Jump to content
  • Member Statistics

    17,508
    Total Members
    7,904
    Most Online
    joxey
    Newest Member
    joxey
    Joined

January 2020 General Discussions & Observations Thread


Rtd208
 Share

Recommended Posts

Late afternoon thoughts...

1. Yesterday, the MJO reached Phase 5 at amplitude of 2.430 (a January record for Phase 5).

2. Historically, the MJO progressed into Phases 7 and 8 at amplitude of 1.000 or above following its being in Phase 5 at an amplitude of 1.500 or above.

3. The idea of a pattern change featuring a trough in the means in the East remains on track.

15-day Mean 500 mb Height Anomalies for the period beginning 10 days after the MJO peaks in Phase 5 at an amplitude of 1.500 or above during the January 5-20 period:
01132020.jpg

4. The 12z EPS, 12z GEFS, and 12z CFSv2 weekly guidance all favor the trough in the means in the East idea for the closing 10 days of January.

 

  • Like 3
Link to comment
Share on other sites

12 minutes ago, Allsnow said:

Yep, weeklies are great looking until mid/end of February. Then the Niña pattern returns with ridge in the East. That makes sense imo with the mjo going around the horn. And I wouldn’t mind a warm start to March this year.

There are mixed forecasts. Some are saying March will be cold and some are saying  it's going to be warm.

Link to comment
Share on other sites

2 hours ago, Allsnow said:

Some Mid Atlantic crush jobs on the idv eps with that closed low look. 
 

It’s definitely going to get active along the east coast. Eps has a potential costal the middle of next week and the following weekend. I like the the axis of the trough around the 25th. 

 

Perhaps this extreme MJO event can jump-start the El Niño. We are getting a decent WWB event unfolding now in the Pacific. I would like to see the northern branch stop competing with the southern stream. A strengthening El Niño could allow the STJ to take over with less  interference from disturbances moving through the Great Lakes.

E2D82A07-FA52-4206-BEDE-864C43515D2A.thumb.gif.236f27f20ccde9fc212d4830290d5762.gif

 

  • Like 4
  • Thanks 1
Link to comment
Share on other sites

Temperatures topped out in the 40s across much of the region. Nevertheless, readings remained above normal for the time of year.

Generally warmer than normal conditions will likely persist through Friday. Readings could continue to average 5°-10° above normal over the next several days. However, a more winter-like pattern lies ahead in the medium-term.

During next weekend, colder air will likely return for a period. At the same time, there is potential for a system to bring New York City and Newark its first measurable snowfall since January 6. Philadelphia could receive its first measurable snowfall since December 11. At present, this appears to be the kind of storm that could bring 1"-3"/2"-4" to Philadelphia to New York City, more to the north and west, including New England, and less to the south and east. Afterward, the cold could become sustained, possibly with some Arctic air.

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 -2.68 today.

Today, the preliminary Arctic Oscillation (AO) figure was +4.698. That was the highest AO figure since December 21, 2016 when the AO was +4.742. That is also the highest January AO figure since January 5, 2005 when the AO was +4.703. Sixteen days later, a blizzard moved into the region dumping more than a foot of snow from Philadelphia to New England.

The AO will likely average +2.000 or above during the January 1-15 period. Since 1950, there were 7 cases when the AO averaged +2.000 or above during that period. Four (57%) saw the AO average for the final 15 days of January average 1.500 or more sigma lower than the January 1-15 figure (1952, 1983, 2005, and 2007) with 1952 and 2005 having a negative average for the latter period. All four had a negative AO average for February. Three (43%) saw smaller declines (1975, 1989, and 1993). All three had February AO averages > 0.000.

No significant stratospheric warming event appears likely through January 21. Wave 2 activity will remain relatively suppressed just past mid-January. Toward January 20, a moderate amplitude Wave 2 could impact the upper stratosphere. Overall, most of the stratosphere is forecast to remain cold on the EPS.

On January 12, the MJO was in Phase 5 at an amplitude of 3.530 (RMM). The January 11-adjusted amplitude was 3.433. The January 12 amplitude was the highest amplitude on record for the MJO's being in Phase 5 during 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. Progression consistent with the historical experience would increase prospects for the development of a colder pattern during late January, which could continue into at least the start of February.

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 January three 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 would be colder than normal overall.

In addition, 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.

Based on sensitivity analysis applied to the latest guidance, New York City has an implied 78% probability of a warmer than normal January.

  • Thanks 1
Link to comment
Share on other sites

The next 8 days are averaging 34degs. , or 2degs. AN.

Month to date is  +9.9[42.5].        Should be +6.9[39.3] by the 22nd.     Using the -4 average  anomaly as currently indicated for the next 17 days, we will be near +2 by the 31st.

44* here at 6am.   43* at 7am.   46* by 10am.     48* by Noon.

Our three main models all have about 2" of Snow near the 18th/19th. and little else, and we have a long boring wait for winter's end.

