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November 2020 General Discussions & Observations Thread

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Temperatures rebounded into the upper 40s after a cold start with most locations seeing low temperatures in the 20s and even teens. Most of the remaining days this month could see readings near or above normal with some short-lived cool shots possible. One such cool shot is likely early next week. December could see above to perhaps much above normal temperatures redevelop during the first week of the month.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 11. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.98°C and the ENSO Region 3.4 anomaly has averaged -1.44°C. La Niña conditions will likely prevail at least through the winter.

The SOI was +20.17.

Today, the preliminary Arctic Oscillation (AO) figure was +2.882.

On November 18 the MJO was in Phase 2 at an amplitude of 1.555 (RMM). The November 17-adjusted amplitude was 1.682.

Based on the latest guidance, no significant stratospheric warming event is likely through at least November 25. The lack of such warming could favor the gradual strengthening of the stratospheric polar vortex. A strong polar vortex, which is favored on the long-range guidance, could have implications for the opening of meteorological winter.

Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 10/11 (91%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. A predominant EPO+/AO+ pattern is very likely for winter 2020-21. It is likely that the Middle Atlantic and southern New England areas will see a warmer than normal winter with below normal snowfall. The November run of the seasonal European guidance suggests that winter 2020-21 will likely be warmer to much warmer than normal in the region.

The potential also exists for below to much below normal seasonal snowfall in the Middle Atlantic and southern New England areas. Since 1970, there were 9 winters that saw the AO and EPO average +0.25 or above. Mean snowfall for Boston, Harrisburg, New York City, Philadelphia, and Washington, DC averaged 50% of the most recent 30-season mean. The largest snowfall deficits relative to the most recent 30-season mean figure were located in the Philadelphia to New York City corridor. In addition, 33% of cases saw less than 10" seasonal snowfall in New York City and 44% saw less than 10" seasonal snowfall in Philadelphia.

Based on sensitivity analysis applied to the latest guidance, there is an implied 95% probability that New York City will have a warmer than normal November. November will likely finish with a mean temperature near 51.0°.

 

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GEFS Extended has the following to offer:       Chance of Snow on Dec. 03, 08, 17-----for a total of 3".         High in the 60's on the 13th and to greet Winter itself-----on the 21st.       Really the first time I am seeing snow from this output-----it does cover over 30 days, so something better happen.         Jan. 18 would mark one full year w/o measurable snow.

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On 11/16/2020 at 3:53 PM, snowman19 said:

It’s starting to look like at least early-mid December at the least may very well be a lost cause, possibly the whole month depending on how bad off we are to start it. A full scale pattern change isn’t just going to happen overnight. I’m starting to think this is going to end up being a January, one month winter for the metro as Isotherm and a couple of others have suggested. Very likely that February is a complete torch, March isn’t looking all that promising either 

what would make you think January would be any good?  and I thought March is usually the coldest month in a La Nina?

 

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On 11/16/2020 at 4:41 PM, dWave said:
Freeze watch for NYC...except for Staten Island and their suburban like overnights. Bye to the growing season. 
Still have a few plants holding on.



FREEZE WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH
WEDNESDAY MORNING...

* WHAT...Temperatures around freezing possible.

* WHERE...New York (Manhattan), Bronx, Kings (Brooklyn),
  Northern Queens and Southern Queens Counties.

* WHEN...From late Tuesday night through Wednesday morning.

* IMPACTS...Frost and freeze conditions could kill sensitive
  vegetation and possibly damage unprotected outdoor plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

byeee to my allergies!  although there still seem to be some around today.....

 

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Good morning, I did not post a minuscule snow outlook on the main forum since it won't affect NYC but tossed it in the nw suburbs portion where even extreme nw NJ may briefly (hour or two) see some snow or sleet Sunday and Wednesday. Wish it were better but I think of this... as scientifically depressing the outlooks herein for this winter, the sample size can always be expanded with normal seasonal snowfall. Timing-timing-timing of short waves with cold air. 

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The next 8 days are averaging 52degs.[47/56].         Making it 47degs., or +3.0.

Month to date is 53.1[+3.6].         Should be 51.3[3.4] by the 28th.

47*(65%RH) here at 6am, m. clear.     46* at 7am.        49* by 9am.      50* at 10am.        54* by Noon.        57* by 1pm.       60* by 2pm.

 

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A+ PNA is now showing up across guidance as we head towards December and it looks to continue through the first half of the month. The GEFS even show signs of Greenland blocking and it's very extended range. Maybe we can finally get some short waves to track underneath us and as we head into December we would not need well below normal temperatures to get some kind of measurable snow which seems to have been missing from December for a long time now

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Morning thoughts...

Yesterday, temperatures rose into the lower and middle 60s in the Great Lakes Region. Some of this warmer air will move into the region for today and tomorrow . As a result, today will be mostly sunny and much warmer than yesterday. High temperatures in the region will likely reach the upper 50s and lower 60s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 59°

Newark: 62°

Philadelphia: 62°

The weekend will start on a mild note, but somewhat cooler air should arrive for Sunday.

