Medium Range-Long Range thread

[Quakertown needs snow]

Long range Euro today bringing some chill to the east starting next wednesday.

Possible clippers?

[iceman56]

Long range Euro today bringing some chill to the east starting next wednesday.

Possible clippers?

A certain met that shall remain nameless in this thread mentioned a parallel to the March 1984 clipper event

in the elusive 7-10 day period.

[NJ_Ken]

I won't comment on the validity of the 84 clipper analog (I will leave that to the pros), but I will say that 84 storm was a heck of a little event for the mid-atlantic. That storm was mostly infamous because the (then) Baltimore Colts packed their moving vans and snuck out of town using the storm as "cover". Up this way, that storm marked the one and only time my town, Cherry Hill, NJ was the bullseye. I am not sure if it was an "official" measurement but local news and TWC reported us with a storm total of 10", which topped even PHL,which got 7". Nothing historic but a darn nice storm in an otherwise mediocre winter.

[HM]

In the last week of Feb and very beginning of Mar, we had a combination of features that led to an upper stratospheric warming over East Asia:

1. A strengthening upper vortex (10mb and up) after Jan SSW

2. An eastern European/western Siberian trough and downstream ridge (favors wave 1 response and EA MT)

3. Tropical forcing transitioning from Indo to west Pac sector (Helps MT)

The planetary waves from Europ-N pac favored a wave 1 response ~ 60-70N as upward wave flux increased (I know EP vectors are toward equator now but there was upward flux). Also their positioning in conjunction with the forcing led to a strong East Asian MT...perhaps the strongest of the cold season.

I don't think this will be the beginning of any type of early final warming but it could slowly morph into that with time. It certainly is not a SSW and only occurred from the hostile Eurasian Sector and strengthening upper stratospheric vortex post-Jan SSW. We had a very similar wave 1 response last March around this time with a similar MJO propagation / Eurasian feature.

It is March so it doesn't necessarily mean what it means mid-winter for the PNA. The amplified flow / RWT will morph into a classic trough-ridge-trough configuration (-EPO) across N PAC with a downstream ridge into the C Plains. The cyclonic wave breaking should continue off the North American East Coast, possibly leading to another -NAO period.

We haven't seen the last of winter and I could see another nor'easter before the month is out. April could be crazy with late-season car topper possible, even into the middle part of the month. But, that is something I am just not willing to get gutsy about.

[phlwx]

Seems very similar to '07...big but brief warm ups, periods of sustained cold....crappy delayed Spring overall.

[am19psu]

In the last week of Feb and very beginning of Mar, we had a combination of features that led to an upper stratospheric warming over East Asia:

1. A strengthening upper vortex (10mb and up) after Jan SSW

2. An eastern European/western Siberian trough and downstream ridge (favors wave 1 response and EA MT)

3. Tropical forcing transitioning from Indo to west Pac sector (Helps MT)

The planetary waves from Europ-N pac favored a wave 1 response ~ 60-70N as upward wave flux increased (I know EP vectors are toward equator now but there was upward flux). Also their positioning in conjunction with the forcing led to a strong East Asian MT...perhaps the strongest of the cold season.

I don't think this will be the beginning of any type of early final warming but it could slowly morph into that with time. It certainly is not a SSW and only occurred from the hostile Eurasian Sector and strengthening upper stratospheric vortex post-Jan SSW. We had a very similar wave 1 response last March around this time with a similar MJO propagation / Eurasian feature.

It is March so it doesn't necessarily mean what it means mid-winter for the PNA. The amplified flow / RWT will morph into a classic trough-ridge-trough configuration (-EPO) across N PAC with a downstream ridge into the C Plains. The cyclonic wave breaking should continue off the North American East Coast, possibly leading to another -NAO period.

We haven't seen the last of winter and I could see another nor'easter before the month is out. April could be crazy with late-season car topper possible, even into the middle part of the month. But, that is something I am just not willing to get gutsy about.

Thanks, HM. That's similar to my line of thinking (though with more of the details filled in). Given the amount of attention I was seeing the 10mb warming given, I thought I was missing something.

