January 2021 General Discussions & Observations Thread

[Eduardo]

6 hours ago, bluewave said:

Something really flipped after the super El Niño. We did get that impressive cold stretch from late December 2017 into early January 2018. But the record warmth that followed with the 80° in February boosted the winter temperature departure to above average. 

My (completely unscientific) hunch is that some big ENSO event is necessary to shake up the PAC pattern and throw some sand in the gears of that jet.  We’ve been stuck in such a crumby PAC pattern for a few years now while other variables have shifted (NAO, AO, MJO, Strat, etc.).

The only thing we haven’t seen since the 15-16 super Niño is another strong/super ENSO episode.  Maybe that’s what it’ll take(?) 

[MJO812]

2nd low on the cmc

[MJO812]

Ukie is south of the cmc

[LibertyBell]

On 1/20/2021 at 11:04 AM, bluewave said:

Our snowfall volatility continues. This was our first measurable snowfall since December 16-17th. You can see the North American snow extent big swings from record highs to record lows since October. It looks like the extent has bottomed out and is entering a rebound phase. 
 

There should've been a snow squall warning with this one, we had snowcovered roads here for an hour or two on the south shore and the snow was falling rapidly, HUGE flakes.  How did NYC only record a T, we had about a half an inch here....didn't see what the airports got.

[LibertyBell]

2 hours ago, Eduardo said:

My (completely unscientific) hunch is that some big ENSO event is necessary to shake up the PAC pattern and throw some sand in the gears of that jet.  We’ve been stuck in such a crumby PAC pattern for a few years now while other variables have shifted (NAO, AO, MJO, Strat, etc.).

The only thing we haven’t seen since the 15-16 super Niño is another strong/super ENSO episode.  Maybe that’s what it’ll take(?) 

you only get one of those every 20 years or so.....so something else needs to happen first.

 

[LibertyBell]

5 hours ago, donsutherland1 said:

Temperatures again rose into the lower 40s across much of the region today. The remainder of the week will be fair and seasonably cold. A much colder air mass will arrive for the weekend. Parts of the region could struggle to reach freezing on Saturday and Sunday.

Meanwhile, Nunavut experienced another day with near record and record high temperatures. High temperatures included:

Eureka: -4° (just missed its daily record from 1985 by 0.2°C)
Grise Fiord: 16° (old record: 9°, 1985)
Iqaluit: 32°
Kimmirut: 35° (old record: 23°, 2003)
Pangnirtung: 30° (old record: 24°, 2007)
Qikiqtarjuaq: 13° (old record: 12°, 2013)
Resolute: 9°

The abnormal warmth will likely continue in Nunavut through Saturday.

As Arctic blocking persists, next week could feature two opportunities for snowfall. The earlier event (January 25-27 timeframe) will likely focus its heaviest snows on the Philadelphia to New York City area. The latter event (January 28-29 timeframe) will likely focus its heaviest snows on the Washington, DC to Philadelphia area. A widespread significant snowfall (6" or above) still appears relatively unlikely. A light or moderate snowfall (2"-4" or 3"-6") remains more likely. However, some of the guidance suggests that the second storm could rapidly intensify, so there is a greater degree of uncertainty for that event in terms of amounts.

AO-/PNA- patterns typically do not produce significant or major snowstorms for the Middle Atlantic or southern New England regions in late January or early February. During the January 20-February 7, 1950-2020 period, there have been 5 storms that brought 4" or more snow to at least two of the following cities--Boston, New York City, or Philadelphia--during an AO-/PNA- pattern. None of those storms brought 6" or more snow to two or more of those cities. Therefore, until the potential events are within 72 hours or less and the guidance suggests otherwise, the base case is against a widespread significant or major snowfall.

Afterward, the evolution of the AO will determine whether potential for measurable snow events will continue into February.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -1.2°C for the week centered around January 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -1.08°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was -1.27 today. That is the first negative value since November 23, 2020 when the SOI was -7.83.

Today, the preliminary Arctic Oscillation (AO) figure was -2.510.

On January 20 the MJO was in Phase 6 at an amplitude of 0.682 (RMM). The January 19-adjusted amplitude was 0.424.

Following a significant stratospheric warming event, the stratosphere is now cooling. The cooling will likely accelerate during the second half of January. As is typical for vortex-splitting events, the major piece of the polar vortex migrated to Eurasia. The end result has been an absence of severe cold in much of North America.

The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Were blocking to disappear, snowfall prospects would diminish.

