January/February Winter Storm Threat Tracker

[PivotPoint]

41 minutes ago, psuhoffman said:

Umm regarding all the mjo talk phase 7 is awful late January and February. We need it into phase 8. 

Sorry you’re right. I forgot 8 was better not 7. My bad

[poolz1]

18 minutes ago, psuhoffman said:

Actually 4/5/6/7 are just bad phases now. As we move later in winter the impact from the forcing changes. 3 becomes good and 7 becomes bad.   

 

I wouldn’t expect any positive impact until it gets into 8. 

Agreed.  With the el nino being lackluster this is a much better indication of what to expect with each phase.  Though the H5 MJO charts with an MEI of >+1 worked well earlier in the season...they dont seem to be lining up now.

[Deer Whisperer]

fantasy snow anyone?

for the sake of lightening the mood for a moment

[Bob Chill]

Just now, Deer Whisperer said:

fantasy snow anyone?

for the sake of lightening the mood for a moment

Get enough of these setups and eventually there will be "the one" that works. Off the top of my head I'll say 1 out of 20 give more than a trace. How many so far this year? 5? Have to be approaching at least a 15% chance at this point. 

[psuhoffman]

@Isotherm

Thanks for the write up. My comments with frd regarding the sswe hurting was tongue in cheek but we were discussing what’s gone wrong so far from those epic looks for this week from 2-3 weeks ago and I think it’s a combo of the western ridge and NAO. The western epo pna is too far west but if the NAO was negative that could be overcome. We actually want systems to try to cut if we have a -NAO 50/50 pattern like was advertised on the weeklies.  I don’t think the location of the tpv has been a problem (although if it was displaced further southeast it could compensate for the less than ideal epo axis) but I do think the fact it’s been strong has been running interference. It’s amplifying the flow around it and deflecting attempts by the war to pump heights into the NAO domain.  Ideally we want that tpv weak. It’s been centered right where ideally we want ridging. Not so much for you as our perfect pattern is a bit too suppressive for NYC. But a tpv there isn’t awful if it’s weak but if strong the flow around that makes it hard to sustain true stable blocking. Some ridging sure but not a true cut off west based NAO block. And that’s what we would need to compensate for the issues out west. I guess I was looking at it from the perspective of how we could have overcome the pacific deficiencies if we had a perfect Atlantic that was teased on the weeklies back in early January. But yea we could go the other way and overcome the Atlantic if the epo and pna were centered further east so I guess it’s a combo of a less than ideal on both sides. But I would rather see that tpv either weaken or displaced into the 50/50 region when the next attempt to develop a -NAO comes around. 

ETA: I know your focused more on the causality and I can’t compete there, mine was more observational. 

[Wonderdog]

According to 18z GFS, Jan. 30 and maybe Feb 3rd are worth watching. I can take tracking one storm on a weekly basis. FV-3 on the other hand....

[MN Transplant]

1 hour ago, snowmagnet said:

What are people seeing in terms of temperatures around here next week?  I’ve seen on Judah Cohen and others twitter pages that the PV is dropping down early next week.  We were looking at maps of below zero temps for a couple of days next week. Is that still showing?  

Bernie Rayno thinks something has a chance coming easy next week. I’ll take any positives, so I’m hoping he’s right. I’m still hanging hope onto something around the 30th. Hoping that the models will get it together after this storm rolls through tomorrow. 

The cold may not be getting as much play as it could be.  Taken literally, the 18z GFS has the coldest 850 temp on record at Minneapolis.  The 12z Euro is top-10 coldest.  Excellent chance it doesn't verify, but that is still a nasty cold airmass rotating through the northern tier of the US.  When you have the cold, there are always chances for something.  Maybe we can get lucky on the retreat.

