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January 2017 Discussion & Observations


dmillz25

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7 minutes ago, nyblizz44 said:

Can you score a KU on the back of a transient block PB?

 

Sure . 

 

You want an POS PNA 1st and foremost .  We have seen times where NAO heads  towards N so there is just enough of a release to allow the center to come far enough N . 

 

 

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2 hours ago, bluewave said:

Yeah, I agree. The signal for +PNA -EPO looks the strongest for the first half of February. It's really tough to speculate on the pattern

for the back half of February at this point. I think much will come down to what happens after this MJO pulse concludes and how the pattern

interacts with the weakening La Nina.

I think it depends what happens with the PV.  Towards day 15 both the EPS and GEFS start to retrograde and drop it towards Hudson Bay.  GEFS moreso but it goes out another 24 hours.  If that happens and heights rise trapping the PV displaced we can roll right through mid Feb as the MJO and its effects on the PNA relax.  Then perhaps as the NAO fades hand back off to the PNA and roll into March.  Thats how the weeklies sort of play it.  If the PV just drops slightly then slides right back over Greenland we probably revert to a hostile look mid Feb once the tropical forcing diminishes.  The SOI drop might mitigate total reversion to a torch pattern but a neutral PNA/EPO and raging positive AO/NAO isnt a good look either.  Then we would be stuck waiting for the next MJO wave late Feb into March to reboot again.  

I know some disagree but I see the NAO cooperating at least for a well timed transient period, as critical.   I just don't think the Pacific SST support a sustained favorable pattern.  Without any help from the AO/NAO were in trouble.  I think we waste the day 6-10 period because as the ridge lifts into a decent spot becoming a block near Hudson Bay, the CONUS is void any cold, so even with a decent storm track we probably just rain.  Then the 10-15 period looks cold/dry.  Maybe we luck out with a clipper.  After that if the NAO stays positive and the PNA relaxes we could escape this "colder" pattern without significant snow.  If the PV drops and we load up a -NAO -EPO neutral PNA pattern for a time we could rock.  

I do think the MJO emerges again and we have another PNA ridge late Feb into March, 1999 keeps showing up an an analog and that would fit, but I don't really feel like waiting to March to try to salvage some of this winter.  I know NYC has lucked out and scored some snow on the only 2 threats all freaking winter, but for everyone else in the mid atlantic were in deep deep trouble.  I think in 128 years of records for my location I cobbled together with coops, this is the third worst snowfall on record to this date.  At this point I can kiss my 38" climo goodbye and am just trying to salvage a respectable ending.  

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This morning, the Southern Oscillation Index (SOI) stood at -26.47, its lowest figure since November 16, 2016. There is a possibility that it could fall to -30.00 or below for the first time since October 29, 2016. This westerly wind burst offers the latest indication that the La Niña event is likely to continue to fade in coming weeks.  The 4-week moving average anomaly of the ENSO Region 1+2 anomaly increased from +0.15°C on December 14 to +0.60°C on January 11. The 4-week moving average anomaly of the ENSO Region 3.4 anomaly warmed from -0.45°C on December 14 to -0.35°C on January 11. That evolution should continue in the weeks ahead. Coupled with the PDO+, that outcome should increase prospects for a PNA+. The PNA is currently positive (preliminary 1/18 value of +0.994). So, at present, I have little change in thinking about the development of an EPO-/PNA+ pattern. It is this pattern that will break the ongoing stretch of warmer to much warmer than normal weather in the eastern U.S. that has seen, among other things, Atlanta register a January record 6 consecutive 70° readings.

Into the first week in February, the guidance suggests that a trough could predominate in parts of the East. If one takes the forecast teleconnections for 1/31 and rolls them forward into the middle of the first week in February, the 500 mb pattern is typical of 2/1-15 patterns in which the EPO-/PNA+ more than offset an AO+. Such patterns have had more frequent measurable snowfalls and 4" or greater snowfalls than climatology.

All said, there is consistency between the pattern forecast on the ensembles and what one would expect to see given the forecast state of the teleconnections. This consistency provides a measure of confidence in the pattern change that has been forecast for some time on the ensembles, beginning around 1/27 +/- 2 days.

However, a few ensemble members have begun to suggest the development of a more strongly positive AO. Under such a scenario, the AO+ could eventually overwhelm the impact of the EPO-/PNA+ blocking. Right now, that’s not the most likely scenario, but it is something that will need to be watched should the more strongly positive AO develop. Run-to-run continuity of the long-range AO forecast has been poor, so there is a lot of uncertainty at the end of the forecast range. For now, most of the ensemble members do not suggest a sufficiently strong AO+ to offset the EPO/PNA blocking.

