January 2020 Mid/Long Term Discussion

[BristowWx]

Just now, Wonderdog said:

What a different look at H5 between 6z and 12z on the GFS. Looks like the 12z is going back to its idea at 0z. Can't keep up with this uncertainly at 300 hrs.

Still not a flake of snow as it looks now.  But if we wanted cold on our side of the world it’s there on this run. Hey it’s not pac puke so we take it. 

[nj2va]

4 minutes ago, Wonderdog said:

What a different look at H5 between 6z and 12z on the GFS. Looks like the 12z is going back to its idea at 0z. Can't keep up with this uncertainly at 300 hrs.

an OP run at 300 hours is going to have run over run changes. 

[Bob Chill]

Just now, BristowWx said:

Still not a flake of snow as it looks now.  But if we wanted cold on our side of the world it’s there on this run. Hey it’s not pac puke so we take it. 

The gfs op and gefs/eps are all signaling a return to a very amplified but still progressive flow. Wild swings on ops run over run will continue for days. Overall guidance (although turning cold) doesn't look promising for snowfall yet. Gotta crawl walk and run here. Crawl phase appears to end sometime around the 30th. Beyond that? Good luck guessing.  

 

[Bob Chill]

One important step that all guidance is showing is splitting unmitigated pac flow sometime between the 26th-28th. I would like to think that part is close to locked in and won't get kicked down the road. That's a very important inflection point. 

[BristowWx]

13 minutes ago, Bob Chill said:

The gfs op and gefs/eps are all signaling a return to a very amplified but still progressive flow. Wild swings on ops run over run will continue for days. Overall guidance (although turning cold) doesn't look promising for snowfall yet. Gotta crawl walk and run here. Crawl phase appears to end sometime around the 30th. Beyond that? Good luck guessing.  

 

Roger.  My biggest take away from that run was there is cold around on our side of the planet if that is even nearly correct it’s real cold.   So I am optimistic.  If this was the cake we were baking that would be the flour. 

[Bob Chill]

6 minutes ago, BristowWx said:

Roger.  My biggest take away from that run was there is cold around on our side of the planet if that is even nearly correct it’s real cold.   So I am optimistic.  If this was the cake we were baking that would be the flour. 

9 times out of 10, flipping out of a sh!t pattern and into a colder pattern doesn't include snowfall. Feb 2015 was an exception. We typically need the cold pattern to establish itself for a week or so before chances start popping up. Going off history in these parts based on what I'm seeing now... our first real chance prob won't happpen until after 1/5. Just a total guess but it's how we roll. 

[BristowWx]

3 minutes ago, Bob Chill said:

9 times out of 10, flipping out of a sh!t pattern and into a colder pattern doesn't include snowfall. Feb 2015 was an exception. We typically need the cold pattern to establish itself for a week or so before chances start popping up. Going off history in these parts based on what I'm seeing now... our first real chance prob won't happpen until after 1/5. Just a total guess but it's how we roll. 

That’s the part that worries me.  We can get cold even really cold but establishment of cold is the long pole in the tent. Regardless, it’s nice to be at the stadium parked and tailgating ready for the game ...instead of being stuck in traffic. 

[psuhoffman]

11 minutes ago, losetoa6 said:

Another run and another possibility per latest Gefs...drops part of the PV down into the conus day 12 or so this time. 

 

That’s a colder look... but not as snowy typically. I preferred the seasonal temps with ridging over the top look better. 

[WxUSAF]

3 minutes ago, psuhoffman said:

That’s a colder look... but not as snowy typically. I preferred the seasonal temps with ridging over the top look better. 

It’s showing a pattern at the end of the run that we’re very familiar with over the last 5-10 years...-EPO/++NAO. Not much consistency past D10. Still shows the pattern reshuffle start around the 28th. That can isn’t getting kicked so far. Seems clear for now that we start purging the Pac airmass after that, but details still TBD.

[Bob Chill]

19 minutes ago, WxUSAF said:

It’s showing a pattern at the end of the run that we’re very familiar with over the last 5-10 years...-EPO/++NAO. Not much consistency past D10. Still shows the pattern reshuffle start around the 28th. That can isn’t getting kicked so far. Seems clear for now that we start purging the Pac airmass after that, but details still TBD.

