2025-2026 ENSO

[bluewave]

25 minutes ago, PhiEaglesfan712 said:

I think 2017 is the only exception, with the historic cold 2nd half of December/first half of January. We stayed overnight (might have been 2 nights) at AC for my sister's 25th birthday, and it was way too cold to go on the Boardwalk. That year, we didn't get the warm-up until mid-January, and we all know about that record warmth in February. Then, of course, the cold/snowy pattern came back for March and April.

Even before that 2nd coldest late December 2017 into early January 2018 period, most areas from Philly to NYC Metro still made it above 55° from the 17th to 25th like every year since 2011. Many of those years the long range models missed that warm up. But once we got past the first week of December, the models played catch up the closer in time we get to the period. 
 

Data for December 17, 2017 through December 25, 2017
Click column heading to sort ascending, click again to sort descending.

Atlantic City Area	ThreadEx	61
CAPE MAY 2 NW	COOP	61
MILLVILLE MUNICIPAL AIRPORT	WBAN	61
ATLANTIC CITY INTL AP	WBAN	61
INDIAN MILLS 2 W	COOP	61
ESTELL MANOR	COOP	61
SOUTH JERSEY REGIONAL AIRPORT	WBAN	61
HAMMONTON 1 NE	COOP	60
ATSION	COOP	60
EB FORSYTHE NEW JERSEY	RAWS	60
PHILADELPHIA/MT. HOLLY WFO	COOP	59
MANASQUAN 1 NW	COOP	59
WRIGHTSTOWN	COOP	59
PENNSAUKEN 1N	COOP	59
Trenton Area	ThreadEx	58
New Brunswick Area	ThreadEx	58
SEABROOK FARMS	COOP	58
HIGHTSTOWN 2 W	COOP	58
TRENTON-MERCER AIRPORT	WBAN	58
NEW BRUNSWICK 3 SE	COOP	58
Newark Area	ThreadEx	57
FREEHOLD-MARLBORO	COOP	57
NEWARK LIBERTY INTL AP	WBAN	57
SOMERSET AIRPORT	WBAN	57
TETERBORO AIRPORT	COOP	56
MARGATE	COOP	56
Atlantic City Marina Area	ThreadEx	56
ATLANTIC CITY MARINA	WBAN	56
WERTSVILLE 4 NE	COOP	56
TETERBORO AIRPORT	WBAN	56
HARRISON	COOP	56
FLEMINGTON 5 NNW	COOP	55
PHILLIPSBURG-EASTON BRIDGE	COOP	55
CANOE BROOK	COOP	55

 

Data for December 17, 2017 through December 25, 2017
Click column heading to sort ascending, click again to sort descending.

MONTAUK AIRPORT	WBAN	57
LAGUARDIA AIRPORT	WBAN	56
WESTHAMPTON GABRESKI AP	WBAN	56
MOUNT SINAI	COOP	56
SHIRLEY BROOKHAVEN AIRPORT	WBAN	56
New York-LGA Area	ThreadEx	56
BRIDGEHAMPTON	COOP	55
FARMINGDALE REPUBLIC AP	WBAN	55
ISLIP-LI MACARTHUR AP	WBAN	55
NY CITY CENTRAL PARK	WBAN	55
RIVERHEAD RESEARCH FARM	COOP	55
UPTON COOP - NWSFO NEW YORK	COOP	55
JFK INTERNATIONAL AIRPORT	WBAN	55
Islip Area	ThreadEx	55
New York-Kennedy Airport Area	ThreadEx	55
New York-Central Park Area	ThreadEx	55

[SnowGoose69]

25 minutes ago, PhiEaglesfan712 said:

I think 2017 is the only exception, with the historic cold 2nd half of December/first half of January. We stayed overnight (might have been 2 nights) at AC for my sister's 25th birthday, and it was way too cold to go on the Boardwalk. That year, we didn't get the warm-up until mid-January, and we all know about that record warmth in February. Then, of course, the cold/snowy pattern came back for March and April.

