billgwx

1 hour ago, Rjay said:

Thanks for joining us the past few days Bill.

You're welcome. Been a while

33 minutes ago, DHS@ABE said:

The 12Z GFS MOS has above freezing surface temperatures at JFK for the entire event. 

I'd look at the resulting wet bulb temperatures from MOS temp and dewpoint more than its forecast temp. A quick and dirty estimate for wet bulb is Dpt + 2/3 * (Tmp - Dpt). Values 32-34 may still get you wet snow, provided snow is what's falling and not sleet or rain...once you lose a snowflake you can't get it back

13 minutes ago, jm1220 said:

Verbatim (laughable of course) the mid level lows seem to track in a way that keeps the mix and dryslot just south of the island. The mix becomes a problem when you start having strong southerly mid level winds. 

Which is what the warmer NAM solutions had been forecasting.

3 minutes ago, forkyfork said:

agree. i just wait for the maps to come out on the better sites to do an analysis. "rgem is nw!" doesn't do anything for me

Let's at least figure out why this is happening.

One storm sticks out in my mind where the NAM scored a warmer coup like this--March 2001. Global models stayed cold, NAM was the first to cast doubt with warmer profiles aloft, it ended up being right. Was at Mount Holly where we had warnings up, got a sloppy 1-3." Eastern Long Island still did very well though.

I've also seen the NAM go too far NW/warm, so it works both ways.

Consistency is key. If the 18Z run goes warm I'll buy it.

2 minutes ago, NJwx85 said:

It must be so cool to actually issue watches/warnings and then come on here and watch people bitch/complain about not getting the warning they wanted

Like being a pro athlete and tuning in to WFAN to hear similar

1 minute ago, NJwx85 said:

The NWS in Upton, NY has issued a WEENIE SUICIDE ALERT in affect immediately and until further notice. 12-18 snow weenies per hour will be cliff jumping over the next 24 hours. Please stay tuned to your local weather authority for the most updated information on this breaking story.

Fake news. We had to stop doing those when we stopped issuing Blizzard Watches

1 minute ago, jm1220 said:

The Euro is also trending more amped aloft it seemed, but hasn’t reflected to the surface yet? Anyway let’s hope. 

Would be reflected more at 700 mb and 850 mb I think...

Want to see other guidance as amped/warm as the 12Z NAM cycles before jumping on it. Latest parallel GFS looked similar at H5 but was cold...oh wait the GFS is often too cold aloft. Anyway, the NAM amplification yesterday didn't appear to be due to convective feedback. But the model's not consistent run-to-run, 12Z'ers amped/warm and the other cycles colder. All that said, I didn't entirely discount the warmer idea yesterday and threw in some south shore/east end mixing for Long Island.

Just now, nycsnow said:

If models hold seems like most of area would qualify for blizzard criteria... that watch is discontinued it would be a winter storm watch to blizzard warning if conditions warranted?? I remember some watches got discontinued

Blizzard watches got discontinued, just because of that one March bust a few years ago. When we've issued them otherwise they worked out quite nicely.

I think the rationale was that we all freak out when the S word is mentioned, throwing the B word in there too early gets everyone jacked up way too much too soon.

Could go winter storm watch to blizzard warning, also winter storm watch to winter storm warning and then issue a shorter fused blizzard warning. We don't typically do that, the Sterling office has.

10 minutes ago, NJwx85 said:

It's Monday morning and the storm isn't supposed to start until late Wednesday afternoon. Watches typically aren't hoisted until 36-48 hours prior to the start. I'm sure if everything holds you will see watches with the afternoon update. 

Too early for a watch. Very long lead times just lead to "watch fatigue," needlessly add to everyone's work, and invariably something goes wrong. We all know it's coming.

9 hours ago, MJO812 said:

Kuchera ratios are way overblown for this storm...does not account for wind for one. I ran them yesterday for the OKX long term forecast for laughs...15:1?? As usual with the big storms, 12:1 probably best inland and 10:1 closer to the coast, less for wet snow or where sleet mixes in per the NAM.

22 minutes ago, SnoSki14 said:

The storm is likely going to correct south soon. The high is too powerful to the north. A gfs/euro compromise is most likely.

