November 2020 General Discussions & Observations Thread

[bluewave]

NYC actually had a more impressive warm minimum record than LGA. This is the first record stretch of warmth that I can remember when NYC had warmer minimums than LGA. The low of 64° in NYC is the 4th highest for the month of November. It was also the warmest 11-5 to 11-11 on record.

 

Time Series Summary for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Ending Date	Mean Avg Temperature Nov 5 to Nov 11	Missing Count
1	2020-11-11	64.6	0
2	1975-11-11	63.1	0
3	1938-11-11	59.7	0
4	1948-11-11	58.7	0
5	2015-11-11	57.9	0

Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Nov
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Highest Min Temperature	Missing Count
1	1971	67	0
2	2015	66	0
3	1956	65	0
4	2020	64	19
-	2018	64	0
-	1938	64	0
-	1936	64	0
-	1929	64	0
-	1895	64	0

 

[Fantom X]

Crazy stuff going on the east coast with this warmth. Makes it seem crazier than Dec 2015 with the super el nino going on then - and not now. 

[donsutherland1]

The historic November warm stretch has now ended. Through mid-month, the temperature will average near to somewhat above normal across the region. Afterward, the probability of a fairly sharp cold shot has continued to increase. That cold shot could usher in a period of below normal temperatures. The development and duration of such a period remain uncertain. Temperatures may rebound toward the end of November.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.5°C for the week centered around November 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.02°C and the ENSO Region 3.4 anomaly has averaged -1.38°C. La Niña conditions will likely prevail at through the winter.

The SOI was +6.74.

Today, the preliminary Arctic Oscillation (AO) figure was +2.590.

On November 11 the MJO was in Phase 8 at an amplitude of 1.356 (RMM). The November 10-adjusted amplitude was 1.260.

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. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. A predominant EPO+/AO+ pattern is 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 potentially 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 82% probability that New York City will have a warmer than normal November. November will likely finish with a mean temperature near 51.0°.

[Rtd208]

Picked up 0.22" of rain for the day.

Two day total 0.82"

[CIK62]

The next 8 days are averaging 46degs.[41/51].         Making it 41degs., or -6.0.

Month to date is 58.1[+7.5].          Should be about 51.3[+2.1] by the 21st.

50*(96%RH) here at 6am-clouds,drizzle.

Tropics:  33.9N 76.0W, ill defined.        32.0N 28.7W---just a little twerp.

[bluewave]

Cooler pattern than the early part of the month coming up. The 500mb height anomalies will slowly shift poleward. So more blocking will promote a drop in temperatures.

First 10 days of month

Day 5 to day 10 EPS forecast 

 

[donsutherland1]

Morning thoughts...

Today will be mostly cloudy and cool. Some areas could see some periods of light rain and drizzle. High temperatures in the region will likely reach mainly the lower and middle 50s. Likely high temperatures around the region include:

New York City (Central Park): 53°

Newark: 55°

Philadelphia: 57°

A strong cold shot is likely early next week.

[Allsnow]

1 hour ago, bluewave said:

Cooler pattern than the early part of the month coming up. The 500mb height anomalies will slowly shift poleward. So more blocking will promote a drop in temperatures.

First 10 days of month

Day 5 to day 10 EPS forecast 

 

Yeah, p2 response of the mjo. Looks blocky in the nao region as well.

 

 

[Allsnow]

I miss the 70 degree temps 

[Brian5671]

3 minutes ago, Allsnow said:

I miss the 70 degree temps 

that was some stretch.  I enjoyed it!  

[bluewave]

9 minutes ago, Allsnow said:

Yeah, p2 response of the mjo. Looks blocky in the nao region as well.

 

 

Yeah, notice how the SE Ridge and ridge south of the Aleutians make a quick return in about 10 days. This lines up really well with the band of near record warm SSTs around 40N across the Atlantic and Pacific.

