December 2018 General Discussion & Observations

[495weatherguy]

9 minutes ago, SnowGoose69 said:

It could but it shouldn’t matter much if the true El Niño climo sets in with the Aleutian low and BC ridge.  If that PAC refuses to cooperate it won’t matter much even if the PV came to this side 

Should I interpret this to mean that the PAC can mean a more zonal flow and moderate temps/less snow?

[snowman19]

13 minutes ago, 495weatherguy said:

Should I interpret this to mean that the PAC can mean a more zonal flow and moderate temps/less snow?

I’m not anticipating it, but if we get to mid-January without the change in the Pacific that I think is coming, and a change is not at least imminent, on the doorstep at that point, then it will be time to get worried. Like I said, I don’t think that’s going to happen. You also don’t need the SSW for the change, the tropospheric forcing should do that on its own without any help from the stratosphere. There are serious doubts emerging today from the experts on the SSW and what actually happens with it anyway, it may not even downwell enough to affect the tropospheric pattern and a split, if it even happens now or a displacement may very well not be favorable for the east this time like it was back in March

[sferic]

1 hour ago, bluewave said:

That was 1-28-77. 

1977-01-28	44	13	28.5	-4.3	36	0	0.02	0.2	2
1977-01-29	13	1	7.0	-25.9	58	0	0.00	0.0	2

Thanks ! That was the event I remember, I was a week off

[donsutherland1]

Through December 26, New York City (Central Park) has a monthly mean temperature of 39.4° (1.2° above normal). Based on the latest guidance, the probability that December will finish with a mean temperature of 40° or above has increased. If so, December 2018 would be the 5th year in the 2010-2018 period to have a monthly mean temperature of 40° or above. That would match the number of such cases during the 1990-1999 period.

During the 1869-1989 period, there were 12 such cases. From 1990-2017 there have been 11 such cases.

Applying sensitivity analysis to the guidance, the most likely range for the December 2018 mean temperature is 39.7° - 40.5°. The implied probability of an above normal month is approximately 99.9%. The implied probability of December's averaging 40° or above has increased to 53%.

Earlier, I mentioned that Winter 1965-66 is among the three El Niño cases since 1950 that featured a positive SOI average, as is very likely this December. For the following January, the SOI averaged -12.0.
Here's a quick comparison of December 1965 and December 2018:

SOI: 1965: +1.6; 2018: +9.0 (through 12/27)
AO: 1965: +0.163; 2018: +0.095 (preliminary figures through 12/27)
Mean Temperature: 1965: 40.5°; 2018: 40.1° (latest estimate)
Snowfall: 1965: Trace; 2018: Trace (through 12/27)

December 2018 has been much wetter than December 1965 with 4.34” to date vs. 1.72” for December 1965. The 1964-66 drought finally broke in September 1966. 1965 recorded just 26.09” precipitation.

January 1, 1966 saw the temperature reach 62°. The latest GFS MOS guidance suggests that the temperature could make a run at 60° on January 1.

Nevertheless, January saw a big pattern change unfold. The AO went negative on 1/2 and then reached -1.000 on 1/8. Afterward, the month featured sustained deep blocking. The monthly AO average was -3.232.

As a result, the monthly mean temperature was 32.2°. Total snowfall was 11.6" as a blizzard affected parts of the East with its heaviest snows just missing New York City. February also featured strong blocking with a monthly AO average of -1.438 with monthly snowfall of 9.8". Again, it bears noting that 1965-66 took place within the context of a historic regional drought.

As noted in an earlier discussion, some big developments that will impact the pattern evolution are ongoing. The SOI is heading lower in discontinuous fashion. Based on ENSO climatology and historic experience with cases featuring a positive December SOI during El Niño events, a negative SOI is very likely in January. The MJO is in Phase 5 with an extreme amplitude in excess of 3.000. A sudden stratospheric warming event is underway and the stratospheric winds have already reversed at 1 mb and are forecast to do so at 10 mb in the next day or two.

 

[doncat]

1 hour ago, IntenseBlizzard2014 said:

 

Finished with 11.6" of snowfall.

Quite the range last March with 24.7" here.

[frd]

38 minutes ago, donsutherland1 said:

As noted in an earlier discussion, some big developments that will impact the pattern evolution are ongoing. The SOI is heading lower in discontinuous fashion. Based on ENSO climatology and historic experience with cases featuring a positive December SOI during El Niño events, a negative SOI is very likely in January. The MJO is in Phase 5 with an extreme amplitude in excess of 3.000. A sudden stratospheric warming event is underway and the stratospheric winds have already reversed at 1 mb and are forecast to do so at 10 mb in the next day or two.

Great post Don.

Do you think once we finally move to the better MJO phases in mid Jan. we lock it in for a while?  

And one last thing, once the SOI  turns negative and stays negative do you still forsee a coupling happening in Pac ?