2020011400_054@007_E1_knyc_I_NAEFS@EPSGRNot cutting it at all.   

  • Like 1
  • Thanks 1
  • Haha 1
  • Sad 1
Link to comment
Share on other sites

The departures and rankings for the first 13 days of January have been even warmer to the  north of the NYC area. Albany is a +14.2 with NYC +9.9. This was the 2nd warmest for Albany and 7th warmest in NYC.

Time Series Summary for Albany Area, NY (ThreadEx)
Click column heading to sort ascending, click again to sort descending.
Rank
Ending Date
Mean Avg Temperature Jan 1 to Jan 13
Missing Count
1 2007-01-13 38.8 0
2 2020-01-13 36.8 0
3 1889-01-13 36.4 0
4 1874-01-13 35.7 0
5 1998-01-13 34.9 0
6 2000-01-13 34.7 0
7 1932-01-13 34.6 0
8 1907-01-13 34.4 0
9 1930-01-13 34.3 0
10 1936-01-13 33.6 0
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 Jan 1 to Jan 13
Missing Count
1 2007-01-13 46.4 0
2 1998-01-13 45.3 0
3 1907-01-13 44.2 0
4 2000-01-13 43.5 0
5 1950-01-13 43.2 0
6 2005-01-13 42.6 0
7 2020-01-13 42.5 0
8 1890-01-13 42.2 0
9 2006-01-13 41.8 0
10 2008-01-13 41.5 0
  • Like 3
Link to comment
Share on other sites

Morning thoughts...

The GEFS and GEFS bias-corrected MJO forecasts have retreated somewhat from a scenario where the MJO moves into Phase 8 in the extended range. However, the extended range of the MJO forecasts does not exhibit high skill, though a trend away from Phase 8 would need to be watched should it develop.

The historical evidence from the MJO's reaching Phase 4 and Phase 5 at amplitudes of 1.500 or above during January 5-20 strongly argues that the MJO will move into Phases 7 and 8. That remains the base case.

Newly published research showed that oceanic heat content continued to increase.

https://link.springer.com/content/pdf/10.1007%2Fs00376-020-9283-7.pdf

Interestingly enough, the long-term mean amplitude of the MJO has also increased. The 1980-99 average amplitude was 1.238. The 2000-19 preliminary average was 1.284. During the last 5 years, the preliminary average was 1.326. However, on scales of a decade or less, there can be fluctuations in MJO amplitude due to internal variability e.g., ENSO.

Finally, the upcoming system that will impact the region this weekend continues to look like the kind that has delivered 1"-3"/2"-4" to such cities as Philadelphia, Newark, and New York City in the past. Higher amounts, generally 3"-6" (with some locally higher figures) had occurred to the north and west of those cities and in parts of New England (cities such as Scranton, Binghamton, Albany, and Boston). Lesser amounts occurred to the south and east (cities such as Atlantic City and Islip). The multi-model mean is reasonably consistent with the historic data (1950-2019).

A 1"-3" snowfall would represent a nice increase in seasonal snowfall for Philadelphia (0.1" season-to-date), Newark (5.1" season-to-date), and New York City (2.7" season-to-date).

Link to comment
Share on other sites

10 minutes ago, donsutherland1 said:

Morning thoughts...

The GEFS and GEFS bias-corrected MJO forecasts have retreated somewhat from a scenario where the MJO moves into Phase 8 in the extended range. However, the extended range of the MJO forecasts does not exhibit high skill, though a trend away from Phase 8 would need to be watched should it develop.

The historical evidence from the MJO's reaching Phase 4 and Phase 5 at amplitudes of 1.500 or above during January 5-20 strongly argues that the MJO will move into Phases 7 and 8. That remains the base case.

Newly published research showed that oceanic heat content continued to increase.

https://link.springer.com/content/pdf/10.1007%2Fs00376-020-9283-7.pdf

Interestingly enough, the long-term mean amplitude of the MJO has also increased. The 1980-99 average amplitude was 1.238. The 2000-19 preliminary average was 1.284. During the last 5 years, the preliminary average was 1.326. However, on scales of a decade or less, there can be fluctuations in MJO amplitude due to internal variability e.g., ENSO.

Finally, the upcoming system that will impact the region this weekend continues to look like the kind that has delivered 1"-3"/2"-4" to such cities as Philadelphia, Newark, and New York City in the past. Higher amounts, generally 3"-6" (with some locally higher figures) had occurred to the north and west of those cities and in parts of New England (cities such as Scranton, Binghamton, Albany, and Boston). Lesser amounts occurred to the south and east (cities such as Atlantic City and Islip). The multi-model mean is reasonably consistent with the historic data (1950-2019).

A 1"-3" snowfall would represent a nice increase in seasonal snowfall for Philadelphia (0.1" season-to-date), Newark (5.1" season-to-date), and New York City (2.7" season-to-date).

Thanks Don. The way this winter has gone it would be fitting for the wave to die before 8.

