January 2021 General Discussions & Observations Thread

[NEG NAO]

12Z Euro stalls next weeks storm out just like the GFSv16

[NEG NAO]

[SnowGoose69]

I’m trying to figure out how this one can fail.  This seems like your classic blocked up pattern storm that shows up a week out and other than fine details never really waivers a ton.  It’s gonna be you’re usual screw job miller B type deal south of PHL probably.  I guess the shortwave could end up dampening and washing out as it traverses the Midwest probably  

[sussexcountyobs]

Is this for Monday/Tuesday next week? All my forecasts I read are showing it for Sunday/Monday

[IrishRob17]

27 minutes ago, sussexcountyobs said:

Is this for Monday/Tuesday next week? All my forecasts I read are showing it for Sunday/Monday

The GFS is faster with it coming in than the Euro, those details will get ironed out over this week.  

Walt started a thread for this potential storm earlier this morning: https://www.americanwx.com/bb/topic/54427-noreaster-snow-ice-rain-for-the-nyc-forum-late-sunday-jan-31-early-tue-feb-2/

 

 

[snowman19]

18 hours ago, Allsnow said:

His Tuesday call of supression looks great. Only 2-4 for sne 

That’s cute. Your call of “a 4-8 inch type deal” for the metro is looking marvelous lol And this turned into 2 separate waves, the first wave did nothing for us today, which is what I said would happen. And I like how you used my rent free quote from the DM. That was good

[bluewave]

31 minutes ago, SnowGoose69 said:

I’m trying to figure out how this one can fail.  This seems like your classic blocked up pattern storm that shows up a week out and other than fine details never really waivers a ton.  It’s gonna be you’re usual screw job miller B type deal south of PHL probably.  I guess the shortwave could end up dampening and washing out as it traverses the Midwest probably  

It looks like the TPV drop into Eastern New England, which snuck up on the models, could give us a much needed assist here. We often get snows several days after an Arctic outbreak as the temperatures are moderating. The rising PNA and lingering -AO can also work in our favor. 

[CIK62]

First 10 days of February averaging 36degs.(30/42) with no real snow at first blush.       If the long range shows snow, it is working from memory only!     You know the score>>> Jan. 20---Feb10 averages 9" so show some snow God Damn It-----the model engine says to itself.    Lol.

At any rate,  the latest LR is in and no change till Week 3 of February.         Supposedly another Strat Warming shortly will produce the party.

Meanwhile find a way to use this useless output to predict lottery outcomes.

[MJO812]

Gfs came further south and stalls the low. 

[sussexcountyobs]

19 minutes ago, MJO812 said:

Gfs came further south and stalls the low. 

Is this a Monday, or Tuesday threat? I hear GFS is like a day faster with this threat.

[donsutherland1]

Tomorrow into Wednesday morning, a weak system will come eastward bringing snow, sleet, freezing rain and rain to parts of the region. Snowfall amounts will be fairly light. Initial snowfall estimates include:

Allentown: 2" or less
Boston: 1"-3"
Hartford: 1"-3"
Islip: 0.5" or less
New York City: 2" or less
Newark: 1" or less
Philadelphia: 1" or less
Worcester: 2"-4"

A few days later during January 28-29, another storm will impact parts of the East Coast. That storm will likely exit off the Southeast coast bringing some accumulating snow to parts of the Southeast and lower Middle Atlantic region, including the Richmond and Washington, DC areas. It now appears that the storm could develop too far offshore to produce an appreciable snowfall.

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.

Overall, the final week of January will feature generally below normal readings. The coldest air mass so far this season could bring the temperature below 20° in Central Park on one or two days late this week.

The ensembles suggest that the PNA could briefly go positive near the end of the month and start of February. That could allow for the potential of a snow event during the February 1-2 period before milder air returns during the first week of February. Some of the guidance suggests that a period of much warmer than normal temperatures could develop for a time once the warmer air moves in.

The ENSO Region 1+2 anomaly was -0.8°C and the Region 3.4 anomaly was -1.1°C for the week centered around January 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.85°C and the ENSO Region 3.4 anomaly has averaged -1.07°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was +10.13 today.