I believe you thought it might sometime in Jan. Thanks  

 

[donsutherland1]

15 minutes ago, frd said:

Great post Don.

Do you think once we finally move to the better MJO phases in mid Jan. we lock it in for a while?  

And one last thing, once the SOI  turns negative and stays negative do you still forsee a coupling happening in Pac ?

I believe you thought it might sometime in Jan. Thanks  

 

Yes to both questions.

[NJwx85]

4 hours ago, psv88 said:

Pretty sure the coast, at least out this way, had a 12+" event last March...

Didn't say they didn't, but I had over 40" last March spread out over four different storms.

[uncle W]

El nino February's in NYC...23 years...eight above average temperatures...15 below average temps......ten above average snowfall...two near average...eleven below average snowfall...six years with a snowstorm 10" or more...eight that had below average temperatures and above average snowfall...

year.....average temperature...snowfall...major snowfalls ...

1952...………...36.2...………………...2.8"...…………...

1958...………...27.4...……………….10.7"...…………...7.9"

1959...………...32.1...………………...0.4"

1964...………...32.9...……………….14.1"...…………...6.8"

1966...………...35.1...………………...9.8"...…………...6.3"

1969...………...32.6...……………….16.6"....………...15.3"

1970...………...33.0...………………...6.4"

1973...………...32.5...………………...0.8"

1977...………...33.5...………………...5.8"

1978...………...27.2...……………….23.0".........…….17.7"

1980...………...31.4...………………...2.7"

1983...………...36.4...……………….21.5".........…….17.6"

1987...…………33.2...………………...7.0"

1988...………...35.0...………………...1.5"

1992...………...36.4...………………...1.0"

1995...………...31.6...……………….11.6"...…………..10.8"

1998...………...40.6...………………….0

2003...………...30.1...……………….26.1"...…………..19.8"

2005...………...36.5...……………….15.8"...…………….7.7".....6.0"

2007...………...28.2...………………...3.8"

2010...………...33.1...……………….36.9"...…………..10.0"....20.9"

2015...………...23.9...……………….13.6"

2016...………...37.7...………………...4.0"

 

[bluewave]

2 hours ago, sferic said:

Thanks ! That was the event I remember, I was a week off

The 76-77 winter was the closest to Little Ice Age cold that many of us have experienced. That was the last top 10 coldest winter in NYC.

NYC coldest winter rankings 

28.4....#8.....76-77

30.3....#18....77-78

31.1....#22....93-94

31.2....#23....02-03

31.4....#24....14-15

 

[uncle W]

1976-77 had 45 days with a max 32 or lower...the next year had 42 days...2013-14 has the most since 1978 with 33 days...2018-19 has two so far thanks to a cold spell in November...

1880-81.....52...........................................2 in 1952-53

1903-04.....47...........................................3 in 1997-98

1976-77...45..........................................3 in 2001-02

1917-18.....45...........................................5 in 1931-32

1887-88.....44...........................................6 in 2007-08

1977-78.....42...........................................6 in 2011-12

1876-77.....41...........................................7 in 1990-91

1892-93.....41...........................................7 in 1992-93

1919-20.....40...........................................7 in 1918-19

1904-05.....40...........................................8 in 1974-75

[Rtd208]

Flood Watch in effect here from late tonight thru Friday evening for 1-2" of rain w/locally higher amounts.

[Dan76]

we can use the rain.

[NJwx85]

9 minutes ago, Rtd208 said:

Flood Watch in effect here from late tonight thru Friday evening for 1-2" of rain w/locally higher amounts.

All local reservoirs are over capacity and most local rivers are still very high from last weekend.

[North and West]

17 minutes ago, Dan76 said:

we can use the rain.

I'm glad someone said it.

[bluewave]

Get ready for some longer range model volatility with the fire hose Pacific Jet development near Japan. 

 

 

[IntenseBlizzard2014]

24 minutes ago, bluewave said:

Get ready for some longer range model volatility with the fire hose Pacific Jet development near Japan. 

 

 

A 930 mB LP to the west of the Aleutians? Jeez. 

[495weatherguy]

38 minutes ago, bluewave said:

Get ready for some longer range model volatility with the fire hose Pacific Jet development near Japan. 

 

 

What is the potential impact on our weather from this?

[weatherpruf]

6 hours ago, allgame830 said:

You guys are funny.... so you only need 12”+ snowstorms to add to your total... HAHA.... what happened last March... that sun angle argument is brought up every single winter it’s an makes me crazy... what should be said is that pecip rates need to be greater as you get later in the season!

