December 2020 General Discussions & Observations Thread

[North and West]

 
Ridiculously misleading tweet. 

For the uninformed (like myself), what does this all mean? Speak to me like I’m five.


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[Rjay]

23 minutes ago, North and West said:

For the uninformed (like myself), what does this all mean? Speak to me like I’m five.


.

Saying this pattern reminds him of a recent historic winter is ridiculous.   The Pacific looks nothing like it did in 2009/2010.  We will definitely have our shots down the road (week 3+) if we can get a well-timed PNA spike.    

We could even cash in with a slightly less atrocious PAC.

[North and West]

Saying this pattern reminds him of a recent historic winter is ridiculous.   The Pacific looks nothing like it did in 2009/2010.  We will definitely have our shots down the road (week 3+) if we can get a well-timed PNA spike.    
We could even cash in with a slightly less atrocious PAC.

History doesn’t repeat itself, but it often rhymes. Nothing is ever a 1-for-1 duplicate.


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[LibertyBell]

On 12/28/2020 at 10:56 AM, donsutherland1 said:

The EPO is positive and is forecast to soar to strongly positive levels early in the first week of January on the EPS.

if I remember right, we had the EPO strongly in our favor for many of those winters earlier in the decade (el nino, la nina and neutral winters.)

[LibertyBell]

12 hours ago, weatherpruf said:

That was a very mild winter, my first year teaching in Elizabeth; are you sure we aren't talking about a different year; there was a storm near Thanksgiving in 88 or 89; can't believe I wouldn't remember something in 1990. 

that was a horrific series of winters..... 88-89, 89-90, 90-91, 91-92.

 

[LibertyBell]

9 hours ago, Stormlover74 said:

Nope definitely 90-91. There was another decent event on January 11th. About 6" before changing to sleet and heavy rain. I remember walking home from school in heavy snow. The late Feb Strom was definitely a nyc east special 

late Feb storm?  what year?  is that the 4-8 30 hr storm that came out of nowhere didn't stick during the day but stuck at night?

 

[LibertyBell]

21 hours ago, NEG NAO said:

While we are waiting for the next snowstorm in the NYC Metro here is a review of snowstorms from 1953 up till the the one just a couple weeks ago:

https://thestarryeye.typepad.com/weather/2014/11/each-winters-snowstorms-1970-2014.html

 

omg this is it!  It was called a very rare "neutercane"- I remember a TV Met on WPIX talking about it (saying it happens about once every 30 years) and completely unpredictable.  Haven't seen one since!  What was supposed to be a frontal passage and just a few showers stalled just offshore and turned into a cyclone that caused a 30 hr period of snow from Newark to the Hamptons, we had 8 inches near JFK- that is my favorite snowstorm memories from that lackluster period.  It didn't snow at all in Philly or Boston, it was a tristate special!  Can someone post the weather maps for this "neutercane"?

Feb. 26, 1991 - A surprise snowstorm dumped 8.9" of wet snow, the biggest accumulation in eight years (since 17.6" buried the City on Feb. 11-12, 1983 ).  Because the temperature was just above freezing for much of the day the snow didn't accumulate much on the streets or sidewalks.  This was the winter's third snowfall of five inches or more.

[LibertyBell]

21 hours ago, NEG NAO said:

While we are waiting for the next snowstorm in the NYC Metro here is a review of snowstorms from 1953 up till the the one just a couple weeks ago:

https://thestarryeye.typepad.com/weather/2014/11/each-winters-snowstorms-1970-2014.html

 

Is this all of them?  It's missing an 8.6 snowstorm that occurred in December in either 1985 or 1986 (I dont remember which.)

Do you know where I can find a list of all NYC snowstorms 4 inches (or 6 inches) and greater?

 

[donsutherland1]

After parts of the region experienced widely scattered snow showers this morning, today was fair and cold. Tomorrow will be mainly cloudy and perhaps a bit milder.

The likely continuation of Arctic blocking through at least the first 10 days of January 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 much warmer than normal across the northeastern United States, Quebec, and much of eastern Canada. After January 10, there is some indication on the EPS that a transition that could lead to a trough's moving into the East could get underway.

The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around December 23. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.70°C and the ENSO Region 3.4 anomaly has averaged -1.15°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +20.86 today.

Today, the preliminary Arctic Oscillation (AO) figure was -2.757.

