December 2016 Discussion & Observations

[Stormman96]

I havent been on here for a long time. But I don't understand what im reading here. blowtorch the next 5 days?  Where?  Above normal yes but a blowtorch???

[psuhoffman]

1 hour ago, qg_omega said:

I expect any positive pna or negative NAO to be transient features... If we get lucky with a well timed S/W we may cash in but overall Jan looks classic La Nina pattern with a strong temp gradient and the cold focused over Montana and intermountain west

It does look like a Niña except were not in a Niña. 1+2 is +.5 and other enso regions are around -.5 and projected to remain near 0. Pretty enso neutral winter. I think people are putting too much blame on Nino when it's likely other factors more so. 

[qg_omega]

19 minutes ago, psuhoffman said:

It does look like a Niña except were not in a Niña. 1+2 is +.5 and other enso regions are around -.5 and projected to remain near 0. Pretty enso neutral winter. I think people are putting too much blame on Nino when it's likely other factors more so. 

There is a lag... It's a la Nina pattern 

[psuhoffman]

3 minutes ago, qg_omega said:

There is a lag... It's a la Nina pattern 

It's very Niña ish. I'm not denying the sensible weather. And this has nothing to do with snow, some really awful snow winters were neutral. There are other factors that can cause a southeast ridge though besides Niña. Not sure what your lag comment means. Even at the lowest point a couple months ago we weren't in a Niña. It never reached the threshold even at its strongest point. We have had stronger ninas have much less of a "typical" Niña pattern that were talking about. I strongly suspect the driver of this is not enso but other factors. One being the SST off the east coast. 

[Paragon]

I tend to agree with you.  ENSO isn't the be all and end all, and we've seen some terrific snow producing "La Nina" winters, especially ones that came after an El Nino.  Also, there can't be a "lag" effect if a La Nina never developed in the first place

As for "blaming" ENSO, isn't a weak la nina supposed to be our second or third snowiest ENSO phase anyway?

 

[Paragon]

Just my 2 cents, but I think we'll just see what we've seen the last few years, which is "real" wintry weather set in after around Jan 20.  Anything that happens in December and early January is usually gravy for our climatology anyway.

 

[qg_omega]

10 minutes ago, Paragon said:

I tend to agree with you.  ENSO isn't the be all and end all, and we've seen some terrific snow producing "La Nina" winters, especially ones that came after an El Nino.  Also, there can't be a "lag" effect if a La Nina never developed in the first place

As for "blaming" ENSO, isn't a weak la nina supposed to be our second or third snowiest ENSO phase anyway?

 

From CPC: La Niña conditions persisted during November, with negative sea surface temperature (SST) anomalies present across most of the central and eastern equatorial Pacific [Fig. 1]. The Niño indices remained negative during November, except for the Niño1+2 index which reflected near-average SSTs in the extreme eastern Pacific late in the month [Fig. 2]. Also, the upper-ocean heat content remained below average [Fig. 3] in association with cooler temperatures at depth [Fig. 4], although this cooling lessened somewhat during the month. Atmospheric convection remained suppressed over the central tropical Pacific and enhanced over part of Indonesia [Fig. 5]. The low-level easterly winds remained enhanced in the west-central tropical Pacific, and upper-level westerly winds persisted across the tropical Pacific. However, these signals were masked at times by intra-seasonal activity. Overall, the ocean and atmosphere system during November reflected a continuation of weak La Niña conditions.

[Paragon]

6 minutes ago, qg_omega said:

From CPC: La Niña conditions persisted during November, with negative sea surface temperature (SST) anomalies present across most of the central and eastern equatorial Pacific [Fig. 1]. The Niño indices remained negative during November, except for the Niño1+2 index which reflected near-average SSTs in the extreme eastern Pacific late in the month [Fig. 2]. Also, the upper-ocean heat content remained below average [Fig. 3] in association with cooler temperatures at depth [Fig. 4], although this cooling lessened somewhat during the month. Atmospheric convection remained suppressed over the central tropical Pacific and enhanced over part of Indonesia [Fig. 5]. The low-level easterly winds remained enhanced in the west-central tropical Pacific, and upper-level westerly winds persisted across the tropical Pacific. However, these signals were masked at times by intra-seasonal activity. Overall, the ocean and atmosphere system during November reflected a continuation of weak La Niña conditions.

