GaWx

1 hour ago, mitchnick said:

Wish I had seen these before I made this post as I would have stuck them in with it. Stole them from my MA forum. Eps ensemble members for Christmas Day temps. Laughable. 

Thanks, Mitch.

For the MidAtlantic, I roughly estimate 55% AN vs 45% BN. So, quite mixed as you’re implying. Thus, the predictability for Christmas and other days nearby is pretty low.

Despite my more optimistic posts in recent days, I always still try to be objective and show everything, good or bad. The Euro Weeklies remain steadfast on a warmer than average SE and Mid-Atlantic westward/solid -PNA through almost the entire run. The torchiest still remains well to the west of the E/SE US thanks to occasional cool-offs likely largely related to CAD saving the day. The NE is not far from normal.
 It tries to cool off in general in the E US toward normal the last week (1/19-25), but it isn’t really exciting looking.

  I continue to hope that just like the models have performed in many cases for the last 3.5 weeks, that they keep busting too warm in the E US.

11 minutes ago, MJO812 said:

Here comes another period that was supposed to be mild but took a turn to the colder side. 

 This has been going on a lot since the Nov 20th and earlier runs were too warm for Thanksgiving week in much of the E US.

1 hour ago, Terpeast said:

Objectively, this was a 4” storm for most of NYC. I don’t think that if cpk gets 3.9” then the winter is an auto fail by this standard. Just as 4.1” doesn’t necessarily mean we’re in for a 50” blockbuster. 

Official totals:

NYC 2.7”

LGA 2.6”

JFK 4.6”

Newark 4.1”

Islip 5.8”

Upton 7.3”

Based on these numbers, this storm on its own is bullish for the rest of the season there imho.

49 minutes ago, wncsnow said:

I don't see much to be excited about. CAD could keep us from torching but no winter weather threats on the horizon. 

 
 Anything to keep any torch short-lived rather than long-lived would be a win for me. Considering that the SE will have had a very enjoyably cold dominated 11/27-12/16: IF the SE can somehow manage for 12/17-31 to be only slightly warmer than normal thanks largely to cool wedges, I’ll consider it a win.

 Models are already significantly colder than they were just a couple of days ago for this weekend (12/20-1), which is continuing the trend of them being mainly too warm since ~Nov 20th. Is this going to extend this too warm trend through 12/21? If so, can we even trust the longer range of the ensembles?

Fwiw, the 12Z GFS has 4 warm periods but all last only ~24 hours with the cool to cold days at least as prevalent.

35 minutes ago, donsutherland1 said:

My thinking for seasonal snowfall for Central Park was 15"-25". It will be interesting to see how things evolve.

So, your high end of 25” is near my new low end as I’m essentially 25”+ for the entire season based on today’s storm (I had no prior prediction). Are you going to raise your prediction from your 15-25” range?

32 minutes ago, binbisso said:

Well cpk will not reach 4" today but many places in the boroughs will. Plus the towns bordering the city will have gotten 6" or more. I'm skeptical this indicator has any value. Maybe just luck. Idk. The big question is how did the nyc metro (within 10 miles of the city) receive 6-8" with a raging pac jet, -pna, +ao and nao and mjo phase 6. From reading on here the last few years I understand nola, Tallahassee, richmond dc and nne can but not the nyc metro on dec 14th no less. Wish someone can explain this 

 Plus the indicator benchmark actually has worked better for 3” (15 out of 15) than for 4” (14 out of 15). Considering what you said (although I think the indicator has value if used correctly…this storm should more than be enough) and that 3” actually has worked better, I feel that this should already be more than enough (and we still have half the month to go, besides) to consider this a bullish indicator for NYC’s coming Jan+ snowfall to be in the vicinity of or above the 30 year normal of 24” for Jan+. Thus, I’m now predicting NYC will have at the very least 21” from Jan onward on top of whatever the Dec total ends up at:

Season…Dec NYC SN...Jan+ NYC SN

20-21…..10.5”….28.1”

17-18……7.7”……33.2”

16-17……3.2”……27.0”

10-11…..20.1”…..41.8”

08-09…..6.0”…..21.6”

05-06…..9.7”…..30.3”

00-01…..13.4”…..21.6”

95-96…..11.5”……64.1”

@bluewave@donsutherland1

 The 48 hour trend on GEFS has been to a -NAO. Keep in mind what we just saw for last week, when the Nov 28th forecast had a +NAO and it ended up as a strong -NAO.

 Dec 12th GEFS:

Dec 14th GEFS:

2 minutes ago, Krs4Lfe said:

Just light snow now, going to end in a few minutes, I'm sure. Becoming quite cold and blustery. Finished off with just about 6" here in Bayside (one of the colder and more elevated spots of Queens). Waiting for the final measurements from CPK, LGA, and JFK, but seems like the lowest amounts are around 3.5 in parts of Brooklyn, Manhattan, Bronx, but Staten Island Queens has widespread 5-6." Seems pretty in line with all forecasts. Nice bust in the good direction though for the suburbs, lots of 6-8 in southern Westchester, northeast and central NJ, and Suffolk County. NYC is surrounded by 6-8 lol, but too warm to start off in the boroughs, knocked us down to 3-6 (which was in line with forecasts).  

