January 2021 General Discussions & Observations Thread

[MJO812]

13 minutes ago, HVSnowLover said:

Good place for the storm to be at hour 186

Suppression  is a concern with this pattern but its a long way out

[IrishRob17]

In @wdragwe trust to start a storm thread when he feels it is time.  This isn’t like some no name weenie, who comes here only in winter, starting a thread based off of one 300 hour model run. 

[SnowGoose69]

1 hour ago, EastonSN+ said:

From what I have been reading it seems like the Para is a scoring higher than GFS.

Even the Para has been trying to crank ridges in the east past day 7 on many of its runs.  It hasn’t been as awful as the GFS but it’s still doing it.  Just look at the difference in the GFS Op runs today at 12Z compared to the Euro at Day 6-10.  One has 534 thicknesses to Atlanta the other has highs of 65 in DC

[Eduardo]

Let’s make a thread to debate whether and when to start threads! 

[HVSnowLover]

19 minutes ago, MJO812 said:

Suppression  is a concern with this pattern but its a long way out

It is but for the coast id rather take my chances on a pattern that favors DC than one that favors the Adirondacks.  

[LibertyBell]

1 hour ago, bluewave said:

The current version of the GFS is on track to get retired in February. The  new v16 parallel has been doing much better with storm tracks. It looks like they fixed the cold and suppressed bias.  Let’s hope the NAM replacement can see the WAA aloft as well as the current NAM did back on December 16-17th with the sleet.

 

 

https://vlab.ncep.noaa.gov/web/environmental-modeling-center/fv3-convective-allowing-forecast-system

UNIFIED FORECAST SYSTEM : CONVECTIVE-ALLOWING FORECAST AND DATA ASSIMILATION SYSTEM

Maybe they should keep running it every 24 hrs....running a model every 6 hours seems to impair its usefulness.

Happy New Year, Chris!

 

[LibertyBell]

4 hours ago, SnoSki14 said:

Arctic cold usually equals dry.

You don't want that if you want snow.

you dont need Arctic cold for snow....I guess some of us drank too much to remember the last decade or so.

 

[LibertyBell]

2 hours ago, Jeff Grann said:

Especially in January. 

exhibit A is January in the 1980s, lots of Arctic air and very little snow.  I like milder Januarys and snow a lot better.

 

[LibertyBell]

2 hours ago, eduggs said:

I think we're giving causal power to "the block" that doesn't actually exist. The global-scale atmospheric features are interconnected.  The upper and lower level features are integrally related.  A change in one feature doesn't really force the other... the changes happen in unison. And the jet streams spinning around the globe are like buckling strings. Movement anywhere along the string affects the whole chain.

Models don't "see" a block and then adjust. Models forecast a pattern that we describe as a block simultaneously with depicting synoptic features that are placed in concert with that block. If models forecast a stronger block they will also forecast synoptic features that appear to be responding to that block. But that is not the models responding to something tangible that has the power to force weather changes.  That is our ability to see into the future evolving in time. The apparent causal connection is just an illusion. Just like the notion that a surface high can force the movement of a surface low. Highs and lows are merely dance patterns linked in a complex choreography with all the features of the atmosphere.

Yep, this is what I've been saying.  Not only is the whole causal connection an illusion so is the whole W->E illusion.

 

[LibertyBell]

On 12/31/2020 at 1:24 PM, Allsnow said:

This year and the previous winter are completely different. The vortex and mjo forcing ended our winter last year. This year the vortex is getting obliterated and we have blocking. I get what you’re saying but this has Merit IMO. 

 

On 12/31/2020 at 12:34 PM, bluewave said:

31	06:58	SE 35 G 41	7.00	Overcast and Windy	BKN006 OVC011	35	34			97%	21	NA	27.42	928.9
31	05:58	SE 39 G 52	5.00	Light Snow Fog/Mist and Windy	SCT009 OVC015	35	34			97%	20	NA	27.48	930.9
31	04:58	SE 44 G 54	5.00	Light Snow Fog/Mist and Windy	FEW011 OVC017	35	34			94%	19	NA	27.57	934.0
31	03:58	SE 44 G 52	7.00	Mostly Cloudy and Windy	BKN024 BKN033	36	33			90%	21	NA	27.65	936.7
31	02:58	SE 44 G 51	7.00	Mostly Cloudy and Windy	FEW027 SCT049 BKN055 BKN070	35	35			99%	19	NA	27.72	939.0
31	01:58	E 44 G 61	3.00	Light Snow Fog/Mist and Windy	BKN007 OVC012	33	33	33	31	99%	17	NA	27.80	941.8
31	00:58	E 54 G 70	2.50	Light Snow Fog/Mist and Windy	BKN008	32	32			99%	14	NA	27.93	946.2
30	23:58	E 60 G 74	2.00	Light Snow Fog/Mist and Windy	FEW006	32	32			100%	13	NA	28.06	950.6
30	22:58	E 61 G 83	0.75	Rain Fog/Mist and Windy	VV002	32	30			93%	13	NA	28.23	956.3
30	21:58	E 52 G 71	0.63	Rain Fog/Mist and Windy	VV001	31	31			99%	13	NA	28.39	961.8

https://w1.weather.gov/obhistory/PASY.html

 

Noticed the other years mentioned were 2014 and 2015.....also winters where we had big turnarounds between December and January.

