December 2020 General Discussions & Observations Thread

[Allsnow]

@bluewave looks like Hartford is going to get another early season snowstorm like last year. I know you were skeptical of that happening again

[bluewave]

11 minutes ago, Allsnow said:

@bluewave looks like Hartford is going to get another early season snowstorm like last year. I know you were skeptical of that happening again

I mentioned that I didn’t look like Hartford would get near another 2nd snowiest snowiest first week of December. The heaviest snows will be to their northeast  time time around. But shows how an unfavorable pattern like last December in NYC can produce for New England.

Time Series Summary for Hartford Area, CT (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Rank	Ending Date	Total Snowfall Dec 1 to Dec 7	Missing Count
1	2003-12-07	18.5	0
2	2019-12-07	16.5	0
3	1949-12-07	12.6	0

[Allsnow]

4 minutes ago, bluewave said:

I mentioned that I didn’t look like Hartford would get near another 2nd snowiest snowiest first week of December. The heaviest snows will be to their northeast  time time around. But shows how an unfavorable pattern like last December in NYC can produce for New England.

Time Series Summary for Hartford Area, CT (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Rank	Ending Date	Total Snowfall Dec 1 to Dec 7	Missing Count
1	2003-12-07	18.5	0
2	2019-12-07	16.5	0
3	1949-12-07	12.6	0

Persistent forecasting can go bad quickly. I’m happy to see the costal storms are back. 

[bluewave]

56 minutes ago, Allsnow said:

Persistent forecasting can go bad quickly. I’m happy to see the costal storms are back. 

It’s not persistent forecasting. It’s persistent patterns. Notice how this is the 2nd December in a row with a big storm during the first week of the month. Early last  December a low went south of Long Island and produced record snowfall amounts to our north. Just a variation on the same theme. The heaviest snowfall axis this time will be further east into New England.

https://www.washingtonpost.com/weather/2019/12/03/northeast-starts-dig-out-after-snowstorm-drops-more-than-two-feet-spots/

12-02-19

[Allsnow]

43 minutes ago, bluewave said:

It’s not persistent forecasting. It’s persistent patterns. Notice how this is the 2nd December in a row with a big storm during the first week of the month. Early last  December a low went south of Long Island and produced record snowfall amounts to our north. Just a variation on the same theme. The heaviest snowfall axis this time will be further east into New England.

https://www.washingtonpost.com/weather/2019/12/03/northeast-starts-dig-out-after-snowstorm-drops-more-than-two-feet-spots/

12-02-19

No two patterns are the same. If it was that easy then we could just set the forecast to whatever happen in that month a year ago. 
 

This h5 look is different then the one we had last December. Earlier this week none of us thought this would produce for sne, yourself included.

[LibertyBell]

This looks like it will be good for interior SNE but not for coastal areas even up there.

[Allsnow]

Some concerning ensemble guidance today for any potential cold air after next weekend. Guidance moving the TPV quickly  into Ak 

[SnoSki14]

9 minutes ago, Allsnow said:

Some concerning ensemble guidance today for any potential cold air after next weekend. Guidance moving the TPV quickly  into Ak 

I wouldn't get too caught up on things. Models have been shifting like crazy lately.

It's also highly unlikely to be locked in. I do like that ensembles continue to show a +PNA and some blocking in the NAO/AO regions.

That could be good come January with much more favorable climo. 

[EastonSN+]

14 minutes ago, Allsnow said:

Some concerning ensemble guidance today for any potential cold air after next weekend. Guidance moving the TPV quickly  into Ak 

Let's hope we score something before it happens.

[snowman19]

15 minutes ago, Allsnow said:

Some concerning ensemble guidance today for any potential cold air after next weekend. Guidance moving the TPV quickly  into Ak 

Yea, it’s definitely concerning. When the TPV moves into AK it typically has good staying power, it’s normally not in and out, transient

[Allsnow]

Yep, we completely lost the -epo look from a few days ago. Canada will be cold so any ridge out west before the 20th can tap colder air then what we have now. 

[MJO812]

46 minutes ago, SnoSki14 said:

I wouldn't get too caught up on things. Models have been shifting like crazy lately.

It's also highly unlikely to be locked in. I do like that ensembles continue to show a +PNA and some blocking in the NAO/AO regions.

That could be good come January with much more favorable climo. 

Just like the models showed a really good pattern , models in the long range should be taken with a grain of salt. 

Heck , the models have a hard time getting a storm right 5-7 days out.

Everyone was praising a great pattern coming up. 

[leo2000]

47 minutes ago, bluewave said:

I am guessing that the -EPO forecasts are having trouble due to the MJO 4. 