Yea, sure seems to be moving in that direction. Quite a bit of spread on how things evolve in early Jan. So much so that I have no idea where this is all going other than some mid winter cold is prob on the way. How long it lasts and whether or not frozen precip is involved won't be known for 7-10 days. 

With the way this year has gone I'm expecting some brand new ways to worry are in our future. Lol. Cold/dry is on the list. Lol

[psuhoffman]

56 minutes ago, WxUSAF said:

It’s showing a pattern at the end of the run that we’re very familiar with over the last 5-10 years...-EPO/++NAO. Not much consistency past D10. Still shows the pattern reshuffle start around the 28th. That can isn’t getting kicked so far. Seems clear for now that we start purging the Pac airmass after that, but details still TBD.

For now I’m hanging my hat on the fact the Atlantic looks good through day 10. After that hopefully it’s wrong. But the issue is it slides the tpv east. That pushes the NAO ridge east. We really need that to either cross the pole or drop. But I’m going to be mildly annoyed if we waste the first extended NAO ridging for 2 weeks then just as the pac gets better the Atlantic goes to crap. 

[Ralph Wiggum]

The euro at the end of the run looks a little like 0z GGEM with the NS energy zipping thru ushering in the CAA and a piece of stj energy hanging back. Obviously is a day slower than the GGEM thus the slower evolution. Might be setting up something for right around NYE.

[Weather Will]

General observation looking at the 12 z suite is that we will have temps 5-15 degrees above from Sunday-to  about NY eve day depending on the timing of  an arctic cold front.  As some have recently noted the concern that The warmth will scour out the snow pack and cold throughout Canada during this period seems to be lessening.  Now back to Christmas preparations....

[poolz1]

39 minutes ago, Ralph Wiggum said:

The euro at the end of the run looks a little like 0z GGEM with the NS energy zipping thru ushering in the CAA and a piece of stj energy hanging back. Obviously is a day slower than the GGEM thus the slower evolution. Might be setting up something for right around NYE.

Not a bad look on the ensemble...workable and an improvement over 0z

[Ralph Wiggum]

46 minutes ago, poolz1 said:

Not a bad look on the ensemble...workable and an improvement over 0z

Very nice

[BristowWx]

28 minutes ago, Ralph Wiggum said:

Very nice

Seems like a set up o don’t remember seeing that often.  Blocked up vice progressive up top.  But if you say it’s good that’s good enough for me.  

[Ralph Wiggum]

1 hour ago, BristowWx said:

Seems like a set up o don’t remember seeing that often.  Blocked up vice progressive up top.  But if you say it’s good that’s good enough for me.  

Never said it was good. Just said nice. Nice patterns dont always equal snow.  Very nice in that it is workable unlike the looks we were getting 72 hours ago .

My thought looking at that is that there is an active stj coming out of the SW Cali coast. There is a 50/50, a ridge in the Eastern nao region, ridge building off the NW coast with the PV downstream trying to meander SSE between the west coast ridge and the ridge in E Canada. 

[Bob Chill]

Eps keeps trending colder d10-15 but looks pretty dry with limited snow chances. Very weak signal around the 4th-6th. Gefs is similar with things turning dry after we transition to cold around NYE.

18z gefs had a bit more of a signal for potential between the 4th-6th. Right now guidance agrees on the big picture in early Jan and also agrees that snow chances are pretty meager and don't expect much before late in the first week of Jan. Of course this is all subject to change every 12 hours or so

[Bob Chill]

Took a closer look at the 18z gefs. I suppose there's a longshot chance around NYE. Something to watch as we pass time wearing sunscreen. 

[Bob Chill]

1 hour ago, losetoa6 said:

Yea...Bob there's a few members with a stout low at or near 50/50 and energy gets forced under us .

216

 

Some interesting looks. I'm actually a little confused why snowfall is sparse on both the eps and gefs. Hopefully that picks up soon. I am really liking the d15 height spread. Nearly every one is wintry and has potential. A lot of broad troughs in the mix. Get that going and our odds of snow are well above normal. About half the members have a closed ull of the coast of Socal. Jan 87 redux.

