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January 2020 General Discussions & Observations Thread

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Just now, Brian5671 said:

I know right?  I took the bait... 

 

Worse than that you bull$%RT^Y&U*I and got caught 

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6 minutes ago, PB-99 said:

 

Worse than that you bull$%RT^Y&U*I and got caught 

LOL.   I did think you were talking CMC and not Euro.  My Bad, but that's not an arctic airmass (outside of ME/NH/VT and even that is retreating) and the overall pattern sucks and does not look to be changing. It's like last year but only warmer...  I hope we get something in Feb, but I won't bet the ranch on it.

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5 minutes ago, Brian5671 said:

LOL.   I did think you were talking CMC and not Euro.  My Bad, but that's not an arctic airmass and the overall pattern sucks and does not look to be changing. It's like last year but only warmer...  I hope we get something in Feb, but I won't bet the ranch on it.

 

I was only pointing out the correction it made from Chicago 2 days ago to off the Delmarva.

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3 minutes ago, PB-99 said:

 

I was only pointing out the correction it made from Chicago 2 days ago to off the Delmarva.

I actually hope this becomes the 50/50 low for the next storm...

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Just now, Brian5671 said:

I actually hope this becomes the 50/50 low for the next storm...

I hope there`s a next storm !

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34 minutes ago, Isotherm said:

 

 

Indeed. One can see the modeled tropical forcing returning to those spatial domains in February, which will play a role in the developing February regime as delineated in my update post.

The other interesting thing is the really delayed responses we have seen following MJO 8 passages during our recent winters. Last February we entered phase 8 but the snowy conditions came in March. February 2018 featured the historic 80 degree warmth shortly after the MJO 8 passage. The record snows came in March 2018. The only reasonably close in time event was the 1-4-18 benchmark blizzard that bottomed out at 950 mb. That came shortly after the phase 8 in late December. The January 2016 blizzard came about 10 days after phase 8. I know that there have been studies showing a snowstorm lag following phase 8. But sometimes it seems to take longer than even the studies have indicated. 

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1 minute ago, psv88 said:

NYC wont reach 20" of snow this year. Thats my call.

Possible. 

 

I think you and I will tho. 

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Just now, psv88 said:

NYC wont reach 20" of snow this year. Thats my call.

tomorrow will be pivotal for this call.   If NYC gets less than 2 inches then this call is looking good-if they put up a 4 or 5 then much tougher IMO.

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5 minutes ago, Snow88 said:

With 2 months to go ? Bold

if you made that call at this point last year one would have been correct.   NYC finished with about 20 inches with a similar YTD going into the 1/20 period.  Finished around 30 here but most of that was from the Nov storm (6) and March storm (11)

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23 minutes ago, bluewave said:

The other interesting thing is the really delayed responses we have seen following MJO 8 passages during our recent winters. Last February we entered phase 8 but the snowy conditions came in March. February 2018 featured the historic 80 degree warmth shortly after the MJO 8 passage. The record snows came in March 2018. The only reasonably close in time event was the 1-4-18 benchmark blizzard that bottomed out at 950 mb. That came shortly after the phase 8 in late December. The January 2016 blizzard came about 10 days after phase 8. I know that there have been studies showing a snowstorm lag following phase 8. But sometimes it seems to take longer than even the studies have indicated. 

 

It is quite interesting, Chris, and I've been ruminating on some hypotheses re: the time-lag and distorted response. One issue, in my view, is base-state resonance. Sometimes the MJO/intraseasonal signal is misaligned with the base state, and as such, when it propagates through typically conducive phases, the N HEM response may not be bonafide/favorable due to the misalignment with the background indicators. For example, 2002-03 had a much more classic AAM/GWO and hadley/walker cell structures concordant with a canonical El Nino, and thus when MJO circulated to 8, we had a more genuine N HEM response.

Another issue, the PDO has become much more negative over the past month, as last winter was. This amplifies -AAM resonance and retards proper +AAM transport.

cdas-sflux_ssta_global_1.png

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34 minutes ago, psv88 said:

NYC wont reach 20" of snow this year. Thats my call.

