December 2016 Discussion & Observations

[PB GFI]

6 minutes ago, bluewave said:

The near record +AO spike was the big disappointment in December. Our only 2 solid -AO's with a La Nina in december since 2000

were 2000 and 2010.

 

I was really on the 5 thru 20 period , and I wrote away that I liked - 3 for the period  l hit that and the WAA 7 days out but busted on the months temp because the last 7 days blew it apart.

And thats always the risk when forecasting 30 day anomalies. 

 

I think the 15 day period in Jan is closer to - 4 with AN snow for the period .

5 thru 20 ...

I will leave the month alone , because I cant see the back 10 days again.

But weak Decembers are just par for the course now I guess .

[Morris]

What the heck is this? December 2015? 60 degrees in the morning....

[bluewave]

11 minutes ago, PB GFI said:

 

I was really on the 5 thru 20 period , and I wrote away that I liked - 3 for the period  l hit that and the WAA 7 days out but busted on the months temp because the last 7 days blew it apart.

And thats always the risk when forecasting 30 day anomalies. 

 

I think the 15 day period in Jan is closer to - 4 with AN snow for the period .

5 thru 20 ...

I will leave the month alone , because I cant see the back 10 days again.

But weak Decembers are just par for the course now I guess .

It's tough to get a cold departure here in December without a really strong -AO pattern.

 

 

 

[CPcantmeasuresnow]

5 days in a row of temperatures almost +10 above normal and todays temperatures again well above normal will now put all 6 NWS recording stations above normal for the month.

With averages now at the six Upton stations in the high 30's for highs and 20's for the lows it looks like December will almost certainly finish above normal for the 18th month in a row.

Not a terrible December but the Christmas time period with the +8-10's was very disappointing again.

[CIK62]

Isn't it really 21 out of the last 22 months that are AN?  If we excuse the miscues  of June 2015---which had more above normal days than below, while finishing a little BN, actually 22 in a row?

[bluewave]

8 minutes ago, CIK62 said:

Isn't it really 21 out of the last 22 months that are AN?  If we excuse the miscues  of June 2015---which had more above normal days than below, while finishing a little BN, actually 22 in a row?

June 2015 was the last colder than normal month. JFM 2015 was the last solid extended run of cold.

But we needed a record breaking  -EPO/+PNA ridge to pull it off.

[Ralph Wiggum]

I am not convinced that we truly get the NAO to go negative for any length of time in the next 15 days or so. The closer we get, the less ridging that is being shown on the ensembles. For example, there was ridging and a block progged to develop over Eastern Greenland near the turn of the month on runs prior to the weekend and that ridging was, for some runs, forecast to move poleward. The closer we are getting, 1) the ridging/transient block is becoming less pronounced 2) any ridging is now East of Greenland rather than centered directly over GL and 3) the ridge is progressing East towards Ireland instead of the pole.

If you move even farther along into the LR and compare the ensembles, we are seeing a similar repeat of this pattern....a ridge tries to develop near or over Greenland. However, with subsequent runs the ensembles are attempting to repeat the process again moving away from a once promising -NAO look at the end of and after the first week of January with a more progressive ridge headed over towards Ireland which never moves poleward.

Not the end of the world, just noting how the NAO has been a real challenge to get into any favorable index this year and that pattern doesnt want to quit. With that said, the EPO/WPO looks good anyway and should provide bouts of BN temps at times the first half of January. For whatever reason, the ensembles in the LR have had a better time forecasting those Pacific indices.....not perfect but better.

Then of course you have the GFS para (which I am not a huge fan of) that is an all out -ao/-nao to the extreme in the LR.

[WEATHERBUFF]

1 hour ago, bluewave said:

The near record +AO spike was the big disappointment in December. Our only 2 solid -AO's with a La Nina in December since 2000

were 2000 and 2010. Both years featured a record snowfall event near the end of the month.

If you look at December for the last 25 years or so this month will below the average.

 

[WEATHERBUFF]

26 minutes ago, CIK62 said:

Isn't it really 21 out of the last 22 months that are AN?  If we excuse the miscues  of June 2015---which had more above normal days than below, while finishing a little BN, actually 22 in a row?

I think many of us are finally realizing that about 2 above average is the new normal.

[bluewave]

4 minutes ago, WEATHERBUFF said:

If you look at December for the last 25 years or so this month will below the average.

 

The only below normal Decembers since 2000 were 2000...2002...2005..2009...2010. They all needed a strong -AO pattern to pull it off.

 

 

[Allsnow]

PB smarter then the models? 

