Winter 2018-19 Is Coming

[thunderbolt]

Do you have a statistic where only half of November there was blocking and the other half there was not 

[AfewUniversesBelowNormal]

It's starting to have that feel of January is going to deliver. 

[AfewUniversesBelowNormal]

I think December is cold and February is warm. 

[EastCoast NPZ]

9 minutes ago, AfewUniversesBelowNormal said:

I think December is cold and February is warm. 

Cold rain followed by warm rain.  Sounds about right.

[AfewUniversesBelowNormal]

North Atlantic SST index, which has accurately predicted 65-70% of Winter's since 1948 (after the fact), and 9-1-3 after new method, is about +0.75 for DJFM. It has a Standard Deviation of 0.45 meaning there is 50% chance of Winter NAO being +0.30 to +1.20. It's in the top 25% of Winters +NAO prediction. 

[EastCoast NPZ]

15 minutes ago, AfewUniversesBelowNormal said:

North Atlantic SST index, which has accurately predicted 65-70% of Winter's since 1948 (after the fact), and 9-1-3 after new method, is about +0.75 for DJFM. It has a Standard Deviation of 0.45 meaning there is 50% chance of Winter NAO being +0.30 to +1.20. It's in the top 25% of Winters +NAO prediction. 

Well,  the one time we had even a transient -NAO it resulted in a storm suppressed to Disney World.  

How could it be any worse?

[psuhoffman]

I decided to post an update to where my feelings are for the whole winter...as well as the justification for it now since we are in a dead period.  I know I am typically an optimist...but I don't blow smoke.  Last year I constantly held out hope for a storm or two to save us from a total fail but I was honest that our goalposts were probably somewhere between a total dud (if we didn't get any luck) and pulling off an average winter if we got lucky.  MOST of us ended up somewhere in between.  Bad year but not in the true dumpster fire category.  

Let me start by categorizing what I mean by a "good/typical/dumpster fire" year.   Some have expectations that are not in line with our reality...so lets look at reality.  I did these numbers for the 3 major airports in our area as well as my backyard.

Looking at the last 30 years what is a top 1/3 snowfall year (Good)

a middle 1/3 year: (Typical)

a bottom 1/3 year (Dumpster fire)

Median:  What is the number you have a 50/50 chance of beating any given year

BWI

19.0"+    = Top 1/3 Good year 

9.1-18.3" = Middle 1/3 Typical year

1.8-8.7"  = Bottom 1/3 Dumpster Fire year

Median 15"

IAD

20.2"+   = Good year

12.7-19.4"= typical year

2.6-12.6"  = dumpster fire year

Median = 15"

DCA (THIS IS GONNA HURT but luckily most of us don't live on a tarmac in the Potomac River)

13.1" +  = Good year

7.5-12.5" = typical year

.1 - 7.4" = dumpster fire year

Median = 10"

Manchester MD

37.5"+    = Good

22.3-37" = typical

8.2-22.3" = dumpster fire

Median 34"

I know those numbers will probably pop a few bubbles...and I am sorry...but that IS OUR CLIMO...learn it, live it, love it.

So... to get into a top 1/3 winter BWI needs to get 19", IAD needs 20.2" and DCA needs 13.1" 

With that in mind... a bad start in no way precludes a good year.  We can get those numbers with just one good storm in a nino year (2016) or just a few decent storms.  Wasting December in no way means we are in trouble.  Additionally most locations are on the board already.  I know BWI has 1.7" and I think IAD is around 3" so far.  So we are right about where we should be.  But so far that is all just climo....what about this year...and what I think will actually happen.

First things have not and are not going differently than my expectations.  I thought the meat of our winter would be January 15 on.  ALL the analogs and guidance suggested that.  There were some fluke exceptions where we had a significant snow event early but in the analog years the vast majority of the snowfall occurred AFTER New Years.  Lets look at those analog years

These were the top 10 years I identified...They are not listed in order of best match but simply chronologically and how those years played out.

Year              snowfall at BWI                How did the year play out

1963-4:  51.8     One snowfall event (8") on 12/23, the rest came after January 12th... Epic from mid January on

1965-6:  32.8"    No appreciable snowfall until after January 22, Epic end of January start to February period

1968-9: 18.6"    4.3" snowfall in mid November...(hmmm) Then no snowfall until after February 8... Several coastals Feb and Mar, lots of mixed events..bad luck that we didn't do better.

