December 2021

[EasternLI]

 

[wdrag]

I'm counting on all our long range specialists to not bury ourselves in short term ugliness and be unable to extricate later during the winter.  I'm seeing the gamut of no winter, to more favorable winter opportunities after Christmas or January.  I don't know, except we'll probably need something to jar the pattern into something that will be a broader snowy impact  along and north of I80. 

Meanwhile, am holding off on a wind thread for Saturday afternoon-early night. Will check SPC D2 tomorrow morning, as well as HRRR/NAM. Many models have near or greater 64kt at 850MB in the Saturday afternoon WAA and 50+kt in the evening CAA.  Both a little stronger wind fields aloft than what has occurred in our last two minimal wind events of early Dec. I'll want to be a little more certain of momentem transfer, so will try and figure it out early Friday. 

[donsutherland1]

Milder air will begin to overspread the region tomorrow. Afterward, temperatures could soar to near record and record levels on Saturday in the Middle Atlantic region in advance of another cold front. Already, the air mass that will send temperatures reaching for records on Saturday resulted in numerous records falling in parts of Texas and Kansas. Records included:

Brownsville: 88° (tied record set in 1919)
Galveston: 80° (old record: 78°, 2004, 2007, and 2019)
Houston: 85° (old record: 84°, 2009) ***tied December record***
Wichita: 69° (old record: 67°, 1896, 1946, and 2020)

Passage of the front could be marked by strong winds and strong to perhaps severe thunderstorms. The front will bring a transient shot of somewhat cooler air to the region. A significant warmup is possible beginning after the middle of next week.

No Arctic blasts appear likely for the foreseeable future. Overall, through December 20th, temperatures will likely be warmer than normal in the means with some short-lived cool shots.

Out West, Denver has yet to see its first measurable snowfall through December 8. The previous record latest first measurable snowfall occurred on November 21, 1934. The progression of Denver's latest first measurable snowfall of the season is as follows:

November 11, 1882
November 16, 1894
November 19, 1931
November 21, 1934

The base case is that the closing 10 days of December could turn cooler, though not necessarily cold. Since 1950, there have been 7 cases where the AO averaged +2.000 or above during the first week in December, as has been the case this year. The mean December 21-31 temperature in New York City was 40.2°. The median temperature was 41.5°. The coldest was 35.3° (1951) and the warmest was 44.0° (1979). In short, this historic experience would suggest that there will be no severe Arctic outbreaks in the East this month. It also suggests that New York City will likely have an average temperature of 40° or above this month.

Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19.

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 1. 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 -0.92°C. La Niña conditions will likely persist into at least late winter.

The SOI was +6.38 today.

The preliminary Arctic Oscillation (AO) figure was +2.037 today

On December 7 the MJO was in Phase 6 at an amplitude of 2.008 (RMM). The December 6-adjusted amplitude was 1.990 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 84% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 42.3° (3.2° above normal).

 

[HeadInTheClouds]

Picked up .5 inch of snow last night with a low of 23. 36 for a high today. 

[LibertyBell]

16 hours ago, Stormlover74 said:

I think dewpoints were in the 60s

I woke up sweating in the middle of the night lol

 

[LibertyBell]

14 hours ago, jm1220 said:

Typical of Nina winters. The upper Midwest is usually favored for big winters then along with the Northwest. 

well someone somewhere usually gets the big snows, I dont think there has ever been a winter where the entire continent is snowless lol

 

[LibertyBell]

12 hours ago, MJO812 said:

Gradient pattern 

all patterns are gradient patterns, it just depends on how far north the gradient is

 

[LibertyBell]

12 hours ago, bluewave said:

The 12z EPS keeps the -PNA trough near the West Coast through Dec 24th.This pumps up the SE Ridge.The -EPO ridge is centered too far west near the Aleutians and the -NAO is too far east based near Europe. 
 

12z EPS for 12z Dec 24th

 

when does the -PNA actually promote a trough on the east coast?  March?

 

[CIK62]

The next 8 days are averaging 48degs.(42/55), or +11---+8 nowadays.

Reached 39/40 all PM-.up to midnite yesterday.      GFS tries for Normality after the above 8 days.    It fails with 36/44 = +5---+2 even nowadays, on the next 9 days after the above 8.

Today: 47-50, wind s. to w., cloudy-then breaks.

42*(68%RH) here at 6am.    43* at 7am.      45* at 9am.     49* at Noon.       50* at 1pm.      54* at 3pm.      51* at 4pm.      49* at 6pm.

 

[donsutherland1]

Morning thoughts…

Today will be partly cloudy milder. High temperatures will likely reach the upper 40s and lower 50s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 50°

Newark: 53°

Philadelphia: 53°

Normals:

New York City: 30-Year: 45.8°; 15-Year: 46.4°

Newark: 30-Year: 46.3°; 15-Year: 47.1°

Philadelphia: 30-Year: 47.4°; 15-Year: 48.3°

Near record or perhaps even record warmth is possible in parts of the region tomorrow ahead of a cold front. Strong winds and strong to sever thunderstorms could mark the frontal passage.