 

[showmethesnow]

The possible favorable changes to the pattern concerning the PAC are initiated Day 8-10 (Roughly day 8 GEFS,  Day 10 EPS) as we start to see the PV make its move eastward towards Greenland. The models have shown for awhile that the pv's influence in the N PAC around Alaska would be substantially reduced as we would see everything mostly shifted eastward. But what I have suspected for while now (because of the ambiguous looks the models have been throwing out in this region) is that we would still see a fairly significant pv presence in this area even after we saw the shift of the main PV eastward. That said I believe the models may now be starting to pick up on this.

If we look at the EPS below note that we are now starting to see strong negative anomalies and weak troughing extending westward through Alaska. This implies to me that the EPS is now possibly moving towards at lest pv associated troughing through that region, if not a piece of pv actually residing in that region. Now the current look is still workable despite the flat flow we are seeing coming off the PAC given the time of year. The problem here is that is probably not the look we get if we do in fact see troughing/piece of pv located close to or through Alaska. Chances are good that we would actually see is a repeat of the troughing extending down the west coast as we are now currently seeing and will see over the coming days. Needless to say this is the last thing we want to see for our snow chances

 

Now the GEFS is also picking up on the idea of a stronger pv presence/influence around Alaska as well. But note we are seeing a difference where the stronger anomalies and troughing are compared to the EPS. These features are running north of Alaska and hooking down into the Aleutians. This is a much more favorable location for this feature and one I want to see. As a result of this we are now seeing the ability for height builds/ridging to extend up the west coast into Alaska. This would go a long way in improving our snow chances. Pretty amazing when you think about it, what just the small shifting of one feature could mean in regards to our snow chances.

 

Now the PAC is just one part of the equation when it comes to our snow chances. Let's see what is occurring in the N Atlantic as the pv shifts.

Interestingly enough, the EPS has a better solution then the GEFS. Note that the stronger neg height anomalies/troughing are situated mostly north of Greenland. This positioning is allowing the ability for stronger height builds northward into Greenland. Considering that we typically see smoothing at this range on the ensembles we would probably see a greater amplification of the troughing and ridging as it neared in time considering what is being presented at this time. Which would be a good look for us as it would place blocking in the central and western portions of the NAO domain. But if we look at the GEFS the neg anomalies and troughing run directly through Greenland (strong +NAO). This is effectively squashing the flow and not allowing the greater heights to build northward as we see on the EPS. And given the look I don't think we could count on seeing an improvement with the heights/ridging even if we consider smoothing. Again we are seeing just a minor shift of a feature that can have a fairly significant impact.

 

 

 

Now if we could see a combination of what the GEFS is suggesting in the PAC as well what the EPS is suggesting in the N Atlantic I believe we would end up with a very good look through the CONUS as far as our snow chances. But we are still 8-10 days away from when all this get jump started by the pv's eastward migration so much can/will still change.

[CAPE]

Glancing at the 0z means, looks like straight up blue across the top at h5 in the LR.  +EPO/+AO/+NAO.

The hints of a building EPO ridge from previous runs are gone for now(or delayed). Despite that, we manage at least seasonable cold, as advertised. Likely some IOD/MJO 'conflicts' still playing into the currently advertised  pattern evolution beyond day 10..

The latest CFS weeklies look pretty nice weeks 2-6. Active look week 2, and general cold beyond that with a -EPO, and even hints of a -NAO week 5.

[CAPE]

Beginning right around the new year continues to look potentially active, with at least somewhat colder air in place. 6z GEFS upped the game a bit. First week of Jan has what looks to be multiple waves tracking just to our south. Rolling through the p-type panels for that period is a fun exercise, and it is also reflected on the snowfall mean.

[psuhoffman]

@showmethesnow @C.A.P.E.

The look briefly looks promising around day 10. We get a dump of cold post day 10 from that very temporary -NAO -epo. There might be a very short window but att guidance says it’s pretty dry. But after that the look across guidance is honestly not that good for a significant snow. It’s hard to find any examples of a decent snowstorm with that h5 look.  It’s not a shutout look...we can get some snow in most patterns except a big SE ridge in January. But we would be hoping for some kind of progressive wave. Anything amplified would cut. Sound familiar.  Rather than try to work with that I’m just holding on to hope that it’s wrong after day 10. I don’t really want to spend prime climo stuck in a pattern where our best shot is to root for strung out waves. 