[HM]

Well the mid-March period is growing more and more interesting. The 12z ECMWF/ensembles will be interesting for sure but I suspect the ensembles will continue to be more robust with the -NAO. The op seemed too far west / amplified with the eastern Canadian PV.

This storm, now, and the couple next week will continue the cyclonic wave breaking and displaced jet across the Atlantic. Between that and the ozone flux in the lowest stratospheric layers, the NAO should have no problem dipping again in a week (also a classic AAM response too going on). This will likely lead to yet another threat for a coastal storm / snowstorm around that time, obviously with the higher elevations / New England most likely to receive the best snow (climo).

It is possible the Mid Atlantic may be more favorable this go around, due to the Tropical Pacific, than what we just went through (despite the date). The core of the cold settling into SE Canada is, for starters, a huge improvement should a -NAO block form. This last blocking episode only really pooled a stale air mass (which worked for our friends to the north).

It seems like we may break for a time after this blocking episode to allow some spring time temps soar in later in the month; but, I think it will end up brief. Winter may not be over then with the potential for some type of weird April snow in the second week, lol. I'm not sure what to make of that but there is some evidence of that happening. Mostly likely a "T" type of thing.

[HM]

By the way, the "clipper" next Thursday-Friday is a legitimate threat but I would hedge toward the GFS. This would keep the best threat for accumulating snow in New England / NY.

Notice that all the deterministic models, so far, today turn this into one heck of a low anomaly and the cold pool sits over Quebec. The GGEM is a snow lover's dream and offers potential for something more serious beyond next week.

[Quakertown needs snow]

Thanks Head Master

Potential is still on the table looking at the runs the last few days thats for sure.

NE is now the jackpot area compared to what our jackpot February was a couple of years ago.

[RedSky]

euro storm alert day 7

 

i hate this winter where is spring

[HM]

 

euro storm alert day 7

 

i hate this winter where is spring

And it definitely has the threat just beyond the clipper. It is faster bringing in the Pacific storms while the -NAO block is retrograding. Great setup!

This winter won't quit.

[Heisy]

Yea HM noticed that, pretty robust block on EURO, I think of those waves could slow down a bit and dig more with that block. Late March HECS? one time. 

[Quakertown needs snow]

euro storm alert day 7

 

i hate this winter where is spring

thats my bday hit

[tcutter]

 

And it definitely has the threat just beyond the clipper. It is faster bringing in the Pacific storms while the -NAO block is retrograding. Great setup!

This winter won't quit.

 

 

 

 

would/could there really be enough cold air around to make this happen??

[NJwinter23]

Yeah awesome long range signals...if you hate spring lol

 

The key for late next week and into early following week will certainly be how much arctic air we can scrap off of the vortex retrograding towards alaska, and pool it underneath our new NAO block. A week later in March = we need that much more help to begin with, and we saw how this latest stale POS bootleg airmass failed the Mid-atl recently..

 

Luckily the op models looked solid today, especially the euro. 

[tombo82685]

 

And it definitely has the threat just beyond the clipper. It is faster bringing in the Pacific storms while the -NAO block is retrograding. Great setup!

This winter won't quit.

Yea, it has a stripe of .1-.2 through the region. Temps away from i95 look good, though the timing isn't ideal during the day. 

[am19psu]

Btw, kudos to the Euro weeklies. I'm surprised a model could sniff out a -nao of this duration and magnitude, but it's been on top of it since before valentine's day

[anthonyweather]

[NJ_Ken]

I know that, after the season we've had (today's minor and happy surprise notwithstanding), there is tendency to just say, "season over" because we are approaching mid-March and climo simply is not on our side.  Of course, there is some validity to that, but it is not quite so bad as you might think.  Yes, if you look at the past 10 years, you will find that PHL has reported only three separate storm events of 1"+ after March 15 (3/17/07, 3/16/04 and 3/18/04), which would imply that we have less than a 1 in 3 chance of seeing a 1" snowfall after next Friday.  However, if you increase your sample size a bit and look at, say, the past 50 years at PHL, you will find that there were a total of 23 events of 1"+ after March 15.  In other words, there is roughly one chance in two that PHL will see a 1"+ snowfall after March 15.  