Daily records for December 11:

Allentown: 61°, 1952 and 1979

Baltimore: 69°, 1979

New York City: 64°, 1879

Newark: 65°, 1966 and 1971

Philadelphia: 65°, 1899 and 1971

Washington, DC: 68°, 1897, 1971, and 1979

[EasternLI]

There's been somewhat of a low frequency signal in the SA atlantic Africa sector. It's been there for some time now. It's identified on the VP 200 charts. That area reflects on the phase 7/8 RMM charts. As the MJO makes It's way towards that area, its constructively interfering with that signal. Amplifying. This has been shown on ensembles for a while now. Also important, the subsidence amplifying and pushing towards the MC. I feel like this adds a bit of confidence that we actually can turn this pattern around. It'll be fascinating to see what transpires with this. 

[TheManWithNoFace]

13 hours ago, bluewave said:

Just select the station and time of year.

https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=NY_ASOS&station=JFK&season=jul&varname=dwpf&year=1893&w=bar&hours=0-23&_r=t&dpi=100&_fmt=png

 

 

Much obliged blue

[Allsnow]

Last three days at the park have been below normal with yesterday having the largest departure of -6. Didn’t get out of the 30’s yesterday. 

[MJO812]

MJO for the Gefs and Euro

[bluewave]

We just had the 10th warmest first week of December from Newark to Islip.

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Rank	Ending Date	Mean Avg Temperature Dec 1 to Dec 7	Missing Count
1	1998-12-07	58.4	0
2	1982-12-07	56.8	0
3	2001-12-07	55.5	0
4	1951-12-07	50.6	0
5	1994-12-07	50.1	0
6	1932-12-07	49.1	0
7	2011-12-07	47.6	0
8	2015-12-07	46.8	0
9	1953-12-07	46.4	0
10	2021-12-07	46.2	0

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Ending Date	Mean Avg Temperature Dec 1 to Dec 7	Missing Count
1	1998-12-07	55.4	0
2	1982-12-07	52.7	0
3	2001-12-07	51.2	0
4	1994-12-07	46.4	0
5	2011-12-07	45.8	0
6	2015-12-07	45.1	0
7	1972-12-07	44.6	0
8	2013-12-07	44.4	0
9	2017-12-07	43.7	0
10	2021-12-07	43.6	0
-	1999-12-07	43.6	0
-	1993-12-07	43.6	0

[binbisso]

@bluewave  The 1st 10 days were not a warm pattern.  It was A unfavorable pattern for snow With 2 cutters which skewed the means.   December 2nd and December 6th were plus 9 + 12 at islip the other 8 days averaged below normal. 

[donsutherland1]

With regard to the MJO, forecasting uncertainty beyond a week notwithstanding, there have been exceptions to what one would typically expect. In December 2001, the MJO moved into Phase 8. The EPO went negative late in the month and then reverted back to predominantly positive values in early January. At present, I still believe the base case is that it will turn cooler during the closing 10 days of the month. Severe cold may not occur in the Middle Atlantic region this month.

Afterwards, there will be a risk that the cooler pattern breaks down after two weeks or so, as the predominant EPO+/AO+/PNA- pattern tries to reassert itself. The Gulf of Alaska SSTs and PDO- may make it difficult to sustain a persistently cold pattern. Hopefully, my concerns will prove incorrect.

Overall, I still don’t think this will be a variation of the 2001-02 winter. But it will likely be mild (DJF anomaly) and the AO-seasonal snowfall data speaks for itself.

[binbisso]

Even this upcoming torch pattern looks Muted.  We get plus 10 departures Saturday and next Thursday and only slightly above normal Sunday through Wednesday  However Sunday's mean will be skewed with the midnight high Saturday night prior to the frontal passage The same probably happens next Friday.  So if guidance is remotely correct 13 of  17 days will average normal and then you will have 4 days at + 10 departures with the cutters due to the unfavorable storm track

[bluewave]

9 minutes ago, binbisso said:

@bluewave  The 1st 10 days were not a warm pattern.  It was A unfavorable pattern for snow With 2 cutters which skewed the means.   December 2nd and December 6th were plus 9 + 12 at islip the other 8 days averaged below normal. 

Your post is a great example of how quickly we normalize the higher temperatures in a warming climate. With the new much warmer 1991-2020 climate normals, all it takes is a +2 to +3 for top 10 monthly warmth in December. So just looking at departures gives the illusion that it really isn’t that warm.

https://www.pnas.org/content/116/11/4905

[binbisso]

11 minutes ago, bluewave said:

Your post is a great example of how quickly we normalize the higher temperatures in a warming climate. With the new much warmer 1991-2020 climate normals, all it takes is a +2 to +3 for top 10 monthly warmth in December. So just looking at departures gives the illusion that it really isn’t that warm.

https://www.pnas.org/content/116/11/4905

 Sorry I disagree This is not the 1990s Our climate is warming pretty rapidly and there's no reason to believe it won't continue. I expect warmer than normal temperatures each month and  year(esp with 30 year averages) Except in anomalously cold patterns.  I'm more impressed with a negative 5 departure than I am with a plus 15. 