I've never seen a case where the low trended north with such a strong CAD in place. 

What i predict is that certain models will look amped the day before but the storm corrects south & east as it develops. 

January 2016? GFS was the most suppressed as usual with that storm, then the NAM/SREF came into view and corrected that fast as they appear to be doing now.

26 minutes ago, bluewave said:

We’ll be good to go if these solutions hold once within the NAM’s best range. The NAM has been our go to model for snowfall with the numerous Euro misses in recent years. I can still remember the NAM bringing home the goods on the January 2016 blizzard while the Euro was too suppressed.

Agree but would also like to see the SREF there too as in Jan 2016.

11 minutes ago, Allsnow said:

The confluence is only going to let this get so far north. Classic track for the metro for a historic winter storm on the gfs 

GFS is notorious for overdoing this confluence via too strong of a polar jet. If models overdo the snowfall across southern Canada this weekend that too could lead to too strong/cold of a high.

9 hours ago, cleetussnow said:

GFS picked this up when it was at hr. 256.  Unusual to still be there even now.

And the ECMWF long range suggested the idea of a mid December NYC snow event in early November!!

2 minutes ago, Stormlover74 said:

Also the GFS would normally be the too far S&E at this range yes?

ECMWF could be too. Miles to go here but the overall big picture looks good

1 hour ago, wdrag said:

Hi! A few different things... just to try to keep perspective.

 I need op GGEM on board... i see some of it's ensembles are there but I need GGEM op on board. I don't think it will be much of a snow storm for us, if it isn't. 

12z NAEFS has slightly warmer thickness than it's 00z/10 version...5540 cutting thru LI now 00z/17.  That increases risk of mix or rain LI, for at least a time. 

Caution on buying in on the ratios til till we know for sure the sounding is all snow,  and that the 1000-500 thickness is preferably ~5400m    Thereafter it's the DGZ and Banding.  WAYYYY too far off for me to count on anything except decent snow I84 north (heart of the ensemble axis). For now we in the NYS forum seem to be close to the gradient  of snow and no snow.  Gradient error's can be very large. 

I've added the WPC D7 GEFS forecast for 3" or greater of snow Or 1/4" water equivalent glaze or combo thereof.  The prob is 30-49% in dark green. 

Will revisit tomorrow morning...

Today's ECMWF H5 vort and sfc low track were a little too far north for my liking for NYC/Long Island to be all in, supporting being cautious in those areas as you point out. Meanwhile GFS was right down the sweet spot. Also, case of models sniffing it out a week early, only to lose it Days 3-5, then come back to it come watch time? We shall see

Southern stream shortwave trough that is staying open and not going neg-tilt before crossing the Mississippi River Valley...check

50-50 low whose back side confluence will maintain New England high pressure/cold air...check

Track of sfc low and H5 vort max...a little too far north for my liking in today's 12Z op ECMWF but sweet in the op GFS

The "1 week" rule where models see it that far out, then lose it days 3-5, then come back days 1-2?  Probably.

The amazing thing is that the teleconnections in the EPS weeklies saw this potential in **early November**

3 hours ago, DTWXRISK said:

 DEC  16  LOOKING   GOOD

Agree. About to take the leash off the dogs

18 hours ago, DTWXRISK said:

bill    very  reasonable...

my POINT   is  not the   THE BLOB  means     XYZ...  my point is hat I have seen it with a La nina    ever  before.

maybe it  means nothing. 

 but  I  dont know that 

Gotcha. Nor have we seen +QBO over 10.0 like we have now with a moderate La Nina. (QBO usually tends to follow ENSO phase with some lag.) Related?

On 12/1/2020 at 11:18 PM, DTWXRISK said:

 

 

A couple of points which I think need to be mentioned because I think you are overlooking them.  Using statistics to show that something is likely to happen is all well and good until the unusual thing that is not supposed to happen does happen.

 

1000 days in a row the farmer comes out every morning and afternoon and feeds the Turkey. The Turkey becomes convinced that  it is special and chosen and that since it has  always been that way it will continue  . Then one day in the month of October when the farmer comes to feed the turkey….  well we all know what happens.

