January 2018 Discussions & Observations Thread

[Rtd208]

Current temp is 5 here.

[Cfa]

Currently 7.1° here, after a low of 6.4°....

First single digits since Feb 2016.

[bluewave]

Arctic sea smoke off Long Beach this morning.

 

 

 

 

[Isotherm]

3 hours ago, nzucker said:

Great post..I think we will be colder than normal thru about Jan 10-15, then have a rapid warm-up with several cutters. 

This has been typical of La Ninas winters with the cold December through mid January, a warmer February, and then a cold March.

The intensification of the PNJ has been synonymous with the fact that the polar vortex was never fully disturbed, and that overall background conditions of -ENSO and low solar/-QBO send mixed signals as to the structure and intensity of the stratospheric vortex. 

As you say, however, I do expect some north Pacific blocking to continue which will continue to make each blast behind a cutter meaningful cold. The current displacement of the polar vortex into the eastern United States may be the most significant since Jan 1994 or Jan 1977, and that is synonymous with the -EPO block.

 

 

Thanks Nate; I concur. I'm already seeing early indications of the development of a tropospheric precursor pattern which could eventually enhance WAF and disturb the SPV more than it has been so far this winter, about 4-5 weeks down the road. This could have implications for late winter, but I think the idea of a not insignificant warmer period has merit for mid winter. Thus far, things are progressing congruously to my outlook with the cold/snowier than normal December-early Jan period. The question will be, how significant are the mild intervals in mid/late Jan? Will they countervail the early month cold anomalies? I'm not sold on abandoning the idea of a normal to warmer than normal January mean just yet. 

[North and West]

Frosted window panes.

Currently 6.


.

[donsutherland1]

Two photos from this morning. The latter shows Arctic sea smoke in the background.

[Eduardo]

17 hours ago, Isotherm said:

The preeminent, highly capricious hemispheric pattern will continue over the coming weeks; however, background forcing mechanisms will increasingly countermand the propitious signals for colder than normal in East. The BDC is beginning to weaken, reflective of warming temperatures in the tropical stratosphere, and decreasing ozone concentrations in the Arctic domain. Wave-2 activity will see a spike over the coming week, though well within typical standard deviations. Wave activity flux will largely decrease over the week 1-2 period as tropospheric-stratospheric energy transfer declines, and the PNJ intensifies. One can see the tightening / consolidation on latest data, although the w2 activity will aid in maintaining a somewhat northward displaced surf zone.

 

Nonetheless, the majority of January will feature a stronger than normal SPV and thus a predilection to downwell these anomalies into the troposphere, preferentially the eastern AO and NAO domains. This will tighten the jet, tending to enhance the West Atlantic Ridge signature. 

 

Conversely, one of the more propitious signals is the development of a mean chi 200 signature not too dissimilar from the structure in 2013-14 which induced poleward ridging in the NE PAC. The MJO will circulate into the IO/Maritime Continent w/ probable maintenance in these regions for the balance of January. However, there will be sufficient off-equator forcing to extend the jet eastward w/ induction of rossby wave breaks (sound familiar?) into the NPAC. Heightened WAF in the NPAC will continue to force the regeneration / pulsing of mid/upper level ridging near/south of AK. 

 

What will be the resultant atmospheric circulation structure? In my opinion, it will be one which largely favors the Lakes/Mid-west and interior Northeast for snowfall, with warm-up / rain / cold -- a very spasmodic roller coaster of temperatures but biased warmer than normal on the East Coast. The NHEM circulation will attempt to force the trough in the Central US, and there will be resistance of the +NAO induced West Atlantic Ridge.

 

In other words, I'm not seeing a blowtorch, but it still looks biased warmer than normal for the East Coast with a largely unfavorable pattern for snowfall. It should be warmer than nromal on the West Coast with colder than normal from the Rockies to the Lakes. AAM tendency will be negative, but with poleward propagation of +AAM anomalies which will maintain a +NAO. Arctic outbreaks will continue; however, with the poleward EPO predilection. We are entering mid winter, so snowfall is certainly possible even in less than favorable patterns. But it will be a step-back from the early winter favorability which would be harmonious with my thoughts on this winter's progression.

 

So much respect for your contributions to this community.  Always a pleasure to read your analyses.  I possess nothing like the knowledge and expertise you have, but I'll pose a few simple questions: (1) Are the "background forcing mechanisms" referenced in your first paragraph Niña-driven, in the main?  And (2) if so, is the Niña actually strong and deep enough to get the ball rolling towards the outcome you foresee. Finally, (3) are we basically talking about a gradient pattern here?

