January Medium/Long Range Discussion Part 2

[psuhoffman]

15 minutes ago, WinterWxLuvr said:

Not so sure we couldn't get a better snow out of the gfs look than the eps look though.

Thats not really much of a ridge in the east.  Those heights could support snow and we'd be more likely to get a wet system .  That eps pattern screams cold , dry, suppressed IMO.

Oh I'm not arguing the gefs is a disaster for our snow chances just pointing out the stark differences right now. A compromise between the two could work well for us. 

[psuhoffman]

11 minutes ago, Ender said:

So, of 20 winters in which the QBO is positive in November and stays positive into February:

• Six had a January that was at least 1.5F above normal.
  • All six were followed by a February that was at or below normal: two were between -.1F and -1.3F of normal and the other four averaged 5.8F below normal. 
  • All six had Feb snowfall of at least 8.8", the average was 15.2". 
• Only four had a December and a January that were at least 1.5F above normal:
  • The subsequent February averaged 3.1F below and March 2.3F below normal. 
  • February in those four years averaged 16.2" of snow (9.8", 10.7", 27.2" and 16.9") 
• Removing some of the constraints and looking at the full set of 20 winters and comparing them to the 48 non "QBO stays positive Nov - Feb" winters 
  • December showed a normal distribution of snowless, versus <2" or >6" snow totals. 
  • January deviated from the non +QBO Winter distribution. 
    • 20% of the non +QBO winters had 2" or less while 50% of the 20 +QBO winters did. 
    • 35% of the non +QBO winters less than 4", but 60% of the +QBO winders did. 
  • For the month of February: 
    • 44% of non +QBO winters had less than 2" of snow and 35% of the 20 +QBO winters did. 
    • 60% of non +QBO winters had less than 4" of snow, but only 35% of the +QBO Winters did.
    • 60% of the +QBO Winter's Februaries had 8.8" or more, 50% had more than ~10" and 40% had more than about 15". That compares to only seven of 48, or 15% of the non +QBO Winter's Feb's getting more than 8.8" and five winters, 10%, with more than 12".
    • While Dulles' average February snowfall is 7", the non +QBO winters only had a 31% chance of getting at least 7" in the month (as opposed to 60% for +QBO Winters) and they had a 63% chance of recording less than 5" in the month. Thus in a winter that has not had a +QBO from November into February there's a better chance that we'll see less than 5" than there is a chance of more than ~9" in a +QBO winter February.
  • March: 
    • 67% of non +QBO winters will have less than 2" in March and 50% will in the +QBO winters
    • 27% chance of more than 6" in a non +QBO winter as opposed to a 40% chance in the +QBO set. 
    • 10% of non +QBO winters get more than 10" of snow in March and only one of 48 such winters saw more than 11", while 25% of the +QBO set had more than 13". 

NOTE: it was necessary to use Baltimore's observations as a supplement to the IAD records for 1948 - 1962 in order to get a history that covered the whole QBO reanalysis period that begins in 1948.

 

Seems to be good news in the data there. And thank you. As someone who likes to play with data myself I know how time consuming it can be. That's awesome you put that together.  Much appreciated!!!!

[Ender]

17 minutes ago, psuhoffman said:

Seems to be good news in the data there. And thank you. As someone who likes to play with data myself I know how time consuming it can be. That's awesome you put that together.  Much appreciated!!!!

Thank you, and you're right. It's tedious as hell. 

[ravensrule]

1 hour ago, Ender said:

So, of 20 winters in which the QBO is positive in November and stays positive into February:

• Six had a January that was at least 1.5F above normal.
  • All six were followed by a February that was at or below normal: two were between -.1F and -1.3F of normal and the other four averaged 5.8F below normal. 
  • All six had Feb snowfall of at least 8.8", the average was 15.2". 
• Only four had a December and a January that were at least 1.5F above normal:
  • The subsequent February averaged 3.1F below and March 2.3F below normal. 
  • February in those four years averaged 16.2" of snow (9.8", 10.7", 27.2" and 16.9") 
• Removing some of the constraints and looking at the full set of 20 winters and comparing them to the 48 non "QBO stays positive Nov - Feb" winters 
  • December showed a normal distribution of snowless, versus <2" or >6" snow totals. 
  • January deviated from the non +QBO Winter distribution. 
    • 20% of the non +QBO winters had 2" or less while 50% of the 20 +QBO winters did. 
    • 35% of the non +QBO winters less than 4", but 60% of the +QBO winders did. 
  • For the month of February: 
    • 44% of non +QBO winters had less than 2" of snow and 35% of the 20 +QBO winters did. 
    • 60% of non +QBO winters had less than 4" of snow, but only 35% of the +QBO Winters did.
    • 60% of the +QBO Winter's Februaries had 8.8" or more, 50% had more than ~10" and 40% had more than about 15". That compares to only seven of 48, or 15% of the non +QBO Winter's Feb's getting more than 8.8" and five winters, 10%, with more than 12".
    • While Dulles' average February snowfall is 7", the non +QBO winters only had a 31% chance of getting at least 7" in the month (as opposed to 60% for +QBO Winters) and they had a 63% chance of recording less than 5" in the month. Thus in a winter that has not had a +QBO from November into February there's a better chance that we'll see less than 5" than there is a chance of more than ~9" in a +QBO winter February.
  • March: 
    • 67% of non +QBO winters will have less than 2" in March and 50% will in the +QBO winters
    • 27% chance of more than 6" in a non +QBO winter as opposed to a 40% chance in the +QBO set. 
    • 10% of non +QBO winters get more than 10" of snow in March and only one of 48 such winters saw more than 11", while 25% of the +QBO set had more than 13". 