Based on sensitivity analysis applied to the latest guidance, there is an implied 91% probability that New York City will have a warmer than normal January. January will likely finish with a mean temperature near 35.0°.

Do you think we could get a repeat of the early Feb 1985 snowfalls?  I think there were two 4-6 inch events within days of each other.  Looks like both storms next week have the potential to do that.  Speaking of which  today is the anniversary of the coldest day I've ever experienced....in 1985 the low was -2 and the high was just 7!

 

[LibertyBell]

9 hours ago, Cfa said:

Later sunsets becoming noticeable now, sky still blue at almost 5, a month ago it’d be black.

I've always wondered, why is there a lag with sunrises not getting earlier until the middle of January?  Why is there an assymetry between sunrises and sunsets?

[LibertyBell]

On 1/20/2021 at 3:01 PM, Allsnow said:

Euro ensemble mean snowfall for next week is 10 inches between 3 storms 

when's the 3rd storm?

[LibertyBell]

On 1/20/2021 at 6:48 PM, donsutherland1 said:

A weak disturbance brought a round of light snow and snow showers across the region today. Snowfall amounts included:

Allentown: Trace
Bridgeport: Trace
Islip: 0.2"
New York City: Trace
Newark: 0.3"
Philadelphia: Trace

The remainder of the week will be fair and seasonably cold. A much colder air mass will arrive for the weekend. Parts of the region could struggle to reach freezing on Saturday and Sunday.

As Arctic blocking persists, next week could feature one or perhaps two more opportunities for snowfall, with the greatest risk focused on the January 25-28 timeframe. However, a widespread significant snowfall (6" or above) still appears relatively unlikely. A light or moderate snowfall is more likely.

AO-/PNA- patterns typically do not produce significant or major snowstorms for the Middle Atlantic or southern New England regions in late January or early February. During the January 20-February 7, 1950-2020 period, there have been 5 storms that brought 4" or more snow to at least two of the following cities--Boston, New York City, or Philadelphia--during an AO-/PNA- pattern. None of those storms brought 6" or more snow to two or more of those cities. Therefore, until the potential events are within 72 hours or less and the guidance suggests otherwise, the base case is against a widespread significant or major snowfall.

Afterward, the evolution of the AO will determine whether potential for measurable snow events will continue into February.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -1.2°C for the week centered around January 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -1.08°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was +4.86 today.

Today, the preliminary Arctic Oscillation (AO) figure was -2.124.

On January 19 the MJO was in Phase 5 at an amplitude of 0.425 (RMM). The January 18-adjusted amplitude was 0.638.

Following a significant stratospheric warming event, the stratosphere is now cooling. The cooling will likely accelerate during the second half of January. As is typical for vortex-splitting events, the major piece of the polar vortex migrated to Eurasia. The end result has been an absence of severe cold in much of North America.

The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Were blocking to disappear, snowfall prospects would diminish.

Based on sensitivity analysis applied to the latest guidance, there is an implied 90% probability that New York City will have a warmer than normal January. January will likely finish with a mean temperature near 35.0°.

got a total for JFK and LGA Don?  We had snow covering parts of the roads here in southern Nassau and it fell quite heavily for a while, I was thinking there'd be a snow squall warning

 

[CIK62]

The next 8 days are averaging 28degs.(23/33).           Making it 23degs., or -9.0.

Finally all models agree on about 6" of snow on the 26th.*****        Next system stays south and gets Maryland-Virginia?         First 5 days of February still look +8.0.

******Prediction:      5" to 8" with borderline 2mT's of  27   to   32 degrees.       About a 16 hour event, roughly    11pm   Mon.     to    3pm   Tues.    Winds NE 15-20mph.

38*(62%RH) here at 6am.          40* by 9am.         44* by 11am.          45* briefly at 2pm.        44* at 3pm.       40* by 7pm.       37* by 11pm.

[bluewave]

Finally, temperatures are just slightly below normal. But nothing outrageously cold for this time of year.

 

[donsutherland1]

Morning thoughts...

At 7:45 am, a line of snow showers, with some embedded pockets of moderate to heavy snow, stretched from central Vermont down to western Massachusetts. That area of snow was pushing eastward. The potential existed for Boston to pick up a small accumulation later this morning or early this afternoon.

That area of snow was associated with a strong push of colder air. The frontal passage will likely be dry in the New York City and Philadelphia areas. As a result, under partly sunny skies, readings will likely top out in the lower and middle 40s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 45°

Newark: 47°

Philadelphia: 47°

Tomorrow will be fair and much colder. The temperature will struggle just to reach freezing in parts of the region. 