On December 28 the MJO was in Phase 4 at an amplitude of 0.160 (RMM). The December 27-adjusted amplitude was 0.061.

Based on the latest guidance, a significant stratospheric warming event near or just after the start of January is likely. The highest levels of the stratosphere will warm during the closing days of December. The warming will begin to descend during the opening week of January. In addition, the mean zonal winds at 1 mb and 10 mb will likely reverse while the mean zonal wind at 30 mb will likely slacken considerably. Toward the end of the first week in January, the top layers of the stratosphere could begin to cool.

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 the first half of January.

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal December. December will likely finish with a mean temperature near 39.1°.

 

[donsutherland1]

36 minutes ago, LibertyBell said:

if I remember right, we had the EPO strongly in our favor for many of those winters earlier in the decade (el nino, la nina and neutral winters.)

Yes, that is correct.

[Stormlover74]

36 minutes ago, LibertyBell said:

late Feb storm?  what year?  is that the 4-8 30 hr storm that came out of nowhere didn't stick during the day but stuck at night?

 

I believe so.  We didn't get much out here

[LibertyBell]

36 minutes ago, Stormlover74 said:

I believe so.  We didn't get much out here

I remember it well.  I wonder if anyone has the JFK total from that storm, as it seemed to be a local jackpot.  A front stalled just offshore and a low formed near the Hamptons and just stalled there creating a narrow band of snow from Newark to Long Island.  If it wasn't for the temps being in the mid 30s most of the day it would have stuck sooner, but it just kept snowing and it started sticking at night.  A 30 hour snowstorm!  I would love to see the hourly obs and a map of that storm!

 

[LibertyBell]

4 hours ago, Rjay said:

 

Ridiculously misleading tweet. 

JB-esque level misleading.  But we must also call out the other extreme too.  There is zero reason to believe that this will be like last winter.  The west to east cause-effect reasoning of the Pacific being behind everything that happens in our weather drives me nuts.  So if weather goes west to east can we say that the Indian Ocean is really what determines our weather since the Indian Ocean is west of the Pacific and therefore it must be the reason behind what happens in the Pacific?  And if you want to go further down the rabbit hole, you can say that the whole west-east (and north-south) analogy is a holdover from the days when people thought the earth was flat.  If you go straight east you'll end up back where you started from (and likewise if you go straight west, due north, or due south.)  In reality everything is connected and there is no such thing as cause and effect because of this interconnectedness.  There is NO cause and effect precisely because EVERYTHING is cause and EVERYTHING is effect.  Ultimately it draws into question this whole simplification of cause and effect which is the greatest fallacy in all of science.  It is the main reason why I love quantum mechanics so much and have ever since a little kid (well 7th grade anyway), it makes no bones about it and doesn't simplify anything and boldly proclaims there is no such thing as cause and effect.  And you can't dare refute it because every single experiment that has ever been performed has confirmed it, even over relativity and Einstein's objections.

 

[CIK62]

The last two days of December are averaging 39degs., (34/39).          Making it 38degs., or +5.

Month to date is 39.3[+1.4].        December should end near 39.2.        The first half of January may end near 39degs. too.      The GEFS is +5 to +12 on each of those travelling 5-Day periods.     Ugly.        The uncorrected GFS is averaging 40degs.(35/44), or +7.0---for the first 15 days of January.

The GEFS Extended still insists on no T below 20 till the 18th.----then we spend the rest of the month in the single digits and/or  sub-zero environment.    As far as snow is concerned, apparently none till the 15th+-----then 2X normal.    Stay tuned.

32*(53%RH) here at 6am.      Up from 30* at 5am.      35* by 11am.      37* by Noon.      39* by 1pm.        41* by 3pm and held till sunset.

[wdrag]

Not sure what the JB tweet was about??,  but probably didn't cover an overlooked narrow band of 1/2"+ period of heavy rain Thursday, somewhere near I-195, to nr southern LI.  Just don't think we can abandon adding up rain qpf the next 6 days in our area.  It might yet have some minor impact on small streams. Have a day. 

[donsutherland1]

Morning thoughts...

Today will be mostly cloudy and still cool. Temperatures will likely top out in the upper 30s and lower 40s across most of the region. Likely high temperatures around the region include:

New York City (Central Park): 43°

Newark: 43°

Philadelphia: 43°

Tomorrow will become milder with periods of rain.