[ForestHillWx]

Maxed out at 9 yesterday. Was at 0 at 9 am today. Currently 2. 

[MJO812]

This reminds me of Jan 2011 when everyone thought January was going to be warm but it remained cold and snowy until February .

There isn't anything to indicate that this month is going to be warm.

[donsutherland1]

Through the 12z runs of the GFS and CMC, the models remain in two distinct camps. The 0z UKMET and 0z/12z CMC brought a widespread accumulating snowfall throughout the region. The 0z ECMWF and 12z GFS brought only a little snowfall to the region except for Long Island. The short-range RGEM suggested more than 6" of snow could fall across much of the area, but it is out of its most reliable range.

So, at least at this point, one cannot dismiss either the no snowfall or significant snowfall scenario for New York City and nearby suburbs. Long Island appears in good shape for a moderate and possibly significant snowfall.

Given where things currently stand, my baseline thinking from yesterday is little changed. I continue to believe that most of Long Island will pick up an accumulating snowfall with eastern Suffolk County having the best chance of seeing 6" or more. NYC and its immediate suburbs will pick up a light snowfall with a small accumulation (up to a few inches possible). Eastern New England could also pick up a significant snowfall, but there's a lot of uncertainty. if the dual-center solution is accurate, the consolidation of systems could occur too far to the south and east to bring most of New England a significant snowfall. Cape Cod, though would have a good chance of seeing 6" or more snow.

If I had to guess some probabilities for NYC:

No snow: Around 20%; Measurable snowfall: 80%; 1" or more: 40%; 2" or more: 30%; 4" or more: 15%; 6" or more: 5%.

This just reflects my baseline idea right now. A larger snowfall still remains on the table. I'd like to see the UKMET and ECMWF confirm such an idea before I have increased confidence in it. I expect the guidance to come into better agreement in coming runs, though good agreement might not occur until sometime between the 1/2 0z and 1/3 0z runs.

[donsutherland1]

1 hour ago, Snow88 said:

This reminds me of Jan 2011 when everyone thought January was going to be warm but it remained cold and snowy until February .

There isn't anything to indicate that this month is going to be warm.

I'm not aware of many warm forecasts. January looks to at least rival December with its cold anomaly. The possibility of a mean January temperature below 30.0° for the first time since January 2015 is certainly there.

[Hailstorm]

12 hours ago, Snow88 said:

9 degrees right now

 

This is the coldest new years eve that I remember. I went outside to shoot fireworks for 10 mins and came right back in. Very cold outside

So it was you! I live about 3 blocks from you and wondered who the heck would set off those loud boomers in the dead middle of night. Were you at Ave. Y at that time?

[Dan76]

15 minutes ago, Hailstorm said:

So it was you! I live about 3 blocks from you and wondered who the heck would set off those loud boomers in the dead middle of night. Were you at Ave. Y at that time?

Isn't that against the law lol

[doncat]

Looks like 18 degrees will do it for high here today, so that's 3 of past 5 days with sub 20 high temp.... Low today was 5....December finished with a  -3 departure.

[BxEngine]

I think wednesday is going to screw up the below freezing streak for NYC. 

[bluewave]

Getting good ice coverage on the major Long Island bays.

 

 

 

 

[Morris]

3 minutes ago, BxEngine said:

I think wednesday is going to screw up the below freezing mark for NYC. 

High of 27 on both the Euro and GFS.

[BxEngine]

2 minutes ago, Morris said:

High of 27 on both the Euro and GFS.

Gfs mos has 29, and winds out of the southwest for a time. I think we overperform a bit. Gonna be close. 

[Morris]

14 minutes ago, BxEngine said:

Gfs mos has 29, and winds out of the southwest for a time. I think we overperform a bit. Gonna be close. 

High of 26 on the 3km NAM.

[LongBeachSurfFreak]

 If we can winds to go calm tonight we should see some ridiculous lows at places like West Hampton. Temps/dews are primed and ready to drop like a rock after sunset away from urban centers 

[Morris]

2 hours ago, LongBeachSurfFreak said:

 If we can winds to go calm tonight we should see some ridiculous lows at places like West Hampton. Temps/dews are primed and ready to drop like a rock after sunset away from urban centers 

2 in Westhampton, now that winds have gone calm.

[donsutherland1]

With today's high temperature of 19° in New York City, today was the 7th consecutive subfreezing day in NYC. This is the longest such stretch since January 16-24, 2005 when the temperature stayed below freezing for 9 consecutive days. Today was also the second day this winter with a high temperature below 20°. The last time that happened was winter 2013-14 when there were three such high temperatures.

[Morris]

57 minutes ago, Morris said:

2 in Westhampton, now that winds have gone calm.

