January 2021 General Discussions & Observations Thread

[snowman19]

7 hours ago, Allsnow said:

You’re trying to hard lol. It’s happening this month. We will have the -epo/+pna/-ao/-nao it’s a deadly combo for snow and cold. The SSW happen yesterday which will seal the deal on January. 

Who knows, maybe this time, at long last, after over 3 winters of the models showing it in the long-range and being dead wrong, there’s really a -EPO period, until it actually happens though, it’s the boy who cried wolf. I have no problem believing the +PNA spike however I think that happens. I guess we’ll see about this big -EPO

[SnoSki14]

2 hours ago, EasternLI said:

Something is lurking out there around the 15/16th maybe. 

 

Looks cold after that with cross polar flow and -nao

Could end up very PDII-ish by the 20th. SE ridge gets a bit stronger but stout -NAO remains with cross-polar flow possible. 

Could set the stage for a widespread overrunner to coastal type event near the 20th. 

I see 4 chances with one on the 8th (long shot but still worth monitoring), the 12/13th (mixed look on models w/better PNA than 8th), the 15/16th (good PNA/atlantic blocking w/arctic air coming south - could see something like Jan 2005), and then 18-20th. 

[snywx]

1 hour ago, sussexcountyobs said:

Light snow falling. 32°

Light snow here as well 

[the_other_guy]

34F when I left at 4 am. 37F when I arrived home at 5pm. 

 

Says so much and nothing at all.

 

 

[donsutherland1]

A relatively quiet weather pattern is in place. Through Friday, partly to mostly sunny and milder than normal conditions will likely prevail.

The likely continuation of Arctic blocking through at least January 15 would typically provide a higher than climatological probability for above normal snowfall. Ideally, an expansive block would be anchored across the Baffin Bay or Greenland, not south of the Davis Strait.

Blocks that are anchored near Newfoundland and Labrador can inhibit opportunities for snowfall and result in warmer to much warmer than normal conditions in the Middle Atlantic and southern New England regions. This is now the most likely scenario for much of the first half of January. Under this scenario, the first 10-15 days of January will likely be generally warmer to perhaps much warmer than normal across the northeastern United States, Quebec, and much of eastern Canada. After January 10, the EPS continues to shows a transition during which a trough will move into the East.

Arctic air will likely shift mainly to Eurasia. However, the evolving pattern could be sufficiently cold to afford opportunities for snowfall if the pattern evolves as currently shown on the EPS. It remains possible that the pattern evolution could lead to a multiweek period with higher than climatological potential for snowfall.

The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -1.2°C for the week centered around December 30. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.80°C and the ENSO Region 3.4 anomaly has averaged -1.10°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +20.07 today.

Today, the preliminary Arctic Oscillation (AO) figure was -3.430.

On January 4 the MJO was in Phase 3 at an amplitude of 0.910 (RMM). The January 3-adjusted amplitude was 0.762.

A significant stratospheric warming event is underway. The mean zonal winds has reversed at 1 mb and will likely reverse at 10 mb and possibly 30 mb. In the wake of this warming event, the polar vortex will likely split. The dominant piece will, as is typical with such events, migrate to Eurasia.

The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Were blocking to disappear, snowfall prospects would diminish. For now, blocking appears likely to continue through at least the first half of January.

 

[Allsnow]

 

[Allsnow]

[eduggs]

For a while now the upcoming period has looked promising based on forecast indices and anomaly averaging.  In fact if you averaged the 500mb heights over the next several days this "pattern" would look fantastic. Yet here we are with most guidance showing no substantial precipitation within 100 miles for at least the next 7 - 10 days.  That's why I hate long range forecasting.  Sure it might sometimes work out for energy traders, but weather is a local phenomenon.  I know that major snow events are statistically more likely during "favorable patterns."  But I've seen so many storms materialize out of lousy patterns... And too-many-to-count good looking patterns fail to deliver. The correlation between forecasted future indices and snow in our backyards is just not strong enough for me to get excited about predictions weeks into the future. 

All that said, we're still within a moderate-sized modeling error of 1 or 2 significant coastal storms over the next 5 days.  So it still bears watching. Modeling has actually become so good that I don't have much confidence in a northward shift of the low tracks.  If this were 2001, or even 2010, I would still hold onto more hope for this period.