[bluewave]

Several times since 1995 NYC has had a snowy December following an extremely high ACE hurricane season.
 

Accumulated Cyclone Energy - Atlantic hide

Season	ACE	TS	HU	MH	NYC Dec Snowfall
2020	180.1015	30	13	6	10.5
2019	132.2025	18	6	3	2.5
2018	132.5825	15	8	2	T
2017	224.8775	17	10	6	7.7
2016	141.2525	15	7	4	3.2
2015	62.685	11	4	2	T
2014	66.725	8	6	2	1
2013	36.12	14	2	0	8.6
2012	132.6325	19	10	2	0.4
2011	126.3025	19	7	4	0
2010	165.4825	19	12	5	20.1
2009	52.58	9	3	2	12.4
2008	145.7175	16	8	5	6.0
2007	73.885	15	6	2	2.9
2006	78.535	10	5	2	0
2005	250.1275	28	15	7	9.7
2004	226.88	15	9	6	3.0
2003	176.84	16	7	3	19.8
2002	67.9925	12	4	2	11.0
2001	110.32	15	9	4	T
2000	119.1425	15	8	3	13.4
1999	176.5275	12	8	5	T
1998	181.7675	14	10	3	2.0
1997	40.9275	8	3	1	T
1996	166.1825	13	9	6	T
1995	227.1025	19	11	5	11.5

 

[LibertyBell]

1 hour ago, bluewave said:

Several times since 1995 NYC has had a snowy December following an extremely high ACE hurricane season.
 

Accumulated Cyclone Energy - Atlantic hide

Season	ACE	TS	HU	MH	NYC Dec Snowfall
2020	180.1015	30	13	6	10.5
2019	132.2025	18	6	3	2.5
2018	132.5825	15	8	2	T
2017	224.8775	17	10	6	7.7
2016	141.2525	15	7	4	3.2
2015	62.685	11	4	2	T
2014	66.725	8	6	2	1
2013	36.12	14	2	0	8.6
2012	132.6325	19	10	2	0.4
2011	126.3025	19	7	4	0
2010	165.4825	19	12	5	20.1
2009	52.58	9	3	2	12.4
2008	145.7175	16	8	5	6.0
2007	73.885	15	6	2	2.9
2006	78.535	10	5	2	0
2005	250.1275	28	15	7	9.7
2004	226.88	15	9	6	3.0
2003	176.84	16	7	3	19.8
2002	67.9925	12	4	2	11.0
2001	110.32	15	9	4	T
2000	119.1425	15	8	3	13.4
1999	176.5275	12	8	5	T
1998	181.7675	14	10	3	2.0
1997	40.9275	8	3	1	T
1996	166.1825	13	9	6	T
1995	227.1025	19	11	5	11.5

 

wow 1995 is the most memorable example but it also happened several times in the early 2000s.....warmer SST causing this?

[North and West]

that was a horrific series of winters..... 88-89, 89-90, 90-91, 91-92.
 

Ah, my formative winters. Imagine being a kid and those are your elementary school winters.



Sent from my iPad using Tapatalk

[donsutherland1]

Tomorrow will be mostly cloudy and milder. Some rain showers or a period of rain is likely, especially during the morning hours. Well north and west of Newark and New York City, there could be some mixed or frozen precipitation.

The likely continuation of Arctic blocking through at least the first 10 days of January 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 much warmer than normal across the northeastern United States, Quebec, and much of eastern Canada. After January 10, there is some indication on the EPS that a transition that could lead to a trough's moving into the East could get underway.

The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around December 23. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.70°C and the ENSO Region 3.4 anomaly has averaged -1.15°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +25.01 today.

Today, the preliminary Arctic Oscillation (AO) figure was -2.446.

On December 29 the MJO was in Phase 4 at an amplitude of 0.355 (RMM). The December 28-adjusted amplitude was 0.163.

A significant stratospheric warming event is now in its early stages. The highest levels of the stratosphere will continue to warm through the first half of the first week of January. The mean zonal winds will likely reverse at 1 mb, 10 mb, and 30 mb making this a major warming event. Toward the end of the first week in January, the top layers of the stratosphere could begin to cool.

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 the first half of January.

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal December. December will likely finish with a mean temperature near 39.2°.

 

[LibertyBell]

2 hours ago, North and West said:

Ah, my formative winters. Imagine being a kid and those are your elementary school winters.



