GaWx

10 minutes ago, Krs4Lfe said:

Well that is a serious risk once you have a big shake up in the Pacific. There needed to be a shakeup because the omega ridge over Central US couldn't last forever, but the storminess that was required to shake up that ridge has the risk to continue to crash into west coast. A trough over the west naturally leads to heights rising in the east, as seen in the 0z Gfs ensembles. The storminess that was needed to push that central US ridge out can be too much of a good thing, as indicated by the 0z GFS ensembles. I would give more credence to that scenario playing out 

Thanks for your reply. I agree it is a risk, unfortunately. But my supported hopes (GEFS 2nd week on avg has been awful and much too warm) are that today’s 0Z EPS’ moderate +PNA, which starts Jan 7th, will prevail:

 Today’s 12Z ens runs will be extra interesting due to this major disagreement in week 2!

 The 0Z EPS (another run with a transition to a +PNA and a chilly E US) and the 0Z/6Z GEFS (staying -PNA and a warm E US) are in different worlds for mid Jan.

 The CPC GEFS forecasts of yesterday vs today show a bad 24 hour trend if you want it cold in the E US in mid-Jan:

Yesterday’s GEFS PNA forecast was heading up/nice trend vs earlier runs:

Today’s 0Z GEFS said never mind, I’ll stay -PNA through the end of the run: yuck

 GEFS 0Z 360 hour 2m temps: mild in E US with the cold way out to the NW….yuck

 But the good news is that the GEFS has had a persistent -PNA and warm E US bias over the 90 day period for this map:

And the EPS, a better performing and recently steadier ensemble, still has a +PNA and a chilly E US:

6 hours ago, Carvers Gap said:

Met, how does that scoring system work?  Blues, reds, yellow, points?  

5 hours ago, Met1985 said:

That's a great question.  I’ll get back to you on that.  Im going to do some research.

Carver/Met,

 I happen to already be knowledgeable about what BAMwx is trying to say. I don’t know why BAMwx is calling it 43 “points” gained for the GEFS. That throws off this tweet and makes it confusing.

 It’s actually 43 heating degree days gained for the period 12/28-1/3 vs what the run had 7 days ago (12/21 run). This means that the 12/21 run was much warmer for that period than the 12/28 run mainly because it largely was still missing the oncoming E US cold period. OTOH, the 12/21 EPS wasn’t nearly as far off because it was significantly colder than the GEFS in the E US due to already figuring it out much earlier than the GEFS. So, it only needed to gain 12 HDDs to fully see the light.

 The blues represent colder changes since 12/21 while the red/yellow means warmer changes.

20 hours ago, jaxjagman said:

Has NINA actually not peaked,i mean the East is warning and the west gets cooler each day

Jax, The OHC has orange for the first time since early July:

 CAD doing its magic in NC! I’m jealous of you caddies. Consider that here it is still 70.8 here (with overcast). But even this is better than high 70s with sunny 24 hours ago and better than earlier this afternoon.

 This contrast between GA and NC was forecasted quite well. 

 Yesterday’s high at KSAV was a sweaty record tying 80.

On 12/24/2025 at 6:09 AM, snowman19 said:

FWIW, The stratospheric guru Judah Cohen thinks there’s going to be a major strengthening of the SPV in January
 

 Well, check this out:

 Look at how much weaker the SPV forecast is at 10 mb based on the 60N mean zonal wind on the Euro Weeklies!

 One week ago (12/21 run): quite strong just about all Jan through Feb 4th with no end in sight (mean 40-47 m/s):

Today (12/28 run): near normal Jan 10th-Feb 11th (mean only 25-35):

6 hours ago, bluewave said:

 

I looked at the NYC snowfall for the 17 -ENSO winters for which Dec was cold and had snowfall of 6”+ (from @donsutherland1updated list):

Year (Dec)..Total Season..Jan+

1872….60.2….29.9

1874….56.4….46.3

1886….31.9….21.6

1893….39.2….30.9

1903….32.4….26.0

1909….27.2….17.4

1915….50.7….42.6

1916….50.7….36.2

1917….34.5….20.1

1922….60.4….51.4

1926….22.3….10.6

1933….52.0….36.6

1942….29.5….21.0

1944….27.1….20.4

1995….75.6….61.2

2000….35.0….21.6

2010….61.9….41.8

————————

Analysis:

-AVG of these Jan+: 31.5” vs 22.1” full 156 year record mean or 143% of mean for Jan+ (median was 29.9”)

-41% (7 of 17) had 35”+ for Jan+ vs only 12% of the other 139 (17 of 139)

-These 17, which are only 11% of the total 156 on record, had:

1. Highest Jan of the 156 on record (2011’s 36.0”) and 3 of top 5 Jans (2011, 1996, 1923)

2. 3rd highest Feb of the 156 (1934’s 27.9”)

3. 2nd highest Mar of the 156 (2016’s 25.5”)

4. Highest Apr of the 156 (1875’s 13.5”) and tie for 5th (1917’s 6.5”)

—————————

My NYC total 2025-6 snow prediction based on these stats:

 40” (most likely range 30-50”)

 This compares to 156 year and 35 year means of 28”.