Not all of us did so hot last March, only the last storm delivered for my region and only after hours and hours of barely a few inches; only by evening did it get going and I believe we were still shy of a foot. We did get an April event that kinda made up for the March events. Snowless Decembers like this were common in the 80's and 90's, and they were usually followed by paltry snow events for the rest of the winter. So when I see this I tend to think it will revert to those kids of winters. However, after Jan 2016, I believe all bets are off. Anything can happen, but usually some of the folks on here can see it coming beforehand, the PB's, Blue Waves, NJwx among others, even Anthony, who can sniff out a snow storm in July, when they start getting excited, I know something is in the wind. And when Forky jumps aboard, I start up the snow blowers....

[495weatherguy]

2 minutes ago, weatherpruf said:

Not all of us did so hot last March, only the last storm delivered for my region and only after hours and hours of barely a few inches; only by evening did it get going and I believe we were still shy of a foot. We did get an April event that kinda made up for the March events. Snowless Decembers like this were common in the 80's and 90's, and they were usually followed by paltry snow events for the rest of the winter. So when I see this I tend to think it will revert to those kids of winters. However, after Jan 2016, I believe all bets are off. Anything can happen, but usually some of the folks on here can see it coming beforehand, the PB's, Blue Waves, NJwx among others, even Anthony, who can sniff out a snow storm in July, when they start getting excited, I know something is in the wind. And when Forky jumps aboard, I start up the snow blowers....

Very well said

[snowman19]

54 minutes ago, bluewave said:

Get ready for some longer range model volatility with the fire hose Pacific Jet development near Japan. 

 

 

If the jet configuration still looks like this come 1/15, it will be a very bad sign. I’m sticking with my thoughts for now, but not going to lie, after today’s guidance, I’m starting to wonder. That is a very troubling sight

[dmillz25]

40 minutes ago, snowman19 said:

If the jet configuration still looks like this come 1/15, it will be a very bad sign. I’m sticking with my thoughts for now, but not going to lie, after today’s guidance, I’m starting to wonder. That is a very troubling sight

Mjo progressing into 6 and eventually 7&8, -NAO due to North Atlantic wave breaking and the eventual effects of the SSW should negate that. Btw that wouldn’t last long probably a week with would bring it to next weekend

[Isotherm]

My winter update analysis, for any interested:

 

[bluewave]

2 hours ago, 495weatherguy said:

What is the potential impact on our weather from this?

Big model swings from run to run and only transient cold shots until the MJO becomes more favorable.

[qg_omega]

24 minutes ago, bluewave said:

Big model swings from run to run and only transient cold shots until the MJO becomes more favorable.

1/15

[psv88]

8 hours ago, NorthShoreWx said:

I was an organized little bugger.  Maybe explains why I am a project manager now. 

 

There was no internet so you had to write things down if you wanted to refer back to them.

 

 

That is impressive. 

[Brian5671]

3 hours ago, snowman19 said:

If the jet configuration still looks like this come 1/15, it will be a very bad sign. I’m sticking with my thoughts for now, but not going to lie, after today’s guidance, I’m starting to wonder. That is a very troubling sight

That Pac Jet was an issue a couple winters ago-can't remember which one, but CA had record snows and we had big time warmth...

[donsutherland1]

Tonight and tomorrow, yet another in a series of storms will bring the region a moderate to significant rainfall. A general 0.50"-1.50" is likely with some locally higher amounts.

Below is a table showing YTD precipitation, 2018's current ranking among the wettest years, and rankings scenarios for a 0.50"-1.50" rainfall for select cities:

In the wake of the storm, Sterling, VA will likely see 2018 become that city's wettest year on record. To date, Sterling has received 65.12" precipitation. Its record is 65.67", which was set in 2003. Earlier today, Green Bay topped its annual record. Green Bay has now received 38.63" precipitation. The old record was 38.36", which was set in 1985.

In addition, the following select locations in the region have already had their wettest year on record:

Atlantic City: 66.18"
Baltimore: 70.05"
Boonton (1 SE), NJ: 75.31"
Elmira, NY: 57.44"
Farmingdale, NY: 48.67"
Hamburg, PA: 74.60"
Scranton: 60.21"
Shirley, NY: 59.82"
Shrub Oak, NY: 65.29"
Upton, NY: 69.33"
Washington, DC: 64.77"

Finally, the December 26 MJO figure is now in. The MJO remained in Phase 5, but its amplitude rose slightly to 3.097.

[SnoSki14]

3 hours ago, snowman19 said:

If the jet configuration still looks like this come 1/15, it will be a very bad sign. I’m sticking with my thoughts for now, but not going to lie, after today’s guidance, I’m starting to wonder. That is a very troubling sight

Weeklies are quite good after week 1. Ensembles look pretty good as well, so things look to be on track. 

Iso had a nice discussion about what has transpired thus far.

[SnowGoose69]

1 hour ago, bluewave said:

Big model swings from run to run and only transient cold shots until the MJO becomes more favorable.

Isn’t phase 7 highly favorable during El Niño?  I know it’s typically hostile otherwise