 

That sample does not even include two of the most memorable storms EVER in the Philadelphia area: The "St Joseph's Day" storm of March 19-21, 1958 where PHL got 11.7" and the immediate northern and western burbs got two or three times that amount and the April 3-4, 1915 storm that dumped for 19.4" and until 1983, was the number 2 single snowstorm EVER at PHL.   

 

The point here is not to try to make the argument that climo FAVORS another nice storm in the mid-Atlantic coastal plain.  It doesn't.  HOWEVER, it is definitely NOT out of the question either so, as long as mother nature is willing to send chances our way, I am going to be here following them.  There is still a (slight) chance that we can save our season with a hail mary as the clock is running out.   

[Heisy]

I know that, after the season we've had (today's minor and happy surprise notwithstanding), there is tendency to just say, "season over" because we are approaching mid-March and climo simply is not on our side.  Of course, there is some validity to that, but it is not quite so bad as you might think.  Yes, if you look at the past 10 years, you will find that PHL has reported only three separate storm events of 1"+ after March 15 (3/17/07, 3/16/04 and 3/18/04), which would imply that we have less than a 1 in 3 chance of seeing a 1" snowfall after next Friday.  However, if you increase your sample size a bit and look at, say, the past 50 years at PHL, you will find that there were a total of 23 events of 1"+ after March 15.  In other words, there is roughly one chance in two that PHL will see a 1"+ snowfall after March 15.  

 

That sample does not even include two of the most memorable storms EVER in the Philadelphia area: The "St Joseph's Day" storm of March 19-21, 1958 where PHL got 11.7" and the immediate northern and western burbs got two or three times that amount and the April 3-4, 1915 storm that dumped for 19.4" and until 1983, was the number 2 single snowstorm EVER at PHL.   

 

The point here is not to try to make the argument that climo FAVORS another nice storm in the mid-Atlantic coastal plain.  It doesn't.  HOWEVER, it is definitely NOT out of the question either so, as long as mother nature is willing to send chances our way, I am going to be here following them.  There is still a (slight) chance that we can save our season with a hail mary as the clock is running out.   

 

GREAT post. +1! We have a tanking AO, MJO traveling into phase 8, cold air could def be available. I'm not getting myself attached, but I certainly ain't saying its over. I personally enjoy spring nor'easters more than Jan noreasters. This storm is a perfect example why....With the different wave lengths storms slow down and can do crazy things. Look at the March 4 2001 500mb pattern that was nuts. Or the huge spring nor easter in 2007 I believe (wasn't a snowstorm, but a really fun storm nonetheless)....Plus the next day after a spring snowstorm you can hit the upper 50s lol. I <333 huge closed off ULLs... Every March until I die I'll pray for a March 58-esque storm to live through. 

[Rainshadow]

I know that, after the season we've had (today's minor and happy surprise notwithstanding), there is tendency to just say, "season over" because we are approaching mid-March and climo simply is not on our side.  Of course, there is some validity to that, but it is not quite so bad as you might think.  Yes, if you look at the past 10 years, you will find that PHL has reported only three separate storm events of 1"+ after March 15 (3/17/07, 3/16/04 and 3/18/04), which would imply that we have less than a 1 in 3 chance of seeing a 1" snowfall after next Friday.  However, if you increase your sample size a bit and look at, say, the past 50 years at PHL, you will find that there were a total of 23 events of 1"+ after March 15.  In other words, there is roughly one chance in two that PHL will see a 1"+ snowfall after March 15.  

 

That sample does not even include two of the most memorable storms EVER in the Philadelphia area: The "St Joseph's Day" storm of March 19-21, 1958 where PHL got 11.7" and the immediate northern and western burbs got two or three times that amount and the April 3-4, 1915 storm that dumped for 19.4" and until 1983, was the number 2 single snowstorm EVER at PHL.   

 

The point here is not to try to make the argument that climo FAVORS another nice storm in the mid-Atlantic coastal plain.  It doesn't.  HOWEVER, it is definitely NOT out of the question either so, as long as mother nature is willing to send chances our way, I am going to be here following them.  There is still a (slight) chance that we can save our season with a hail mary as the clock is running out.   