Any chance LGA can beat 3.6”? If so, it would mean their heaviest single storm total in nearly 4 years (Jan of 2022) and heaviest in Dec in 5 years.

 On Nov. 4th, I made airline reservations with some friends to arrive this morning at LaGuardia from Savannah at 11:14AM for my first NYC trip since the summer of 2011 and their first trip there ever. Due to unexpected issues that suddenly came up with my friends, we had to cancel the very next day (fully refunded back to CC immediately). This had been emailed to me from what I had booked:

Sunday 14 Dec 25

Flight Information

Delta Air Lines

/Republic Airways Delta Connection DL 5603

Savannah,

New York La Guardia,

09:05 AM

11:14 AM

Terminal C

 It’s a good thing we canceled this trip because this originally scheduled departure of 9:05AM from SAV has still not taken off and as of now isn’t scheduled to depart til 12:30PM!

6 minutes ago, Krs4Lfe said:

That would probably boost them to 3", considering ratios are likely closer to 10:1 now that temps are a few degrees colder than this morning. Do you know how much LE has fallen at LGA and JFK since then 

LE 7-10AM:

LGA 0.13”

JFK 0.17”

These compare to the NYC 0.14”.

14 minutes ago, hooralph said:

In Riverside Park, in the 100s (about a mile as the crow flies from CPK station), looks like about 3.5” ?

stunning. If you are sitting at your computer raging about the official measurement and not getting out and enjoying it, you’re doing it wrong…

CPK station picked up 0.14” of liquid equivalent 7-10AM since the 7AM 1.1” measurement per the link below. When adding what they got since 10AM with it still falling, they could approach 0.20” liquid equivalent since the 1.1” measurement.

https://forecast.weather.gov/data/obhistory/KNYC.html

20 minutes ago, mob1 said:

30 at the park now with snow continuing. I really hope this brings them to some semblance of a respectable number. 

Knowing them though, the final will probably be something silly like 1.3"

The 1.1” at NYC was as of 7AM when it was having “light snow” (vis 1 mile). Since then, the vis dropped to 0.75 miles vis (still called light snow) at 8 AM followed by moderate snow at both 9AM and 10AM with only 1/2 mile vis. One would think they’ll have much more than 1.1” when this is done (shortly).

1 hour ago, bluewave said:

I recently complied the data in more detail after getting some comments on exactly where the cutoff may be. This is what I posted in the NYC metro forum a few days ago and I will update when this month is complete. It seems to be that 4 to maybe 5 inches is where the cutoff level is. But the main takeaway is that the average to above average seasons went 6”+ in December.

 

The snowfall data below is what I post each December for La Niña conditions using the newer RONI definition due to the warming of the global oceans. The December to seasonal snowfall relationship has worked 14 out of the last 15 times.

My guess is the reason for the reliability as an early seasonal marker for below and normal to above average snowfall across the entire season is related to the La Niña seasonal progression. They tend to be more frontloaded in nature so their seasonal snowfall pattern is usually revealed early on in December. Plus in our warmer climate we have been noticing more repeating patterns perhaps related to non linear convective thresholds being met in tropical oceans driving the forcing.

The relationship holds for NYC, EWR, and LGA. I will post the data for NYC below which is similar to the other two stations. For the sake of this discussion I have been using 4” of snow in December as the cutoff. But it’s possible that it could actually be a little higher around 5” inches based on the available data. So it’s fine if someone else wants to use a 4-5” snowfall range for December snowfall as the cutoff line for below and normal to above normal seasonal snowfall.

I am not making the argument that the December snowfall is causing the outcome of the rest of the season to change. Just that it serves as a marker of what expect the rest of the season. Sometimes two data points can be related due to other underlying variables that may not yet be fully sampled by our current scientific understanding.  

I will update this post once we have the complete December snowfall data.

NYC December to seasonal snowfall during the most recent 15 La Niña seasons as defined by RONI in either the fall into winter

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

24-25….2.8”….12.9”

22-23….T……….2.3”

21-22…..0.2”……17.9”

20-21…..10.5”….38.6”

17-18……7.7”……40.9”

16-17……3.2”……30.2” the one case in the last 30 years that didn’t work out

11-12……0.0”…..7.4”

10-11…..20.1”…..61.9”

08-09…..6.0”…..27.6”

07-08……2.9”…..11.9”

05-06…..9.7”…..40.0”

00-01…..13.4”…..35.0”

99-00…..T……….16.3”

98-99……2.0”…..12.7”

95-96…..11.5”……75.6”

 

Chris,

 So, your data shows that 3”+ actually worked better with a perfect 15 out of 15 with regard to predicting snowfall Jan+. Why not consider using 3” as the cutoff instead of 4”?