 

[Allsnow]

19 minutes ago, bluewave said:

Yeah, notice how the SE Ridge and ridge south of the Aleutians make a quick return in about 10 days. This lines up really well with the band of near record warm SSTs around 40N across the Atlantic and Pacific.

 

It will be interesting to see where the mjo goes after p2. If we enter the warm phases it will probably get torchy for December. 
 

The weeklies yesterday didn’t look nearly at bad as they did on Monday. They had more of a -nao look with a changing pacific 

[the_other_guy]

16 hours ago, Fantom X said:

Crazy stuff going on the east coast with this warmth. Makes it seem crazier than Dec 2015 with the super el nino going on then - and not now. 

The size and scope of that was unbelievable.

Due to the colder mins and large swings, this stretch didnt even come close in numbers. But it was close in that “unnatural” feeling.

 

 

[snowman19]

3 hours ago, Allsnow said:

Yeah, p2 response of the mjo. Looks blocky in the nao region as well.

 

 

MJO phases 3-6 are expected to be favored this winter, which makes sense given the SST setup in the tropical PAC. The thing that is disturbing, and Griteater mentioned this over a month ago, is the possibility of flat Aleutian ridging, instead of poleward ridging, which is being shown in the long range. He expects this flat Aleutian ridging to be dominant this winter given the anomalies he looked at in the North Pacific back during October, not what we want to see

[SnoSki14]

Weak MJO signal though. Looks like it may stay in circle.

AO/NAO likely to drop to near neutral late November. Several forecasts actually have Dec being the most favorable winter month with Jan a close 2nd.

Favorable in this winter will still be unfavorable overall but they'll likely be a few opportunities for snow. 

The fast flow of the pacific makes it really difficult to forecast anything beyond 5 days.

[BucksCO_PA]

1 hour ago, jfklganyc said:

The size and scope of that was unbelievable.

Due to the colder mins and large swings, this stretch didnt even come close in numbers. But it was close in that “unnatural” feeling.

DEC 2015 was just sick, looking at the Philly figures the past 6 days averaged 11.7 degrees above average while the 6 day super torch during late DEC 2015 averaged +25.8 degrees. PHL recorded 10 days which averaged 20(+) degrees above average that month. 65 degree DP's on Christmas Eve.......ridiculous stuff.

[bluewave]

14 minutes ago, BucksCO_PA said:

DEC 2015 was just sick, looking at the Philly figures the past 6 days averaged 11.7 degrees above average while the 6 day super torch during late DEC 2015 averaged +25.8 degrees. PHL recorded 10 days which averaged 20(+) degrees above average that month. 65 degree DP's on Christmas Eve.......ridiculous stuff.

That +13 December was one of the most extreme events that we have seen so far this century. The record breaking WAR was at the start of our warmest 5 winter stretch on record. It has been a dominant force through the year including the winters.
 

 

[Brian5671]

warm atlantic SST's likelyy contributing...

[bluewave]

41 minutes ago, Brian5671 said:

warm atlantic SST's likelyy contributing...

Those are some of the fastest rising SSTs on the planet.

 

[CIK62]

The EURO Control has our next 'Flirts with 70 Degrees' during first week of December.       Around Christmas it has the Hudson Bay region of Canada at +40!.         Aren't you glad that this is our source of 'Arctic Air'.

[rclab]

4 minutes ago, CIK62 said:

The EURO Control has our next 'Flirts with 70 Degrees' during first week of December.       Around Christmas it has the Hudson Bay region of Canada at +40!.         Aren't you glad that this is our source of 'Arctic Air'.

At this rate I might even live long enough to pick my own fresh ingredient for my favorite Pina colada. As always ......

[LibertyBell]

On 11/12/2020 at 10:08 AM, donsutherland1 said:

The final high temperature at Svalbard Lufthavn was 49 degrees.

https://twitter.com/Ketil_Isaksen/status/1326768433577537536?s=20

Never heard of this place before lol, is 49 impressive for them?

 

[LibertyBell]

4 hours ago, bluewave said:

Those are some of the fastest rising SSTs on the planet.