[PivotPoint]

@Isotherm

Interesting write up Iso and very informative on the pna. I relate it to the likened of baking a cake -- the pna are the ingredients and the nao the oven. Yes, you need the oven at the right temp to get a great cake but if you start with crappy ingredients (upstream pna) then how much does the temp (downstream blocking) really matter in the end. I know my analogy is an over simplification of the concept. Nevertheless, thanks for your insigh

What's your opinion on how the western Atlantic ridge has fit into the overall EC track and if it really is a spoiler or just seems that way due to (at times) less than ideal placement? Thanks

 

@psuhoffman

Good stuff too. In your estimation where exactly do you want the tpv placement to be to allow the war progression into the nao space?

Thanks

[Jebman]

Fascinating disco.

[Bob Chill]

@psuhoffman

One thing other than the nao that can really help everyone along the coast is the PNA flipping postive. I know you know that backwards and forwards... just posting general (obvious) thoughts. We now have the eps, gefs, and geps building a +pna late in their runs. We can focus on the other parts of the runs that don't look good or we (entire east coast) can focus on a tangible feature that would literally reshuffle the storm track for the better practically on a dime.

Even though ens mean h5 looks like we should be warm for a time d10-15, mean 2m temps don't coincide and are still right at or below normal from the 30th through the ends of the runs. That's more than a subtle hint that buried inside means are more than just a few solutions keeping cold air nearby or overhead. My guess is that a number of members are keeping the tpv in eastern canada while the longwave pattern goes through changes in the Pac. Even if we do go warm for a time, as long as it's part of a reshuffle for the better I personally don't care. A couple 55 degree days would actually be kinda nice...

It's entirely possible that we do get a +pna/-nao combo going faster than we think. At the very least a +pna can fix a good portion of what's killing storm chances up and down the coast. In the meantime we may score some sort of event somewhere around the 30th. 18z gefs very much keeps hope alive as well. Half decent ens run for that period.

[Isotherm]

25 minutes ago, psuhoffman said:

@Isotherm

Thanks for the write up. My comments with frd regarding the sswe hurting was tongue in cheek but we were discussing what’s gone wrong so far from those epic looks for this week from 2-3 weeks ago and I think it’s a combo of the western ridge and NAO. The western epo pna is too far west but if the NAO was negative that could be overcome. We actually want systems to try to cut if we have a -NAO 50/50 pattern like was advertised on the weeklies.  I don’t think the location of the tpv has been a problem (although if it was displaced further southeast it could compensate for the less than ideal epo axis) but I do think the fact it’s been strong has been running interference. It’s amplifying the flow around it and deflecting attempts by the war to pump heights into the NAO domain.  Ideally we want that tpv weak. It’s been centered right where ideally we want ridging. Not so much for you as our perfect pattern is a bit too suppressive for NYC. But a tpv there isn’t awful if it’s weak but if strong the flow around that makes it hard to sustain true stable blocking. Some ridging sure but not a true cut off west based NAO block. And that’s what we would need to compensate for the issues out west. I guess I was looking at it from the perspective of how we could have overcome the pacific deficiencies if we had a perfect Atlantic that was teased on the weeklies back in early January. But yea we could go the other way and overcome the Atlantic if the epo and pna were centered further east so I guess it’s a combo of a less than ideal on both sides. But I would rather see that tpv either weaken or displaced into the 50/50 region when the next attempt to develop a -NAO comes around. 

 

@psuhoffman - 

You may have a valid point with respect to non-optimal TPV location, though, intensity wise, the tropospheric vortex has been running weaker than normal this winter. The proxy of which is z150 zonal winds, which indicates upper tropospheric vortex strength:

 

With respect to the MJO, the apposite maps for El Nino are different than the ones you posted above. Phase 7 Jan/Feb is actually quite good, particularly in the high latitudes:

 

 

 

 

Further, VPM diagnostics have been superior to other guidance, though the ECMWF is now in concordance on eastward propagation to phase 7. This will likely continue propagating through low-orbit phase 7 and 8.