 

[sussexcountyobs]

2:58pm 32.0/23.9 Cloudy. Calm.

[LibertyBell]

On 12/31/2020 at 1:25 PM, Allsnow said:

I think canonical Niña February is in trouble because of the ssw and this not acting like a nina

Canonical anything no longer exists thanks to the new patterns setting up thanks to human induced climate change.  The good thing is we'll be heating up the planet through at least 2050!  Maybe all the added plastic is having an effect too

 

 

[LibertyBell]

1 minute ago, bluewave said:

Happy New Year to you also. They actually used to run the Euro once a day  before they got more sophisticated. I think they mostly use the off hour 6z and 18z runs for tweaks in the short term forecast.

 

 

Thanks Chris....any data on the accuracy numbers before and after the change?

 

[LibertyBell]

17 hours ago, Wentzadelphia said:

Thought this was interesting. I knew I had seen a similar H5 looking map. The event shown on today’s 12z euro looks really similar to December 18-20 1995. Any older people on here remember that one?

"older" people eh lol

 

[LibertyBell]

16 hours ago, Rjay said:

I think NYC finishes January +3 but with multiple snow threats.  Pretty crazy to think about.   

MUCH better than January finishing -6 with zero snow threats...which was often the case during the 80s.

 

[LibertyBell]

13 hours ago, SnowGoose69 said:

Yeah it was a good example of terrible pacific good Atlantic with a snow event.  I always show that event as an example of what a -NAO does 

The greatest December snowstorm I had seen up to that point.

 

[LibertyBell]

6 hours ago, bluewave said:

Yeah, we could easily finish with above normal January snowfall and a warm departure. Islip averaged 38.0° in March 2018 and finished with 31” of snow. The NYC average in January is 32.6°. So March 2018 temperatures in a January would have been +5.4. It really comes down to getting a favorable Pacific and storm track with just cold enough for snow. February 2017 was another example on Long Island. Islip recorded 14.7”of snow at an average temperature of 37.8. NYC was able to go to 10.4” in December with a 39.3 average temperature. That’s why I think that we’ll continue to experience great snowstorms even as the winters continue to warm. We showed  a few winters ago that we could go 40/40. 
 

 

If anything the milder winters may be aiding bigger snowfalls as warmer means more humid also.

 

[LibertyBell]

20 hours ago, donsutherland1 said:

In coming days, a positive to strongly positive EPO will coincide with a negative to strongly negative AO. Since 1950, there were 13 cases where the EPO was +1.000 or above while the AO was -1.500 or below for at least three consecutive days during the January 1-20 period. In 3 cases, the Arctic block extended southward into the Middle Atlantic region (January 1-4, 1955; January 15-17, 1998; and, January 1-3, 2003). 

The composite pattern is one that favors above to much above normal temperatures and little or no snowfall through at least the first 10 days of January in much or all of the Middle Atlantic Region and southern New England. Central and Upstate New York, along with central and northern New England would have greater opportunities for snowfall.

Based on the latest guidance, there is a growing possibility that New York City’s Central Park could have a mean temperature of 40° or above during the January 1-10 period. There have been 20 prior cases since record-keeping began in 1869.

It still appears possible that the January 10-15 period could mark a transition to a potentially snowier pattern. The key will be the continuation of Arctic blocking. 

Following such warm starts to January, 60% of the above cases saw less than 2” snow during the second half of January. However, in the 30% of cases with 4” or more snow during the second half of January, the AO was predominantly negative. Half of those cases saw 10” or more snow during the second half of January (1907, 1966, and 2005).

Although a continuation of Arctic blocking cannot ensure a snowy second half of January—1998 is one such exception, largely on account of the super El Niño—the general absence of such blocking has seen little or no snowfall during the January 16-31 period following such warm starts to January.

Things to watch for going forward if a snowy second half of January is likely:

Continuation or reinforcement of the persistent AO- regime

Development of a trough underneath the block that extends into the Middle Atlantic region

The coldest air in the hemisphere will likely be focused on Europe on account of what increasingly looks like a polar vortex-splitting major stratospheric warming event. Severe cold’s migration to Europe does not mean that snowfall will be lacking.