@donsutherland1

 Well, I just saw it updated for Dec 11th. It, indeed, looks like it finally was headed back toward phase 8. Technically, they’re calling 12/11 a very weak phase 7. Good chance I think that it returned to phase 8 on 12/12 (inside the circle)! We should know by tomorrow evening about 12/12.

2 hours ago, Krs4Lfe said:

It’s astonishing how quickly winters have changes from the 2010s to the 2020s. This was peanuts a decade ago. This decade; a 4 inch snow storm feels like a lot. Makes me realize how good the 2021 winter was. Only above average snowfall since 2018. 2022 and 2019 were around 20 here in NYC, but the other 4 years were almost complete ratters.

 A 4” snow seems like it would be considered quite a notable and impactful snow there and in most places. I understand that it’s not considered “major” up north, but down south it sure is in most areas like Atlanta. In Savannah, that would easily be in the historic category like the absolutely amazing and unheard of nearly 3” of mainly sleet (some snow finally fell pretty late into the storm) I got in January.

 Will NYC reach 4”? That’s the magic amount for a total in Dec that @bluewaveand @donsutherland1have said is an excellent predictor in La Niña winters for above average for Jan+.

 The 12/8-10 MJO were all in very weak 5-6 (essentially neutral):

 In the interest of showing objectivity, I expect the 12Z Euro, which is about to be released, to not be as cold as the 0Z that I posted 3 temp anom maps from. But the overall trends toward not as warm, more CAD, and instability of models within just a week seems real to me and tells me not to bet the farm at least yet on a mainly mild 12/18-31 mid-Atlantic south like has been suggested by ens. means. We’ll see.

Edit for 12:55 update on 12Z Euro vs 0Z:

-12/20 map not quite as cold but still BN

-12/22 and 12/25 maps much warmer

—————

I expected this because 0Z was such a cold run and thus appeared to go too far. But regardless, 12/20 is overall still trending colder in model consensus and models remain unstable telling me to not bet too heavily on late month mild domination.

The dreaded 0Z Euro E US torch: awful!

12/20:

12/22:

12/25:

 I remain on “hope the Euro Weeklies for Jan fail miserably mode” because not only did today’s hold onto the mild pattern (though consistent blowtorch still well W of the E US thanks probably to refreshing CAD at times), they warmed that final week of the run (1/19-25) vs yesterday:

H5 yesterday’s run for 1/19-25:

H5 today’s run for 1/19-25:

2m yesterday’s run for 1/19-25:

2m today’s run for 1/19-25:

Edit: Lakes to NE still average near normal temps almost every week of the run.

12 minutes ago, TheClimateChanger said:

 

NG bulls want the opposite of this EPS HDD trajectory (see left graph): the cold part through 12/15 was dialed in to prices many days ago:

3 minutes ago, Maestrobjwa said:

Thanks! Where do you find that? Been interested in the PDO because of how much the negative state screwed with snow chances the last decade.

https://s2s.worldclimateservice.com/climatepanel/
 

Then click on 2nd map on right.

Just now, Maestrobjwa said:

So...how's the PDO looking?

WCS: Pretty steady for now but still within a longer term (6 month) rise:

 Today’s GEFS PNA forecast is the most negative for this Dec that I can recall:

 This implies the realistic chance for a sub -1 Dec PNA. Whereas that’s bad news for those wanting E US cold in the 2nd half of Dec in the MidAtlantic/OH Valley south, it isn’t necessarily bad news for January prospects. That’s because in the vast majority of cases for -ENSO, the PNA in January rose sharply from Dec:

PNA Dec/Jan for -ENSO for strongly -PNA in Dec

- 1955-6: -2.1/-1.3 (rose 0.8)

- 1961-2: -1.2/-0.1 (rose 1.1)

- 1964-5: -1.7/-0.2 (rose 1.5)

- 1971-2: -1.5/-1.4 (rose 0.1)

- 1984-5: -1.6/+1.6 (rose 3.2)

- 1996-7: -1.2/+0.6 (rose 1.8)

- 2008-9: -1.4/+0.6 (rose 2.0)

- 2010-1: -1.8/+1.3 (rose 3.1)

- 2012-3: -1.0/+0.6 (rose 1.6)

- 2013-4: -0.9/+1.0 (rose 1.9)

- 2021-2: -1.6/+1.0 (rose 2.6)

So, average PNA rise Dec to Jan for these was a whopping 1.8!

Dec temperature anomalies: coldest N Rockies to N Plains/mild much of SE 1/3:

Jan temp. anomalies: coldest shifts 1,000 miles SE and warmth gone

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table

 Natural gas is down still another 3% on the day, which brings the total drop since the peak of 8 days ago to a very steep 25% on an anticipated much warmer E US pattern (though maybe not to a torch in the means as I stated in my prior post) starting mid to late next week and continuing for the foreseeable future! At least that’s some good news for future heating bills.

@Stormchaserchuck1