ETA: root for the GEPS. 

[CAPE]

8 minutes ago, psuhoffman said:

@showmethesnow @C.A.P.E.

The look briefly looks promising around day 10. We get a dump of cold post day 10 from that very temporary -NAO -epo. There might be a very short window but att guidance says it’s pretty dry. But after that the look across guidance is honestly not that good for a significant snow. It’s hard to find any examples of a decent snowstorm with that h5 look.  It’s not a shutout look...we can get some snow in most patterns except a big SE ridge in January. But we would be hoping for some kind of progressive wave. Anything amplified would cut. Sound familiar.  Rather than try to work with that I’m just holding on to hope that it’s wrong after day 10. I don’t really want to spend prime climo stuck in a pattern where our best shot is to root for strung out waves. 

Agreed. If the CFS actually has a clue, I would be ok with what it's advertising overall, with an EPO ridge and a mostly neutral AO/NAO look, and a piece of the TPV on our side, although not necessarily in an ideal spot. This look would be acceptable for mid-late Jan:

[cbmclean]

1 hour ago, psuhoffman said:

@showmethesnow @C.A.P.E.

The look briefly looks promising around day 10. We get a dump of cold post day 10 from that very temporary -NAO -epo. There might be a very short window but att guidance says it’s pretty dry. But after that the look across guidance is honestly not that good for a significant snow. It’s hard to find any examples of a decent snowstorm with that h5 look.  It’s not a shutout look...we can get some snow in most patterns except a big SE ridge in January. But we would be hoping for some kind of progressive wave. Anything amplified would cut. Sound familiar.  Rather than try to work with that I’m just holding on to hope that it’s wrong after day 10. I don’t really want to spend prime climo stuck in a pattern where our best shot is to root for strung out waves. 

ETA: root for the GEPS. 

Won't gave access to the models for a bit.  GEP look good?

[showmethesnow]

1 hour ago, psuhoffman said:

@showmethesnow @C.A.P.E.

The look briefly looks promising around day 10. We get a dump of cold post day 10 from that very temporary -NAO -epo. There might be a very short window but att guidance says it’s pretty dry. But after that the look across guidance is honestly not that good for a significant snow. It’s hard to find any examples of a decent snowstorm with that h5 look.  It’s not a shutout look...we can get some snow in most patterns except a big SE ridge in January. But we would be hoping for some kind of progressive wave. Anything amplified would cut. Sound familiar.  Rather than try to work with that I’m just holding on to hope that it’s wrong after day 10. I don’t really want to spend prime climo stuck in a pattern where our best shot is to root for strung out waves. 

ETA: root for the GEPS. 

Where the pv is currently depicted in the extended on both models it will be hard to maintain any sort of -epo/-nao regime for long, if at all. How it is evolving on the models at this time our hope is probably that both models are under playing the southward drop of that feature. See the models start placing that closer to Hudson Bay and I think chances are pretty good we see the upper latitude blocking showing up in both domains with even an outside shot of seeing a possible attempt at bridging between them.

[poolz1]

The only thing good about today's MJO plot is that the models have been pretty bad with the LR forecasted phase....Both the GEFS and EPS take it back to the warm phases or heading toward them after a brief visit with phase 7.  

It's been the most ambiguous season so far in terms of main drivers...besides the +IOD i guess.  I have no idea where the LR is heading...neither do the models and neither do the mets I follow/read.  

[frd]

1 hour ago, psuhoffman said:

 It’s not a shutout look...we can get some snow in most patterns except a big SE ridge in January. But we would be hoping for some kind of progressive wave. Anything amplified would cut. Sound familiar.  Rather than try to work with that I’m just holding on to hope that it’s wrong after day 10. I don’t really want to spend prime climo stuck in a pattern where our best shot is to root for strung out waves. 

The general idea that run to run model changes would be frequent, and at times significant,  is really holding true so far.  I would not want to issue a 30 day forecast because the swings in modeling are really extreme.  I really feel many mets are even at a loss. 