Until we had all of those December block busters last decade, March was the 3rd snowiest month of the season for PHL.  I know fruit farmers must be ecstatic at this March being March, they took a big hit last spring with April's cold snap.  I remember Lowes selling tomato plants last March.

[NJ_Ken]

Until we had all of those December block busters last decade, March was the 3rd snowiest month of the season for PHL.  I know fruit farmers must be ecstatic at this March being March, they took a big hit last spring with April's cold snap.  I remember Lowes selling tomato plants last March.

 

I know the sample size is much too small to come to any kind of reasonable (or even unreasonable) conclusions about mid-Atlantic "climo" going forward, but it really feels like our climate (and, yes, I realize that, by definition, a possible 15-year trend canNOT be defined as "climate") is different the past 15 years or so.  I won't begin to guess at the reasons and whether those reasons implicate short term or long term changes (or, more likely, no changes at all since this is all well within the range of expected yearly fluctutations), but it really "feels" like going back to the 90s and before, that the mid-Atlantic coastal plain's winters and particularly snowfall was skewed toward later in the season with most measurable snow falling between Xmas and, say, the first week of April.  In recent years, it seems that more of our snow tends to happen earlier in (or even BEFORE the onset of) winter, starting around December 1 (with the seemingly now semi-regular early November or late October snow) and ending by mid-to-early March.  

 

I suppose that somebody much smarter than me could find a way to link these changes (or prove there is no link whatsoever) to the dearth of late summer sea ice in the Arctic.  Regardless, for now it is just something that makes me curious.  Maybe a hundred years from now, some real and provable trend will be more apparent.... or maybe not.  

[Rainshadow]

I know the sample size is much too small to come to any kind of reasonable (or even unreasonable) conclusions about mid-Atlantic "climo" going forward, but it really feels like our climate (and, yes, I realize that, by definition, a possible 15-year trend canNOT be defined as "climate") is different the past 15 years or so.  I won't begin to guess at the reasons and whether those reasons implicate short term or long term changes (or, more likely, no changes at all since this is all well within the range of expected yearly fluctutations), but it really "feels" like going back to the 90s and before, that the mid-Atlantic coastal plain's winters and particularly snowfall was skewed toward later in the season with most measurable snow falling between Xmas and, say, the first week of April.  In recent years, it seems that more of our snow tends to happen earlier in (or even BEFORE the onset of) winter, starting around December 1 (with the seemingly now semi-regular early November or late October snow) and ending by mid-to-early March.  

 

I suppose that somebody much smarter than me could find a way to link these changes (or prove there is no link whatsoever) to the dearth of late summer sea ice in the Arctic.  Regardless, for now it is just something that makes me curious.  Maybe a hundred years from now, some real and provable trend will be more apparent.... or maybe not.  

 

Ken,

 

I would agree of late it feels like we lost March as a "winter" month, have had much better Aprils and have gained more of the early or way early in the season snow events.  Also it seems like the winters are getting very binary, feast or famine, with respect to snow and when it does snow, its not the run-of-the-mill storm, its the blockbuster.   

[Heisy]

EURO shows multiple LR snow threats, nothing large ATM, but wouldn't take much with the block to get something to dive down farther S

[NJ_Ken]

Ken,

 

I would agree of late it feels like we lost March as a "winter" month, have had much better Aprils and have gained more of the early or way early in the season snow events.  Also it seems like the winters are getting very binary, feast or famine, with respect to snow and when it does snow, its not the run-of-the-mill storm, its the blockbuster.   

 

I agree, Tony.  I know in the mid-Atlantic obs thread this past week there was a lot of talk about how they (and I feel the same way about the Philly area) don't seem to get very many 2" to 4" or 3" to 5" snowstorms anymore.  It seems like every storm is either under 2" or more than 12"+.  Obviously, even in the best of times, we live in an area with widely varying snowfall from year to year so this "trend" is well within what could arguably be considered normal yearly fluctuations.  Still, at least to this weenie, it feels like something larger is going on.   