Thanks.  In regards to weak la nina being amongst the snowier ENSO phases, isn't a typical WLA pattern one in which we have normal to slightly below normal Dec temps with near normal to slightly above normal snowfall, which transitions to a warmer than normal January, which eventually transitions back to a normal to below normal temp pattern for late January and February and March and near normal to somewhat above normal snowfall? Normal snowfall being between 20-25" for this area.  All other factors being equal of course.

 

[psuhoffman]

3 hours ago, Paragon said:

I tend to agree with you.  ENSO isn't the be all and end all, and we've seen some terrific snow producing "La Nina" winters, especially ones that came after an El Nino.  Also, there can't be a "lag" effect if a La Nina never developed in the first place

As for "blaming" ENSO, isn't a weak la nina supposed to be our second or third snowiest ENSO phase anyway?

 

There are way more permutations to this then some account for when we just blame enso. Yes if we look at a analog for all ninas we see a pattern similar to this. But that's lazy to just run with that. Looking only at weak ninas, which we don't even currently qualify as (or even in November officially even though ncep described the pattern liberally as Niña without clasifying it as such) we do not see even close to this kind of severe se ridge nw Arctic cold signal. Add in the fact that we have seen years with a much stronger negative enso anomaly produce nothing like this severe a persistent SE ridge. 96 even was a more negative enso state then right now.  It's as if the Niña affects are on sterroids even though the Niña is on life support.

There are also other factors here like west v east based Nino and Niña. Our best combo tends to be west Nino east Niña, and weak to moderate. Although perhaps that's redundant as all west ninos have been weak to mod. We have yet to record a super west Nino. Maybe we get 500" in that scenario. Lol 

Then add in all the other influences. The cold pool off the PAC nw. The warm Atlantic sst. The pdo flip. Relatively hostile nao AO combo which can't be solely Niña related as we had a pretty good nao in early winter 95/96 and 2010/11 with cold enso conditions. The qbo likely isn't helping as that is in a hostile state for blocking.  

All that said a west based cold neutral enso does absolutely nothing to help us. So while it's probably not the dominant force behind this pattern it does play a part as a more favorable enso state could help to mitigate other hostile factors. It's true that whatever tropical forcing there is, is located in a bad spot for us. But it's so weak that it can not overpower the pattern. But it's in no way helping to stop the other bigger problems we have that are. 

[psuhoffman]

2 hours ago, Paragon said:

Thanks.  In regards to weak la nina being amongst the snowier ENSO phases, isn't a typical WLA pattern one in which we have normal to slightly below normal Dec temps with near normal to slightly above normal snowfall, which transitions to a warmer than normal January, which eventually transitions back to a normal to below normal temp pattern for late January and February and March and near normal to somewhat above normal snowfall? Normal snowfall being between 20-25" for this area.  All other factors being equal of course.

 

Keep in mind the sample size on specific types of ninas is still small enough to wonder what "typical" is. How do you lump 1996 and this year in the same category, yet if we were just using enso phase and strength they would be in the same basket. 

[psuhoffman]

3 hours ago, qg_omega said:

From CPC: La Niña conditions persisted during November, with negative sea surface temperature (SST) anomalies present across most of the central and eastern equatorial Pacific [Fig. 1]. The Niño indices remained negative during November, except for the Niño1+2 index which reflected near-average SSTs in the extreme eastern Pacific late in the month [Fig. 2]. Also, the upper-ocean heat content remained below average [Fig. 3] in association with cooler temperatures at depth [Fig. 4], although this cooling lessened somewhat during the month. Atmospheric convection remained suppressed over the central tropical Pacific and enhanced over part of Indonesia [Fig. 5]. The low-level easterly winds remained enhanced in the west-central tropical Pacific, and upper-level westerly winds persisted across the tropical Pacific. However, these signals were masked at times by intra-seasonal activity. Overall, the ocean and atmosphere system during November reflected a continuation of weak La Niña conditions.

Yes cpc liberally classified the pattern as WEAK Niña in sensible weather even though the enso state has not and likely will not reach official Niña threshold this season. But the pattern over the conus you attribute to Niña is more typical of a healthy Niña not the current cold neutral signal were talking about.  As I said above much more pronounced ninas have failed to produce this effect. Yes it's true the location of tropical forcing this year will do nothing to help up wrt snow but it's too weak to be causing this severe of a conus pattern by itself. It's a hostile combo of sst in several locations, qbo, pdo, and perhaps factors I am yet ignorant of. I just feel simplifying this to "its Niña" is missing the whole picture. 