 

[HeadInTheClouds]

12 minutes ago, eduggs said:

For a while now the upcoming period has looked promising based on forecast indices and anomaly averaging.  In fact if you averaged the 500mb heights over the next several days this "pattern" would look fantastic. Yet here we are with most guidance showing no substantial precipitation within 100 miles for at least the next 7 - 10 days.  That's why I hate long range forecasting.  Sure it might sometimes work out for energy traders, but weather is a local phenomenon.  I know that major snow events are statistically more likely during "favorable patterns."  But I've seen so many storms materialize out of lousy patterns... And too-many-to-count good looking patterns fail to deliver. The correlation between forecasted future indices and snow in our backyards is just not strong enough for me to get excited about predictions weeks into the future. 

All that said, we're still within a moderate-sized modeling error of 1 or 2 significant coastal storms over the next 5 days.  So it still bears watching. Modeling has actually become so good that I don't have much confidence in a northward shift of the low tracks.  If this were 2001, or even 2010, I would still hold onto more hope for this period.

 

8th-9th chance is pretty much done but 12-13th bears watching. Euro has significant event for that time period. If CMC comes on board I would get excited. GFS is garbage and I trust nothing it shows beyond 72 hours. 

[MJO812]

35 minutes ago, HeadInTheClouds said:

8th-9th chance is pretty much done but 12-13th bears watching. Euro has significant event for that time period. If CMC comes on board I would get excited. GFS is garbage and I trust nothing it shows beyond 72 hours. 

Ukie is flat for next week. Euro is alone. 

[eduggs]

1 minute ago, MJO812 said:

Ukie is flat for next week. Euro is alone. 

Good chance Euro joins the consensus or at least moves towards it tonight. Doesn't mean the threat is dead though.

[MJO812]

This was the northern stream energy that was lagging for the 12th storm. It dug all the way south and then formed this.

[LibertyBell]

On 1/4/2021 at 11:33 PM, RedSky said:

The .10" counts 

 

it really shouldn't.....for years I've noticed that whomever is measuring the snowfall at Central Park is rounding it to the nearest half inch....there are a lot of snowfalls ending in .0 or .5 inch and some were very obviously undermeasured (like Jan 1996 most notably.)

 

[LibertyBell]

3 hours ago, eduggs said:

For a while now the upcoming period has looked promising based on forecast indices and anomaly averaging.  In fact if you averaged the 500mb heights over the next several days this "pattern" would look fantastic. Yet here we are with most guidance showing no substantial precipitation within 100 miles for at least the next 7 - 10 days.  That's why I hate long range forecasting.  Sure it might sometimes work out for energy traders, but weather is a local phenomenon.  I know that major snow events are statistically more likely during "favorable patterns."  But I've seen so many storms materialize out of lousy patterns... And too-many-to-count good looking patterns fail to deliver. The correlation between forecasted future indices and snow in our backyards is just not strong enough for me to get excited about predictions weeks into the future. 

All that said, we're still within a moderate-sized modeling error of 1 or 2 significant coastal storms over the next 5 days.  So it still bears watching. Modeling has actually become so good that I don't have much confidence in a northward shift of the low tracks.  If this were 2001, or even 2010, I would still hold onto more hope for this period.

 

Jan 2016 was a significant shift northward....I'm not sure how much more accurate for east coast storm tracks the models are than they were in 2010 beyond 3 days to be honest.

 

[LibertyBell]

7 hours ago, donsutherland1 said:

A relatively quiet weather pattern is in place. Through Friday, partly to mostly sunny and milder than normal conditions will likely prevail.

The likely continuation of Arctic blocking through at least January 15 would typically provide a higher than climatological probability for above normal snowfall. Ideally, an expansive block would be anchored across the Baffin Bay or Greenland, not south of the Davis Strait.

Blocks that are anchored near Newfoundland and Labrador can inhibit opportunities for snowfall and result in warmer to much warmer than normal conditions in the Middle Atlantic and southern New England regions. This is now the most likely scenario for much of the first half of January. Under this scenario, the first 10-15 days of January will likely be generally warmer to perhaps much warmer than normal across the northeastern United States, Quebec, and much of eastern Canada. After January 10, the EPS continues to shows a transition during which a trough will move into the East.

Arctic air will likely shift mainly to Eurasia. However, the evolving pattern could be sufficiently cold to afford opportunities for snowfall if the pattern evolves as currently shown on the EPS. It remains possible that the pattern evolution could lead to a multiweek period with higher than climatological potential for snowfall.