1977-8:  34.3:    No appreciable snowfall until after January 13th

1986-7:  35.2"    No snowfall until after January 22....then epic run 

1994-5:   8.2"       What snowfall fell was in February

2002-3:   58.1"    7.4" on Dec 5th... 2.3" on xmas, the rest came after January 5th

2004-5:    18"   No snowfall until January 19th...  Good pattern the rest of the winter...bad luck we didn't do better, lots of low end hits that just missed being bigger storms

2009-10:  77"   The big Dec HECS of course...but other then a couple other 1" events the rest of the snow came January 30th on...

2014-15:  28.7"   Nothing before January 6th.  A couple minor events in January but most of the snow came in an epic run Feb 14th on.

So....out of the 10 best analog years since 1960...9 out of 10 beat the median at BWI.  7 ended up being a top 1/3 snowfall year, 2 ended up in the middle 1/3 but towards the high end of it...and only one ended up a dumpster fire.  But does not getting a lot of snowfall early in the winter mean we are leaning towards that one dumpster fire year...or definitely towards the middle 1/3 years... not necessarily.  Even in the greatest years the best snowfall period came AFTER mid January.  And in several of the epic years 1966, 1978, 1987, 2015 all the snow came after mid January.  So the fact that we are not getting dumped with snow in December does not indicate we aren't on track with the analogs we identified.  Additionally... there is luck factored in here.  We just missed a major snowstorm by 50 miles.  In another post later I am going to do a post analysis of what happened there but in the global pattern its pretty insignificant.  So somehow we were right in identifying this as a good year for places like Richmond and Fredricksburg and Charlottsville but wrong for DC because the storm missed by 50 miles because a stupid NS vort dove down at exactly the wrong time to suppress things?  I Don't buy that.  We also had a perfect h5 vort pass last week and there just wasn't any surface reflection until off NJ.  We have been generally cold and stormy for the whole cold season so far.  And the difference between what we had and getting one hit and all of us sitting around 6-10" right now is just luck IMO.  Obviously that is subjective and feel free to disagree with me.  

There certainly aren't any signs we are heading towards 1994-5 when the AO looked like this in December...that was a big warning sign.

But why am I confident we are still on track for a good season...because all of the factors that were identified as probably leading to a snowy winter are still there.  And the long range guidance is still indicating that the pattern will become favorable for snowfall....wait for it... the second half of winter...which is exactly what the analogs said should happen.  So basically nothing has happened that wasn't expected imo.

First this is the current SST

Still looks like a borderline weak/moderate central based modoki nino to me... also notice the warmer waters still persisting south of Alaska as well as the cooler (relative) waters to the southwest of there.  That indicates at least a somewhat -PDO configuration that should support a predominantly -EPO +PNA configuration.  But are there any signs it's collapsing in a bad way...well this is the current NCEP projections

Certainly still looks favorable until Spring.  

Additionally look at where we want and do not want convection.  Remember our cold phases on the MJO are 8-1-2 and the really crappy ones are 4-5-6-7

This is a map of where convection is located during MJO phases

Look where 8 and 1 are...right where the warmer waters associated with the central based nino are... additionally there is cooler waters where we do not want convection.  No guarantee but it does favor the mjo either being weak or skewed towards cold phases.  So far it has...with stronger waves through cold phases then quicker or weaker traverses of the warm phases.  I expect that to continue.

Additionally the PV continues to get beat around like a pinata.  There has been no indication that we are likely heading towards a strongly positive AO this year and all indications are (given nino climo) that it likely only trends down from here.  

This is what a composite of all the analog years shows the rest of the way...

January

February

Looks a lot like the euro and uk seasonal outlooks... as well as what the end of the euro weeklies are advertising come mid January.  

So there are never any sure things until we are shoveling but I see nothing that indicates we have deviated from the expected course this winter.  As of right now I still fully expect a very favorable pattern to set in at some point during the second half of the winter (January 10th on).  Some years that started earlier...some years not until February... but the second half was where its at in all the analog years and the first half was a barren wasteland in some of the good years even...so we are doing alright so far being on the board and having had some legit chances.  I am sticking with my call that this is likely to end up a good snowfall winter by the end... just have to be patient.  