[Brian5671]

with today's warmth, even KNYC will go above normal now for December.  (for whatever reason they were a degree colder than surrounding stations for the month)

[bluewave]

2 minutes ago, Brian5671 said:

with today's warmth, even KNYC will go above normal now for December.  (for whatever reason they were a degree colder than surrounding stations for the month)

The high temp there this month is the coldest among JFK,EWR,and LGA. Even though the leaves dropped, there still may some shading of the sensor.

[CIK62]

GFSx has a dismal start to JAN.  Says we will already be +12 by the  morning of the 4th.  Thus the remaining 28 days will have to be 36/28 = -1.3 to get us to normal.  In effect ,JAN. will have to be a BN month for this to happen.    

[PB GFI]

15 minutes ago, Allsnow said:

PB smarter then the models? 

 

2 days ago I  said this would turn colder after the 5th 

 

 

It is slowly becoming this . 

 

 

 

 

 

 

 

 

[Allsnow]

2 minutes ago, PB GFI said:

 

2 days ago I  said this would turn colder after the 5th 

 

 

It is slowly becoming this . 

 

 

 

 

 

 

 

 

Well I think it was pretty well forecast that we would have chances after the 5th. I'm not really sure why you think you made this milestone prediction. That map above looks like the cold dumping into the west, not good for snow along the east coast. Bluewave is right that we have a week then the pattern breaks down 

[nzucker]

2 hours ago, PB GFI said:

 

The GFS is garbage and the Euro is making the same error I explained on here 3 days ago .

The EPS loves to dump the trough in the west.

I dont just look at models , I look at why they are wrong.

 

They are wrong day 14 15 , just like 3 days its 10 to 15 looks nothing like the new 8 to 13 .

 

We can always cut even in great patterns , but this is coming , dont get fooled.

It looks a bit better than the Dec pattern plus we have climo on our side. The 06z GFS had the AK block further east which limits the chances for cutters with a more neutral PNA. We really want the block centered near Fairbanks, not the Aleutian Islands. That forces the PV towards Hudson Bay which beats down the SE ridge. While we are not immune from cutters because the NAO is weak,  the pattern has trended more favorably I think.

[PB GFI]

On 12/24/2016 at 0:04 PM, PB GFI said:

 

Yeh , I am.buying the EPS EPO and NAO.

 

When you check the EPS day 6 thru 10  2 M anomalies you can see the departures.

BN in the N/E.

 

That ridge thats there in the SE day 10 thru 12 will get beaten down with those 2 features .

 

Thats why I think that ridge is transient and what follows is probably coast to coast cold .

 

 

Man all people have to do is go back and read that the argument here was after the 5th . The day 10 - 15 ridge posted 3 days ago is beaten down in the the 8 to 13 .

 

Go look at the 5 day mean 3RD  - 8TH that was posted / which I said was wrong , now go look at the new day 8 - 13 .

 

The ridge gets beaten down after the 5th ,if that was the opinion of several here . I missed it . 

 

[Isotherm]

2 hours ago, bluewave said:

 

This is a -PNA/ La Nina pattern. So that's why the mean trough remains in the west. We saw the same pattern in December with the warm start

Dec 1-9..cold Dec 11-20...warm 21-31. Sure the dates and the duration of the warm and cold intervals may change, but this is classic La Nina.

Models overestimate the cold and underestimate the warm. That's why December will be warm when some of the long range forecasts were colder.

 

 

Agreed. Not certain what exactly the expectations are for the subsequent pattern, but here are the facts as I see them. December will finish with temperature departures of at least +1 for most of the area, congruous with my outlook. It was an abysmal month for the majority on the coast, as the singular highlight was a light snow event changing to rain. 60 degrees is being achieved today.

 

The regime heretofore has exemplified a classic La Nina/-AAM background state, even considering unimpressive SSTA signature, which was anticipated due to the propensity for other oscillations to force the mean z500 to date. The brewer dobson circulation continues to rapidly weaken w/ decreasing ozone and contemporaneous intensification of the polar night jet. The MJO signal will propagate eastward at z200 but it is not sufficiently coherent / amplified to overwhelm the interseasonal low frequency forcing which will quickly resume its mean position by January 10th. The mechanism for the poleward ridge weakens within about a week, and we should see retrogression of that feature due to forcing alterations as well as changes in hemispheric torques.

 

The resultant should be vortex consolidation following a transient technical, ineffective -NAO, with contemporaneous retrogression of the trough, projecting strongly onto the climatological -AAM regime.