[donsutherland1]

6 hours ago, LibertyBell said:

Do you think we could get a repeat of the early Feb 1985 snowfalls?  I think there were two 4-6 inch events within days of each other.  Looks like both storms next week have the potential to do that.  Speaking of which  today is the anniversary of the coldest day I've ever experienced....in 1985 the low was -2 and the high was just 7!

 

I suspect that the second storm could be even more suppressed, if anything. If so, it is possible that it would bring little or nothing to the New York City or Newark areas. 

[donsutherland1]

5 hours ago, LibertyBell said:

got a total for JFK and LGA Don?  We had snow covering parts of the roads here in southern Nassau and it fell quite heavily for a while, I was thinking there'd be a snow squall warning

 

0.2” at both JFK and LGA.

[bluewave]

10 hours ago, Eduardo said:

My (completely unscientific) hunch is that some big ENSO event is necessary to shake up the PAC pattern and throw some sand in the gears of that jet.  We’ve been stuck in such a crumby PAC pattern for a few years now while other variables have shifted (NAO, AO, MJO, Strat, etc.).

The only thing we haven’t seen since the 15-16 super Niño is another strong/super ENSO episode.  Maybe that’s what it’ll take(?) 

14  out of 17 winter months warmer than average is pretty extreme. We knew something was up when December 2015 went +13.3. It appears to have been a climate shift to warmer winters.
 

NYC

Dec 15....+13.3

Jan 16....+1.9

Feb 16....+2.4

Dec 16....+0.8

Jan 17....+5.4

Feb 17....+6.3

Dec 17....-2.5

Jan 18.....-0.8

Feb 18....+6.7

Dec 18....+2.6

Jan 19....-0.1

Feb 19....+0.9

Dec 19....+0.8

Jan 20....+6.5

Feb 20....+4.8

Dec 20.....+1.7

Jan 21.....+5.2....so far

[rclab]

2 minutes ago, bluewave said:

14  out of 17 winter months warmer than average is pretty extreme. We knew something was up when December 2015 went +13.3. It appears to have been a climate shift to warmer winters.
 

NYC

Dec 15....+13.3

Jan 16....+1.9

Feb 16....+2.4

Dec 16....+0.8

Jan 17....+5.4

Feb 17....+6.3

Dec 17....-2.5

Jan 18.....-0.8

Feb 18....+6.7

Dec 18....+2.6

Jan 19....-0.1

Feb 19....+0.9

Dec 19....+0.8

Jan 20....+6.5

Feb 20....+4.8

Dec 20.....+1.7

Jan 21.....+5.2....so far

Good morning ‘b’, I’m not sure which is more frightening. The fact that a single event was the cause or the possibility that it could happen again..... As always ....

[SnoSki14]

I'm keeping an eye on the coastal post 26th threat. Big NAO/AO rise is a good precursor to a coastal storm. 

Don't think it'll be as suppressed as models currently show.

[MJO812]

35 minutes ago, SnoSki14 said:

I'm keeping an eye on the coastal post 26th threat. Big NAO/AO rise is a good precursor to a coastal storm. 

Don't think it'll be as suppressed as models currently show.

I agree

NAO AO and PNA rising

[SnoSki14]

CMC/GFS show definite storm signal 29th. 

[snowman19]

2 hours ago, SnoSki14 said:

CMC/GFS show definite storm signal 29th. 

The new Euro gives Bermuda a snowstorm next Friday

[MJO812]

20 minutes ago, snowman19 said:

The new Euro gives Bermuda a snowstorm next Friday

Good 

 

[EastonSN+]

10 minutes ago, MJO812 said:

Good 

 

Yeah they deserve so win one 

[LoboLeader1]

You want snow, head west.......

 

 

 

[the_other_guy]

15 hours ago, LibertyBell said:

I've always wondered, why is there a lag with sunrises not getting earlier until the middle of January?  Why is there an assymetry between sunrises and sunsets?

Goodie! We can start talking about sun angle soon. haha

[IrishRob17]

15 hours ago, LibertyBell said:

I've always wondered, why is there a lag with sunrises not getting earlier until the middle of January?  Why is there an assymetry between sunrises and sunsets?

Tilt of the earths axis. 

[sussexcountyobs]

Moderate to heavy snow shower falling now.

[Eduardo]

16 hours ago, LibertyBell said:

I've always wondered, why is there a lag with sunrises not getting earlier until the middle of January?  Why is there an assymetry between sunrises and sunsets?