All I'm hoping for regarding NYC is they reach 17.7 inches this season. Why 17.7 ? Because 17.7 will get their 30 year average for the 1991-2020 period to 30 inches. Then they won't have to rely on next November and December. As we all know December is becoming very unreliable.

If next January the averages are calculated and they're at 29.9, it will annoy me. Their current average if it doesn't snow between now and Dec 31 is 29.5 inches.

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9 minutes ago, CPcantmeasuresnow said:

All I'm hoping for regarding NYC is they reach 17.7 inches this season. Why 17.7 ? Because 17.7 will get their 30 year average for the 1991-2020 period to 30 inches. Then they won't have to rely on next November and December. As we all know December is becoming very unreliable.

If next January the averages are calculated and they're at 29.9, it will annoy me. Their current average if it doesn't snow between now and Dec 31 is 29.5 inches.

if it is 29.9" its because they undermeasure small events...

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Sometimes I have to laugh. It is a bold call to say NYC finished with less than 20 inches this season, but not a bold call to say that NYC will wind up with 25-30 inches? Right now both solutions are BOTH bold. Why? Because we could easily get 0-5 for the rest of the season or one big bomb that drops 22 inches in February. Both are equally likely at this point in time. So stop arguing over bold calls or not. Hell JB makes bold calls every year and people hang on his every word because he often calls for cold. I have noticed those with cold biases on social media tend to have more followers.... Hmm....

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7 minutes ago, JustinRP37 said:

Sometimes I have to laugh. It is a bold call to say NYC finished with less than 20 inches this season, but not a bold call to say that NYC will wind up with 25-30 inches? Right now both solutions are BOTH bold. Why? Because we could easily get 0-5 for the rest of the season or one big bomb that drops 22 inches in February. Both are equally likely at this point in time. So stop arguing over bold calls or not. Hell JB makes bold calls every year and people hang on his every word because he often calls for cold. I have noticed those with cold biases on social media tend to have more followers.... Hmm....

I agree

Stupid to say either one

One storm can bring us to average

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1 hour ago, Isotherm said:

 

It is quite interesting, Chris, and I've been ruminating on some hypotheses re: the time-lag and distorted response. One issue, in my view, is base-state resonance. Sometimes the MJO/intraseasonal signal is misaligned with the base state, and as such, when it propagates through typically conducive phases, the N HEM response may not be bonafide/favorable due to the misalignment with the background indicators. For example, 2002-03 had a much more classic AAM/GWO and hadley/walker cell structures concordant with a canonical El Nino, and thus when MJO circulated to 8, we had a more genuine N HEM response.

Another issue, the PDO has become much more negative over the past month, as last winter was. This amplifies -AAM resonance and retards proper +AAM transport.

cdas-sflux_ssta_global_1.png

-PDO means more of a -pna correct? Which has been another red flag lately,  the inability for the pac to corporate. I was reading that warm waters south of ak might not Be that good for us anymore. It might be a magnet for low pressures. I believe 09–10/02-03 didn’t have those warm pool there. 
 

The lag effect has been noticeable in p8 for DJF. Question @bluewave @Isotherm why no lag effect in p8 during November? Shorter wave lengths? 

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41 minutes ago, Allsnow said:

-PDO means more of a -pna correct? Which has been another red flag lately,  the inability for the pac to corporate. I was reading that warm waters south of ak might not Be that good for us anymore. It might be a magnet for low pressures. I believe 09–10/02-03 didn’t have those warm pool there. 
 

The lag effect has been noticeable in p8 for DJF. Question @bluewave @Isotherm why no lag effect in p8 during November? Shorter wave lengths? 

if true that would explain November and March snowfalls being on the increase.

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3 hours ago, Allsnow said:

-PDO means more of a -pna correct? Which has been another red flag lately,  the inability for the pac to corporate. I was reading that warm waters south of ak might not Be that good for us anymore. It might be a magnet for low pressures. I believe 09–10/02-03 didn’t have those warm pool there. 
 