 

You seem to have discounted the idea that the moderate La Nina  is going to break down in the second half of the winter despite the overwhelming amount of data and model simulations  that show  that is going to happen.  Of course you may be discounting that or you may decide that the models are overdoing the decay of the moderate la Nina and it won't happen until spring. That was perfectly reasonable and possible. But I think it is a risk assumption to assume that the moderate La Nina is going to continue at current intensity for the entire winter.

 

The speculation or assumption that the PDO  is going to be negative and that the EPO  is going to be generally positive is also in my opinion a risky assumption given the return of the enormous blob of warm SSTAs  that have developed in the northeastern Pacific.  The last time  we had  “ the blob’  feature we were not  in  any kind of Enso event --  not   a weak moderate or  strong La Nina   and or  El  Nino.

Even if you are a fan of horror movies (aka "The Blob") got to see things in greater perspective, which to me is the entire North Pacific being warm, aka -PDO. I think that will work to maintain the moderate Nina for longer, with any weakening holding off til late Feb or beyond.

Nicely done especially with respect to the MJO, and had came to similar conclusions. Doesn't mean we here in the NYC area can't experience periods of cold and snow (mid December potential case in point) but it's not looking like a cold/snow lover's winter here. Some other things to consider:

While October Siberian snowfall was 10th highest on record of the last 50+ years, its signal for cold and snow in the Northeast has not worked out well in recent years. Judah Cohen suspects persistently low Arctic sea ice may be playing a role here, and I also notice that in recent years North American October snowfall has been very high and may be stealing the show there.

I've wondered how the QBO could influence this winter. It's totally out of phase with the ongoing moderate ENSO phase, which has never happened before in the period of record. Looking at its potential influence alone suggests less potential for ozone transport from the tropics to the polar regions, which in turn offers less potential for weakening of the polar vortex, implying an overall a +AO phase for this winter.

Moderate La Niña events of yore in NYC were some of the coldest and snowiest in the city's history. But I think almost all were embedded in multi-year La Niña events, and featured pronounced below normal 500 mb heights over all of Canada and persistent high latitude blocking near Scandinavia, also above normal heights to a lesser degree extending from the eastern U.S across the north Atlantic to Britain, and below normal heights from the subtropical Atlantic eastward to the Middle East. Recent moderate La Niña events (all warm in NYC) all featured persistent high latitude blocking centered over central Siberia, much below normal heights centered over Alaska (+EPO), and above normal heights over most of the temperate regions.

To add local flavor to the I looked at two things: (1) average October/November temperatures in Central Park with those of DJF and (2) Central Park winter snowfall in seasons following previous winters with less than 10." Of the last 30 years, those with October/November temperature anomaly trends similar to those of this year, above normal as a whole where November positive anomalies were greater than those of October, were 80% likely to see a warm winter with below normal snowfall. The only predictor to show any skill for a cold winter overall was a cold October, but with only about 55-60% confidence. Other trends in NYC October and November anomalies (warm to cold or vice versa) had little skill. As for (2), only one following winter of record featured an ongoing moderate La Niña, (1998-99, with much below normal snowfall of 12.7 inches), and all the following winters with above normal snowfall occurred during El Niño events.

Not quite obsolete as it provides a lot of info you can't get from other soundings, not quite keeping up with the times either. Could do so much more given developers with the right focus.

Too early. Wake me up when September ends

That said, it should be noted that the Arctic sea ice minimum this month tied for 2nd lowest in recorded history. The record year 2012 was a real outlier, with a severe Arctic storm that August adding to losses above and beyond, so this is about as good as it gets so far. Anyway, that min is bound to have some effect on things this winter, but of course by itself means nothing without the nearer term snowfall response in Siberia in October, the longer term response (usually in northwestern Siberia) of anomalous surface high pressure in November, and still we must look out for wild cards that same month--recurving typhoons and other factors that could throw a wrench in the works. Locally we don't want October and November to both be warm months...

Wasn't weak sauce if you were looking at the Newark and JFK TDWR radar base velocities...low-topped nastiness given the steep low level lapse rates and very dry sub-cloud air. Trees down in Teaneck NJ and I bet elsewhere along the storm's path from Pompton Lakes all the way into the south Bronx. Still looking for damage reports...