December 2019 Med/Long Range Disco

[psuhoffman]

34 minutes ago, WxUSAF said:

Haven't seen the EPS past D10, but I like the evolution of the pattern on the GEFS and the GEPS.  Keep that AO negative and we'll be in good shape.  Doesn't look as cold, but still probably seasonal on balance after D7.  

Eps had no appreciable change from the last few runs. 

[JakkelWx]

BAMWX supports the idea of a trend to colder than normal risks for December.

What is interesting is the ridge in the SW US. That would signify a weakening of the STJ. EPS showing the idea of a -NAO developing just in time for Thanksgiving. Should be fun.

[WinterWxLuvr]

15 minutes ago, JakkelWx said:

BAMWX supports the idea of a trend to colder than normal risks for December.

What is interesting is the ridge in the SW US. That would signify a weakening of the STJ. EPS showing the idea of a -NAO developing just in time for Thanksgiving. Should be fun.

That ridge in the southwest would signify to me that we would be depending on something northern stream to dig enough to get under us. More than not that ends up being cold and dry. 

[Chris78]

24 minutes ago, JakkelWx said:

BAMWX supports the idea of a trend to colder than normal risks for December.

What is interesting is the ridge in the SW US. That would signify a weakening of the STJ. EPS showing the idea of a -NAO developing just in time for Thanksgiving. Should be fun.

At some point were due for a - nao Dec/Jan/Feb. Its been several years. I would say the WD index is pretty high lol.

[CAPE]

55 minutes ago, WinterWxLuvr said:

That ridge in the southwest would signify to me that we would be depending on something northern stream to dig enough to get under us. More than not that ends up being cold and dry. 

I know you know this, but looking at composites/means do not imply that the given anomaly will be there 100% of the time. Give me a general cold look imby and I will take my chances every time- If its dry, its dry. Can't snow if it's not cold enough. You clearly view things from the other end of the stick, but thats a function of our disparate climo in this region.

eta- I thought you preferred a cold winter with multiple low end events (eg NS) rather than an overall mild winter with one big dog(2016). Also, good chance the atmosphere behaves more like a weak Nino than a Nina, so there should be some STJ action undercutting any ridging out west.

[CAPE]

54 minutes ago, psuhoffman said:

Eps had no appreciable change from the last few runs. 

EPS looks damn good. GEFS looks good wrt to HL/NA blocking, but trends towards lower heights out west. Not necessarily a bad thing, but I prefer the EPS look.

[WinterWxLuvr]

39 minutes ago, C.A.P.E. said:

I know you know this, but looking at composites/means do not imply that the given anomaly will be there 100% of the time. Give me a general cold look imby and I will take my chances every time- If its dry, its dry. Can't snow if it's not cold enough. You clearly view things from the other end of the stick, but thats a function of our disparate climo in this region.

Yeah it’s a two headed coin. Gotta have the cold. And we certainly can’t score with a whopping se ridge. A little bit of one can help sometimes. I guess for me my thoughts are if it’s stormy enough we will get lucky some with temps. And yes, those means only give a broad outline. What is shown is better than the reverse.

[Bob Chill]

16 minutes ago, Chris78 said:

At some point were due for a - nao Dec/Jan/Feb. Its been several years. I would say the WD index is pretty high lol.

For reasons that nobody really knows for sure... the NAO has an embedded decadal or multi-decadal cycle. It's streaky over longer time scales. Obvioulsy we've been experiencing the bad streak lately and luckily "stole" 2 damn good winters during this big +NAO streak. What made the 2013-15 stretch so special (and unusual) was the # of snow events.

I'm way too lazy to look it up but I'm pretty much 100% sure you will find few if any winters in the last 100 years that featured a strongly + NAO and 10 or more snow events. It was a remarkable stretch that will probably never happen again in my lifetime. It's not like we need some raging -nao to get snowfall but that stretch was raging positive. From a wx enthusiast perspective, those back to back winters should be at the top of the anomalous/unusual list. 

I'm really hoping current guidance is a sign that the bad streak is over. A -nao really helps with marginal setups and tricky stromtracks. We don't even need below normal temps in the heart of winter to get snow with a nice stormtrack. Cutters can still happen with a -nao but even with those have a much better shot of front end snowfall when HP is doing like 90mph NE into the Atlantic. I'm really sick of cold high pressures running away all winter.  