If I start to see things that truly trouble me for the whole winter prospects...I will say so.  Nothing so far really sticks out to me as a warning sign.  Now resume the panic over every cutter on the day 15 op runs!!!

 

 

[ravensrule]

Great post PSU. Thank you very much for that. 

[WxUSAF]

Excellent post @psuhoffman!  We'll get ours.  The thought of an 02-03 redux gets me very...um...(nsfw)

[EastCoast NPZ]

Good times are always ahead.... 2 weeks, or the second half.  We just wasted a months worth of cold and are almost certainly about to waste the next several weeks.  Things will get great, just as soon as our avg temps hit 50F.

[psuhoffman]

14 minutes ago, EastCoast NPZ said:

Good times are always ahead.... 2 weeks, or the second half.  We just wasted a months worth of cold and are almost certainly about to waste the next several weeks.  Things will get great, just as soon as our avg temps hit 50F.

90% of our snowfall comes AFTER Christmas, that is just our climo.  The snowiest month for us is February.   I know you like early seasons snow, but expecting it only sets yourself up for frustration every year.  

[EastCoast NPZ]

39 minutes ago, psuhoffman said:

90% of our snowfall comes AFTER Christmas, that is just our climo.  The snowiest month for us is February.   I know you like early seasons snow, but expecting it only sets yourself up for frustration every year.  

Oh, trust me, I don't expect it; just hope for it.  I haven't had a measurable December snow now for 5 years.  It should be a helluva lot more common than that.  I am sick of punting the first third, or half, of winters.

[psuhoffman]

4 minutes ago, EastCoast NPZ said:

Oh, trust me, I don't expect it; just hope for it.  I haven't had a measurable December snow now for 5 years.  It should be a helluva lot more common than that.  I am sick of punting the first third, or half, of winters.

It's streaky. For a while we had a run of early snow and no March snow. Lately march has been a snowy month and December not. We don't have a particularly snowy climo so our snow comes in streaks in general. We can't afford to be picky about when. 

[Ji]

47 minutes ago, psuhoffman said:

90% of our snowfall comes AFTER Christmas, that is just our climo.  The snowiest month for us is February.   I know you like early seasons snow, but expecting it only sets yourself up for frustration every year.  

NC got it...why ccant we

[psuhoffman]

Just now, Ji said:

NC got it...why ccant we

We could have. Bad luck. But we did in 2002, 2003, 2005, 2007, 2009, 2013...

[Maestrobjwa]

2 minutes ago, Ji said:

NC got it...why ccant we

Just didn't break that way this time, man...we didn't roll favorable dice this time--par forthe course! (now we can see how much of an aberration Dec 2009 was, lol)

[frd]

5 minutes ago, Ji said:

NC got it...why ccant we

You know this is interesting,  it went down like this before a long time ago   1908  

Also of interest,  the old timer saying thunderstorm in the South and then a Southern Snowstorm a week to 10 days later.  That is a JB one, but seems to work more often than not .  

 

 

[ravensrule]

1 hour ago, WxUSAF said:

Excellent post @psuhoffman!  We'll get ours.  The thought of an 02-03 redux gets me very...um...(nsfw)

Excited i'm sure is the word you are looking for. 

[Maestrobjwa]

27 minutes ago, psuhoffman said:

We could have. Bad luck. But we did in 2002, 2003, 2005, 2007, 2009, 2013...

Yep...a roll of the dice! (beside 2009 and 2002, 2013 is the most memorable because of that Ravens game, lol)

[WxUSAF]

1 minute ago, Maestrobjwa said:

Yep...a roll of the dice! (beside 2009 and 2002, 2013 is the most memorable because of that Ravens game, lol)

I was at that game.  Worst game to watch ever until the last 6 minutes. 

[Maestrobjwa]

Just now, WxUSAF said:

I was at that game.  Worst game to watch ever until the last 6 minutes. 

Hahaha There's probably a reason why nobody remembers the rest of it...lol

[Maestrobjwa]

3 hours ago, frd said:

You know this is interesting,  it went down like this before a long time ago   1908  

Also of interest,  the old timer saying thunderstorm in the South and then a Southern Snowstorm a week to 10 days later.  That is a JB one, but seems to work more often than not .  