New run

Old run

That pesky MJO in phases 5-6 ugh

 

[JustinRP37]

Not everyone was praising the great pattern. Plenty have been pointing out why this year isn't a great year. I am deeply concerned. Even looking at Killington (granted I probably won't get there this year), they are well below where they should be for this time of year. While sure we might get a big storm at some point, I do wish we could actually get some freaking sustained cold! Even this pattern isn't 'cold'. There are still tiny flies coming in my windows when I have them open. I am excited though as we will be moving further north to the Carmel area, so hopefully a bit more snow up there during the winter! Finally pulled the plug on a new place, so bye to southern Westchester for now. 

[MJO812]

2 minutes ago, JustinRP37 said:

Not everyone was praising the great pattern. Plenty have been pointing out why this year isn't a great year. I am deeply concerned. Even looking at Killington (granted I probably won't get there this year), they are well below where they should be for this time of year. While sure we might get a big storm at some point, I do wish we could actually get some freaking sustained cold! Even this pattern isn't 'cold'. There are still tiny flies coming in my windows when I have them open. I am excited though as we will be moving further north to the Carmel area, so hopefully a bit more snow up there during the winter! Finally pulled the plug on a new place, so bye to southern Westchester for now. 

Enjoy man

Even the northern areas of NY are struggling right now.

[MJO812]

It snowed in Georgia once again before it snowed in Philly and NYC 

Smh

[JustinRP37]

Just now, MJO812 said:

Enjoy man

Even the northern areas of NY are struggling right now.

Thanks! I am excited to be further north as much as I love southern Westchester, it will be nice to be up by mountains too. I just hope we do get these overnight freezing temperatures this weekend. Would love for these tiny flies to die off for the year. It is just frustrating without truly cold air. I'd take warm days if we could at least get cold nights! Fingers crossed for snow to get us all in a festive mood, even if it is just a dusting. I am worried though about the ski areas because they need this season as do us winter sports people. Being outside really keeps risks of covid down, and it is still good exercise. Most importantly just getting outside is good for mental health. We all need more of this!

[snowman19]

56 minutes ago, bluewave said:

I am guessing that the -EPO forecasts are having trouble due to the MJO 4. 

New run

Old run

 

How many times now over the last 3 winters have the ensembles shown a massive -EPO/-NAO/-AO pattern in the long range only for it to never verify and just completely disappear?

[bluewave]

28 minutes ago, MJO812 said:

Just like the models showed a really good pattern , models in the long range should be taken with a grain of salt. 

Heck , the models have a hard time getting a storm right 5-7 days out.

Everyone was praising a great pattern coming up. 

That’s why I was pointing out since late November to view those 300+ hr eps forecasts with caution. The EPS  skill falls off pretty quickly after the 7-10 day period. But you could see the more Niña-like Maritime continent MJO forcing coming up. Now the EPS is starting to correct for that 7-8 days out with the more +EPO pattern.

New Forecast 

Old Forecast

 

[MJO812]

4 minutes ago, bluewave said:

That’s why I was pointing out since late November to view those 300+ hr eps forecasts with caution. The EPS  skill falls off pretty quickly after the 7-10 day period. But you could see the more Niña-like Maritime continent MJO forcing coming up. Now the EPS is starting to correct for that 7-8 days out with the more +EPO pattern.

New Forecast 

Old Forecast

 

Good job

We really need to get out of this LA Nina pattern. This pattern really helps NNE.

[MJO812]

7 minutes ago, snowman19 said:

How many times now over the last 3 winters have the ensembles shown a massive -EPO/-NAO/-AO pattern in the long range only for it to never verify and just completely disappear?

We use to get those alot in past winters but it seem like mother nature hates us.

[MJO812]

9 minutes ago, JustinRP37 said:

Thanks! I am excited to be further north as much as I love southern Westchester, it will be nice to be up by mountains too. I just hope we do get these overnight freezing temperatures this weekend. Would love for these tiny flies to die off for the year. It is just frustrating without truly cold air. I'd take warm days if we could at least get cold nights! Fingers crossed for snow to get us all in a festive mood, even if it is just a dusting. I am worried though about the ski areas because they need this season as do us winter sports people. Being outside really keeps risks of covid down, and it is still good exercise. Most importantly just getting outside is good for mental health. We all need more of this!

What part are you going to ?

[the_other_guy]

50 minutes ago, JustinRP37 said:

Thanks! I am excited to be further north as much as I love southern Westchester, it will be nice to be up by mountains too. I just hope we do get these overnight freezing temperatures this weekend. Would love for these tiny flies to die off for the year. It is just frustrating without truly cold air. I'd take warm days if we could at least get cold nights! Fingers crossed for snow to get us all in a festive mood, even if it is just a dusting. I am worried though about the ski areas because they need this season as do us winter sports people. Being outside really keeps risks of covid down, and it is still good exercise. Most importantly just getting outside is good for mental health. We all need more of this!