[CAPE]

Just now, WinterWxLuvr said:

Yeah it’s a two headed coin. Gotta have the cold. And we certainly can’t score with a whopping se ridge. A little bit of one can help sometimes. I guess for me my thoughts are if it’s stormy enough we will get lucky some with temps. And yes, those means only give a broad outline. What is shown is better than the reverse.

Never easy or simple in this region. Often a flawed pattern ends up getting it done. That works better for you than me though lol.

[Bob Chill]

8 minutes ago, C.A.P.E. said:

Never easy or simple in this region. Often a flawed pattern ends up getting it done. That works better for you than me though lol.

IMO our region has the most near misses than any other location in the east. The good thing is we generally get some chances every winter. The bad thing is too many things can often go wrong.

The "wrong list" is proportionate from west to east. My area is ok most of the time as forum divider storms usually have enough frozen precip to put me somewhere in the middle. Once you get as far east as your hood it becomes an island of sorts sometimes. You root for different things with events that hit you flush. If we get some blocking that changes the disparity in your favor as locations across our sub become more equalized. 

[Scarlet Pimpernel]

16 minutes ago, Bob Chill said:

For reasons that nobody really knows for sure... the NAO has an embedded decadal or multi-decadal cycle. It's streaky over longer time scales. Obvioulsy we've been experiencing the bad streak lately and luckily "stole" 2 damn good winters during this big +NAO streak. What made the 2013-15 stretch so special (and unusual) was the # of snow events.

I'm way too lazy to look it up but I'm pretty much 100% sure you will find few if any winters in the last 100 years that featured a strongly + NAO and 10 or more snow events. It was a remarkable stretch that will probably never happen again in my lifetime. It's not like we need some raging -nao to get snowfall but that stretch was raging positive. From a wx enthusiast perspective, those back to back winters should be at the top of the anomalous/unusual list. 

I'm really hoping current guidance is a sign that the bad streak is over. A -nao really helps with marginal setups and tricky stromtracks. We don't even need below normal temps in the heart of winter to get snow with a nice stormtrack. Cutters can still happen with a -nao but even with those have a much better shot of front end snowfall when HP is doing like 90mph NE into the Atlantic. I'm really sick of cold high pressures running away all winter.  

One reason why 2013-14 is way up there on my list of winters...in the years that I've been here, at least (since 2001).  Depending on the day and how I feel, I rate that winter as better even than 2002-03, despite the KU event that February.  Yeah, I know, it's sacrilege to declare anything other than '09-10 better than '02-03, but you know what I mean.  Not a single KU event in '13-14, and only one event that scored a foot-plus where I'm at (in Feb. 2014), but the sheer number of moderate or better events was astonishing.  Especially given the overall winter pattern that season.  Not to mention how late in the season we got those.

I'd argue we can do well with a "bootleg" -NAO too, like the Blizzard of 2016.  A small precursor clipper helped "keep it in place" just long enough to deliver that two days later.  But there's always an element of luck there, too.  (ETA:  And that blizzard occurred after a gut-punching warm December that was +11 on the month!!).

[BristowWx]

2 minutes ago, Bob Chill said:

IMO our region has the most near misses than any other location in the east. The good thing is we generally get some chances every winter. The bad thing is too many things can often go wrong.

The "wrong list" is proportionate from west to east. My area is ok most of the time as forum divider storms usually have enough frozen precip to put me somewhere in the middle. Once you get as far east as your hood it becomes an island of sorts sometimes. You root for different things with events that hit you flush. If we get some blocking that changes the disparity in your favor as locations across our sub become more equalized. 

I notice those near misses the most with clippers in recent times.  I could be off my rocker but it seems they have trended north over the years.  They hardly get underneath us anymore.  Maybe that was always the case and I have selective memory.  

[CAPE]

12 minutes ago, Bob Chill said:

IMO our region has the most near misses than any other location in the east. The good thing is we generally get some chances every winter. The bad thing is too many things can often go wrong.

The "wrong list" is proportionate from west to east. My area is ok most of the time as forum divider storms usually have enough frozen precip to put me somewhere in the middle. Once you get as far east as your hood it becomes an island of sorts sometimes. You root for different things with events that hit you flush. If we get some blocking that changes the disparity in your favor as locations across our sub become more equalized. 