Sent from my iPad using Tapatalk

and my high school winters

 

[sferic]

11:30PM Moderate freezing rain in Liberty NY @ 31.8 degrees

 

@crossbowftw3 how about you?

[CIK62]

The last day of December is averaging 43degs.(39/47), or +10.

Month to date is 39.1[+1.5].         December should end at 39.4.

The uncorrected (GFS, 0Z) first 15 days of January are averaging 40degs.(36/45), or +7.0.

48*(94%RH) here at 6am----Up from 43* at Midnite.         46* since Noon-2pm.        37* by 11pm.

[crossbowftw3]

8 hours ago, sferic said:

11:30PM Moderate freezing rain in Liberty NY @ 31.8 degrees

 

@crossbowftw3 how about you?

It stayed rain all night here 

[Rtd208]

Picking up some decent rain here this morning. 

0.37" of rain so far today.

Current temp 45

[donsutherland1]

Morning thoughts...

Rain will end from west to east from late this morning to mid-afternoon. Temperatures will likely hold nearly steady in the middle 40s across most of the region. Likely high temperatures around the region include:

New York City (Central Park): 45°

Newark: 46°

Philadelphia: 46°

Clouds will increase tomorrow and rain could arrive.

[forkyfork]

assuming no more rain today my yearly precip total is 47.36" 

[Rtd208]

Picked up 0.54" of rain so far today.

Current temp 41

[donsutherland1]

December is ending with a monthly mean temperature of 39.2° (1.7° above normal). The warmer than normal December was consistent with historic experience following an exceptionally warm November.

Nevertheless, parts of the region are currently above normal in terms of seasonal snowfall. Seasonal snowfall amounts to date include:

Albany: 27.4" (10.6" above normal)
Baltimore: 1.6" (1.8" below normal)
Binghamton: 51.6" (27.0" above normal)
Boston: 17.3" (10.0" above normal)
Bridgeport: 10.0" (4.2" above normal)
Buffalo: 33.8" (2.4" below normal)
Burlington: 10.9" (12.4" below normal)
Caribou: 34.4" (0.7" below normal)
Harrisburg: 11.7" (6.0" above normal)
Islip: 7.5" (1.6" above normal)
New York City: 10.5" (5.4" above normal)
Newark: 11.9" (6.1" above normal)
Philadelphia: 6.6" (2.9" above normal)
Portland: 20.1" (5.0" above normal)
Providence: 10.0" (0.2" below normal)
Washington, DC: Trace (2.8" below normal)

The preliminary AO average for December was -1.673. The AO was negative on 87% of days, at or below -1.000 on 77% of days, and at or below -2.000 on 35% of days.

The likely continuation of Arctic blocking through at least the first 10 days of January 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 much warmer than normal across the northeastern United States, Quebec, and much of eastern Canada. After January 10, there is some indication on the EPS that a transition that could lead to a trough's moving into the East could get underway.

The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around December 23. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.70°C and the ENSO Region 3.4 anomaly has averaged -1.15°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +32.12 today.

Today, the preliminary Arctic Oscillation (AO) figure was -2.984.

On December 30 the MJO was in Phase 3 at an amplitude of 0.457 (RMM). The December 29-adjusted amplitude was 0.356.

A significant stratospheric warming event is now in its early stages. The highest levels of the stratosphere will continue to warm through the first half of the first week of January. The mean zonal winds will likely reverse at 1 mb, 10 mb, and 30 mb making this a major warming event. Toward the end of the first week in January, the top layers of the stratosphere could begin to cool.

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.

In large account due to a very warm start to the month, January will likely feature above to much above normal temperatures across the northern Middle Atlantic and southern New England regions.

 

[bluewave]

Only the 2nd time out of 16 Decembers for NYC in the 39.0° range to reach 10” of snow.

 

23	1999	39.9	T
24	1889	39.7	6.0
25	1991	39.6	0.7
26	1987	39.5	2.6
-	1911	39.5	8.5
28	1949	39.4	1.3
-	1918	39.4	0.3
30	1974	39.3	0.1
-	1928	39.3	2.0
-	1912	39.3	11.4
33	2020	39.2	10.5
34	1951	39.1	3.3
-	1932	39.1	9.4
36	1986	39.0	0.6
-	1973	39.0	2.8
-	1881	39.0	1.3