I think it's because, since the Earth orbits the sun elliptically, the speed of its rotation varies slightly during different times of the year.  Thus, not every solar day is exactly 24 hours long.  IIRC, solar days are slightly longer during the (Northern Hemisphere's) Winter Solstice and slightly shorter during the Summer Solstice--although I might very well have that backwards.  In any event, we still set our clocks based on a 24-hour day (y'know, to keep life orderly) and the difference in time between how we set our clocks and how fast the Earth is actually rotating yields that impression of "asymmetry" you noticed.  In short, the asymmetry is created by the discrepancies between solar days and 'clock days.'

 

I hope this is right.  Been a loong time since I took Earth Science. 

[donsutherland1]

Colder air drilled into the region with a few snow flurries and snow showers. A much colder air mass will cover the region during the weekend. Parts of the region could struggle to reach freezing tomorrow and again on Sunday.

The closing week of January will likely be colder than normal across the region. Milder weather will likely return during the first week of February. Some of the guidance suggests that temperatures could surge to much above normal levels for a time.

Meanwhile in northern Canada, Nunavut experienced another day with near record and record high temperatures. High temperatures included:

Coral Harbour: 22° (old record: 20°, 1963)
Iqaluit: 33°
Kimmirut: 36° (old record: 14°, 2003)
Kinngait: 29° (old record: 17°, 1980)
Kugaaruk: 19° (old record: 6°, 1995)
Naujaat: 25° (old record: 3°, 1995)
Pangnirtung: 32° (old record: 20°, 2000)
Qikiqtarjuaq: 15° (missed record from 2013 by 0.2°C)

The abnormal warmth will likely continue in Nunavut through tomorrow.

As Arctic blocking persists, next week could feature two opportunities for snowfall. The earlier event (January 25-27 timeframe) will likely focus its heaviest snows on the Philadelphia to New York City area. The latter event (January 28-29 timeframe) will likely focus its heaviest snows in an area running from Richmond to Washington, DC.

A widespread significant snowfall (6" or above) still appears relatively unlikely, especially for the first event. A light or moderate snowfall (2"-4" or 3"-6") remains more likely. However, some of the guidance suggests that the second storm could rapidly intensify, so there is a greater degree of uncertainty for that event in terms of amounts.

AO-/PNA- patterns typically do not produce significant or major snowstorms for the Middle Atlantic or southern New England regions in late January or early February. During the January 20-February 7, 1950-2020 period, there have been 5 storms that brought 4" or more snow to at least two of the following cities--Boston, New York City, or Philadelphia--during an AO-/PNA- pattern. None of those storms brought 6" or more snow to two or more of those cities. Therefore, until the potential events are within 72 hours or less and the guidance suggests otherwise, the base case is against a widespread significant or major snowfall.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -1.2°C for the week centered around January 13. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.73°C and the ENSO Region 3.4 anomaly has averaged -1.08°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was +1.14 today.

Today, the preliminary Arctic Oscillation (AO) figure was -2.238.

On January 21 the MJO was in Phase 6 at an amplitude of 1.071 (RMM). The January 20-adjusted amplitude was 0.684.

Following a significant stratospheric warming event, the stratosphere is now cooling. The cooling will likely accelerate during the second half of January. As is typical for vortex-splitting events, the major piece of the polar vortex migrated to Eurasia. The end result has been an absence of severe cold in much of North America.

The significant December 16-17 snowstorm during what has been a blocky December suggests that seasonal snowfall prospects have increased especially from north of Philadelphia into southern New England. At New York City, there is a high probability based on historic cases that an additional 20" or more snow will accumulate after December. Were blocking to disappear, snowfall prospects would diminish.

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 January. January will likely finish with a mean temperature near 35.2°.

 

[bluewave]

NYC having a better snowfall departure than CAR and BOS through January 22nd highlights the challenges of seasonal forecasting with many competing influences.

CLIMATE REPORT 
NATIONAL WEATHER SERVICE NEW YORK, NY
433 PM EST FRI JAN 22 2021

...................................

...THE CENTRAL PARK NY CLIMATE SUMMARY FOR JANUARY 22 2021...
VALID TODAY AS OF 0400 PM LOCAL TIME.

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1869 TO 2021


WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST      
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR     
                                                  NORMAL           
...................................................................
   