Yes a legit block and a moderate Nino combo is a great equalizer. Otherwise it's mostly a crap shoot. I don't mind a Nina because we can get plenty cold, and with the baroclinic boundary further east I can catch the edge of offshore coastals/developing Miller Bs like a couple winters ago. Chased back to back early Jan big storms at the beach, and still came home to 6" of snow that stayed around for 5-6 days both years. Ofc west of the bay it was classic cold/dry. Last winter my yard failed every way possible lol. Was uncanny.

[Bob Chill]

3 minutes ago, Always in Zugzwang said:

One reason why 2013-14 is way up there on my list

It's a subjective grading system but for me 13-14 was the all time greatest tracking winter of my life. Minimal deadspace, events from first week of Dec to last week of March, and some damn crazy stuff like snow in the teens multiple times including March. Even had an all snow west track! The low temps we had at times were crazy too. Bay froze shore to shore at the bridge... one helluva year on so many levels. 

1 minute ago, BristowWx said:

I notice those near misses the most with clippers in recent times.  I could be off my rocker but it seems they have trended north over the years.  They hardly get underneath us anymore.  Maybe that was always the case and I have selective memory.  

Prob a function of a nasty +AO through many recent years. Not a good pattern to get clippers running through central VA....

[poolz1]

2 minutes ago, Bob Chill said:

It's a subjective grading system but for me 13-14 was the all time greatest tracking winter of my life. Minimal deadspace, events from first week of Dec to last week of March, and some damn crazy stuff like snow in the teens multiple times including March. Even had an all snow west track! The low temps we had at times were crazy too. Bay froze shore to shore at the bridge... one helluva year on so many levels. 

 

I loved 13-14....The "cold smoke" winter!  14-15 was great but I was fringed on the big storm that year.

13-14 and 09-10.  Both incredibly snowy winters but two different beasts.  Its a tough decision as to which one I'd prefer a repeat....I do live for the big storms and to have 3 in one season!  But, constant tracking and then scoring on most of them is pretty fulfilling.  Even if they were not all 12"+ events.

[CAPE]

20 minutes ago, Bob Chill said:

It's a subjective grading system but for me 13-14 was the all time greatest tracking winter of my life. Minimal deadspace, events from first week of Dec to last week of March, and some damn crazy stuff like snow in the teens multiple times including March. Even had an all snow west track! The low temps we had at times were crazy too. Bay froze shore to shore at the bridge... one helluva year on so many levels. 

 

That was a seriously fun winter. Lots of luck involved, but hey sometimes things just go our way. The frozen inland waters and even large parts of the bay was awesome too. Love that stuff.

eta- I think that was the winter that featured the epic poetry thread. lol fun times.

[psuhoffman]

1 hour ago, C.A.P.E. said:

EPS looks damn good. GEFS looks good wrt to HL/NA blocking, but trends towards lower heights out west. Not necessarily a bad thing, but I prefer the EPS look.

Guidance hints at a split flow to me with energy crashing into the west that occasionally lowers heights there. That can work. Probably not in late November but give me that setup between about Dec 15 and March 5 and I’ll roll the dice. 

[Chris78]

40 minutes ago, Bob Chill said:

For reasons that nobody really knows for sure... the NAO has an embedded decadal or multi-decadal cycle. It's streaky over longer time scales. Obvioulsy we've been experiencing the bad streak lately and luckily "stole" 2 damn good winters during this big +NAO streak. What made the 2013-15 stretch so special (and unusual) was the # of snow events.

I'm way too lazy to look it up but I'm pretty much 100% sure you will find few if any winters in the last 100 years that featured a strongly + NAO and 10 or more snow events. It was a remarkable stretch that will probably never happen again in my lifetime. It's not like we need some raging -nao to get snowfall but that stretch was raging positive. From a wx enthusiast perspective, those back to back winters should be at the top of the anomalous/unusual list. 

I'm really hoping current guidance is a sign that the bad streak is over. A -nao really helps with marginal setups and tricky stromtracks. We don't even need below normal temps in the heart of winter to get snow with a nice stormtrack. Cutters can still happen with a -nao but even with those have a much better shot of front end snowfall when HP is doing like 90mph NE into the Atlantic. I'm really sick of cold high pressures running away all winter.  

Its been so long sometimes I think we forget what a legit - nao block can do lol.

After the disaster of the long range models/ weeklies of last year ,Ive learned a lesson on not to put alot of faith in guidance of the overall pattern past about 2 weeks. Generally it seems like persistance wins out and patterns always take longer to flip than first advertised. It was pretty amazing that week after week thr Euro weeklies showed a great pattern developing and it just never materilized. 