 

 

 

[psuhoffman]

15 minutes ago, PivotPoint said:

@Isotherm

Interesting write up Iso and very informative on the pna. I relate it to the likened of baking a cake -- the pna are the ingredients and the nao the oven. Yes, you need the oven at the right temp to get a great cake but if you start with crappy ingredients (upstream pna) then how much does the temp (downstream blocking) really matter in the end. I know my analogy is an over simplification of the concept. Nevertheless, thanks for your insigh

What's your opinion on how the western Atlantic ridge has fit into the overall EC track and if it really is a spoiler or just seems that way due to (at times) less than ideal placement? Thanks

 

@psuhoffman

Good stuff too. In your estimation where exactly do you want the tpv placement to be to allow the war progression into the nao space?

Thanks

If it’s weaker it doesn’t matter as much so long as it’s not over the NAO domain. But ideally getting it weakened and stretched with a lobe displaced into the 50/50 area is our perfect look. 

[Isotherm]

3 minutes ago, Bob Chill said:

@psuhoffman

One thing other than the nao that can really help everyone along the coast is the PNA flipping postive. I know you know that backwards and forwards... just posting general (obvious) thoughts. We now have the eps, gefs, and geps building a +pna late in their runs. We can focus on the other parts of the runs that don't look good or we (entire east coast) can focus on a tangible feature that would literally reshuffle the storm track for the better practically on a dime.

Even though ens mean h5 looks like we should be warm for a time d10-15, mean 2m temps don't coincide and are still right at or below normal from the 30th through the ends of the runs. That's more than a subtle hint that buried inside means are more than just a few solutions keeping cold air nearby or overhead. My guess is that a number of members are keeping the tpv in eastern canada while the longwave pattern goes through changes in the Pac. Even if we do go warm for a time, as long as it's part of a reshuffle for the better I personally don't care. A couple 55 degree days would actually be kinda nice...

It's entirely possible that we do get a +pna/-nao combo going faster than we think. At the very least a +pna can fix a good portion of what's killing storm chances up and down the coast. In the meantime we may score some sort of event somewhere around the 30th. 18z gefs very much keeps hope alive as well. Half decent ens run for that period.

 

Bob, I concur, and would add that one of the primary reasons weak Nino's are felicitous for -NAO is the long-wave structure in and of itself -- which this winter has been devoid of thus far: Aleutian low, Boise, ID ridge axis, downstream trough, which naturally tends to send cyclonic wave breaks northward and force the -NAO.

[Isotherm]

21 minutes ago, PivotPoint said:

@Isotherm

Interesting write up Iso and very informative on the pna. I relate it to the likened of baking a cake -- the pna are the ingredients and the nao the oven. Yes, you need the oven at the right temp to get a great cake but if you start with crappy ingredients (upstream pna) then how much does the temp (downstream blocking) really matter in the end. I know my analogy is an over simplification of the concept. Nevertheless, thanks for your insigh

What's your opinion on how the western Atlantic ridge has fit into the overall EC track and if it really is a spoiler or just seems that way due to (at times) less than ideal placement? Thanks

 

@psuhoffman

Good stuff too. In your estimation where exactly do you want the tpv placement to be to allow the war progression into the nao space?

Thanks

 

 

@PivotPoint, I think the west Atlantic is a "result" forced by other mechanisms, rather than a cause in and of itself. It's partially a function of the upstream dilemma delineated above re: Nina-esque forcing, which, as this ameliorates over the coming week(s), should begin to decrease the WAR's deleterious effects. The WAR is also a function of the oscillating, positive NAO. A classic -NAO features low-heights from the East Coast across the ATL to Europe.  

[Bob Chill]

2 minutes ago, Isotherm said:

 

Bob, I concur, and would add that one of the primary reasons weak Nino's are felicitous for -NAO is the long-wave structure in and of itself -- which this winter has been devoid of thus far: Aleutian low, Boise, ID ridge axis, downstream trough, which naturally tends to send cyclonic wave breaks northward and force the -NAO.

It's been a strange year. Ensemble skill beyond d10 has been unusually bad. Even when the hemispheric longwave pattern went through significant changes it kind of snuck up instead of coming into focus d10+. 