I can't believe I am starring at my first back to back below average snowfall winter since 06/07 07/08

  • Like 1
Link to comment
Share on other sites

16 minutes ago, EastonSN+ said:

Thanks Don. The way this winter has gone it would be fitting for the wave to die before 8.

I can't believe I am starring at my first back to back below average snowfall winter since 06/07 07/08

Even if so, what an amazing run, 12 years without a below normal couplet.   I had thought BDR was close to normal last year after the March snows brought us up but if we did finish below it was just below.

Link to comment
Share on other sites

Just now, Brian5671 said:

Even if so, what an amazing run, 12 years without a below normal couplet.   I had thought BDR was close to normal last year after the March snows brought us up but if we did finish below it was just below.

Agreed. That that was the only back to back below average snowfall this century!

 

Link to comment
Share on other sites

30 minutes ago, EastonSN+ said:

Thanks Don. The way this winter has gone it would be fitting for the wave to die before 8.

I can't believe I am starring at my first back to back below average snowfall winter since 06/07 07/08

 

The wave does not die before 8.

 

It goes into 7 /8 /1 and if it dies you are left with a cold signal until something usurps it.

 

But right now the MJO heads into 8 and off towards 1.

 

 

twc_globe_mjo_vp200.png

 

  • Thanks 1
Link to comment
Share on other sites

40 minutes ago, PB-99 said:

 

The wave does not die before 8.

 

It goes into 7 /8 /1 and if it dies you are left with a cold signal until something usurps it.

 

But right now the MJO heads into 8 and off towards 1.

Tbf the models did back off of the MJO heading towards 8. The Euro actually has it circling back towards 6 for early Feb, which would be a disaster for winter lovers. 

Hopefully it's wrong but the Euro did nail the phase 4/5 trajectory. Don mentioned its accuracy isn't as good coming out of those phases so the jury is still out. 

However if it's correct then we'd only have a 2 week wintry stretch from this weekend into 1st week of February before the warmth returns. 

Link to comment
Share on other sites

3 minutes ago, SnoSki14 said:

Tbf the models did back off of the MJO heading towards 8. The Euro actually has it circling back towards 6 for early Feb, which would be a disaster for winter lovers. 

Hopefully it's wrong but the Euro did nail the phase 4/5 trajectory. Don mentioned its accuracy isn't as good coming out of those phases so the jury is still out. 

However if it's correct then we'd only have a 2 week wintry stretch from this weekend into 1st week of February before the warmth returns. 

This is more or less what occurred last year but on a severe scale.  The trip through 7 was so short that by this stage we already were seeing the models at Day 14-16 go warmer as the wave went back into 3 or 4 within 2 weeks.  This is a longer trip through 7 and might re emerge into 6 which isn’t quite as terrible 

Link to comment
Share on other sites

4 minutes ago, SnowGoose69 said:

This is more or less what occurred last year but on a severe scale.  The trip through 7 was so short that by this stage we already were seeing the models at Day 14-16 go warmer as the wave went back into 3 or 4 within 2 weeks.  This is a longer trip through 7 and might re emerge into 6 which isn’t quite as terrible 

There remain a lot of similarities to last year with subtle differences that make things seem new. 

I think Jan/Feb will swap places with last year's Jan/Feb where Jan 2020 ends up as the torch month while Feb is near normal. 

I still feel mid to late Feb and March will bring the majority of BN temps and snow as Atlantic blocking finally shows itself in a big way. 

Link to comment
Share on other sites

19 minutes ago, SnoSki14 said:

Tbf the models did back off of the MJO heading towards 8. The Euro actually has it circling back towards 6 for early Feb, which would be a disaster for winter lovers. 

Hopefully it's wrong but the Euro did nail the phase 4/5 trajectory. Don mentioned its accuracy isn't as good coming out of those phases so the jury is still out. 

However if it's correct then we'd only have a 2 week wintry stretch from this weekend into 1st week of February before the warmth returns. 

 

Stop using the RIMM plots, they are garbage. The MJO does not circle back, the wave is moving off.

 

 

20200114_082250.png

Link to comment
Share on other sites

From what I can see the reason you are still getting the loop on the rmm plots is a kelvin wave in p6. You can see it on the roundy plots. This is still going to go around the horn. 

 

 


27D4D45E-0AA3-42A3-9799-DB784C7997F5.thumb.png.dec058d3002c487754143486f6801624.png

That pink line is the kelvin wave in warm phases. But the real mjo is in p8 by feb 10th

CCE06A1B-35DE-41BC-9A91-84B387D522DD.gif.75bac63fccb53f97dd8588dc3a6c52fa.gif

  • Like 2
Link to comment
Share on other sites

19 minutes ago, PB-99 said:

 

Stop using the RIMM plots, they are garbage. The MJO does not circle back, the wave is moving off.

 

 

20200114_082250.png

From God's lips to Peanut Butter-99's fingertips will make it so!! Seriously though, you ignore Don's concerns to your peril. Consider it a lesson in model analysis.

  • Weenie 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...