 

This is definitely causing the lobster population to migrate north.

 

[Cfa]

Can’t mention Dec 2015 without Feb 2015, having two extremely opposite cold/warm months occuring in the same year was insane.

[bluewave]

23 minutes ago, LibertyBell said:

This is definitely causing the lobster population to migrate north.

 

Yeah, I just saw this story a few days ago.

 

[donsutherland1]

Light rain and drizzle predominated into the afternoon before drier air and clearing skies began working into the region. To date, New York City has received 38.35" precipitation this year. Based on 1971-2019 climatology, New York City will very likely see annual precipitation finish somewhere between 42.50" and 47.50", making 2020 the driest year since 2017 when 45.04" was recorded or perhaps 2016 when total precipitation was 42.17". Farther south in the Middle Atlantic region, both Baltimore and Washington, D.C. are nearing 50.00" total precipitation. Already, 2020 has become Baltimore's 26th wettest year on record and Washington's 21st wettest year on record.

The weekend will commence with fair but cool weather. A strong cold front will move across the region, bringing a period of briefly heavy rain and perhaps some thunder on Sunday. Much cooler air will then move into the region early next week. That strong cold shot could usher in a period of below normal temperatures. The duration of a colder than normal period remains uncertain. Temperatures may rebound toward the end of November.

While readings will likely be colder than normal in the Middle Atlantic and southern New England areas during the middle of next week, a fresh surge of exceptionally warm air will move into the southwestern United States from Mexico. As a result, Phoenix could see another round of near-record to record high temperatures during the November 16-19 period. Phoenix could experience its latest 90° temperature on record. The existing record was established on November 15, 1999 when the temperature reached 90°.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.5°C for the week centered around November 4. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.02°C and the ENSO Region 3.4 anomaly has averaged -1.38°C. La Niña conditions will likely prevail at through the winter.

The SOI was +11.26.

Today, the preliminary Arctic Oscillation (AO) figure was +3.017.

On November 12 the MJO was in Phase 1 at an amplitude of 1.297 (RMM). The November 11-adjusted amplitude was 1.358.

Based on the latest guidance, no significant stratospheric warming event is likely through at least November 20. The lack of such warming could favor the gradual strengthening of the stratospheric polar vortex. A strong polar vortex 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. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO. A predominant EPO+/AO+ pattern is 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 potentially 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 78% probability that New York City will have a warmer than normal November. November will likely finish with a mean temperature near 50.7°.

 

[donsutherland1]

1 hour ago, LibertyBell said:

Never heard of this place before lol, is 49 impressive for them?

 

This place is in the high Arctic at 78N latitude. For perspective, the average July high temperature is 45 degrees. The average high temperature at this point in time is around 23 degrees.

[LibertyBell]

3 hours ago, donsutherland1 said:

This place is in the high Arctic at 78N latitude. For perspective, the average July high temperature is 45 degrees. The average high temperature at this point in time is around 23 degrees.

Wow, I'd be curious to see what my favorite Northern Hemisphere research station hit- Summit Camp, Greenland.  It's the coldest spot in the Northern Hemisphere, as it is at the very top of the Greenland Ice Cap.

 

[donsutherland1]

27 minutes ago, LibertyBell said:

Wow, I'd be curious to see what my favorite Northern Hemisphere research station hit- Summit Camp, Greenland.  It's the coldest spot in the Northern Hemisphere, as it is at the very top of the Greenland Ice Cap.

 

The exceptional warmth was well east of Greenland. It was focused on an area extending from Scandinavia to northwestern Russia.

[CIK62]

The next 8 days are averaging 46degs.[42/53].        Making it 41degs., or -5.0.

Month to date is 57.4[+6.9].      Should be about 51.1[+2.4] by the 23rd.

Tropics:   13.5N  75.8W---not another one!

47*(70%RH) here at 6am, m. clear.    46*(72%RH) at 7am.        52* by 2pm.      48* by 11pm.