Of note,  the same theme the last two weeks, pretty subtle yet significant changes on the modeling, ie. the -NAM state for example. Overall trends up top in the last 72 hours are not very good as you know.  A lack of cooperation in the drivers at play, maybe the seasonal models had a clue, although that determination is still yet to be determined. 

 I really don't like the looks of the TPV and its location out in fantasy land. Unfortunately I believe the progression to a more conducive winter pattern that can reload and has real snow potential will have to wait possibly, although there is a window as the PNA goes + near days 8 to 12.   

Funny thing is with the reasoning of the two camps , as we discussed before, one warmer less snow and then the other more seasonal and maybe snow potential, well the momentum seems to change with the modeling. There have been some set backs in terms of real threat window, and so  far Philly and the surrounding areas have had multiple low end snow events,  but every one has under-performed.  Certainly not a positive trend, even HM admits to the trace phenomenon. Another thing I was looking for was the occurrence of a "significant "snow event prior to December 15th to aid in providing some support for an above seasonal snowfall potential. These may or may not be clues as well as to the future.  

Another observation from the NE forum, from Tip. He mentioned how cold air was not holding on and was surprised how certain events up North trended warmer. Sounds like our area right, LOL . He posted that he felt we needed to establish deep cold air source with a -EPO and then intervals of + PNA. ( Of note on or near Jan 2nd  to the 4 th we do enter a forecasted period of + PNA. ) I like to see what happens then.

Wondering if the best pattern does go down in the second part of the winter. There are several analogs/outlooks  that support that idea, along with a few Nino winters starting after Jan 15th in terms of snowfall and colder outcomes.  Whether they prove useful in this day and age and background state , hard to say. Things are still progressing in terms of forcing and continued developments up top.  

Bottom line, very hard pattern to predict and just enjoy the holiday season and treasure those in your life   

Very bottom a post by Don S courtesy 33andrain - my take away (I think we all know this , but ) from it is the importance of a - AO and a + PNA. Those are your clues to Jan to March IMHO. 

 

Some interesting posts below regarding the IOD and the HL.  

 

 

 

From Don S  courtesy 33andrain  

 

Dreams of a white Christmas for the Middle Atlantic and southern New England regions will have to wait for at least another year. Milder air is now pushing into the region and will likely predominate through the much or all of the remaining days of December.

 

Through December 21, snowfall amounts for select cities include:

 

Allentown: 2.1" (1.6" below normal)
Atlantic City: 0.5" (2.1" below normal)
Boston: 11.5" (4.9" above normal)
Bridgeport: 5.5" (1.9" above normal)
Harrisburg: 0.2" (3.5" below normal)
Hartford: 21.1" (14.8" above normal)
Islip: 4.3" (1.7" above normal)
New York City: 2.5" (0.5" below normal)
Newark: 4.2" (0.7" above normal)
Philadelphia: 0.1" (2.1" below normal)
Providence: 8.0" (1.0" above normal)
Worcester: 25.3" (13.5" above normal)

 

Despite the warmth, which could take monthly departures toward and perhaps even above normal across many parts of the region, dreams of a snowy January persist. Perhaps a key to whether those dreams are realized will be the state of the Arctic Oscillation (AO) and Pacific North America (PNA) pattern.

 

Since 1950, 52 snowstorms brought 6" or more snow to at least one of the following cities: Boston, New York City, or Philadelphia. 60% of those storms had an AO-, 64% had a PNA+, and 38% had an AO-/PNA+. From among the 18 storms that brought 6" or more snow to at least two of those cities, 83% occurred with an AO-, 83% occurred with a PNA+, and 67% had an AO-/PNA+. From among the 11 storms that brought 6" or more snow to all three of those cities, 91% occurred with an AO-, 91% occurred with a PNA+, and 82% had an AO-/PNA+.

 

  

 

[Bob Chill]

@frd Wes did a great scatter plot with AO and 4" or greater snowstorms. The plot clearly showed the importance of a -AO and 4"+ storms for DCA as the correlation was somewhere around 70%. Might be higher...

I'm not digging too deep into anything right now as we're still over a week away from even being in the longshot game. Jan can be a friendly month with snowfall and hostile teleconnections. Just need some luck (as always).