[bluewave]

14 hours ago, psuhoffman said:

It does look like a Niña except were not in a Niña. 1+2 is +.5 and other enso regions are around -.5 and projected to remain near 0. Pretty enso neutral winter. I think people are putting too much blame on Nino when it's likely other factors more so. 

Cold neutral/weak can produce exactly the same pattern as a moderate La Nina. The most important factor with a La Nina seems to be

if we can get enough -EPO/+PNA/-AO/-NAO to turn into a favorable pattern for snow and cold. So longer range we want to see improvements

in those teleconnections to mute -PNA/SE ridge which is the usual La Nina default setting.

 

 

 

 

[psuhoffman]

1 hour ago, bluewave said:

Cold neutral/weak can produce exactly the same pattern as a moderate La Nina. The most important factor with a La Nina seems to be

if we can get enough -EPO/+PNA/-AO/-NAO to turn into a favorable pattern for snow and cold. So longer range we want to see improvements

in those teleconnections to mute -PNA/SE ridge which is the usual La Nina default setting.

 

 

 

 

Agreed but it's worse then mute most of the "other factors" have been working against us not helping. That looks to change soon.  I believe the current location and strength of tropical forcing isn't helping us one bit but also isn't dominant enough to kill us if we get other things lined up in our favor. Merry Christmas. 

[CIK62]

Next 8 days, including today look to be +9,   42 versus 33.

http://www.nws.noaa.gov/cgi-bin/mos/getmex.pl?sta=KACY&sta=KEWR&sta=KNYC&sta=KJFK&sta=KLGA

[psv88]

46 and beautiful

[uncle W]

with the ao so positive I'm surprised it hasn't hit 60 yet...

[JerseyWx]

48° here, fantastic weather.

[bluewave]

25 minutes ago, uncle W said:

with the ao so positive I'm surprised it hasn't hit 60 yet...

Tuesday is probably our best shot this week. But LGA already hit 61 last weekend while the AO was in a steep rise.

 

 

[bluewave]

The EPS produces a warm up right after the New Year ahead of a cutter. But the stronger -EPO in recent runs results in a colder pattern after January 5th.

So post January 5th looks like our next chance of a -10 or lower daily departure and maybe our next 3" or more snowfall at the coast.

 

 

 

 

 

[PB GFI]

11 minutes ago, bluewave said:

The EPS produces a warm up right after the New Year ahead of a cutter. But the stronger -EPO in recent runs results in a colder pattern after January 5th.

So post January 5th looks like our next chance of a -10 or lower daily departure and maybe our next 3" or more snowfall at the coast.

 

 

 

 

 

 

I agree that  the -EPO in the 10 to 15  will see the pattern begin to mute the SE ridge as well push positives poleward on both sides of the continent. 

 

My argument yesterday was that those 2 features should push the pattern.

I made the point away that when we look at the new EPS at 500 on day 10  , that NEG was likely to show up over Minnesota and not Washington state like it did 5 days ago in its day 15.

 

So we begin to change between the 5th and 10 th and I think we are coast to coast cold from the 10th thru 20th.

[bluewave]

55 minutes ago, PB GFI said:

 

I agree that  the -EPO in the 10 to 15  will see the pattern begin to mute the SE ridge as well push positives poleward on both sides of the continent. 

 

My argument yesterday was that those 2 features should push the pattern.

I made the point away that when we look at the new EPS at 500 on day 10  , that NEG was likely to show up over Minnesota and not Washington state like it did 5 days ago in its day 15.

 

So we begin to change between the 5th and 10 th and I think we are coast to coast cold from the 10th thru 20th.

I am not sure yet how many BN days we can get from this next EPO dip. We got 9 days out of the last EPO drop.

We can only get so much mileage out of these -EPO episodes without more help from the PNA/AO/NAO.

 

 

 

[PB GFI]

1 hour ago, bluewave said:

I am not sure yet how many BN days we can get from this next EPO dip. We got 9 days out of the last EPO drop.

We can only get so much mileage out of these -EPO episodes without more help from the PNA/AO/NAO.

 

 

 

 

The ensembles take the NAO negative . 