0 now in Westhampton.

[tim]

17 minutes ago, Morris said:

0 now in Westhampton.

..3* here in Eastport.

[Isotherm]

5 hours ago, doncat said:

Looks like 18 degrees will do it for high here today, so that's 3 of past 5 days with sub 20 high temp.... Low today was 5....December finished with a  -3 departure.

18.6F high and 3.2F low today. My high yesterday was actually colder due to clouds -- only 16F. The 28th's high was 19.5F. December finished -2.7 here. We were near normal at Christmas, so significant decrease in several days.

[donsutherland1]

Perhaps a lesson in complexity and model convergence that might be somewhat applicable to the potential January 4 storm--whether the ultimate track is too far offshore or sufficiently close to bring significant snows to much of the region:

From Kocin, Uccellini, et al., "The Blizzard of 25-27 December 2010: Forecast Assessment:"

The entire suite of European, Canadian and U.S. models didn't converge on the correct forecast scenario until 36 to 48 hours prior to the onset of the heaviest snow, generally late on the 24th through early on the 25th. furthermore, the significant model differences on 24 December 2010 contributed to forecaster uncertainty. Many of the GFS/GEFS and SREFS members trended with a storm system closer to the coast and therefore a heavier snow solution for New York City. Meanwhile, the ECMWF forecasts kept the track farther offshore, suggesting the storm would not be too severe, even though earlier ECMWF forecasts indicated more of a threat several days before the storm. It wasn't until the 1200 UTC 25 December model cycles that all the models converged on a solution that put New York City squarely in the are of heavy snowfall and blizzard conditions on 26 December.

[Isotherm]

10 hours ago, Eduardo said:

So much respect for your contributions to this community.  Always a pleasure to read your analyses.  I possess nothing like the knowledge and expertise you have, but I'll pose a few simple questions: (1) Are the "background forcing mechanisms" referenced in your first paragraph Niña-driven, in the main?  And (2) if so, is the Niña actually strong and deep enough to get the ball rolling towards the outcome you foresee. Finally, (3) are we basically talking about a gradient pattern here?

 

Thanks! Appreciate the kinds words. 1) Partially Nina driven, a combination of worsening tropical forcing, GWO/AAM cycling, and other internal mechanisms such as the brewer-dobson circulation which governs ozone transport, among others; 2) It's not as much about the magnitude of SSTA's as much as it is the cycling and orientation of tropical forcing which can often resemble ENSO events stronger than the current. In the pre-season, I thought this winter's tropical forcing pattern would more closely resemble a moderate or stronger La Nina, even though SSTA's weren't reflective of that. The NPAC ridging is classic Nina pattern. The December pattern was expected to be the major aberration month, with a gradual retrogression thereafter; 3) Not a real gradient pattern (in the sense of latitudinal thermal gradients); the cold should try to pool in the mid-west / rockies eastward to the appalachains, and the one constant this winter has been a predominately +NAO, which will continue to resist the eastward expansion of cold in the means. MJO cycling will act contemporaneously to force SE-ridging in the means as well. We'll have arctic shots, but the pattern doesn't look great for coastal snow potential after the 10th.

[nzucker]

15 minutes ago, Isotherm said:

 

Thanks! Appreciate the kinds words. 1) Partially Nina driven, a combination of worsening tropical forcing, GWO/AAM cycling, and other internal mechanisms such as the brewer-dobson circulation which governs ozone transport, among others; 2) It's not as much about the magnitude of SSTA's as much as it is the cycling and orientation of tropical forcing which can often resemble ENSO events stronger than the current. In the pre-season, I thought this winter's tropical forcing pattern would more closely resemble a moderate or stronger La Nina, even though SSTA's weren't reflective of that. The NPAC ridging is classic Nina pattern. The December pattern was expected to be the major aberration month, with a gradual retrogression thereafter; 3) Not a real gradient pattern (in the sense of latitudinal thermal gradients); the cold should try to pool in the mid-west / rockies eastward to the appalachains, and the one constant this winter has been a predominately +NAO, which will continue to resist the eastward expansion of cold in the means. MJO cycling will act contemporaneously to force SE-ridging in the means as well. We'll have arctic shots, but the pattern doesn't look great for coastal snow potential after the 10th.

There may be one more coastal snow attempt after the Thursday one around Day 10. Looks like a potential second trough coming into the TN/MS Valley...some of the GFS runs show this cyclogenesis potential.

[donsutherland1]

Danbury (DXR) and Westhampton (FOK) were -1° at 9 pm.

[Morris]

58 minutes ago, Morris said:

0 now in Westhampton.

-1