I brought this up several times this month but using the hindsight 20/20 analysis, the PDO was a red flag in November. I disregarded it because like everyone else I expected a standard weak west based nino pattern to take shape. Mid/late Nov added to my confidence because the AO tanked and we got an unusually large snow event for Nov standards. Then the big southern storm happened and the future looked that much brighter. But it all fell to pieces immediately after that... lol

Looking back over the past 6 weeks or so, the Pac has behaved pretty much like you would expect with a -PDO. I think the Pac gave us a sign that it would be hostile even before the mjo rounded the bend into weenie hell. I'll never ignore the PDO region again though. Luckily the pdo has come around and is now starting to look pretty good again. Would support the idea of a more +pna going forward. We'll know soon enough.

[psuhoffman]

2 minutes ago, Isotherm said:

 

@psuhoffman - 

You may have a valid point with respect to non-optimal TPV location, though, intensity wise, the tropospheric vortex has been running weaker than normal this winter. The proxy of which is z150 zonal winds, which indicates upper tropospheric vortex strength:

 

With respect to the MJO, the apposite maps for El Nino are different than the ones you posted above. Phase 7 Jan/Feb is actually quite good, particularly in the high latitudes:

 

 

 

 

Further, VPM diagnostics have been superior to other guidance, though the ECMWF is now in concordance on eastward propagation to phase 7. This will likely continue propagating through low-orbit phase 7 and 8.

 

 

 

Interesting about the tpv. Lately it’s been generating some extreme negative h5 anomalies so I guess I equated that with strength, bad assumption but the negative heights there where ideally we want higher heights and the enhanced flow around it into the NAO domain seems to be continually blunting attempts at ridging there. 

I stopped using the nino mjo plots since the last cycle seemed to be behaving more like am enso neutral.  If the forcing is about to take on a more nino characteristic then hopefully phase 7 will be beneficial.  

As I added a bit ago your dealing with causality which is much more complicated than my merely observational thoughts.  Thanks for you’re input. Hope this goes as planned! 

[PivotPoint]

6 minutes ago, Isotherm said:

 

 

@PivotPoint, I think the west Atlantic is a "result" forced by other mechanisms, rather than a cause in and of itself. It's partially a function of the upstream dilemma delineated above re: Nina-esque forcing, which, as this ameliorates over the coming week(s), should begin to decrease the WAR's deleterious effects. The WAR is also a function of the oscillating, positive NAO. A classic -NAO features low-heights from the East Coast across the ATL to Europe.  

Got it. Thank you

So if PNA ridge axis is in a more ideal spot then that in-turn promotes downstream troughing which can create wave breaks which can contribute to forcing that pumps heights into the NAO... I have that right? Thus, Atlantic ridge is a domino affect of upstream mechanics of PNA, which in large part, are Nina/nino driven during winter months. So since we've been in a weak Nino do we still expect Nino type results with the pna or the Nina-esque as you mentioned...

[psuhoffman]

28 minutes ago, Bob Chill said:

@psuhoffman

One thing other than the nao that can really help everyone along the coast is the PNA flipping postive. I know you know that backwards and forwards... just posting general (obvious) thoughts. We now have the eps, gefs, and geps building a +pna late in their runs. We can focus on the other parts of the runs that don't look good or we (entire east coast) can focus on a tangible feature that would literally reshuffle the storm track for the better practically on a dime.

Even though ens mean h5 looks like we should be warm for a time d10-15, mean 2m temps don't coincide and are still right at or below normal from the 30th through the ends of the runs. That's more than a subtle hint that buried inside means are more than just a few solutions keeping cold air nearby or overhead. My guess is that a number of members are keeping the tpv in eastern canada while the longwave pattern goes through changes in the Pac. Even if we do go warm for a time, as long as it's part of a reshuffle for the better I personally don't care. A couple 55 degree days would actually be kinda nice...

It's entirely possible that we do get a +pna/-nao combo going faster than we think. At the very least a +pna can fix a good portion of what's killing storm chances up and down the coast. In the meantime we may score some sort of event somewhere around the 30th. 18z gefs very much keeps hope alive as well. Half decent ens run for that period.