6 hours ago, bluewave said:

The distribution of the snowfall this month between ISP, PHI, and BOS is not what we typically see when Islip has a snowy 10”+ December. This is the first time since 1988 that ISP has 10”+ in December and either Philly or Boston doesn’t have at least 10” also.

It’s why we may not be able to use the snowy December winter analogs that followed the other 10” December years on the list. This is due to the 10” at ISP being the first December with two 5”+ clippers that had narrower areas with heavy snow than benchmark coastal snowstorms that also affected Philly or Boston in the other snowy Decembers at Islip.

So it will be interesting to see how the rest of the winter plays out at all three locations. 

All 10”+ snowy Decembers at ISP and the Boston and Philly snowfall

2009…ISP…25.3”….BOS….15.2”….PHI….24.1”

2002…ISP….16.0”….BOS….11.1”……PHI….8.4”

2003…ISP….15.5”…..BOS….21.5”….PHI….6.0”

2010….ISP….14.9”…..BOS…..22.0”…PHI…12.7”

1995….ISP…..13.3”…..BOS…..12.6”….PHI….7.3”

2025….ISP…12.4”…..BOS…..2.3”……PHI….4.5”

1969….ISP….12.0”…..BOS……12.6”….PHI….7.5”

1975…..ISP….11.4”…..BOS…..19.3”……PHI….7.5”

1963…..ISP…..11.0”….BOS….17.7”…….PHI….8.0”

2000….ISP…..10.8”….BOS….4.5”….…PHI…..10.5”

2008….ISP…..10.4”….BOS….25.3”…..PHI…..0.4”

1988…..ISP…..10.4”….BOS….3.7”……PHI…..0.4”

 

 

 I looked at the NYC snowfall for the 17 -ENSO winters for which Dec was cold and had snowfall of 6”+ (from @donsutherland1updated list):

Year (Dec)..Total Season..Jan+

1872….60.2….29.9

1874….56.4….46.3

1886….31.9….21.6

1893….39.2….30.9

1903….32.4….26.0

1909….27.2….17.4

1915….50.7….42.6

1916….50.7….36.2

1917….34.5….20.1

1922….60.4….51.4

1926….22.3….10.6

1933….52.0….36.6

1942….29.5….21.0

1944….27.1….20.4

1995….75.6….61.2

2000….35.0….21.6

2010….61.9….41.8

————————

Analysis:

-AVG of these Jan+: 31.5” vs 22.1” full 156 year record mean or 143% of mean for Jan+ (median was 29.9”)

-41% (7 of 17) had 35”+ for Jan+ vs only 12% of the other 139 (17 of 139)

-These 17, which are only 11% of the total 156 on record, had:

1. Highest Jan of the 156 on record (2011’s 36.0”) and 3 of top 5 Jans (2011, 1996, 1923)

2. 3rd highest Feb of the 156 (1934’s 27.9”)

3. 2nd highest Mar of the 156 (2016’s 25.5”)

4. Highest Apr of the 156 (1875’s 13.5”) and tie for 5th (1917’s 6.5”)

—————————

My NYC total 2025-6 snow prediction based on these stats:

 40” (most likely range 30-50”)

 This compares to 156 year and 35 year means of 28”.

 Our area had a sweaty 80 high today.

51 minutes ago, BlizzardWx said:

It was 86 degrees at my place today. I hope we can get some payback later into January. EPS weeklies definitely looking more promising mid month. 

When you consider that both the EPS and GEFS have had a notable -PNA bias/notable warm bias from your area eastward and that all -ENSO -PNA Decs have transitioned to +PNA Jans, these consistently much better pattern maps for mid-Jan are quite encouraging. Just 5 days ago, the EW had this ugly -PNA for 1/12-18:

  I’ve been quite curious about what phases the MJO would be in during the heart of the widespread historic US warmth of late Dec, Dec 23-27. We needed to wait due to several days of reporting lag. Would any of it be in the typically chilly in the E 1/2 of the US phase 8? 

 Well, now we have the answer for the first 3 days, Dec 23-25: not surprisingly, none of those first 3 days were in phase 8. It turns out that Dec 23-4 were in very weak phase 7 while Dec 25 was in very weak phase 6, which I consider intuitive:

2025          12          23 -0.28945175      0.37228486               7  0.47157007      Gottschalk10_method:_OLR_&_ACCESS_wind      
        2025          12          24 -0.12800699      0.45807526               7  0.47562456      Gottschalk10_method:_OLR_&_ACCESS_wind      
        2025          12          25  0.16766728      0.36077648               6  0.39783412      Gottschalk10_method:_OLR_&_ACCESS_wind

 Based on a combo of the above diagram and a related adjustment to the model prog consensus, I’m predicting that Dec 26th will be in very weak 4 and Dec 27th will be in either weak 3 or weak 2.