Im also a big believer that luck and randomness play a big part in our snow totals lol

[WxUSAF]

7 minutes ago, psuhoffman said:

Guidance hints at a split flow to me with energy crashing into the west that occasionally lowers heights there. That can work. Probably not in late November but give me that setup between about Dec 15 and March 5 and I’ll roll the dice. 

I just saw the 324hr EPS posted elsewhere.  Yeah, that's a real nice look for a winter storm, just maybe not in late November.  

[BristowWx]

9 minutes ago, WxUSAF said:

I just saw the 324hr EPS posted elsewhere.  Yeah, that's a real nice look for a winter storm, just maybe not in late November.  

It’s ok from my view.  It wouldn’t be a Torchgiving...all we can ask for..or at least all I can ask for

[psuhoffman]

43 minutes ago, WinterWxLuvr said:

Yeah it’s a two headed coin. Gotta have the cold. And we certainly can’t score with a whopping se ridge. A little bit of one can help sometimes. I guess for me my thoughts are if it’s stormy enough we will get lucky some with temps. And yes, those means only give a broad outline. What is shown is better than the reverse.

The thing is usually storms run the temperature boundary. So it’s hard to get a ton of precip and be under a monster ridge all winter. It’s also hard to be near the boundary all winter and never end up on the right side for any of the storms. We only need a few to hit Climo.  Rare years like 1998 can happen where the whole continent is void of cold so storms ride the boundary between sun tropical and cool but not cold enough air but that’s rare  

On the flip side it’s also hard at our latitude to be consistently so far north of the boundary all winter that we are just cold/dry for a very long stretch.  Yea 1977 can happen but that’s equally rare.  

What’s more common in a bad pattern is that we get transient cold where we never make it that far into the cold airmass and there is no mechanism (blocking/displaced PV/ 50/50) to resist the push of warmth that will naturally come with the next “wave” in the atmosphere. Without any resistance once the flow backs ahead of the next wave the boundary races to our north and the storm cuts as it rides that boundary.  Hence warm wet cold dry.  

But other than having fun with the running joke that’s not really a problem of “dry during the cold”. It’s a problem of the longwave pattern not being right to offer enough resistance to the WAA that’s comes with 99% of any precip event (other than that rare late bombing perfect coastal we get once every blue moon while a white elk runs by and a leprechaun does a jig on the roof). 

 Usually we can see hints of that problem in the pattern. Any really cold pattern is likely to be a little “dryer” since storms run the boundary and if we are that cold the boundary isn’t likely close. But sooner or later a wave will come and of there is enough resistance in the flow then...boom. Give me the right longwave pattern from range and I’ll take my chances on the details once the short range comes. 

[midatlanticweather]

13 - 14 was the best tracking year of my life. One of my favorite quotes from @Bob Chillthat year was that the atmosphere could fart and it would end up being snow. It was such a unique winter. I like the big ones too, but they come and go too fast. Having snow every 3 to 5 days, or at least something to track, was fun. One time when post storm depression did not have long because something was always on the horizon. 2002 - 2003 and 2009 - 2010 will always have special memories for the big ones. 2013 - 2014 was a special almost the whole winter. 

 

 

 

 

[WinterWxLuvr]

Besides clippers another thing that seems to be gone anymore are the broad troughs the seem  to be backed up against the front range of the Rockies with a piece of energy running down the slope into the lower Mississippi valley and cranking a storm that runs through the mid south and turns the corner up the coast. Just a memory. Possibly selective but those seem like they used to be more common. 

[psuhoffman]

2 hours ago, Bob Chill said:

What made the 2013-15 stretch so special (and unusual) was the # of snow events.

I'm way too lazy to look it up but I'm pretty much 100% sure you will find few if any winters in the last 100 years that featured a strongly + NAO and 10 or more snow events.

1960-61

Raging positive NAO. 40” at DCA. And the rare trifecta of above avg snow all 3 winter months. 8.7”, 13.6”, 18”. 

1961, 1994, 2014 all had the commonality of  extreme ridging in either the epo or pna domain that bullied the pattern downstream.  They also all shared that the AO was neutral or slightly negative because the ridging in the pacific domain was so extreme it encroached into the AO domain.  1994 didn’t end as well wrt snow but it was only a slight adjustment on a few storms from being an epic snow year in DC.  1994 though featured the furthest west of the ridge axis on the pac side of all 3 years and so more SE ridging.  