The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -1.2°C for the week centered around December 30. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.80°C and the ENSO Region 3.4 anomaly has averaged -1.10°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +20.07 today.

Today, the preliminary Arctic Oscillation (AO) figure was -3.430.

On January 4 the MJO was in Phase 3 at an amplitude of 0.910 (RMM). The January 3-adjusted amplitude was 0.762.

A significant stratospheric warming event is underway. The mean zonal winds has reversed at 1 mb and will likely reverse at 10 mb and possibly 30 mb. In the wake of this warming event, the polar vortex will likely split. The dominant piece will, as is typical with such events, migrate to Eurasia.

The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Were blocking to disappear, snowfall prospects would diminish. For now, blocking appears likely to continue through at least the first half of January.

 

Blocking looks like it will get stronger in the second half of January, Don?

 

[wdrag]

No topic considerations from me, beyond the failed Jan 8-9 topic, until the GGEM comes on board.  GGEM may be later coming on board than initial projections from GFS 15,16,EC but I'm waiting til the GGEM  is on board.  That's when I think there is a good chance of verification, Even then, there can be failure. At a minimum 1 GGEM cycle and preferably two successive 12 hr GGEM cycles.   (Ive checked back on the GGEM for this Jan 8-9 NYC subforum failed event...it was blocked quite far south with the 00z/3 cycle). 

[wdrag]

Cold outbreaks and stratwarm.  I see no big cold outbreaks here for at least the next two weeks.  I'm hearing of the stratwarm induced cold outbreak...  stratwarm or not,  aren't we due for at least a short 3 day period of 10 to15F below normal before the end of met winter?  Seems normal to me.

If daily 10 below normal lasts for virtually all of a week, that I think that is more notable. Hope it comes, otherwise no skating this winter on Culvers Lake in nw NJ.(second successive winter of poor ice thickness). 

[CIK62]

The next 8 days are averaging 36degs.(32/40).        Making it 31degs., or -2.0.

Models hopelessly lost when it comes to snow.        Musical Chairs and Illegal Forward Passes abound.        No reason to post amounts/dates before next run alters it.      Gonna be a long uncertain wait. 

37*(75%RH) here at 6am, m. clear.      40* by 11am.       39* at Noon.     42* by 2pm.        36* by 7:00pm.

[MJO812]

26 minutes ago, CIK62 said:

The next 8 days are averaging 36degs.(32/40).        Making it 31degs., or -2.0.

Models hopelessly lost when it comes to snow.        Musical Chairs and Illegal Forward Passes abound.        No reason to post amounts/dates before next run alters it.      Gonna be a long uncertain wait. 

37*(75%RH) here at 6am.

Models lost when it comes to snow ? What are you looking at ?

[MJO812]

18 minutes ago, bluewave said:

There is a reason that all the storms are going to our south with mild temperatures here. The block is too south based. Notice the higher heights pressing down into New England. We may have to wait until the retrogression gets underway with the ridge pulling back to NW Canada for better snow chances and cold. But we will have to be patient as this really doesn’t get underway until mid to late January.  The models have been saying this for a while.

Watch the 12th to 15th timeframe

[wdrag]

8 hours ago, eduggs said:

For a while now the upcoming period has looked promising based on forecast indices and anomaly averaging.  In fact if you averaged the 500mb heights over the next several days this "pattern" would look fantastic. Yet here we are with most guidance showing no substantial precipitation within 100 miles for at least the next 7 - 10 days.  That's why I hate long range forecasting.  Sure it might sometimes work out for energy traders, but weather is a local phenomenon.  I know that major snow events are statistically more likely during "favorable patterns."  But I've seen so many storms materialize out of lousy patterns... And too-many-to-count good looking patterns fail to deliver. The correlation between forecasted future indices and snow in our backyards is just not strong enough for me to get excited about predictions weeks into the future. 

All that said, we're still within a moderate-sized modeling error of 1 or 2 significant coastal storms over the next 5 days.  So it still bears watching. Modeling has actually become so good that I don't have much confidence in a northward shift of the low tracks.  If this were 2001, or even 2010, I would still hold onto more hope for this period.

