. That's a bust I'd like to have rather than the reverse.

 

 

I got wrecked on the Dec monthly as the last 9 days killed me  but  my 2 week forecasts have been pretty good .

My Dec 5 th thru 20 th BN call made on Nov 27th ended - 3 at KNYC and the call made on Dec 10 was for Dec 25 to Jan 10 to finish AN.

That period also had AN snow inside the 2 weeks , and the WAA was caught .

Thats the good the bad and the ugly.

3 for 4 , I will take it

Now does that mean I am right here? No , but it does mean I am done with 30 day forecasts and I am gona stick with whats worked .

 

I put my hand over the N/E day 13 to 15 and see all those other features and really have a hard time seeing a ridge into the M/A knowing what those 500s should yield .

 

[Isotherm]

Winter's progression thus far has been congruous with expectations, as we close the books on our first meteorological month of winter. Below are images depicting the December 2016 z500 NHEM pattern and my primary analog (1973-74) DJF z500. Typically analogs do no work identically due to the chaotic / stochastic nature of weather, but this is very close overall. Low heights over W Canada / N USA, +NAO/AO, and Aleutian ridging. The poleward ridge in December 2016 was not potent, as the most anomalous positives remained south of Alaska. December's temperatures were warmer than normal for most of the East (+0.5 to +2) with below normal snowfall at the major coastal sites. Going forward, the upcoming period will be much more propitious for snowfall, in contrast to the failed attempt in mid December insofar as producing a significant snowfall.

 

 

The primary discrepancy b/t mid December and the upcoming regime will be the surge of higher geopotential heights downstream in the NATL, permitting a further SE baroclinic zone. The anticyclonic wave breaking coupled with some influence from the ewd propagating upper divergence signal (MJO related) through the Atlantic will aid in temporarily slowing the north atlantic jet.

 

As we move out further into the future, tropical forcing progression is suggestive of a retrogression of the EPO domain block into the WPO domain space, with likely more poleward proclivities than we saw in December. The lowering of geopotential heights near British Columbia and the concomitant -AAM/-PNA retracted jet pattern will invariably induce SE-ridge redevelopment. To the extent that the longer term -NAO signal is genuine, heights will be sufficiently suppressed such that a blowtorch temperature regime would be precluded in mid January. However, even with a -NAO, normal to warmer than normal air would likely return if the Pacific retrogression continues. With respect to the stratospheric progression, there will be a war b/t improved tropospheric wave driving while contemporaneously other variables such as weakening BDC and westerly upper stratospheric shear stress destructively interfere with vortex weakening. However, the tropospheric precursor pattern should induce a surge of heightened wave-2 which peaks around January 20th. We will see if that is sufficiently potent to produce perturbation and/or SSW event down the road (would be talking late January for first attempt probably). This would have ramifications for the February pattern. The problem of course is that very rarely have we seen a major SSW with this winter's exogenous forcing mechanisms. It can still happen though. For now, let's hope that the upcoming period produces a significant snow event for the east coast. I would still err warmer than normal for January, but it shouldn't be a blowtorch departure.

[PB GFI]

Give me 2 weeks of Feb 94  here and if Jan finishes plus 1 to 2 no one will care.

That's whats on the table IMO .

2 weeks of an active BN pattern .

Snowy....

Neg PNA  , Neg NAO sitting  N of the Barroclinic zone 

 

 

[UlsterCountySnowZ]

3 hours ago, PB GFI said:

The answer to why are people excited is the EPS .

 

Mentioned this earlier, EPS is BN throughout mid Jan, with many storm chances with the exception of a few days next week.... I like the  Jan 6-15 timeframe, I think we see a couple decent events 

[brooklynwx99]

00z GFS looks to be keying on the second wave @ hr 144... much more Euro-like. Heights are much lower on the east coast as well.

[brooklynwx99]

Massive differences between the 18z and 00z runs of the GFS through 180 hours. Doesn't even look like the same model. The second wave is the main player on the 00z, unlike the 18z. 

00z

18z

[MJO812]

CMC is also focusing on one storm which barely misses the coast

 

Some snow for the area on the CMC

[mattinpa]

40 minutes ago, Snow88 said:

CMC is also focusing on one storm which barely misses the coast

 

Some snow for the area on the CMC

GFS just misses to the south and east on the 00z run. Lots of potential though. Shows a big storm.

[TauntonBlizzard2013]

46 minutes ago, Snow88 said:

CMC is also focusing on one storm which barely misses the coast

 

Some snow for the area on the CMC

CMC is a pretty good look at this range.... clips SE New England 

[Animal]

14 minutes ago, mattinpa said:

GFS just misses to the south and east on the 00z run. Lots of potential though. Shows a big storm.

Can't shovel potential. Every winter season, people post up about storms 7 days away on models. Just saying odds don't favor anything more that a few inches. 

[NortheastPAWx]

Euro says, what storm?

[RedSky]

15 minutes ago, NortheastPAWx said:

Euro says, what storm?

Yeah it's all your fault, try going to Florida

 

[nzucker]

28 minutes ago, NortheastPAWx said:

Euro says, what storm?

What does it show?

[brooklynwx99]

7 minutes ago, nzucker said:

What does it show?