2014-15 was perhaps the true oddball.  Yea 3 instances in 50 years is rare but 2014-15 is the only example of a raging positive NAO and AO all 3 months and still above average snowfall.  We got super lucky with a consistent pna ridge and a PV often parked over Quebec for much of Feb and March.  That extreme and rare combo overcame the most hostile high latitudes possible.  There are no good comps to that in the last 50 years and we will probably not see it again.  

 

[cbmclean]

1 hour ago, Always in Zugzwang said:

ETA:  And that blizzard occurred after a gut-punching warm December that was +11 on the month!!

December 2015 will haunt my dreams for a long time, and not in a good way.  Down here in NC we were 70+ for like two weeks straight.  It was a warm, soupy airmass as well.  Didn't get below 60 F for days on end at night.  Mosquitoes and gnats were buzzing.  Had to cut on the AC.  I think it actually ht 80 F on Christmas day where I was.

[psuhoffman]

@Bob Chill

BTW...2002-3 shared a lot in common with those years after the blocking in December faded. From Jan on the NAO was positive with a weakly - AO and yet the pacific bullied the pattern very similar to those other years.  I bring that up because 2002-3 is a great match wrt north pac SST, IOD sst, QBO, and Atlantic SST profile. The only flaw is enso.  And some of those other years share some commonality to the pattern now also. 

[Maestrobjwa]

1 hour ago, psuhoffman said:

3 hours ago, Bob Chill said:

What made the 2013-15 stretch so special (and unusual) was the # of snow events.

I'm way too lazy to look it up but I'm pretty much 100% sure you will find few if any winters in the last 100 years that featured a strongly + NAO and 10 or more snow events.

1960-61

Raging positive NAO. 40” at DCA. And the rare trifecta of above avg snow all 3 winter months. 8.7”, 13.6”, 18”. 

Well I mean...it was the 60s: probably our snowiest decade on record--it's gotta be, lol I mean my goodness, that was a golden age if you were a snow lover: Not one year was below 18"...and at least 7 of the 10 were above average! (what, did we go without la Ninas that decade?) Would love to know what kind of dynamics were at play that decade! (of course we did kinda pay for it between 1970 and 1978, lol)

[showmethesnow]

To say we have seen improvements in these last few days in regards to the pv (500 mb) migrating westward would be an understatement. My fear of possibly seeing that feature plant itself for a period of time close to Alaska now seem unwarranted. As it stands now we are looking at only a short period of a CONUS wide warmup as PAC air floods NA on the pvs initial move westward. And even that looks to be mitigated in the NE US  as we are seeing decent troughing induced by the higher heights/ridging in the NAO domain backing the flow. Though we might struggle with climo temps with the pv located on the other side of the globe in the extended the look being presented now is a far more forgiving look then what was being offered up several days ago.

[osfan24]

10 hours ago, poolz1 said:

I loved 13-14....The "cold smoke" winter!  14-15 was great but I was fringed on the big storm that year.

13-14 and 09-10.  Both incredibly snowy winters but two different beasts.  Its a tough decision as to which one I'd prefer a repeat....I do live for the big storms and to have 3 in one season!  But, constant tracking and then scoring on most of them is pretty fulfilling.  Even if they were not all 12"+ events.

Definitely both very cool in their own ways. I would still take the winter with the three big dogs, especially because some forget that there were some nice little systems that hit us leading up to the first big January storm. Plus, getting a big storm before Christmas was pretty amazing.

I'll always remember 13-14 though as one of the top winters. Just wall-to-wall legit winter is how I'll remember it. Tracking storms nonstop for 3-4 months. And it wasn't just the snow. It seemed like wall-to-wall cold as well with a lot of crazy snows with temps in the teens and low 20's, even into March. 14-15 was like a very poor man's 13-14. Still a nice winter but just fell short of 13-14 in almost every way. Amazing stretch though. Pretty sure between 2009-2010, the fun storm in 2011, 13-14, 14-15 and the big dog in 2016, we've gotten so spoiled that we forget what normal winters are like. I know I have.

[Rtd208]

DT (WxRisk)

https://www.wxrisk.com/potentially-some-good-news-for-east-coast-winter-weather-lovers-2019-20/?fbclid=IwAR0FzQeqCTBbiP99-KBtUoJdW4rZttm5Md_kbgbLUMvlRup51hClHReGJ8o