Today, the preliminary Arctic Oscillation (AO) figure was -3.380.

On January 24 the MJO was in Phase 6 at an amplitude of 1.900 (RMM). The January 23-adjusted amplitude was 1.766.

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 99% probability that New York City will have a warmer than normal January. January will likely finish with a mean temperature near 35.0°.

 

[CIK62]

The last 6 days of January are averaging 28degs.(24/31).      Making 24degs., or -8.0.

Month to date is 36.7[+4.4].         January should end between 34.2 and 35.0.

The winter(12/21...... to date) is 167/36=+4.6.     Last year at this time it was +6.9.

All models have 10" to 15" of Snow for the period Jan.31---Feb. 02.*****

However, the GEFS Extended dropped from 50" to just 10".      Toilet paper supply still increasing.      So is the amount of sh.t.      Where is the janitor?

*****All GFS snow gone already on the 06Z run.       MISTER JANITOR YOU ARE NEEDED HERE RIGHT NOW.... ................

35*(48%RH) here at 6am.     37* by 9am.           38*/37* by Noon.

[MJO812]

11 hours ago, sussexcountyobs said:

Is this a Monday, or Tuesday threat? I hear GFS is like a day faster with this threat.

Monday into Tuesday 

[bluewave]

Some notable delayed cold records coming up later in the week. NYC should finally drop below 20° and HPN could get down to 12° or colder. This would be the 3rd latest to drop below 20° in NYC. It would be the 2nd latest for HPN to reach 12. The latest on record for HPN was set just last year. So this is the most recent version of how challenging it has been for winter cold since December 2015.

KNYC   GFSX MOS GUIDANCE   1/26/2021  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 TUE  26| WED 27| THU 28| FRI 29| SAT 30| SUN 31| MON 01| TUE 02 CLIMO
 X/N  39| 34  42| 26  34| 15  26| 16  32| 23  32| 30  38| 30  37 24 39

Frost/Freeze Summary for NY CITY CENTRAL PARK, NY
Each section contains date and year of occurrence, value on that date.
Click column heading to sort ascending, click again to sort descending.

Year	Last	Value	First	Value	Season Length
1931	02-15 (1931)	16	02-16 (1932)	18	365
2001	02-22 (2001)	17	02-05 (2002)	19	347
2012	01-22 (2012)	18	01-22 (2013)	13	365
1974	02-15 (1974)	18	01-15 (1975)	17	333
1981	03-18 (1981)	17	01-09 (1982)	17	296

 

 

KHPN   GFSX MOS GUIDANCE   1/26/2021  0000 UTC                       
 FHR  24| 36  48| 60  72| 84  96|108 120|132 144|156 168|180 192      
 TUE  26| WED 27| THU 28| FRI 29| SAT 30| SUN 31| MON 01| TUE 02 CLIMO
 X/N  36| 30  38| 24  32| 12  21| 10  30| 15  29| 26  34| 24  34 21 38

Frost/Freeze Summary for WESTCHESTER CO AP, NY
Each section contains date and year of occurrence, value on that date.
Click column heading to sort ascending, click again to sort descending.

Year	Last	Value	First	Value	Season Length
2019	03-08 (2019)	12	02-15 (2020)	9	343
2006	01-16 (2006)	11	01-25 (2007)	11	373
2012	01-16 (2012)	10	01-22 (2013)	11	371
1954	-	-	01-21 (1955)	12	-
1974	02-10 (1974)	9	01-20 (1975)	9	343

[donsutherland1]

Morning thoughts...

At 8:05 am, pockets of snow, sleet, and freezing rain were moving north and eastward in central and southern Pennsylvania. That precipitation/will move into the region later this morning or early this afternoon.

Today will be cloudy with periods of light snow, sleet, freezing rain, and rain developing. Minor accumulations are possible in New York City and Philadelphia (generally 1” or less). North and west of New York City, from the Hudson Valley into southern New England, 1”-3” snow is possible. East of a line running from Philadelphia to New York City, including Long Island, generally 0.5” or less of snow is likely. Temperatures will likely top out in the middle and upper 30s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 37°

Newark: 38°

Philadelphia: 39°

Precipitation will end tomorrow morning.