NOTE: it was necessary to use Baltimore's observations as a supplement to the IAD records for 1948 - 1962 in order to get a history that covered the whole QBO reanalysis period that begins in 1948.

 

Amazing work. Thanks for putting that   

 together.  

[CAPE]

Seems the 0z GEFS has suddenly moved towards the -epo/+pna idea in the long range. Major change from previous runs where it wanted to leave the trough out west. Good agreement among the global ensembles now on the general pattern progression.

[showmethesnow]

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

Seems the 0z GEFS has suddenly moved towards the -epo/+pna idea in the long range. Major change from previous runs where it wanted to leave the trough out west. Good agreement among the global ensembles now.

Definitely made a move towards the EPS with pulling the southwest trough out quicker. But even still that pause is delaying the evolution of the pattern on the GEFS by roughly 4 days compared to the EPS. Think if we were to see the GEFS pull that trough through the southwest without delay, as the EPS does, we would see the two models in very good agreement.  The look on the EPS even improved compared to its previous runs. Also have to wonder if the EPS may like the period centered roughly around day 12 for something popping up. 

[CAPE]

9 minutes ago, showmethesnow said:

Definitely made a move towards the EPS with pulling the southwest trough out quicker. But even still that pause is delaying the evolution of the pattern on the GEFS by roughly 4 days compared to the EPS. Think if we were to see the GEFS pull that trough through the southwest without delay, as the EPS does, we would see the two models in very good agreement.  The look on the EPS even improved compared to its previous runs. Also have to wonder if the EPS may like the period centered roughly around the 12th for something popping up. 

GEFS moved towards that evolution. It is slower than the eps, but that may correct in future runs. Just glad to see it cave some, such that there is no longer such a wide disparity.

[showmethesnow]

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

GEFS moved towards that evolution. It is slower than the eps, but that may correct in future runs. Just glad to see it cave some, such that there is no longer such a wide disparity.

Agree wholeheartedly. Thought that was a very positive sign seeing the GEFS's move towards bringing that feature out quicker. Also the fact that the EPS not only held it's ground but actually improved was another plus. 

For what it's worth, just looked at the snowfall maps and the time period centered around day 12, and though somewhat minor, does have a spike in snowfall. Not worth looking into the details at this time (individual members, temps, etc...) but maybe??? I just want something to track besides a pattern.

[Ji]

Agree wholeheartedly. Thought that was a very positive sign seeing the GEFS's move towards bringing that feature out quicker. Also the fact that the EPS not only held it's ground but actually improved was another plus. 

For what it's worth, just looked at the snowfall maps and the time period centered around the 12'th, though somewhat minor, does have a spike in snowfall. Not worth looking into the details at this time (individual members, temps, etc...) but maybe??? I just want something to track besides a pattern.

Uh the 12th is 24 days away!

Sent from my SM-G930V using Tapatalk

[showmethesnow]

 

11 minutes ago, Ji said:

Uh the 12th is 24 days away!

Sent from my SM-G930V using Tapatalk
 

Opps, my bad. Meant day 12.  

[Wonderdog]

2 minutes ago, Ji said:

Uh the 12th is 24 days away!

Sent from my SM-G930V using Tapatalk
 

LOL. But I was thinking the 12th was 27 days away. Didn't know the EPS went out that far.

[showmethesnow]

Just now, Wonderdog said:

LOL. But I was thinking the 12th was 27 days away. Didn't know the EPS went out that far.

You have to spend the big bucks if you want access to that time range. Or of course you could just look at the weeklies.

[showmethesnow]

A good sign on the 06Z GEFS is that it is much more aggressive with the trough it sets up in the Eastern CONUS in the longer range.

[mdsnowlover]

what's very interesting is that, at the end of the gfs 6z run, the low it shows over n. carolina giving us snow is the same feature that dt shows in his video could be an east coast snowfall as seen on the ensemble run.It also corresponds to the beginning of feb pattern change that dt says is sopromising

[Ralph Wiggum]

what's very interesting is that, at the end of the gfs 6z run, the low it shows over n. carolina giving us snow is the same feature that dt shows in his video could be an east coast snowfall as seen on the ensemble run.It also corresponds to the beginning of feb pattern change that dt says is sopromising

Is this a legit 384 hour threat or just a promising one?