SNOWFALL (IN)                                                              
  TODAY            0.0           8.5  2005   0.2   -0.2      0.0      
  MONTH TO DATE    T                         4.8   -4.8      2.3      
  SINCE DEC 1     10.5                       9.6    0.9      4.8      
  SINCE JUL 1     10.5                       9.9    0.6      4.8      

 

CLIMATE REPORT 
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
431 PM EST FRI JAN 22 2021

...................................

...THE BOSTON MA CLIMATE SUMMARY FOR JANUARY 22 2021...
VALID TODAY AS OF 0400 PM LOCAL TIME.

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2021


WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST      
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR     
                                                  NORMAL           
...................................................................
   

SNOWFALL (IN)                                                              
  TODAY            0.0           9.1  2005   0.4   -0.4      0.0      
  MONTH TO DATE    0.3                       9.4   -9.1      3.1      
  SINCE DEC 1     13.3                      18.4   -5.1     14.6      
  SINCE JUL 1     17.6                      19.7   -2.1     14.6

 

CLIMATE REPORT 
NATIONAL WEATHER SERVICE CARIBOU ME
431 PM EST FRI JAN 22 2021

...................................

...THE CARIBOU ME CLIMATE SUMMARY FOR JANUARY 22 2021...
VALID TODAY AS OF 0400 PM LOCAL TIME.

CLIMATE NORMAL PERIOD: 1981 TO 2010
CLIMATE RECORD PERIOD: 1939 TO 2021


WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST      
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR     
                                                  NORMAL           
...................................................................
   

SNOWFALL (IN)                                                              
  TODAY            0.4           5.3  1981   0.9   -0.5       T       
  MONTH TO DATE    7.8                      17.9  -10.1     29.8      
  SINCE DEC 1     34.1                      40.8   -6.7     47.7      
  SINCE JUL 1     42.2                      53.0  -10.8     70.7    

[jm1220]

3 hours ago, bluewave said:

NYC having a better snowfall departure than CAR and BOS through January 22nd highlights the challenges of seasonal forecasting with many competing influences.

CLIMATE REPORT 
NATIONAL WEATHER SERVICE NEW YORK, NY
433 PM EST FRI JAN 22 2021

...................................

...THE CENTRAL PARK NY CLIMATE SUMMARY FOR JANUARY 22 2021...
VALID TODAY AS OF 0400 PM LOCAL TIME.

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1869 TO 2021


WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST      
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR     
                                                  NORMAL           
...................................................................
   

SNOWFALL (IN)                                                              
  TODAY            0.0           8.5  2005   0.2   -0.2      0.0      
  MONTH TO DATE    T                         4.8   -4.8      2.3      
  SINCE DEC 1     10.5                       9.6    0.9      4.8      
  SINCE JUL 1     10.5                       9.9    0.6      4.8      

 

CLIMATE REPORT 
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
431 PM EST FRI JAN 22 2021

...................................

...THE BOSTON MA CLIMATE SUMMARY FOR JANUARY 22 2021...
VALID TODAY AS OF 0400 PM LOCAL TIME.

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2021


WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST      
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR     
                                                  NORMAL           
...................................................................
   

SNOWFALL (IN)                                                              
  TODAY            0.0           9.1  2005   0.4   -0.4      0.0      
  MONTH TO DATE    0.3                       9.4   -9.1      3.1      
  SINCE DEC 1     13.3                      18.4   -5.1     14.6      
  SINCE JUL 1     17.6                      19.7   -2.1     14.6

 

CLIMATE REPORT 
NATIONAL WEATHER SERVICE CARIBOU ME
431 PM EST FRI JAN 22 2021

...................................

...THE CARIBOU ME CLIMATE SUMMARY FOR JANUARY 22 2021...
VALID TODAY AS OF 0400 PM LOCAL TIME.

CLIMATE NORMAL PERIOD: 1981 TO 2010
CLIMATE RECORD PERIOD: 1939 TO 2021


WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST      
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR     
                                                  NORMAL           
...................................................................
   

SNOWFALL (IN)                                                              
  TODAY            0.4           5.3  1981   0.9   -0.5       T       
  MONTH TO DATE    7.8                      17.9  -10.1     29.8      
  SINCE DEC 1     34.1                      40.8   -6.7     47.7      
  SINCE JUL 1     42.2                      53.0  -10.8     70.7    

You think that's bad? Syracuse is at 29" of snow for the season, normally by now they have 67". They're getting maybe 6" of lake effect tonight though but they're in a deep hole. Binghamton an hour drive or so south of them is at 60" because of the crazy snow band from the 12/17 storm.