 

Thus, my interpretation is that there will be a transient window of opportunity for about 5-7 days, prior to the resumption/redevelopment of the SE ridge / NW trough tropospheric pattern. January still looks warmer than normal to me. Not a furnace (that wasn't expected), but it will be very difficult to finish below normal. For most on the coast, we will be heading into the second week of January with less than 3 inches of snow on the season. So I truly hope the window produces something, otherwise 50% of meteorological winter will be over with a very ugly picture.

 

[nzucker]

At 

1 minute ago, Isotherm said:

 

Agreed. Not certain what exactly the expectations are for the subsequent pattern, but here are the facts as I see them. December will finish with temperature departures of at least +1 for most of the area, congruous with my outlook. It was an abysmal month for the majority on the coast, as the singular highlight was a light snow event changing to rain. 60 degrees is being achieved today.

 

The regime heretofore has exemplified a classic La Nina/-AAM background state, even considering unimpressive SSTA signature, which was anticipated due to the propensity for other oscillations to force the mean z500 to date. The brewer dobson circulation continues to rapidly weaken w/ decreasing ozone and contemporaneous intensification of the polar night jet. The MJO signal will propagate eastward at z200 but it is not sufficiently coherent / amplified to overwhelm the interseasonal low frequency forcing which will quickly resume its mean position by January 10th. The mechanism for the poleward ridge weakens within about a week, and we should see retrogression of that feature due to forcing alterations as well as changes in hemispheric torques.

 

The resultant should be vortex consolidation following a transient technical, ineffective -NAO, with contemporaneous retrogression of the trough, projecting strongly onto the climatological -AAM regime.

 

Thus, my interpretation is that there will be a transient window of opportunity for about 5-7 days, prior to the resumption/redevelopment of the SE ridge / NW trough tropospheric pattern. January still looks warmer than normal to me. Not a furnace (that wasn't expected), but it will be very difficult to finish below normal. For most on the coast, we will be heading into the second week of January with less than 3 inches of snow on the season. So I truly hope the window produces something, otherwise 50% of meteorological winter will be over with a very ugly picture.

 

I didn"t look at this at as a horrid December. There were a few days of nice cold and 17F set the 2010s decadal low for the month. We got 4" here on 12/17, which, even though quickly washed away, was a decent snowfall for Dec. I think Dec 1st averages are 48/32 so it's usually not that wintry. The suburbs may pick up 1-2" Thursday as well and even NYC may see a coating. 

The problem is we can't achieve a real -NAO. The best we can get is a weak NATL ridge for a week, which gives us a week or 10 days of opportunities with the EPO tanking. 

I agree that ozone and stratospheric temps are underappreciated. The lack of ozone to absorb IR may be causing the record low stratospheric temps and 4SD +AO. If we cannot weaken that vortex, all blocking episodes will be transient and revert ro the mean -ENSO/-AAM/SE ridge.

[pazzo83]

34 minutes ago, bluewave said:

The high temp there this month is the coldest among JFK,EWR,and LGA. Even though the leaves dropped, there still may some shading of the sensor.

The leaf drop was late again this year - we still have some lower level brush and a few trees with leaves.

[nzucker]

Isotherm, I think we are getting what we expected this winter. People got excited w the vortex split in Oct, and that did lead to a decent Nov 20-Dec 17 period, esp in the interior where we expected the winter to feature above average snow.

I expect we'll have a period of cold/snow Jan 5-15, then a milder Jan 15-Feb 15 pattern w the low AAM and strong vortex, keeping the cold bottled to the northwest. Maybe the vortex weakens in sync w warming ENSO to give us a good March.

Winter seems like a weak version of 71-72/83-84/07-08. 

[TriPol]

3 hours ago, Morris said:

What the heck is this? December 2015? 60 degrees in the morning....

 

I'll take it as long as we get January 2016 all over again!

[pazzo83]

3 minutes ago, TriPol said:

 

I'll take it as long as we get January 2016 all over again!

[NortheastPAWx]

I picked the wrong winter to leave NEPA.

[snywx]

2 minutes ago, NortheastPAWx said:

I picked the wrong winter to leave NEPA.

Yes you did lol..  

 

[psv88]

54. Feels delightful outside. 

Another above normal month, the beat goes on. 

[psv88]

Temp just spiked in the last few minutes, up to 56...wind shift must have brought in the warmer air

[Brian5671]

sun is out here now, feels like April.   55

[Stormlover74]

8 minutes ago, psv88 said:

Temp just spiked in the last few minutes, up to 56...wind shift must have brought in the warmer air

Was 58 earlier now a chilly 55