 The catskills are still completely shut down. scary. I can’t wait to put on the skis

[qg_omega]

1 minute ago, jfklganyc said:

 The catskills are still completely shut down. scary. I can’t wait to put on the skis

its just bad luck, if this storm was 200 miles west like the Euro was forecasting, the ski resorts in NY would be cashing in and NH and Maine would be raining, it just is what it is

[JustinRP37]

50 minutes ago, MJO812 said:

What part are you going to ?

Going to Carmel, NY for now. About my max for commuting for the time being. But very excited to be closer to skiing (even if not the big mountains of the north).

7 minutes ago, jfklganyc said:

 The catskills are still completely shut down. scary. I can’t wait to put on the skis

Yeah it is mind boggling how many areas have still not even been able to do a test run of the snow making systems. We could use a week with lows in the mountains being below 27. Let's make it happen! Right now the best skiing is in New Jersey... Inside a building off I-95. Depressing. 

[Allsnow]

 

[the_other_guy]

10 minutes ago, Allsnow said:

 

At least we arent under the orange or yellow zone from cuomo or on that map

[MJO812]

I'm going to pray the gfs has a clue in mid December

[donsutherland1]

A sustained period of cooler than normal to near normal temperatures is poised to develop this coming weekend following a storm that will bring a general 0.50"-1.50" rainfall from Philadelphia to New York City, with lesser amounts north and west of that line and higher amounts to the east of that line. Accumulating snow is likely in much of New England, including the Boston area.

Likely snowfall amounts include:

Boston: 2"-4"
Caribou: 8"-14"
Concord: 5"-10"
Hartford: 2"-4"
Portland: 4"-8"
Providence: 1"-3"
Worcester: 6"-12"

Since 1950, there were 5 storms that brought 2" or more snow to Boston and no measurable snow to New York City during the December 1-10 period. The biggest snowfall in Boston during these storms occurred during December 5-6, 1981 when Boston picked up 12.9" snow. The single such case with an AO-/PNA+ pattern and a cool ENSO Region 3.4 anomaly occurred during December 8-9, 2001 when Boston saw 4.3" snow.

There remains uncertainty about the timing of the next change toward milder conditions. The development of a AO-/PNA+ pattern has shifted the outlook toward colder temperatures during the first half of December (consistent with statistical guidance) in parts of the Middle Atlantic region. Exceptional cold is unlikely through mid-December. A milder pattern could develop toward the winter solstice and the closing 10 days of December could wind up generally warmer than normal. The duration of the current AO-/PNA+ pattern will be key to how long the colder pattern persists.

Meanwhile, an extended duration much warmer than normal regime will persist in western Canada through the middle of next week. Today, record high temperatures there included:

Fort Providence, NT: 35° (old record: 29°, 2009)
Norman Wells, NT: 32° (old record: 26°, 1972)
Watson Lake, YT: 36° (old record: 27°, 2016)
Wrigley, NT: 32° (old record: 24°, 1972)

Statistical guidance based on the ENSO state and teleconnections would typically favor a colder regime for the first half of December in the Middle Atlantic and southern New England regions. Both historic experience following exceptionally warm November cases suggest that a warmer than normal December remains the base case even if the first half of the month winds up colder than normal. Almost 90% of cases with a November mean temperature of 51.5° or above in Central Park (2020 saw the temperature average a record 52.9° in November) went on to record a warmer than normal December and just over three-quarters of such cases saw December register a monthly mean temperature of 40.0° or above.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.87°C and the ENSO Region 3.4 anomaly has averaged -1.40°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +6.23.

Today, the preliminary Arctic Oscillation (AO) figure was -1.777. The preliminary PNA value was +1.650.

On December 3 the MJO was in Phase 4 at an amplitude of 0.960 (RMM). The December 2-adjusted amplitude was 0.983.

Based on the latest guidance, no significant stratospheric warming event is likely through the middle of the second week of December. Some warming above 3 mb is likely toward the latter part of the first week of December on account of strong Wave 1 activity. Recent guidance is a bit more impressed with the warming.

Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 10/11 (91%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. A predominant EPO+/AO+ pattern is very likely for winter 2020-21. It is likely that the Middle Atlantic and southern New England areas will see a warmer than normal winter with below normal snowfall.

 

 

[LibertyBell]

Don any idea if this will be a cold and dry or cold and stormy pattern?  If it doesn't snow the cold will be worthless.