 

fwiw, i agree w all you stated herein, 06z/6 GEFS or not. Models are gradually improving.  IF you havre large scale support with little room for stream sensitivity interruptions, the storms occur as outlooked a week or more in advance.  But in lesser large scale rdiges/trough dominance with a more unstable pattern (many short waves), the so called D3-4 surprise (uh-oh) changes occur, resulting in a big change in the forecast reality. I see us in a somewhat unstable pattern now with the dominance being blocking north of 50N in N America, and a general troughness in the southern USA. 

I use this 52 member NAEFS as general reasonable anticipation of D8-14.  I check its 00z outlooks vs itself and the 12z outlooks vs itself, and while it cools a bit in central North America during mid month... to me it says we're near or above normal through at least the 20th here in the northeast USA.  Sometimes this NAEFS is wrong but often, I think it reasonable.  And,  while I haven't verified, the EPS, I think it best to look at EPS 500MB and 850MB departures from seasonal  normals, not the sfc temp, which may???be biased a little cold, sometimes because of climo snow cover. This latter contention on my part about EPS cold bias in temps at distance from T0 could be wrong, but think it's wise to check that vs EPS projected 850MB departure from normal temps.  

[snowman19]

41 minutes ago, bluewave said:

The OP Euro has been too unreliable and amped up with post day 5 storm threats. The flatter and more suppressed EPS has been closer to reality. Now can one storm sneak in during a suppressed pattern? Sure. But it’s pure thread the needle until the ridge pulls back by mid to late month.

The op Euro has been garbage so far this winter, not only too amped, but has been flip flopping like crazy

[Brian5671]

2 hours ago, wdrag said:

Cold outbreaks and stratwarm.  I see no big cold outbreaks here for at least the next two weeks.  I'm hearing of the stratwarm induced cold outbreak...  stratwarm or not,  aren't we due for at least a short 3 day period of 10 to15F below normal before the end of met winter?  Seems normal to me.

If daily 10 below normal lasts for virtually all of a week, that I think that is more notable. Hope it comes, otherwise no skating this winter on Culvers Lake in nw NJ.(second successive winter of poor ice thickness). 

Cold has certainly been limited the last few years.   Feels more like DC or Richmond of late....

[donsutherland1]

Morning thoughts...

Today will become partly to mostly sunny. Temperatures will likely reach the lower 40s in much of the region. Likely high temperatures around the region include:

New York City (Central Park): 42°

Newark: 43°

Philadelphia: 43°

Mainly fair and somewhat milder than normal temperatures will prevail through much of the week.

[eduggs]

3 minutes ago, snowman19 said:

The op Euro has been garbage so far this winter, not only too amped, but has been flip flopping like crazy

It seems like there have been more shortwave troughs and ridges than usual over North America so far this winter. I'm not sure if that's real or just my impression. But if true, presumably the models would have a tendency to "flip flip" based on the sensitivity of the interactions between different features. I like the term - unstable pattern - that Walt used.

[donsutherland1]

5 hours ago, LibertyBell said:

Blocking looks like it will get stronger in the second half of January, Don?

 

It’s too soon to tell. The polar vortex should remain weak through much of the month. Nevertheless, the EPS weeklies are forecasting the development of an EPO+/AO+/PNA- pattern for late January. At this point, that’s beyond their skillful range.

[snowman19]

11 minutes ago, donsutherland1 said:

It’s too soon to tell. The polar vortex should remain weak through much of the month. Nevertheless, the EPS weeklies are forecasting the development of an EPO+/AO+/PNA- pattern for late January. At this point, that’s beyond their skillful range.

It looks like they want to pop a big Aleutian ridge at the end of this month. Whether or not that actually happens is the big question since we are talking almost 4 weeks away.... 

[Brian5671]

18 minutes ago, donsutherland1 said:

It’s too soon to tell. The polar vortex should remain weak through much of the month. Nevertheless, the EPS weeklies are forecasting the development of an EPO+/AO+/PNA- pattern for late January. At this point, that’s beyond their skillful range.

If that happens it's lights out here for winter-that's a torch.

[Rjay]

1 hour ago, MJO812 said:

Watch the 12th to 15th timeframe

It would take some luck.   S/w traffic jam at 500mb. 

[snowman19]

9 minutes ago, Rjay said:

It would take some luck.   S/w traffic jam at 500mb. 

Exactly. If something is going to happen, more than likely it’s post 1/16 or so