[bluewave]

9 minutes ago, binbisso said:

 Sorry I disagree This is not the 1990s Our climate is warming pretty rapidly and there's no reason to believe it won't continue. I expect warmer than normal temperatures each month and  year(esp with 30 year averages) Except in anomalously cold patterns.  I'm more impressed with a negative 5 departure than I am with a plus 15. 

By that logic, the first week of December in 1976 wasn’t really the 2nd coldest on record at Newark. There was only one record cold day out of 7 when the low dropped to 9°. None of the other days had lows in the single digits. So you can see where your line of reasoning leads to.

[binbisso]

28 minutes ago, bluewave said:

By that logic, the first week of December in 1976 wasn’t really the 2nd coldest on record at Newark. There was only one record cold day out of 7 when the low dropped to 9°. None of the other days had lows in the single digits. So you can see where your line of reasoning leads to.

 Maybe I'm looking at this incorrectly I don't know.   Our climate is warming With greater increments each decade and there's no reason to believe that would stop.  This year should end up warmer than last year and the next year warmer than this year.  so if a year/decade can end up cooler than the previous year/decade that would surprise me more.

[the_other_guy]

17 minutes ago, bluewave said:

By that logic, the first week of December in 1976 wasn’t really the 2nd coldest on record at Newark. There was only one record cold day out of 7 when the low dropped to 9°. None of the other days had lows in the single digits. So you can see where your line of reasoning leads to.

You have issues when people try to engage you with a counterpoint 

He makes valid points; so do you.

There is a new normal. He is saying, it’s not all that many days above normal. You are looking at the historical perspective of every week being in a top 10 because we are warmer now than 120 years of records prior to this point.
 

His counterpoint (not failed reasoning) is that running around like chicken little every year it is warm is bizarre when it is the new normal. We have another poster that keeps referencing old baselines vs the new baseline with “nowadays.”

It is good to have a historical perspective, but it is also fair to point out that the baseline as changed and the temps aren’t all that unusual. In a weather based forum vs a climate based forum, it is important to at least acknowledge what he is saying

[psv88]

3 minutes ago, jfklganyc said:

You have issues when people try to engage you with a counterpoint 

He makes valid points; so do you.

There is a new normal. He is saying, it’s not all that many days above normal. You are looking at the historical perspective of every week being in a top 10 because we are warmer now than 120 years of records prior to this point.
 

His counterpoint (not failed reasoning) is that running around like chicken little every year it is warm is bizarre when it is the new normal. We have another poster that keeps referencing old baselines vs the new baseline with “nowadays.”

It is good to have a historical perspective, but it is also fair to point out that the baseline as changed and the temps aren’t all that unusual. In a weather based forum vs a climate based forum, it is important to at least acknowledge what he is saying

Disagree. We can’t just accept that we are causing a spike in temps and shrug it off as normal. It needs to be in the forefront because while it is our current reality, it is not “normal”. 

[psv88]

4 minutes ago, binbisso said:

 Maybe I'm looking at this incorrectly I don't know.   Our climate is warming With greater increments each decade and there's no reason to believe that would stop.  This year should end up warmer than last year and the next year warmer than this year.  so if a year/decade can end up cooler than the previous year/decade that would surprise me more.

No. This is accepting failure. 

[forkyfork]

it hasn't been that warm because of climate change. 

[binbisso]

12 minutes ago, psv88 said:

No. This is accepting failure. 

 I'm not saying we shouldn't do everything we can to try and reverse climate change  However do you think anything's gonna change in the foreseeable future.  I don't.  Warmer is the new normal that's just the way it is and there's nothing that I on my own can do about it

[binbisso]

2 minutes ago, forkyfork said:

it hasn't been that warm because of climate change. 

 I know I shouldn't take the bait but are you joking or do you have   other reasoning

[donsutherland1]

FYI, it appears that Denver finally saw its first measurable snowfall of the season. NWS will be providing an update soon. That update will confirm whether the light snow was, in fact, measurable.

[bluewave]

18 minutes ago, jfklganyc said:

His counterpoint (not failed reasoning) is that running around like chicken little every year it is warm is bizarre when it is the new normal. We have another poster that keeps referencing old baselines vs the new baseline with “nowadays.”

I don’t understand what you mean by running around like chicken little. Putting our temperatures in perspective is very important otherwise we just normalize everything away in a few years. That was what the study that I posted earlier discussed. New baselines are deceptive since a +2 to +3 in December today is getting near the top ten warmest. So it could lead some to say that such a small warm departure really isn’t out of the ordinary.