 

 

And here's the kicker about the winter that would follow: It was a nina, yet we (at least BWI) still totaled a little over 31 inches that season...and it was a la nina!! Say wha? Lol

[Bob Chill]

1 hour ago, Maestrobjwa said:

And here's the kicker about the winter that would follow: It was a nuna, yet we (at least BWI) still totaled a little over 31 inches that season...and it was a la nina!! Say wha? Lol

95-96 was a mod nina

[Maestrobjwa]

23 minutes ago, Bob Chill said:

95-96 was a mod nina

Ohhh trust me, I'm well aware (I still don't understand how that happened)...so that's what, two Nina's in the 20th century that produced? Lol (I actually haven't researched the other ones, but...if I had to bet...)

[psuhoffman]

30 minutes ago, Bob Chill said:

95-96 was a mod nina

Yea we just got lucky that the nao tanked various times that winter.  In doing analog research for last year I noticed that in a Nina if we can get the nao to tank we actually can do ok. The problem is that there seems to be a negative correlation between La Niña and the nao where typically the nao is positive in Nina years. Additionally it's almost impossible for us to get any appreciable snow without any high latitude blocking in a Nina. So epo and pna driven patterns that can work in a neutral or nino year are shutout patterns in a Nina.  Last two years fit. The only blocking we got was in march and we finally scored a decent hit last year and came really close in 2017. The rest of the year teased us with half decent looks but ultimately without blocking were futile. The key to getting a fluke win in a Nina is to get lucky with the nao. Maybe the solar minimum saved us in 96. Or maybe just pure luck. 

[Maestrobjwa]

1 minute ago, psuhoffman said:

Yea we just got lucky that the nao tanked various times that winter.  In doing analog research for last year I noticed that in a Nina if we can get the nao to tank we actually can do ok. The problem is that there seems to be a negative correlation between La Niña and the nao where typically the nao is positive in Nina years. Additionally it's almost impossible for us to get any appreciable snow without any high latitude blocking in a Nina. So epo and pna driven patterns that can work in a neutral or nino year are shutout patterns in a Nina.  Last two years fit. The only blocking we got was in march and we finally scored a decent hit last year and came really close in 2017. The rest of the year teased us with half decent looks but ultimately without blocking were futile. The key to getting a fluke win in a Nina is to get lucky with the nao. Maybe the solar minimum saved us in 96. Or maybe just pure luck. 

That's what I was wondering...was that what did it? Lol (any correlation between a minimum and the nao?)

[psuhoffman]

10 minutes ago, Maestrobjwa said:

Ohhh trust me, I'm well aware (I still don't understand how that happened)...so that's what, two Nina's in the 20th century that produced? Lol (I actually haven't researched the other ones, but...if I had to bet...)

Read my post above to bob. It's all nao in a Nina. The only two good nina years featured a lot of blocking. Additionally I looked at every warning criteria snowfall at BWI during a Nina since 1950. I found that 90% came during or just after a -nao period. Then I looked at the few exceptions and found even those when examining the h5 look featured bootleg blocking that maybe didn't show up on a nao numerical chart but worked just the same. So basically out of 12 analog years there wasn't a single fluke lucky warning event without some high latitude blocking help.  

Typically we do way better with blocking. But other patterns can work sometimes in other years. But apparently in a nina it's blocking or bust for us.  Add in that blocking seems less prevalent in ninas and that really limits our chances to have a big year. 

[psuhoffman]

4 minutes ago, Maestrobjwa said:

That's what I was wondering...was that what did it? Lol (any correlation between a minimum and the nao?)

There seems to be yes but it's a small sample size. 

[frd]

3 hours ago, Maestrobjwa said:

And here's the kicker about the winter that would follow: It was a nuna, yet we (at least BWI) still totaled a little over 31 inches that season...and it was a la nina!! Say wha? Lol

Even though psu and Bob chimmed in on this I bet that year had early season blocking and that it reappeared later in the season. Too tired to look it up. 

And yes, you can get a stout - NAO in a Nina , harder to do but as mentioned here it can happen.    

The same things we look for now as clues to the upcoming winter most likely happened that year ( early - AO / -NAO in same form or fashion ) over a century ago.