[NJ_Ken]

EURO shows multiple LR snow threats, nothing large ATM, but wouldn't take much with the block to get something to dive down farther S

 

Even the GFS seems to show a lot of potential over the next 8 to 10 days.  I wouldn't go so far as to say I am excited at this point, but I am definitely watching.  

[ago4snow]

Ken,

 

I would agree of late it feels like we lost March as a "winter" month, have had much better Aprils and have gained more of the early or way early in the season snow events.  Also it seems like the winters are getting very binary, feast or famine, with respect to snow and when it does snow, its not the run-of-the-mill storm, its the blockbuster.   

When I was a boy, we had a great meteorologist on the local ABC station in Philadelphia named Francis Davis. He was actually a physics teacher at  Drexel University and not just another pretty face reading the weather. He also tried to explain to the public some of the concepts behind the atmospheric forces controlling our weather. Obviously, much has changed in 45 years, but he spoke about a roughly 90 day cycle in which the atmosphere goes through a change from a cold, long wave trough pattern over a particular area of the conus to a reversal of the pattern over the next 90 days. Clearly, the atmosphere is much more complex than this when we look at things such as the MJO, but to this day, I can’t help but look at that pattern and think that the odds are strongly against us if we have a cold pattern set up in the east during the Sept-Nov period. The last two winter seasons have been textbook in that regard with a favorable trough pattern for Sept-Nov and a mild pattern Dec-Feb. It’s another reason why I think at least one good snowstorm in December seems to somewhat correlate with a snowy winter. Like I said, I'm not sure sure if this line of thinking rates any higher than looking at the woolly caterpillar, but when I look at an ambiguous long range forecast it sort of tips the scale for me.  

[Rainshadow]

When I was a boy, we had a great meteorologist on the local ABC station in Philadelphia named Francis Davis. He was actually a physics teacher at  Drexel University and not just another pretty face reading the weather. He also tried to explain to the public some of the concepts behind the atmospheric forces controlling our weather. Obviously, much has changed in 45 years, but he spoke about a roughly 90 day cycle in which the atmosphere goes through a change from a cold, long wave trough pattern over a particular area of the conus to a reversal of the pattern over the next 90 days. Clearly, the atmosphere is much more complex than this when we look at things such as the MJO, but to this day, I can’t help but look at that pattern and think that the odds are strongly against us if we have a cold pattern set up in the east during the Sept-Nov period. The last two winter seasons have been textbook in that regard with a favorable trough pattern for Sept-Nov and a mild pattern Dec-Feb. It’s another reason why I think at least one good snowstorm in December seems to somewhat correlate with a snowy winter. Like I said, I'm not sure sure if this line of thinking rates any higher than looking at the woolly caterpillar, but when I look at an ambiguous long range forecast it sort of tips the scale for me.  

 

A couple of studies I have done have correlated autumn (October in general) temperatures and ensuing winters.  Its tough to not be above normal of late, but the October part has worked since the late 1800s.  As quirky as it is, it has about a 70% success rate.  The last October was also warm and it seems tougher to not have warm months, so maybe its working lately be default.  Patterns cant keep on running the table, just wonder how both can be shown to be correct.  For a while there has been discussion about the weak correlation of flipping the nao signal for October for the winter.  -NAO and warm October can peacefully co-exist as its influence is not as strong as it is in the winter, plus wavelengths are different then. So maybe its the type of troffiness, I don't know. However,  I can statistically corroborate your post about Decembers, since 1950 get a 6" or more event in December in PHL, there is an 89% chance you'll get at least one more that winter and a 44% chance you'll get two or more additional. 

[Bliz299]

For ago4snow, http://www.broadcastpioneers.com/francisdavis.html . I too remember Francis Davis. He and Wally Kinnan were WAY ahead of anyone else in the weather. Very enjoyable to some of us for sure.

[NJ_Ken]

For ago4snow, http://www.broadcastpioneers.com/francisdavis.html . I too remember Francis Davis. He and Wally Kinnan were WAY ahead of anyone else in the weather. Very enjoyable to some of us for sure.

 

My earliest weather memories were of the late Jim O'Brien giving the forecast on Philly's ABC station (it was an Accuweather forecast at that point, though I am not sure when they signed on).