In the meantime, inspired by the work of Hooralph, here’s a sortable table of New York City’s 10” or greater snowstorms (1950-present):

https://public.tableau.com/profile/don.sutherland#!/vizhome/NYC10Snowstorms1950-Present/Dashboard1

Hey Don, I wanted to see how many of the smaller less well predicted storms of the 80s and 90s I could remember...could you possibly increase the list down to the 6"+ storms or even 4"+ and one where such amounts were reached or exceeded at any of the local airports too?  Thanks!

 

[LibertyBell]

13 hours ago, SnowGoose69 said:

Yeah it was a good example of terrible pacific good Atlantic with a snow event.  I always show that event as an example of what a -NAO does 

Did any of the other nice events in 95-96 occur under similar circumstances?

 

[SnowGoose69]

6 minutes ago, LibertyBell said:

Did any of the other nice events in 95-96 occur under similar circumstances?

 

Not really.  The PAC was really good otherwise, even for the earlier December events which I think two changed to rain at the coast.  The pattern out west broke down for a while there in mid to late December.  

[donsutherland1]

11 minutes ago, LibertyBell said:

Hey Don, I wanted to see how many of the smaller less well predicted storms of the 80s and 90s I could remember...could you possibly increase the list down to the 6"+ storms or even 4"+ and one where such amounts were reached or exceeded at any of the local airports too?  Thanks!

 

I will have to work on that. It will require some time.

[LibertyBell]

11 minutes ago, SnowGoose69 said:

Not really.  The PAC was really good otherwise, even for the earlier December events which I think two changed to rain at the coast.  The pattern out west broke down for a while there in mid to late December.  

It would be amazing if we could have a reference base for all the different major storms accompanied by index values when those events occured.

[LibertyBell]

12 minutes ago, donsutherland1 said:

I will have to work on that. It will require some time.

Thanks Don, I wonder how large the list would be if we just went from 1980 onwards.

 

[SnowGoose69]

3 minutes ago, LibertyBell said:

It would be amazing if we could have a reference base for all the different major storms accompanied by index values when those events occured.

Up until recently there were hardly any major events with a positive NAO.  Certainly there were some big overrunning type storms or southwest flow events but these borderline KU events with deep coastal lows occurring with positive NAOs is mostly something that’s only occurred in the last decade 

[Rjay]

1 hour ago, Eduardo said:

Let’s make a thread to debate whether and when to start threads! 

We start storm threads when Walt decides to start them.  That's how we're rolling this winter.   

[Rjay]

1 hour ago, IrishRob17 said:

In @wdragwe trust to start a storm thread when he feels it is time.  This isn’t like some no name weenie, who comes here only in winter, starting a thread based off of one 300 hour model run. 

Dude is a legend.  

[White Gorilla]

47 minutes ago, Rjay said:

We start storm threads when Walt decides to start them.  That's how we're rolling this winter.   

I bow my head to Mr Walt Drag.  Such a loaded pro. 

[ForestHillWx]

Had a brief period of graupel/sleet. Now cold rain. 

[bluewave]

2 hours ago, LibertyBell said:

If anything the milder winters may be aiding bigger snowfalls as warmer means more humid also.

 

We have had a wide temperature range for our 10”+ snowfall months since Dec 09. The Islip data shows a monthly average temperature range from 21.6° to 38.0°. Since the 15-16 winter, the snowiest months have been toward the warmer end of the temperature scale. The main ingredients for a snowy month are teleconnections, storm track, 50/50 low, high pressure to the north, and just cold enough at storm time. Just cold enough often comes down to a low at least into the mid 20s a few days before or during the storm. Sometimes the lows in the 20s before the storm warm to low 30s during storm time. Those are the heavy wet snow events with high water content.

Islip.......SN.......TEMP....DEP

Dec 09...25.3”....34.5°...-1.1

Feb 10...21.7”....31.4°...-1.4

Dec 10...14.9”....31.5°....-4.1

Jan 11...34.4”.....27.1°...-3.5

Feb 13...31.4”.....32.1°...-0.7

Jan 14...25.2”.....27.7°...-2.9

Feb 14...24.5”....29.7°....-3.1

Jan 15...30.2”.....28.7°....-1.9

Feb 15...13.4”....21.6°.....-11.2

Jan 16....24.8”...33.3°....+2.7

Feb 16....13.2”....35.7°....+2.9

Jan 17....14.0”....36.2°....+5.6

Feb 17....14.7”....37.8°....+5.0

Jan 18....22.0”....30.1......-0.5

Mar 18...31.9”.....38.0°.....-1.3

[Jeff Grann]

2 hours ago, LibertyBell said:

exhibit A is January in the 1980s, lots of Arctic air and very little snow.  I like milder Januarys and snow a lot better.

 

Yes. Many don't understand its better to have a milder, stormy pattern in January. Yeah you will get skunked especially along the coast but you have a chance for a well timed blockbuster storm that would've been surpressed  or never happened at all if the East was overwhelmed with cold dry air at the coldest time of the year