The lag effect has been noticeable in p8 for DJF. Question @bluewave @Isotherm why no lag effect in p8 during November? Shorter wave lengths? 

 

That is partially the issue. -PDO promotes -PNA in the means, and MJO coherence/amplification in autumn has a much different effect on the circulation across the high-latitudes, due in part to wave-lengths, as well as a typically more decoupled stratosphere-troposphere.

The SSTA profile of 2002-03 was more conducive for troughiness south of Alaska, which teleconnects to PNA spikes in the classical location, sufficiently far east for us. There is often much chatter and excitement about the warm pool south of Alaska, but from my perspective, I tend to think a cold pool is more felicitous. 

This is a classic +PDO structure.

 

anomnight.1.18.2003.gif

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7 hours ago, Allsnow said:

The mjo the last two years has been incredibly  frustrating. All we do well with it is amplitude in the warm phases. And when we do get favorable phases (ex feb 2019 and January 2020) we don’t get the response we are expecting. For some reason the mjo in cold phases during November has worked better lol.

 

Admittedly, I didn’t see how bad the pv was going to hurt us this winter. Once it continued to strengthen and couple with the atmosphere it was lights out. 

 

 

The mjo in phase 8/1/2 is great...except when it actually goes in any of those phases...then it sucks. 

I have a thought...not even a theory yet since all I’ve done is kick it around in my head, but it seems to me over the years that when the tropical base state is good...then strong mjo waves in cold phases correlate well.  But when we are in years where the base state is crap and we wait for the anomaly of a wave into favorable phases to come it typically doesn’t do much good and the response is muted. 

I am not saying the mjo is not a causation but that the reason for the strong pattern correlations might be partially due to the fact that cold years that have a pattern correlated to cold mjo phases tend to spend much more time in those cold phases. So it skews the mean. I wonder if cold phases in otherwise unfavorable winters have the same correlation.  

When we have had flips associated with the mjo it usually happens when a longer term overall change in the atmospheric base state is occurring, like March 2018 when a long term blocking period set in. 

I just don’t remember lots of instances when things were a hot mess for a long time and the mjo wave into 8 suddenly saved us. Usually it makes it “better” but not good enough. 

Like I said this is just a thought for now and I could be injecting perception bias here. I would have to study the data to see if there is anything too this. 

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3 hours ago, Isotherm said:

 

It is quite interesting, Chris, and I've been ruminating on some hypotheses re: the time-lag and distorted response. One issue, in my view, is base-state resonance. Sometimes the MJO/intraseasonal signal is misaligned with the base state, and as such, when it propagates through typically conducive phases, the N HEM response may not be bonafide/favorable due to the misalignment with the background indicators. For example, 2002-03 had a much more classic AAM/GWO and hadley/walker cell structures concordant with a canonical El Nino, and thus when MJO circulated to 8, we had a more genuine N HEM response.

Another issue, the PDO has become much more negative over the past month, as last winter was. This amplifies -AAM resonance and retards proper +AAM transport.

cdas-sflux_ssta_global_1.png

I’m just getting caught up on the thread but I think this is saying in a much more scientific way what I just said more observationally. 

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31 minutes ago, forkyfork said:

the PDO might not be a real thing

 

The periodicity seemed to be apparent from the 1930s-1990s, with ostensible biphasic signature. However, since about 2000, during the time wherein we should have descended into a negative PDO, we have averaged positive (especially after 2013 we detached from the cycle). So, it seems the PDO has become statistical noise when one measures the past 25 years or so.

 

pdo_tsplot_jan2017.png

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Tomorrow, a quick-moving system could bring New York City and Newark its first measurable snowfall since January 6. Philadelphia, where just 0.1" snow has fallen this winter, could receive its first measurable snowfall since December 11.

Snowfall estimates for select locations are:

Albany: 3"-6"
Binghamton: 3"-6"
Boston: 2"-4"
Bridgeport: 2"-4"
Islip: 1"-3"
New York City: 2"-4"
Newark: 2"-4"
Philadelphia: 2" or less
Poughkeepsie: 3"-6"
Scranton: 3"-6"

The last time New York City had a snowfall of 2.0" or more was March 3-4, 2019 when 5.0" snow fell. The last time Philadelphia picked up 2.0" or more snow was March 1, 2019 when 3.0" snow accumulated.