It buries the energy for the second wave off the west coast. It never comes ashore, so there is no storm. I'm not sure if that has anything to do with the Euro's tendency to hold energy back, but it's just another possibility. OP runs are almost like individual ensemble members at this point in time. 

[nzucker]

8 minutes ago, brooklynwx99 said:

It buries the energy for the second wave off the west coast. It never comes ashore, so there is no storm. I'm not sure if that has anything to do with the Euro's tendency to hold energy back, but it's just another possibility. OP runs are almost like individual ensemble members at this point in time. 

I mean there's pretty strong signals for a storm given the teleconnections and modeling, but at 8 days out there's still a good chance none of this snow threat happens. So many different things could go wrong...we never get the 2nd piece of energy, it goes OTS as a southern slider, it consolidates too much and cuts way west. 

Still really like the pattern Jan 5-15. GFS shows another storm around the 12th too. Going to be a couple big threats.

ECM does like to meander energy in the Southwest, too, so wouldn't be surprised to see this one come back.

[brooklynwx99]

14 minutes ago, nzucker said:

I mean there's pretty strong signals for a storm given the teleconnections and modeling, but at 8 days out there's still a good chance none of this snow threat happens. So many different things could go wrong...we never get the 2nd piece of energy, it goes OTS as a southern slider, it consolidates too much and cuts way west. 

Still really like the pattern Jan 5-15. GFS shows another storm around the 12th too. Going to be a couple big threats.

ECM does like to meander energy in the Southwest, too, so wouldn't be surprised to see this one come back.

I agree. The HP and potential 50/50 low are also good signs to see, even at long leads. The GEFS and EPS show some high-latitude blocking through the 15th, so the pattern could be a productive one for sure. 

[nzucker]

2 minutes ago, brooklynwx99 said:

I agree. The HP and potential 50/50 low are also good signs to see, even at long leads. The GEFS and EPS show some high-latitude blocking through the 15th, so the pattern could be a productive one for sure. 

Yes, the Canadian high pressure is very strong due to the EPO/WPO block to the north. There is a large pool of -30C 850s that forms over Central Canada and migrates to Quebec, as well as dense low level cold that should set up some damming/ageo flow potential. It looks like a classic overrunning set-up to me, at least for the Jan 7-8 storm.

If that NAO block could continue to retrograde towards western Greenland and Baffin Bay, that could set up more potential for a KU/MECS. Some models have even shown a weak low pressure moving through the GoA, which leads to a brief but potent PNA spike. It's asking a lot for these to occur in tandem but if they do, watch out.

I gained a bit of latitude on you moving to the Bronx. I'm now in Hunts Point instead of Bay Ridge, though I'd probably give up my latitude to get back to Bay Ridge, love it there. I'm working in the Bronx charter school system now, though.

[Animal]

2 hours ago, NortheastPAWx said:

Euro says, what storm?

Morning afd from mt holly nws mentions they prefer a suppressed storm track. 

[Ralph Wiggum]

Euro says, what storm?

Yet the generally progressive NAVGEM moves that Western energy onshore like the 0z gfs and a juicy system tracks to Wisconsin.

These massive changes at this range from model to model and from one run to the next should not be causing people to write this one off just yet. Several possibilities still on the table.

[Ralph Wiggum]

Notice how the 0z EPS is already backing off on the strength of the Greenland block and the -PNA forces the SE ridge to return after January 10th.

Models have been forecasting too much blocking over the North Atlantic longer range since late November. As we get closer the models

correct to weaker blocking there.

New run



 

old run



 

 

 

 

 

 

 

 

 

Exactly....I had noted this trend in here last week with modeled ridging/blocking at Day 10+ becoming weaker and more transient and progressing to Ireland as lead times shorten since back in November. Going to be tough to overcome that this season. We are going to need a SSWE to reverse the trend imo tho a few vehemently disagree and say a weakening La Nina will allow a -NAO to take hold in Feb alone without a SSWE.

[SnowGoose69]

1 hour ago, bluewave said:

Notice how the 0z EPS is already backing off on the strength of the Greenland block and the -PNA forces the SE ridge to return after January 10th.

Models have been forecasting too much blocking over the North Atlantic longer range since late November. As we get closer the models

correct to weaker blocking there.

New run

 

old run

 

 

 

 

 

 

 

 

 

That appears to be driven mainly by another cutting system.  Even with a -NAO I think that 3-5 day period torches.  It just would torch slightly less.

[EasternLI]

The big difference that I noticed WRT NAO on the EPS is that notice what happens with the midweek system. Yesterdays run you can see the more poleward Greenland ridging, that occurs after the mid week cutter. Last nights run, the cutter is gone, it redevelops right over NYC on the EPS. That scenario doesn't pump up the Greenland ridge like the cutter scenario would.

[dmillz25]

The ULL in Canada also has something to do with the day 7 storm disappearing. No SE ridge when we need it and digs the wave too far south

[Ralph Wiggum]

23 minutes ago, SnowGoose69 said:

That appears to be driven mainly by another cutting system.  Even with a -NAO I think that 3-5 day period torches.  It just would torch slightly less.

NAVGEM shows a cutter next weekend fwiw.