I think the pna problem is linked to the epo though. When we had that ideal full latitude ridge out west both were aligned. As the epo pulled west when the pacific forcing resumed negative influence the pna eroded also. But your 100% right that getting that back could offset. I’ve been coming at this from the perspective that the pac forcing has been what it is and so maybe with some help on the other side we could overcome it. Isotherm made a great point though that both are linked and so it might be all or nothing here. 

[midatlanticweather]

Thank you @Isotherm @psuhoffman and @Bob ChiII for the in depth analysis and insight. I just went to school for a bit and loved it! 

[Bob Chill]

18 minutes ago, PivotPoint said:

Got it. Thank you

So if PNA ridge axis is in a more ideal spot then that in-turn promotes downstream troughing which can create wave breaks which can contribute to forcing that pumps heights into the NAO... I have that right? Thus, Atlantic ridge is a domino affect of upstream mechanics of PNA, which in large part, are Nina/nino driven during winter months. So since we've been in a weak Nino do we still expect Nino type results with the pna or the Nina-esque as you mentioned...

Feb can be a friendly month and cut us some slack with perfect patterns. Even without a -nao, a well oriented +pna can deliver all by itself. Not just small storms either. PD2 hit without traditional blocking and was practically entirely driven by a +pna. Feb 2013 was also entirely pna (and epo) driven. The axis near Boise is very important without blocking though. Further west and storms cut. A good general rule of thumb is when a pna ridge axis is west of Boise we need a -nao or at least a transient 50/50 or the storm track is nw of our region. A pna ridge axis east of Boise and we don't want any strong blocking or it's a southern slider.

These aren't hard and fast rules as exceptions always exist and every event has its own personality. But as a general rule these are good guidelines. When looking at ensemble mean panels it's good practice to use the Boise rule to get a feel for how good (or bad) the potential is at long leads.

[poolz1]

41 minutes ago, psuhoffman said:

Interesting about the tpv. Lately it’s been generating some extreme negative h5 anomalies so I guess I equated that with strength, bad assumption but the negative heights there where ideally we want higher heights and the enhanced flow around it into the NAO domain seems to be continually blunting attempts at ridging there. 

I stopped using the nino mjo plots since the last cycle seemed to be behaving more like am enso neutral.  If the forcing is about to take on a more nino characteristic then hopefully phase 7 will be beneficial.  

As I added a bit ago your dealing with causality which is much more complicated than my merely observational thoughts.  Thanks for you’re input. Hope this goes as planned! 

Heh, that's an interesting point....still learning here.... So, if the SOI starts a neg dive would you expect the nino MJO plots to be more representative?  On the flip side...earlier in the season the nino plots worked well even during the warm phases. 

I'm starting to realize that this novice may never grasp this relationship..lol maybe thats why it keeps me interested.

[Bob Chill]

I just posted in the wrong thread again...lol... but it's worth a little disco here. Eps has 40 out of 50 members dropping at least a little snow around the 30th. Only 13 are over 2". 17 out 20 members of the 18z gefs drop at least a little with half of those dropping 2"+. 

I know some people don't care about light events but I like every snow event regardless. If we pull off a 2-4" event then this January is actually very good compared to the vast majority. 15-20" in a month in most of our yards with 3 accum events is an A+ month. We all grade on our own metrics but saying this month is a disaster is very unreasonable imho. Statistically it's prob at least 90th percentile of all winter months. I can't think of any Januaries other than 2016 and 95-96 that have been better. 

[Deer Whisperer]

11 minutes ago, Bob Chill said:

I just posted in the wrong thread again...lol... but it's worth a little disco here. Eps has 40 out of 50 members dropping at least a little snow around the 30th. Only 13 are over 2". 17 out 20 members of the 18z gefs drop at least a little with half of those dropping 2"+. 

I know some people don't care about light events but I like every snow event regardless. If we pull off a 2-4" event then this January is actually very good compared to the vast majority. 15-20" in a month in most of our yards with 3 accum events is an A+ month. We all grade on our own metrics but saying this month is a disaster is very unreasonable imho. Statistically it's prob at least 90th percentile of all winter months. I can't think of any Januaries other than 2016 and 95-96 that have been better. 