 Will we get back into phase 8 before the end of Dec? The GEFS, JMA, and CFS with my adjustments suggest likely not whereas the adjusted Euro suggests there’s a chance for at least one day of weak 8 then.

 Will we get back into phase 8 in early Jan? As of now there’s a moderate chance of mainly a weak 8, but that’s all I can say right now due to model disagreement and it being too far out for a confident prediction.

2 hours ago, donsutherland1 said:

1917 also had a mean temperature of 25.0° for December 

 

Corrected Table:

Note: The initial table was constructed from summing daily snowfall amounts. Not all daily amounts are in the NYC climate record. Thus, doing so understates the monthly figures. Here's the correct table using the monthly figures.

 For -ENSO (17 seasons):

1872 10.6

1874 14.5

1886 6.6

1893 9.4

1903 15.6

1909 11.1

1915 0.7

1916 5.8

1917 13.2

1922 24.5

1926 5.7

1933 0.1

1942 9.5

1944 12.3

1995 26.1

2000 8.3

2010 36.0

Mean/median: 12.4/10.6

 Interestingly, the lowest 2 Jans and highest 3 Jans were -ENSO.

 Today’s Euro Weeklies were better overall for E US, incl 1/12-18

Today H5:

Yesterday 2m:

Today 2m:

38 minutes ago, donsutherland1 said:

December 2025 will finish with a mean temperature below 35.0°C (coldest since 2010) and more than 6" of monthly snowfall. Below is how January fared in terms of snowfall following cold and snowy Decembers.

 Just looking at the 8 cases that were during -ENSO (16, 22, 26, 33, 42, 44, 95, 10), the Jan SN mean/median rises to 12.8”/9.9”.

17 minutes ago, TheClimateChanger said:

Like in Pittsburgh, Monday afternoon may be in the upper 20s but the high is likely to be near 60 degrees!

Thanks. However, when I did my estimates, I took into account that the 12/29 highs would be at midnight from there through OH/IN, ATL, to BRO, etc. I did the same for 12/28 highs in the Plains/upper MW and the 12/30 highs in the NE. If anything my 31 est. for 12/28-31 is slightly high. I est. 33, 26, 29, 33 for 12/28-31.

 For similar reasons, there were 11:59PM lows to take into account, which I did.

1 hour ago, TheClimateChanger said:

Either way, a VERY respectable anomaly. From a historical standpoint, this could wind up warmer than any December prior to 2015 if PRISM is close. Not sure what's going on with recent Decembers. 3 of the past 4 were even warmer. So from a historical standpoint, EXTREMELY impressive, but from the vantage point of recent years, pretty ho-hum national anomaly. It doesn't appear to be data error, because the USCRN network suggests recent Decembers were even warmer than given by the nClimDiv numbers.

 I see ~no chance for Dec ‘25 to come in warmer than Dec ‘39’s 37.7. Through the 27th (last widespread US warm day), MTD could rise to ~38.2. But 12/28-31 are progged to avg ~31. That would bring the full Dec back down to ~37.2.

1 hour ago, TheClimateChanger said:

Not too shabby. I think this might wind up warmer than any December prior to 2015.

 

 I see ~no chance for Dec ‘25 to come in warmer than Dec ‘39’s 37.7. Through the 27th (last widespread US warm day), MTD could rise to ~38.2. But 12/28-31 are progged to avg ~31. That would bring the full Dec back down to ~37.2.

-NYC now up to 7.2” snow this month, snowiest since Jan of ‘22. Thus, using stats @bluewaveand @donsutherland1got me informed about, I’m now forecasting a season total of 30” min., highest since at the very least 20-21.

-NYC headed to ~5 BN this month, coldest vs norm since Mar of ‘15!

La Guardia was at 4.1” as of 7AM. So, all NYC area official reports are now above 4”.

 Anyone see LaGuardia’s total? Other than that, I think every NYC official station got 4”+.

C Park was up to 0.49” liquid equiv as of 7AM. Was that that far off? How much liquid was forecasted?

Just now, wthrmn654 said:

Next central park update is at 1 am

They got an additional 0.20” of liquid equivalent 7-11PM. As of 7 PM, they had had only .01”.

 Today’s Euro Weeklies, which are overall fairly similar to yesterday, still have that new +PNA in the means for 1/12-18:

 This setup continues more strongly into the subsequent week, 1/19-25, than was seen yesterday:

13 minutes ago, wncsnow said:

There are some positive changes but its far from a slam dunk. The EPS is still not quite cold enough for most for the 4th-7th. The Op GFS looks terrible. The GEFS isnt there yet either. 

 

Things are looking up for Jan just as our buddy Buc-ee is doing:

 
Natural has us up 4% today. This is one of the reasons:

The 12Z GEFS has this at the end: more W coast ridging than prior runs along with a pronounced weakening of the Aleutian ridge:

 The result is an increasing hint on the GEFS of an Arctic high plunging down ~Jan 9th-11th along with a second one to follow:

The SW Canadian air that might be brought down then is very cold:

BAMwx video update from Michael Clark this morning: