January 2021 General Discussions & Observations Thread

[MJO812]

17 minutes ago, NEG NAO said:

0Z GFS north again for next weeks event - no real redevelopment before it encounters any blocking

There is blocking. Gfs is wrong. 

Para is further south and CMC  shreds the 1st wave and then squashes the 2nd wave.

Models also have a threat on the 29th.

[NEG NAO]

14 minutes ago, MJO812 said:

There is blocking. Gfs is wrong. 

Para is further south and CMC  shreds the 1st wave and then squashes the 2nd wave.

Models also have a threat on the 29th.

[NEG NAO]

0Z GFSv16

[MJO812]

Euro

[MJO812]

[LibertyBell]

12 hours ago, bluewave said:

This is our 3rd year in a row with long stretches between measurable snowfall. 

NYC

11-15-18...........6.4”......1-18-19....0.5

1-18-20..............2.1........no measurable snowfall the rest of the season

12-17-20...........10.5......no measurable snowfall through 1-18-21

 

It looks like the pattern gets more unfavorable every year, and that's regardless of whatever ENSO phase we're in.

 

[LibertyBell]

12 hours ago, SnowGoose69 said:

I'm beginning to think we need another 82-83/97-98/15-16 Nino to change this 

are you sure?  one out of those three had amongst our least snowy seasons of all time, and the other two were very mild with one hit wonders (granted those hits we did have were two of our best snowstorms ever.)

 

[LibertyBell]

12 hours ago, bluewave said:

We haven’t seen this type of 8 year progression before. 

13-14 to 14-15...cold and snowy

15-16,16-17,17-18....record warmth and record snows

18-19 to 19-20......... record warmth and below normal snows long gaps between snows

20-21.........................warmth continuing and a long gap between snowfall so far

I thought this kind of reminded me of the 80s actually.  But of course much less cold lol.

 

[LibertyBell]

11 hours ago, bluewave said:

We need the south based blocking to ease up a bit. 
 

Latest EPS weeklies Jan 25 Feb1 

500 mb

Temp departures

 

Precip departures

 

 

This south based block is a new wrinkle....is this the first time we've ever had one of these?  If not, possible analogs of years that had them?  I've only ever heard of west based blocks and east based blocks, this is the first time anyone has ever brought up a south based block, so it sounds like something new.

 

[North and West]

I thought this kind of reminded me of the 80s actually.  But of course much less cold lol.
 

It’s the tranquility that does it for me, in regards to reminding me of my childhood. Just nothing going on precipitation wise.

I’m concerned about drought later in the year.


.

[wdrag]

Good Tuesday morning everyone,  I've an errand to run shortly so I'll start the thread for 25-26 only at about 9A.  Still fraught with uncertainty but looks cold enough for any qpf to be a snow or ice mix except the usual mess for LI, with an ice/snow line in my mind either I78 or I195. SOOOOO early so will probably play it a loose and tighten up the topic as the days move along. Later, Walt

[CIK62]

The next 8 days are averaging 33degs.(28/38).          Making it 28degs., or -4.0.

No snow to talk of because there is no precipitable water to talk of.       0Z GFS does not go below 20 for remainder of month.       O6Z GFS is colder, but just as dry.       06Z and 18Z runs have the brain of a Russett Potato.

EURO has 12" and the CMC gave it up yesterday for  the 25th/26th.    EURO is a northerly branch job only, thin W-E swath.   Plus a follow-up twin for the 30th.    Choose your favorite output.

Starting with Dec. 21 we are +5.4 to date, just like J,F,M last year.        To date this month is 37.9.       If the last 13 days  are Normal, we would end up at 35.6.

35*(70%RH) here at 6am.          40* by 11am.         41* by Noon.       43* by 3pm.       40* by 5pm.

[donsutherland1]

4 hours ago, LibertyBell said:

This south based block is a new wrinkle....is this the first time we've ever had one of these?  If not, possible analogs of years that had them?  I've only ever heard of west based blocks and east based blocks, this is the first time anyone has ever brought up a south based block, so it sounds like something new.

 

No. It’s happened before. Here’s one discussion I posted concerning the January 1-20 period:

https://www.americanwx.com/bb/topic/54083-december-2020-general-discussions-observations-thread/?do=findComment&comment=5773757

Through January 18, the January mean temperature is 37.9° in New York City.

[EastonSN+]

26 minutes ago, bluewave said:

The 0z Euro was as good  a thread the needle as you will ever see for the 26th. Could be a first with winter wavelengths for such a deep -PNA trough in the West tracking perfectly from west to east under -AO block. The next system actually has more of a +PNA as heights build out West. So root for the Euro over the other guidance if you like rabbit out of a hat snowstorms. People would quickly forget the snow drought over the last month.

 

I know that there is no basis to "we are due for a fluke", however if we can score in 2011/2012 and last January, then we can score SOMETHING in this pattern.

However, looking at the modeling sans EURO, suppression looks to be the issue (south based NAO).

Middle Atlantic may get rocked.

[EastonSN+]

4 minutes ago, donsutherland1 said:

No. It’s happened before. Here’s one discussion I posted concerning the January 1-20 period:

https://www.americanwx.com/bb/topic/54083-december-2020-general-discussions-observations-thread/?do=findComment&comment=5773757

Through January 18, the January mean temperature is 37.9° in New York City.

Thanks Don.

Given that Boston was the only City to realize accumulating snow in those cases, do you give much weight to the models showing the middle Atlantic getting snow, or do you believe once we get closer in time the south based NAO will "shred" the systems.

[donsutherland1]

Morning thoughts...

Today will be partly sunny. Temperatures will likely reach the lower 40s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 43°

Newark: 44°

Philadelphia: 45°

A weak cold frontal passage could bring a few snow flurries tomorrow. A strong cold front could move across the region late in the week bringing a period of light snow or flurries.

[EastonSN+]

13 hours ago, MJO812 said:

From Orh in SNE

Weeklies went wild with the -AO/NAO well into February. If that is correct, we’re either in for more torture or a lot of fun. Can’t punt with that look. (Well I guess you can but it’s like punting on 4th and 2 at your opponent 40 down by 7 with 4 min to go)

 

I did not personally like the look of the weeklies below. Did have the negative NAO but south based past week 2 and looks like linked to the SE Ridge.

Of course they are the weeklies so take with a grain of salt.

https://apps.ecmwf.int/webapps/opencharts/products/extended-anomaly-z500?base_time=202101180000&projection=opencharts_global&valid_time=202103010000

[donsutherland1]

11 minutes ago, EastonSN+ said:

Thanks Don.

Given that Boston was the only City to realize accumulating snow in those cases, do you give much weight to the models showing the middle Atlantic getting snow, or do you believe once we get closer in time the south based NAO will "shred" the systems.

There are some differences from the pattern shown in that late December post concerning January 1-20. In this case, there is model consensus that the EPO will go negative for a time before returning to positive levels. That opens the door for some snowfall potential for the Middle Atlantic region, but that’s not a good pattern for significant (6” or above) snowfalls. It will be interesting to see what the ECMWF shows today after the 0z run had a sizable snow event.

[bluewave]

1 hour ago, EastonSN+ said:

I know that there is no basis to "we are due for a fluke", however if we can score in 2011/2012 and last January, then we can score SOMETHING in this pattern.

However, looking at the modeling sans EURO, suppression looks to be the issue (south based NAO).

Middle Atlantic may get rocked.

Yeah, we need to ease up on the south based blocking suppression risk for the OP Euro to work out. The 0z Euro run was showing what needs to happen with the 2 storms. There aren’t that many years with the strongest AO blocking sitting just east of The Canadian Maritimes. The record holders for the previous strongest south based blocking for the entire winter were 2005, 1969, and 1951.

 

[SnowGoose69]

2 hours ago, EastonSN+ said:

I did not personally like the look of the weeklies below. Did have the negative NAO but south based past week 2 and looks like linked to the SE Ridge.

Of course they are the weeklies so take with a grain of salt.

https://apps.ecmwf.int/webapps/opencharts/products/extended-anomaly-z500?base_time=202101180000&projection=opencharts_global&valid_time=202103010000

I believe shortening wavelength as we progress through Feb would make that link up less likely to occur but I'm not sure on that.

[Eduardo]

20 hours ago, SnowGoose69 said:

I'm beginning to think we need another 82-83/97-98/15-16 Nino to change this 

 

7 hours ago, LibertyBell said:

are you sure?  one out of those three had amongst our least snowy seasons of all time, and the other two were very mild with one hit wonders (granted those hits we did have were two of our best snowstorms ever.)

 

I think he meant that we need another big event like a super Niño to reshuffle the PAC and tame the firehose jet that's killed our last few winters.  I tend to agree with that.

[MJO812]

30 minutes ago, SnowGoose69 said:

I believe shortening wavelength as we progress through Feb would make that link up less likely to occur but I'm not sure on that.

Weeklies doesn't look bad at all

Serviceable 

[snowman19]

39 minutes ago, MJO812 said:

Weeklies doesn't look bad at all

Serviceable 

After last winter’s debacle, I don’t trust them as far as I can throw them. They were just dreadful, they kept showing a great pattern that never materialized, so many people got burnt by them 

[gravitylover]

Looks like some snow blossoming on radar to my WNW. The way the clouds settled in over the last 30 minutes sure makes it feel like it's about to snow. 37/27/ VRBL SW-W 3-7

[bluewave]

40 minutes ago, snowman19 said:

After last winter’s debacle, I don’t trust them as far as I can throw them. They were just dreadful, they kept showing a great pattern that never materialized, so many people got burnt by them 

They have been getting the areas of the positive and negative 500mb height anomalies correct for North America. But the magnitude of the anomalies will always get refined the closer in we get. Maybe they corrected stronger on the blocking this month due to the lagged effect from the SSW and individual wave breaks?

Jan 4 forecast for Jan 25-Feb 1

Jan 11 forecast for Jan 25-Feb 1

Jan 18 forecast for Jan 25- Feb 1

 

 

 

 

 

[the_other_guy]

No lack of snow in Catskills...

 

Actively snowing too

[bluewave]

It’s ridiculous how warm the minimums have been in Northern New England this month. Caribou is +17 on the minimums and +8.1 on the maximums. This gives a +13.1 average departure.
 

Climatological Data for Caribou Area, ME (ThreadEx) - January 2021
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Min Temperature	Avg Temperature	Avg Temperature Departure	HDD	CDD	Precipitation	Snowfall	Snow Depth
Sum	521	328	-	-	740	0	0.97	7.3	-
Average	28.9	18.2	23.6	13.1	-	-	-	-	6.7
Normal	19.8	1.2	10.5	-	981	0	1.59	14.6	-
2021-01-01	23	8	15.5	3.3	49	0	0.00	0.0	5
2021-01-02	22	12	17.0	5.0	48	0	0.33	4.0	5
2021-01-03	25	7	16.0	4.3	49	0	0.00	0.0	9
2021-01-04	26	21	23.5	12.1	41	0	0.00	0.0	9
2021-01-05	29	22	25.5	14.3	39	0	T	T	8
2021-01-06	30	19	24.5	13.5	40	0	0.04	0.3	7
2021-01-07	29	21	25.0	14.2	40	0	0.00	0.0	7
2021-01-08	24	21	22.5	11.9	42	0	0.02	0.2	6
2021-01-09	31	20	25.5	15.1	39	0	T	T	6
2021-01-10	28	7	17.5	7.3	47	0	0.00	0.0	6
2021-01-11	27	7	17.0	6.9	48	0	T	T	6
2021-01-12	32	23	27.5	17.6	37	0	0.04	0.6	6
2021-01-13	32	24	28.0	18.2	37	0	T	0.1	7
2021-01-14	33	26	29.5	19.8	35	0	T	T	7
2021-01-15	34	26	30.0	20.4	35	0	T	T	6
2021-01-16	33	21	27.0	17.5	38	0	0.38	0.6	6
2021-01-17	33	30	31.5	22.0	33	0	0.15	1.3	7
2021-01-18	30	13	21.5	12.1	43	0	0.01	0.2	8
2021-01-19	M	M	M	M	M	M	M	M	M
2021-01-20	M	M	M	M	M	M	M	M	M
2021-01-21	M	M	M	M	M	M	M	M	M
2021-01-22	M	M	M	M	M	M	M	M	M
2021-01-23	M	M	M	M	M	M	M	M	M
2021-01-24	M	M	M	M	M	M	M	M	M
2021-01-25	M	M	M	M	M	M	M	M	M
2021-01-26	M	M	M	M	M	M	M	M	M
2021-01-27	M	M	M	M	M	M	M	M	M
2021-01-28	M	M	M	M	M	M	M	M	M
2021-01-29	M	M	M	M	M	M	M	M	M
2021-01-30	M	M	M	M	M	M	M	M	M
2021-01-31	M	M	M	M	M	M	M	M

[gravitylover]

Looks like I missed out on the first round of snow showers this afternoon, maybe one of the popcorn kernels will roll over me.

[Allsnow]

The eps today with a colder look to enter February. 

[donsutherland1]

Through the first 50 days of meteorological winter, the AO has averaged -1.900. It has been negative on 96% of days. It has been at or below -1.000 on 84% of days and at or below -2.000 on 50% of days. This blocking will likely continue into at least the closing days of January.

Overnight into tomorrow morning, some snow showers and show flurries are likely. Parts of the region could pick up a coating of snow. There could be some additional opportunities for snowfall during the remainder of January, as blocking continues. However, significant or major snowstorms are probably not very likely.

There continues to be ensemble support for some light snow or flurries in parts of the region during the January 21-23 timeframe during the passage of a strong cold front. Another timeframe highlighted by the ensembles is January 25-28. The latter period may have greater potential. However, neither period is likely to produce a significant snowfall (6" or above) for the Washington, DC to Boston corridor.

AO-/PNA- patterns are typically not snowy. The frequency of measurable snowfall is just over 90% of climatology in Boston and Philadelphia and around 80% of climatology in New York City for the January 21-31, 1950-2020 period. The frequency of 2" or more daily snowfall was just above 90% of climatology for Philadelphia, but fell sharply to 50% of climatology in New York City and 65% of climatology in Boston. For daily snowfall amounts in excess of 2", the frequency fell sharply for Philadelphia. As a result, such patterns typically have produced significant snowstorms (6" or above snowfall) in the northern Middle Atlantic and southern New England regions during late January. The biggest snowfalls during an AO-/PNA- pattern during the January 20-31, 1950-2020 period were as follows: Boston: 7.3", January 21, 2011; New York City: 4.2", January 21, 2011; and, Philadelphia: 3.0", January 20, 2000.

Afterward, the evolution of the AO will determine whether potential for measurable snow events will continue into February.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -1.2°C for the week centered around January 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -1.08°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was +22.99 today.

Today, the preliminary Arctic Oscillation (AO) figure was -2.012.

On January 18 the MJO was in Phase 4 at an amplitude of 0.636 (RMM). The January 17-adjusted amplitude was 1.007.

Following a significant stratospheric warming event, the stratosphere is now cooling. The cooling will likely accelerate during the second half of January. As is typical for vortex-splitting events, the major piece of the polar vortex migrated to Eurasia. The end result has been an absence of severe cold in much of North America.

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.

Based on sensitivity analysis applied to the latest guidance, there is an implied 87% probability that New York City will have a warmer than normal January. January will likely finish with a mean temperature near 35.2°.