GaWx

1 hour ago, BlizzardWx said:

I've been trying to think about what is "going wrong" with such a prolific -WPO to be talking about record warmth down my way. Do you know if a -WPO is typically good for the southern Plains? Is it perhaps atypical to have a -WPO paired with a -PNA or is that typical? I know when I look at the current pattern it seems reasonable to have a west coast trough downstream of that high but maybe sometimes ridging extends further southeast? 

Mostly just trying to build my understanding for this index. 

 I’ll check now for December. These 9 were solidly -WPO Decembers dominating throughout the entire month:

2013, 2010, 2009, 2005, 1995, 1989, 1980, 1961, and 1956. Of these:

1) Cold in the S Plains?

2013, 2009, 2005, 1989, 1961

2) Near normal S Plains?

2010, 1995

3) Mild S Plains?

1980, 1956

 So, strong -WPO Decembers leaned somewhat to the cold side in the S Plains, but only 5 of 9 averaged cold. It looks like this year may end up averaging near normal based on a cold 1st half and mild 2nd half. But we’ll see.

PNA for these 9 Decembers:

2013: moderate -PNA

2010: strong -PNA

2009: weak +PNA

2005: strong +PNA

1995: moderate +PNA

1989: moderate +PNA

1980: weak -PNA

1961: strong -PNA

1956: weak -PNA

 So, PNA for these solidly -WPO Decembers is very mixed.

 Well, as of Dec 13th, the MJO still hasn’t returned to phase 8! It was in 8 only Dec 3rd-7th. Dec 8th-13th have all been in very weak (essentially neutral) phases 5-7. I still think it has a good chance to get back into 8 very soon, but we’ll see:

 The 12/13/25 WPO of -3.48 is the most negative WPO on any day in December since 12/25/1996!

 The only Decembers since 1948 with at least one day lower than -3.48 are:

1996, 1989, 1983, 1977, 1966, 1955

I just took a walk in very refreshing and invigorating 40 degree single digit dewpoint air along with beautiful blue skies and light winds. I love this wx!

OHC has been rising sharply the last 30 days:

21 minutes ago, SnowGoose69 said:

That looks like a lock.  Unfortunately if the PNA is still -2 to -3 that won't work, even getting it to 0 is ideal

Yeah, unfortunately here’s the ugly truth for E US cold preferrers (NG is down another 1% today making it a whopping 26% drop from the peak 11 days ago):

left graph has EPS HDD (latest out/0Z in purple); note the cliff dive it takes from today’s very cold 33 HDD, which is a whopping 10 above the normal of 23, to 12/18’s mild 18, which is 6 below the normal of 24! It later gets as low as 15 on 12/25, which is 10 below the normal of 25!

3 hours ago, Buckethead said:

I'm starting out at 23. I wasn't expecting that!

Sent from my Pixel 10 Pro using Tapatalk
 

2 hours ago, Met1985 said:

Must be something about part of the PV rotating through and out.

 It looks like that’s the case (rotated quickly through and out) per 850 temps on the models:

7PM in degrees C last night near the coldest brrrrr!

1AM last night had already warmed some with coldest already rotating to E NC/VA:

7AM this morning had warmed a lot everywhere!

16 minutes ago, PhiEaglesfan712 said:

Looks like it's completely in the center. That's a bullseye if we're playing darts.

Indeed. The official RMM record always puts it in one of the 8 phases (6, 5, 6, 7, 7 per the bolded below for 12/8-12), but, regardless, this is about as bullseye/weak as you can get for a 5 day period:

2025          12           8  0.16185258      0.31161267               6  0.35113916      Gottschalk10_method:_OLR_&_ACCESS_wind      
        2025          12           9  0.23143651      0.18252292               5  0.29474986      Gottschalk10_method:_OLR_&_ACCESS_wind      
        2025          12          10  0.12193847      0.22910139               6  0.25953120      Gottschalk10_method:_OLR_&_ACCESS_wind      
        2025          12          11 -9.49310213E-02  0.16355878               7  0.18911207      Gottschalk10_method:_OLR_&_ACCESS_wind      
        2025          12          12 -2.23553125E-02  8.96196812E-02           7  9.23658386E-02  Gottschalk10_method:_OLR_&_ACCESS_wind

https://www.bom.gov.au/clim_data/IDCKGEM000/rmm.74toRealtime.txt

MJO still hadn’t gone back into 8 as of 12/12 with it technically still in a very weak 7 per the record: so, 12/8-12 in very weak phases 5-7 essentially neutral with it not far from the center

38 minutes ago, suzook said:

If you had any cajones, you would go for a walk this morning. Ha, just kidding. Currently 17 degrees here. BRRRRRR.

No, I’ll pass lol.

26.6 is coldest I saw for here (at 7:40 AM)

 The official (airport) low was 25 as of 7AM.

 Cold air (SE style) is always appreciated by cold weenies like me because heat/humidity are so dominant much of the year. I had an invigorating walk just after it went through here early this evening. It was still in the upper to mid 50s, but it still felt so clean and crisp due to the combo of the the wind and dewpoints plunging into the mid-20s! Dry cold gives me so much energy! We’d better enjoy it while we still have it.

 Forecast is for low 20s even down in this area! But there’s still a long ways to go with it still at 43.5 here.

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).