Finally, as with Isotherm’s discussion yesterday, I have some concerns about at least a relaxation in the colder pattern toward mid-February. There is some risk of a large-scale pattern change with the EPO ridge retrograding to the Aleutians and a ridge building into eastern North America.

By then, I expect that the Northeast will have experienced one or more accumulations of snow and possibly a widespread 4” or greater event if some of the past evolutions of similar patterns are representative. PB GFI has also discussed the snowfall potential.

If one looks at the latest GFS ensemble 8-day objective analogs, one finds the following dates in the mix: 1/25/1958, 1/24/1978, and 2/6/2006. Among the 11-day objective analogs are: 1/23/1961, 1/26/1978, 2/9/2006

February 1-15 snowfall amounts were as follows:
1958: 4.3” (10.2” through 2/16)
1961: 17.4”
1978: 21.9”
2006: 26.9”

AO01182017.jpg

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1 hour ago, UlsterCountySnowZ said:

Agreed, but we're still 5-6 days out, no thread till atleast Friday plz

  It's been well modeled on all OP and ensemble runs for days.  This isn't your normal coastal storm set up.  It's not like we're waiting for a northern stream s/w to drop out of the arctic and phase to make a storm bomb off the VA Capes.  This is a closed cut-off low.  6 and 12 hour differences don't make or break this forecast.  

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5 minutes ago, Rjay said:

  It's been well modeled on all OP and ensemble runs for days.  This isn't your normal coastal storm set up.  It's not like we're waiting for a northern stream s/w to drop out of the arctic and phase to make a storm bomb off the VA Capes.  6 and 12 hour differences don't make or break this forecast.  

And its not a snowstorm for the coast so we know the models will lock in 5 days out

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5 minutes ago, bluewave said:

Whether transient or extended, it just wants to snow around here with even with short 5-10 day bursts of cold like we saw in December and earlier this month.

It would be great if we could extend the early February cold and snow potential into the second half of the month. But a clearer picture will probably energe

once we see the guidance closer to the start of February. All a place like JFK needs is another 9-10 inches of snow on the season to break even.

NYC could salvage an above climo year but it would still be an overall crappy winter for most of the east.  Snowfall in a given yard is kind of fluky but big picture its been pretty pathetic for most of the east outside places that lucked out with the early January storm.  

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6 minutes ago, psuhoffman said:

NYC could salvage an above climo year but it would still be an overall crappy winter for most of the east.  Snowfall in a given yard is kind of fluky but big picture its been pretty pathetic for most of the east outside places that lucked out with the early January storm.  

What impresses me the most about the pattern from last winter through this month is the ability to produce snowfall with very limited cold.

This January will probably be the warmest for several locations to still achieve above normal January snowfall. 

 

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15 minutes ago, bluewave said:

What impresses me the most about the pattern from last winter through this month is the ability to produce snowfall with very limited cold.

This January will probably be the warmest for several locations to still achieve above normal January snowfall. 

 

You're right about that.  One would think in this type of January pattern that snow wouldn't even be a consideration.  Granted, I only received a few inches here this month, and the NYC area has done far better.

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37 minutes ago, bluewave said:

What impresses me the most about the pattern from last winter through this month is the ability to produce snowfall with very limited cold.

This January will probably be the warmest for several locations to still achieve above normal January snowfall. 

 

I have had a discussion at times in the mid atlantic forum about the fluke nature of snowfall in a particular location.  Some use snowfall results to choose analogs, for instance, and I always find that risky since it can be so skewed by a lucky storm or two.  To prove a point a couple years back we were looking at some snowstorms that hit our area during just absolutely atrocious patterns.  You would look at the H5 and think HUH, it snowed then?   I think my area has had a bit of bad luck to have almost nothing, and yours a bit of good luck to be above climo and somewhere in between would be an indication of the overall pattern this year.  But in the long run things average out.  We might get a better pattern and something stays suppressed south of NYC then in the end places like Hagerstown MD (with almost identical snowfall avg) and NYC both end up in the same spot with regards to climo when its all said and done.  I do think NYC is advantaging lately from the warm water off the coast influencing storm tracks.  There has to be something, its too long of a string or pattern to just ignore it.  

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the winter of 1948-49 is the warmest snowiest for NYC...a 19.3" storm ( in Battery Park ) in December...another 6-10" storm the last day in February...Snow on March 18TH...record highs sprinkled throughout...after that winter NYC went seven years before the next 10" storm...

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48 minutes ago, JerseyWx said:

You're right about that.  One would think in this type of January pattern that snow wouldn't even be a consideration.  Granted, I only received a few inches here this month, and the NYC area has done far better.