[bluewave]

I think that the amplified MJO 7 is helping us with the PNA and EPO. Notice the west based block trying to link  up with the Aleutian Ridge. The area of deeper blues are getting squeezed further SW off the West Coast than earlier runs. This can help us with the snow potential around Feb 1-2. The other thing to watch is if the MJO can make it over to Phase 8 before weakening in early February. The Euro has it currently stalling out in Phase 7 for a time. So we will probably need to watch later runs to see how they update.

New run

Old run

 

 

 

[MJO812]

6 minutes ago, bluewave said:

I think that the amplified MJO 7 is helping us with the PNA and EPO. Notice the west based block trying to link  up with the Aleutian Ridge. The area of deeper blues are getting squeezed further SW off the West Coast than earlier runs. This can help us with the snow potential around Feb 1-2. The other thing to watch is if the MJO can make it over to Phase 8 before weakening in early February. The Euro has it currently stalling out in Phase 7 for a time. So we will probably need to watch later runs to see how they update.

New run

Old run

 

 

 

The rising PNA and NAO might help us out for next week's  storm.

[EastonSN+]

18 minutes ago, bluewave said:

I think that the amplified MJO 7 is helping us with the PNA and EPO. Notice the west based block trying to link  up with the Aleutian Ridge. The area of deeper blues are getting squeezed further SW off the West Coast than earlier runs. This can help us with the snow potential around Feb 1-2. The other thing to watch is if the MJO can make it over to Phase 8 before weakening in early February. The Euro has it currently stalling out in Phase 7 for a time. So we will probably need to watch later runs to see how they update.

New run

Old run

 

 

 

GEFS also stalls in 7. Is 7 generally good in Feb?

[SACRUS]

Still looks like a major 2 day warmup possible between 2/4 - 2/7.  

[SnoSki14]

23 minutes ago, SACRUS said:

Still looks like a major 2 day warmup possible between 2/4 - 2/7.  

Seems likely with amplified MJO in 6/7 though -AO could dilute it somewhat.

Despite Jan being a mild month overall I did notice the lack of 50+ temperatures we often see due to the AO.

[Brian5671]

37 minutes ago, EastonSN+ said:

GEFS also stalls in 7. Is 7 generally good in Feb?

7 is warm-you want 8-1-2 for cold

[MJO812]

Pattern  looks good in the long range on the gfs.  We just need the mjo to go into 8.

[wdrag]

Don and others (Bluewave etal) who may look at this predictive data a lot...   has the EPS or GEFS been better at LR predictions of the AO, NAO, PNA, EPO lets say at 10 days, and 16 days?

I see some differences in the these ensembles...the GEFS overall a little more favorable for winter.  

Not sure who said winter over?   Doesn't look that way to me yet into mid Feb.

 

Maybe it is over, and I don't/didn't realize it???

Thanks,

Walt

[snowman19]

7 hours ago, bluewave said:

Phase 7 is better for us in January and the very beginning of February. You can see the Arctic shot coming up in a few days followed by the snow potential February 1-2. But phase 7 gets warmer for us by around February 5th and beyond. It would be more a ridge just off the a West Coast and a trough in the Plains. So we could get back to more of a south based -AO by around February 5th and a warm up. Then we’ll have to see what the MJO does after the period around the 5th.

Yea, phase 7 in a La Niña winter, especially as you get beyond the first week of February is a strong warm signal in the east

[donsutherland1]

Since December 1, the Arctic Oscillation (AO) has averaged -1.987. Winter 2020-21 is the 11th winter since 1950-51 where the AO averaged -1.500 or below for the December 1-January 26 period. Winter 2020-21 is unique in that it is the only winter from those cases that had no mean trough anywhere over the CONUS.

Snowfall totals today included:

Allentown: Trace
Bridgeport: 0.8"
Islip: 0.1"
New York City: 0.1"
Newark: 0.5"

The weak storm responsible for today's precipitation wil slowly move away overnight into tomorrow with a few additional periods of light preciptitation. All precipitation will end tomorrow followed by slow clearing.