 

The EPS creates a nice ridge bridge and the NEG may flow underneath.

The cold that is coming is colder than what we just saw .

 

 

[bluewave]

5 minutes ago, PB GFI said:

 

The ensembles take the NAO negative . 

 

The EPS creates a nice ridge bridge and the NEG may flow underneath.

The cold that is coming is colder than what we just saw.

 

It's a pretty weak negative NAO on the EPS as the blocking looks to be EPO dominant again.

[PB GFI]

40 minutes ago, bluewave said:

 

It's a pretty weak negative NAO on the EPS. 

 

We don't need anomalous when you are blocking the PAC up at the same time.

 

That's a weak / low height ridge , a weak -NAO with a 2SD -EPO may allow you to be on the right side of the barroclinic zone .

 

The colder Dec 5 thru 20 idea  worked , I was AN Dec 25 to Jan 10 .

I think the next BN period starts Jan 5 ( 5 days earliier than I thought ) and lasts thru the 20 th 

 

[Morris]

30 minutes ago, PB GFI said:

 

We don't need anomalous when you are blocking the PAC up at the same time.

 

That's a weak / low height ridge , a weak -NAO with a 2SD -EPO may allow you to be on the right side of the barroclinic zone .

 

The colder Dec 5 thru 20 worked , I was AN Dec 25 to Jan 10 .

I think the next BN period starts Jan 5 ( 5 days earliier than I thought ) and lasts thru the 20 th 

 

You also had a numeric value for your December negative departure forecast.

[PB GFI]

3 hours ago, Morris said:

You also had a numeric value for your December negative departure forecast.

 

There were 4  forecasts made at KNYC in December .

 

BN Dec 5 thru 20  - 3 verified  .. worked 

AN snow  Dec 5 thru 30  3.2 verified in 2 weeks when the month averages 4.8 ..worked 

 

Dec 25 thru Jan 10 AN .. Should verify the first 10 will out duel the back 5 .

 

Dec - 3 for the month ,, bust , last week killed the departure. 

 

Thats 3 out of 4 .  Happy with the result.

 

What were your calls for December? What did you base it off ? 

 

 

[CPcantmeasuresnow]

NYC high of 50 today and a low of 39 exactly 10 degrees above normal for the date,

Not exactly ideal Christmas weather but I'll repeat the same mantra until I'm blue in the face, it was still a hell of a lot better than last year, and on top of it I had about a 40% white Christmas. The way the last 5 Decembers have gone this is Utopia.

Merry Christmas and Happy Chanukah to all.

[nzucker]

28 minutes ago, CPcantmeasuresnow said:

NYC high of 50 today and a low of 39 exactly 10 degrees above normal for the date,

Not exactly ideal Christmas weather but I'll repeat the same mantra until I'm blue in the face, it was still a hell of a lot better than last year, and on top of it I had about a 40% white Christmas. The way the last 5 Decembers have gone this is Utopia.

Merry Christmas and Happy Chanukah to all.

Today was actually a perfect XMAS in Westchester if it wasn't going to be super white. Temps in the mid to upper 40s, a nice breeze followed by a clear night, and plenty of patches of snow left from piles and plowing. 

[Morris]

1 hour ago, CPcantmeasuresnow said:

NYC high of 50 today and a low of 39 exactly 10 degrees above normal for the date,

Not exactly ideal Christmas weather but I'll repeat the same mantra until I'm blue in the face, it was still a hell of a lot better than last year, and on top of it I had about a 40% white Christmas. The way the last 5 Decembers have gone this is Utopia.

Merry Christmas and Happy Chanukah to all.

Midnight low of 36

[bluewave]

Just goes to show how tough it is to run a cold departure here in December. We are on track for the 6th milder than normal December in a row

going back to 2011. Several stations already have a warm monthly departure with more warmth to close out the month this week.

NEW YORK CITY-CENTRAL PARK
 KNYC   GFSX MOS GUIDANCE  12/26/2016  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 MON  26| TUE 27| WED 28| THU 29| FRI 30| SAT 31| SUN 01| MON 02 CLIMO
 X/N  49| 48  58| 36  47| 36  47| 35  43| 31  40| 37  46| 40  50 26 39

NYC....-0.5

LGA...+0.8

JFK...+0.7

ISP.....-0.2

BDR...+1.1

EWR...-0.1