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58 minutes ago, bluewave said:

But we have seen in recent year how our pattern has not followed strict ENSO expectations at times. Unfortunately, that firehose Pacific Jet is classic La Niña. So we are getting a combination of the warmest La Niña and El Niño influences at the same time.

Not that it matters much, because the source region ( Canada ) is very warm at this time, but do you buy the + PNA look in early December?  

We are indeed getting unusual responses and progressions currently, as you mentioned. It will be fascinating to see what the pattern brings us in Jan and Feb where the majority of the seasonal consensus is little snow and much above normal temps. Hard to fight the warmer persistence whether from Nino or Nina like background states. But, I would still keep an eye open for the unusual outcome, in this new unusual climate recently. 

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1 hour ago, frd said:

Not that it matters much, because the source region ( Canada ) is very warm at this time, but do you buy the + PNA look in early December?  

We are indeed getting unusual responses and progressions currently, as you mentioned. It will be fascinating to see what the pattern brings us in Jan and Feb where the majority of the seasonal consensus is little snow and much above normal temps. Hard to fight the warmer persistence whether from Nino or Nina like background states. But, I would still keep an eye open for the unusual outcome, in this new unusual climate recently. 

People see a +PNA and start yelling “it’s going to be cold in the east!!” No, not when Canada is torched because the +EPO floodgates are open. December, 2011 was +PNA and a torch. We are also going to have +NAO and +AO

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3 hours ago, snowman19 said:

Here is the new EPS through December 4th, no cold air or high latitude blocking to be found. If this is correct, December is in HUGE trouble: 

 

Do the gefs

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54 minutes ago, Allsnow said:

If we can get the models to continue trending with the +pna it would offer us a chance as we get deeper into December 

Exactly

They have been talking about this in the SNE thread. The shift towards a possible colder pattern in the long range might have to do with the mjo.

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31 minutes ago, snowman19 said:

People see a +PNA and start yelling “it’s going to be cold in the east!!” No, not when Canada is torched because the +EPO floodgates are open. December, 2011 was +PNA and a torch. We are also going to have +NAO and +AO

Just keep in mind their above normal is probably below normal for us. So if the flow is from Canada it will get cool in the East. By late December/early January Canada’s avg highs are way below freezing 

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1 hour ago, bluewave said:

A +PNA in early December wouldn’t be a surprise due to the mixed influences that we are seeing. This is what happed during the December 2011 La Niña. Notice how similar the 500 mb pattern is for us during November 2020 and 2011. It was noted in the seasonal discussions how that winter didn’t follow strict La Niña expectations. The +EPO +PNA +NAO gave us a warm December in 2011. 

https://climate.washington.edu/events/2012winter/

The warm winter temperatures that extend from the Rockies to the eastern seaboard are hard to ignore in Figure 4. We note here that this was an unusually warm winter for the rest of the United States, which does not correspond to conditions during a typical La Niña, indicating that there were other factors.

B45C6AA3-0F4D-41D2-85FE-53DB7E46D034.gif.8c9595e3b179629ed5a9ce8c46b38750.gif

0E13F633-D0C8-4D91-975F-3337908D9315.gif.7348e4dcf6ae0392d6a801aae3287ad0.gif

B89CB855-E897-41A0-9EBB-79A21F4FD4EB.gif.632c0215085035676cb62e6960a675c6.gif

I think that 2011 mostly got sunk by the AK vortex and then January into February got sunk by an SSW which forced what would have been a west or central based -NAO into an uber east based NAO that actually made the pattern even more hostile  

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17 minutes ago, SnoSki14 said:

MJO will play little to no role here unlike the last couple Decembers which progressed from phases 3-6. 

Not sure what MJO was in 2011

I think it was a non factor.  In 01-02 the MJO was a big factor being mostly 3-4-5 all winter.

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6 minutes ago, bluewave said:

A +PNA during a La Niña December would set up an odd combination with the firehose Pacific Jet. We usually get a +PNA in December with El Niño and dominant STJ. The STJ allows undercutting of the ride at times for more wintery threats. But a strong La Niña PAC Jet with a +PNA  would also pump the SE Ridge and allow more cutter storm tracks and warmer temperatures.

Agree. But it depends on where the ridge sets up. If it’s not off the west coast then the southeast ridge won’t pump that much. If we were entering a -epo/-pna pattern then I would say absolutely the ridge will be on roids 

 

A fast pac with a +pna could allow disturbances to be more progressive also.

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2 minutes ago, bluewave said:

If it’s a flat +PNA ridge with a +EPO and +NAO, then it will pump the WAR or SE Ridge. This pattern has become more common in December since 2011. 

2E677A68-BFC8-4A9C-B716-091B78A8C69F.png.324908f0d18414aa3d217cb8383ae8c4.png

 

What an awful map for Winter

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1 minute ago, jm1220 said:

Yep, essentially shuts cold air down from getting south of the border and floods the continent with Pacific air. 

If we get a flow from Canada, their above normal is below here, it could potentially work for us as we work into mid December. 
 

Above all else we need a good pacific to have a chance 

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63* in NYC (2pm)is even 5 degrees beyond what the Wack-A-Do GFS had slated for today.      If it makes you feel better, I have just 60* as of 2:30pm.   [Made it to 61* by 4pm].

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