[mdsnowlover]

3 minutes ago, Ralph Wiggum said:

Is this a legit 384 hour threat or just a promising one?

cant say for sure as  what is your thinking. but i thought it was very poingnant that dt pointed out the feature on ensemble and gfs is showing it.

[mdsnowlover]

1 minute ago, losetoa6 said:

Eps made a notable jump south with the day 8/9system . Nice cluster off  ocean City  with many sub 990 lows . Not much cold air but a reasonable size cluster has it just cold enough for snow. Of course areas with elevation would be favored but something to watch while we get bored with golfing and highs in the 50s. 

are you referring to the threat on 384 gfs, which is showing snow??

[showmethesnow]

The period I had mentioned last week that the models suggested a significant low in the east (roughly centered around day 8 now) is now showing some promise. Looking at the EPS individual members snowfalls, we went from basically nothing on previous runs to now the 00Z showing 20-25% of the members showing snow with a handful showing somewhat significant snow. The common theme is that they are showing a bombing low just off the eastern seaboard. Most are Miller B transfers of a low that rides just to our south and west. The means of the EPS seem to favor this type of evolution.

[mdsnowlover]

1 minute ago, showmethesnow said:

The period I had mentioned last week that the models suggested a significant low in the east (roughly centered around day 8 now) is now showing some promise. Looking at the EPS individual members snowfalls, we went from basically nothing on previous runs to now the 00Z showing 20-25% of the members showing snow with a handful showing somewhat significant snow. The common theme is that they are showing a bombing low just off the eastern seaboard. Most are Miller B transfers of a low that rides just to our south and west. The means of the EPS seem to favor this type of evolution.

ah yes, i believe i know what youre talking about now as dt referred to this scenario as in between storm in pattern change, think its all rain though, not surethough

[mitchnick]

31 minutes ago, mdsnowlover said:

what's very interesting is that, at the end of the gfs 6z run, the low it shows over n. carolina giving us snow is the same feature that dt shows in his video could be an east coast snowfall as seen on the ensemble run.It also corresponds to the beginning of feb pattern change that dt says is sopromising

I think you mean 0z run.

[showmethesnow]

3 minutes ago, mdsnowlover said:

ah yes, i believe i know what youre talking about now as dt referred to this scenario as in between storm in pattern change, think its all rain though, not surethough

About the only way we can make this work for our region is if the low bombs out just off our coast. Otherwise we are most likely SOL because temps will just not be there.. 

[mdsnowlover]

2 minutes ago, showmethesnow said:

About the only way we can make this work for our region is if the low bombs out just off our coast. Otherwise we are most likely SOL because temps will just not be there.. 

think it gives new england a snow storm, not us,

[mdsnowlover]

5 minutes ago, losetoa6 said:

Here's day 8 eps ...

There some members with real bombs in this time frame.  About 15 % show some snow. 

rather close to the coast,sure looks good and a lot closer than 384 gfs. what is precedent airmas like temp wise??

[poolz1]

CMC is in line with the eps.  Almost heartbreaking to see the lack of cold with a storm like the 00z cmc is showing.  Would just need marginal cold with a bombing low like that (984 on top of AC)....At least it is something of vague interest while we wait for things to shift.

[showmethesnow]

5 minutes ago, mdsnowlover said:

think it gives new england a snow storm, not us,

At roughly day 8 I am sure there will be changes, possibly major, but at this point the mean mslp would suggest this would run out to sea maybe skimming the coastal regions up north at best. The 500's on the other hand would suggest we see this run up the coast somewhat. Guess we will see.

[mdsnowlover]

2 minutes ago, showmethesnow said:

At roughly day 8 I am sure there will be changes, possibly major, but at this point the mean mslp would suggest this would run out to sea maybe skimming the coastal regions up north at best. The 500's on the other hand would suggest we see this run up the coast somewhat. Guess we will see.

good analysis on your part ty

[psuhoffman]

31 minutes ago, Ralph Wiggum said:

Is this a legit 384 hour threat or just a promising one?

 

28 minutes ago, mdsnowlover said:

cant say for sure as  what is your thinking. but i thought it was very poingnant that dt pointed out the feature on ensemble and gfs is showing it.

The pattern is legit. Specific threats are still fantasy at 240+ hours.  Guidance isn't going to get the timing and strength of vorts or SWs exact at that range. But the general idea of there being a window of opportunity is real. 

[showmethesnow]

1 minute ago, psuhoffman said:

 

The pattern is legit. Specific threats are still fantasy at 240+ hours.  Guidance isn't going to get the timing and strength of vorts or SWs exact at that range. But the general idea of there being a window of opportunity is real. 

Some promising developments overnight. Wonder how long they will last.

[mappy]

thanks to the usual guys for the great discussion. no one should be focusing on any specific threat this far out. just pay attention to the overall pattern. 

[mdsnowlover]

3 minutes ago, showmethesnow said:

Some promising developments overnight. Wonder how long they will last.

overall pattern responding to emerging MJO and strato warming??