Small events are nice, but are more appreciated when the snow sticks to the road. I am stubborn about that

[jaydreb]

10 minutes ago, Bob Chill said:

I just posted in the wrong thread again...lol... but it's worth a little disco here. Eps has 40 out of 50 members dropping at least a little snow around the 30th. Only 13 are over 2". 17 out 20 members of the 18z gefs drop at least a little with half of those dropping 2"+. 

I know some people don't care about light events but I like every snow event regardless. If we pull off a 2-4" event then this January is actually very good compared to the vast majority. 15-20" in a month in most of our yards with 3 accum events is an A+ month. We all grade on our own metrics but saying this month is a disaster is very unreasonable imho. Statistically it's prob at least 90th percentile of all winter months. I can't think of any Januaries other than 2016 and 95-96 that have been better. 

I would take a light event in a heartbeat but are we talking a nice cold snow (like last week’s) or some crap changeover  at the tail end of a rainstorm?  There’s a difference in how the snow accumulates.  

[EastCoast NPZ]

24 minutes ago, Bob Chill said:

I just posted in the wrong thread again...lol... but it's worth a little disco here. Eps has 40 out of 50 members dropping at least a little snow around the 30th. Only 13 are over 2". 17 out 20 members of the 18z gefs drop at least a little with half of those dropping 2"+. 

I know some people don't care about light events but I like every snow event regardless. If we pull off a 2-4" event then this January is actually very good compared to the vast majority. 15-20" in a month in most of our yards with 3 accum events is an A+ month. We all grade on our own metrics but saying this month is a disaster is very unreasonable imho. Statistically it's prob at least 90th percentile of all winter months. I can't think of any Januaries other than 2016 and 95-96 that have been better. 

1987

[snowmagnet]

21 minutes ago, Bob Chill said:

I just posted in the wrong thread again...lol... but it's worth a little disco here. Eps has 40 out of 50 members dropping at least a little snow around the 30th. Only 13 are over 2". 17 out 20 members of the 18z gefs drop at least a little with half of those dropping 2"+. 

I know some people don't care about light events but I like every snow event regardless. If we pull off a 2-4" event then this January is actually very good compared to the vast majority. 15-20" in a month in most of our yards with 3 accum events is an A+ month. We all grade on our own metrics but saying this month is a disaster is very unreasonable imho. Statistically it's prob at least 90th percentile of all winter months. I can't think of any Januaries other than 2016 and 95-96 that have been better. 

Thanks for that bit of insight. I think 2” on 4/5 of the EPS is huge considering the past couple of days of nada.  I keep telling my snow-loving friends that we “might” get something around the 30th.  I agree that January isn’t usually that great, (except for those 2 amazing storms). I moved back into the DC area after college in ‘94. I was so glad I didn’t miss ‘96.  It was one of my most memorable storms. And then 2016...exactly 3 years ago today.  

I’m still holding out hope for all of us to do well the next 2 months... as if we have any control over the weather.  

 

[Ji]

I just posted in the wrong thread again...lol... but it's worth a little disco here. Eps has 40 out of 50 members dropping at least a little snow around the 30th. Only 13 are over 2". 17 out 20 members of the 18z gefs drop at least a little with half of those dropping 2"+. 
I know some people don't care about light events but I like every snow event regardless. If we pull off a 2-4" event then this January is actually very good compared to the vast majority. 15-20" in a month in most of our yards with 3 accum events is an A+ month. We all grade on our own metrics but saying this month is a disaster is very unreasonable imho. Statistically it's prob at least 90th percentile of all winter months. I can't think of any Januaries other than 2016 and 95-96 that have been better. 

Just imagine if it wasnt a blowtorch

[LP08]

That’s an interesting ICON solution for next week with the frontal passage.  Phase at our latitude and slams up into New England.

 

[yoda]

Maybe a little something here on the 00z GFS for the 30th or so?

[Deer Whisperer]

Just looking at the band of precip, it appears larger. Raw weenie eye looking for anything decent