Ahead of the storm, the temperature will likely fall near 20° in New York City tomorrow morning. Outside the City, many locations will see minimum temperatures in the teens.

Following this weekend, warmer conditions will likely develop. Nevertheless, at least some colder air will likely return during the closing week of the month. At that point, the cold could become sustained and it could continue into at least the first week of February.

With a mean temperature of 42.7° during January 1-15, 2020 ranked as the 6th warmest such period on record in New York City. Since 1869, just 2/13 (15%) cases (2000 and 2005) that saw the temperature average 40.0° or above during January 1-15 went on to have a colder than normal January. The mean monthly temperature for those 13 cases was 37.2°.

The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was +0.5°C for the week centered around January 8. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.27°C and the ENSO Region 3.4 anomaly has averaged +0.50°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions.

The SOI was -16.62 today.

Today, the preliminary Arctic Oscillation (AO) figure was +1.950.

No significant stratospheric warming event appears likely through January 25. Wave 2 activity will remain relatively suppressed. Overall, most of the stratosphere is forecast to remain cold on the EPS. 

On January 16, the MJO was in Phase 6 at an amplitude of 3.178 (RMM). The January 15-adjusted amplitude was 3.041.

This was the 8th consecutive day during which the MJO had an amplitude of 3.000 or above. This is the longest such stretch since January 27-February 11, 2018 when the MJO had an amplitude of 3.000 or above for 16 consecutive days. There have been only 8 cases where the MJO had an amplitude of 3.000 or above for 7 or more consecutive days. The shortest period from the start of that stretch that saw the MJO's amplitude fall below 1.000 was 20 days. The mean period was 36 days. The longest period was 55 days. Based on this historic experience, the MJO likely won't reach low amplitude until near or after the end of January.

Since 1974, there were 8 prior cases where the MJO reached Phase 4 at an amplitude of 1.500 or above in the January 5-20 period. In 7 or 88% of those cases, the MJO progressed into Phases 7 and 8.

Further, the MJO was in Phase 4 at an amplitude of 2.273 on January 7 with an AO of +4.048. Since 1974, there were three January cases when the MJO was in Phase 4 at an amplitude of 2.000 or above and an AO of +3.000 or above. In all three cases the Week 3-4 period was colder than the Week 1-2 period (smallest change: 2.7° in 1993; largest change 16.8° in 2007). The change in 14-day average temperatures from the above three cases would imply a January 22-February 3 mean temperature of 10°-12° below the January 8-21 mean temperature in New York City. This data implies that the latter two week period as a whole would be colder than normal overall. However, uncertainty about the extended range has increased.

Moreover, an MJO in Phase 7 at an amplitude of 2.000 or above typically sees measurable snowfall consistent with overall January 16-31 climatology. That would imply approximately 2 measurable snow events for Philadelphia to New York City and 2-3 such events for Boston during the closing two weeks of January. The first such event should occur tomorrow.

Based on sensitivity analysis applied to the latest guidance, New York City has an implied 94% probability of a warmer than normal January. The monthly mean temperature could finish near 36.5° in New York City.

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The GFS has the last 14 days of January averaging 36.5 or +4.5.        Using a -6 for today and +10.1 for the first 16 days,  we are probably going to finish near 39.4 for the month.      Just 6 runs ago the GFS had 20.1 for the same overlapping period.           This run kicks off February 01---02 at a +12 pace.          Accuweather which raised its January forecast just after the month started from +1 to +6,  has just raised its February outlook to -1, from (sorry---do not know what it was before).       More importantly, they feel they did not raise it enough as they wait on PV evolution.

A trough made up of AN heights:

 

https://www.cpc.ncep.noaa.gov/products/predictions/814day/814analog.off.gif2020011712_054@007_E1_knyc_I_NAEFS@EPSGR

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