The coldest air mass so far this season will begin moving into the region on Thursday. In its wake, Friday and Saturday could see high temperatures only in the lower and middle 20s in much of the region. Central Park will likely see its first teens of the season.

The ensembles suggest that the PNA could approach positive levels or even briefly go positive near the end of the month into the start of February. That could allow for the potential of a snow event during the February 1-2 period before milder air returns during the first week of February.

The ENSO Region 1+2 anomaly was -0.8°C and the Region 3.4 anomaly was -1.1°C for the week centered around January 20. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.85°C and the ENSO Region 3.4 anomaly has averaged -1.07°C. La Niña conditions will likely prevail at least through meteorological winter.

The SOI was +25.16 today.

Today, the preliminary Arctic Oscillation (AO) figure was -3.444.

On January 25 the MJO was in Phase 6 at an amplitude of 1.890 (RMM). The January 24-adjusted amplitude was 1.903.

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 near 100% probability that New York City will have a warmer than normal January. January will likely finish with a mean temperature near 35.0°.

 

[LibertyBell]

On 1/25/2021 at 2:32 PM, bluewave said:

It looks like the TPV drop into Eastern New England, which snuck up on the models, could give us a much needed assist here. We often get snows several days after an Arctic outbreak as the temperatures are moderating. The rising PNA and lingering -AO can also work in our favor. 

it also looks like that suppressed event on the 28th may be setting us up for the big one here

[LibertyBell]

18 hours ago, bluewave said:

Phase 7 is better for us in January and the very beginning of February. You can see the Arctic shot coming up in a few days followed by the snow potential February 1-2. But phase 7 gets warmer for us by around February 5th and beyond. It would be more a ridge just off the a West Coast and a trough in the Plains. So we could get back to more of a south based -AO by around February 5th and a warm up. Then we’ll have to see what the MJO does after the period around the 5th.

Looks like we could be going into Phase 8 after the middle of February?

 

[LibertyBell]

18 hours ago, SnoSki14 said:

Seems likely with amplified MJO in 6/7 though -AO could dilute it somewhat.

Despite Jan being a mild month overall I did notice the lack of 50+ temperatures we often see due to the AO.

yeah a friend of mine thought it was ridiculous when I told him this was a mild month- he said if it's mild why dont we have temps in the 50s and 60s like we did last January?

[LibertyBell]

On 1/25/2021 at 5:44 AM, tmagan said:

Last top 30 coldest Central Park winter... 1993 - 1994

Last top 30 coldest Central Park autumn... 1976

what about 10-11 and 14-15?  those were mighty cold.  02-03 and 03-04 were too

[LibertyBell]

On 1/25/2021 at 7:57 AM, bluewave said:

The extreme south based blocking pattern with the +EPO has produced a real temperature oddity for NYC this month. Even with the current average temperature around 37°, this was the 4th lowest January  monthly maximum temperature in NYC since 1980 at only 51°. The current forecast has this high holding for the rest of the month. Even when the coming  Arctic air lowers this average temperature, it will still be way above the other years since 1980 with such a low monthly high temperature. So you can brag that we finally beat a cold record from Jan 94.

New York City...
   Central Park, NY
   Ptcldy   Snow     Flrrys   Ptcldy   Sunny    Sunny    Mocldy
     /38    30/34    33/39    30/34    22/29    15/32    25/38
      /00    20/80    70/40    20/20    00/00    00/00    20/30

Lowest January high temperatures in NYC since 1980
 

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

Rank	Year	Highest Max Temperature	Avg Temperature
1	2009	47	27.9
2	1981	49	26.2
3	2003	50	27.5
4	2021	51	37.0
5	2011	53	29.7
-	1988	53	29.5
6	2001	54	33.6
7	1994	55	25.5
-	1991	55	34.9

this may be why people I know think that this has been a really cold month!  When I tell them it's been mild they refuse to believe it because there haven't been 50s and 60s like we had last January.  To most people around here, temps below 50 are considered cold.