 

26 minutes ago, psuhoffman said:

I have had a discussion at times in the mid atlantic forum about the fluke nature of snowfall in a particular location.  Some use snowfall results to choose analogs, for instance, and I always find that risky since it can be so skewed by a lucky storm or two.  To prove a point a couple years back we were looking at some snowstorms that hit our area during just absolutely atrocious patterns.  You would look at the H5 and think HUH, it snowed then?   I think my area has had a bit of bad luck to have almost nothing, and yours a bit of good luck to be above climo and somewhere in between would be an indication of the overall pattern this year.  But in the long run things average out.  We might get a better pattern and something stays suppressed south of NYC then in the end places like Hagerstown MD and NYC both end up in the same spot with regards to climo when its all said and done.  I do think NYC is advantaging lately from the warm water off the coast influencing storm tracks.  There has to be something, its too long of a string or pattern to just ignore it.  

A local station like JFK is a great example of how the snowfall this month is running well ahead of what was expected in the past with this type of January warmth.

This will get even more impressive as the average January temperature continues to climb with the very mild readings forecast well into late month.

JFK January mean temp...32.7....snowfall....6.3"

Current JFK average monthly temperature is 36.4 and rising with 11.1" for January so far

Past Januaries with 36.0 to 39.0 average monthly temperatures and snowfall:

1967....36.3...2.8"

1972....36.4...1.7"

1989...36.4....4.7"

1973...36.5...0.8"

1993...36.8...0.8"

2012...37.2..1.6"

2007...37.3...1.7"

1995...37.8...0.1"

1975...37.9...0.6"

2002...38.9..4.1"

2006...39.1..2.1"

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17 minutes ago, bluewave said:

 

A local station like JFK is a great example of how the snowfall this month is running well ahead of what was expected in the past with this type of January warmth.

This will get even more impressive as the average January temperature continues to climb with the very mild readings forecast well into late month.

 

Current JFK average monthly temperature is 36.4 and rising with 11.1" for January so far

Past Januaries with 36.0 to 39.0 average monthly temperatures and snowfall:

1967....36.3...2.8"

1972....36.4...1.7"

1989...36.4....4.7"

1973...36.5...0.8"

1993...36.8...0.8"

2012...37.2..1.6"

2007...37.3...1.7"

1995...37.8...0.1"

1975...37.9...0.6"

2002...38.9..4.1"

2006...39.1..2.1"

The warmest January I can find in NYC that had at least 10" of snow is 1964...

year.....temp.....snowfall...

2017....36.1......10.1"....as of 1/17...

1964....35.7......13.3"....

1869....35.1......15.1"....

1907....34.9......10.0"

1909....34.7......11.3"

 

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21 minutes ago, uncle W said:

the winter of 1948-49 is the warmest snowiest for NYC...a 19.3" storm ( in Battery Park ) in December...another 6-10" storm the last day in February...Snow on March 18TH...record highs sprinkled throughout...after that winter NYC went seven years before the next 10" storm...

As I recall we also lucked out in 90-91 with a 6-8" storm just after Christmas which melted in 2 days, a 5-6" event in January which flipped to sleet and rain at night and then a decent storm at the end of February which I think was a 6"+ even east of the city. Despite a mild winter with no real arctic blasts the coast did ok and even made it to average 

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33 minutes ago, uncle W said:

The warmest January I can find in NYC that had at least 10" of snow is 1964...

year.....temp.....snowfall...

2017....36.1......10.1"....as of 1/17...

1964....35.7......13.3"....

1869....35.1......15.1"....

1907....34.9......10.0"

1909....34.7......11.3"

 

While last January wasn't nearly as warm at JFK, it was still the warmest January on record with over 20".

January 2016...31.3".....34.6

January 1996...20.3".....31.2

January 2011...20.1".....29.1

January 1978...20.1".....29.2

 

 

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On 1/16/2017 at 0:53 PM, nzucker said:

You were wrong. I know that's hard for you to admit, but you busted. Everyone on the board thinks you were wrong. 

My forecast this week is Tuesday 45/41, Wesnesday 48/37, Thursday 50/37...we don't live in Seattle, lows near 40F is a torch in mid January. My average low is 25F and all the forecast lows are at least +12. How is that not a torch? Are you kidding me?

Once again you think you're better than the models. You delude yourself, you're not.

 

Accountability ....

 

This busted  3 degrees inside 24 hours and 7 degrees in only 48 hours .

 

Makes my 3 day period of a 2 degree bust from 12 days out taste good .

 

Amazing what a NE wind has done since 18z Friday,  just pinned temps in the upper 30s to a  max of  very low  40s 

 

This is the first time I have done this , maybe it will teach some not to throw stones .

This one  was a long time  coming .

 

 

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1 hour ago, Allsnow said:

I'm not sure how long the +pna lasts. The gefs break it down by the start of February and by then we need to hope for good placement of the pv lobe. 

IMG_0019.JPG

Yep. 384 hour is always accurate.

A much better pattern will be here by next weekend and beyond

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