Yeah I think 2018 was the year where in southeast parts of the US all the trees opened and there was major damage from frosts in March and April 

[snowman19]

Besides the “blob” situation, a pronounced -PMM has developed as well
 

[GaWx]

 Today’s Euro Weeklies update:

1) 4th run in a row with a very weak SPV late Nov/early Dec with today’s having ~25% of members with a very early major SSW, the highest yet of any run!

2) After having warmed up significantly in the E US the last 3 runs for most of November/early Dec from the cold Nov 2-9 and then mainly NN Nov 10-Dec 7 of the Oct 26 run, today’s has cooled back down notably for much of Nov 10-Dec 7 and is downright cold for the new week (Dec 8-14) with a solid -AO for Nov 24-Dec 14. Keep in mind that the Euro often has trouble seeing cold too far out. So, seeing BN all the way out at weeks 5-6 in today’s run is noteworthy and will be followed closely for future trends:

—————
Week six H5:

Week five 2m temps:

 

Week six 2m temps:

 

[Krs4Lfe]

3 hours ago, snowman19 said:

Besides the “blob” situation, a pronounced -PMM has developed as well
 

I don’t believe that’s where we would want all the storminess. That’ll keep knocking into west Canada and west coast and the ridge will keep rolling over. Not a good look to funnel in cold arctic air into CONUS, which is necessary for our snow chances. 

[jm1220]

7 minutes ago, Krs4Lfe said:

I don’t believe that’s where we would want all the storminess. That’ll keep knocking into west Canada and west coast and the ridge will keep rolling over. Not a good look to funnel in cold arctic air into CONUS, which is necessary for our snow chances. 

We need ridging into Alaska to drive cold air south from there. A more rounded ridge pointed into Canada would just bring Pacific mild air in. In December especially near the coast the source region for airmass is very important. And obviously a roaring Pacific jet would tend to knock the ridge down and nudge it east. 

[GaWx]

 Is it my imagination or does it really take an extra click to get to this thread now?

[snowman19]

Per the latest SST maps, the cooling in the western IO is still going strong, along with warming in the eastern part. My guess is that it bottoms out/peaks within the next 2 weeks either very close to, or at -2 on the weekly numbers. If so, this will be one of the strongest -IOD events in history….

[snowman19]

Lowest since 2012 in that part of the arctic….

[GaWx]

10 hours ago, GaWx said:

 Is it my imagination or does it really take an extra click to get to this thread now?

Bump: I don’t think it’s my imagination. I’ll start from the main page:

https://www.americanwx.com/bb/
 

 This is what I see, which is a change from how it had been for years:

———————

  What is different is seeing “General Forecasting and Discussion” instead of seeing the following below “Tropical HQ”. 

 

——————

 So, now one has to click on “General Forecasting and Discussion” as an extra step before only after that being able to click on “Weather Forecasting and Discussion”, which then leads to seeing this thread.

 Are any others seeing this change?

[Krs4Lfe]

1 hour ago, snowman19 said:

Lowest since 2012 in that part of the arctic….
 

More evidence towards why there is a lack of cold air in Canada. Any early season wintry weather would require an ideal storm track to tap into a cold air source, of which there is none to be found. 

[snowman19]

23 minutes ago, Krs4Lfe said:

More evidence towards why there is a lack of cold air in Canada. Any early season wintry weather would require an ideal storm track to tap into a cold air source, of which there is none to be found. 

I think the biggest issue is the record strong -IOD event ongoing. Just posted on this earlier. That is definitely going to have global consequences in how the forcing goes, December in particular. You aren’t going to have an event this strong and not effect the tropical forcing patterns, especially in the early part of met winter 

[GaWx]

12 minutes ago, snowman19 said:

I think the biggest issue is the record strong -IOD event ongoing. Just posted on this earlier. That is definitely going to have global consequences in how the forcing goes, December in particular. You aren’t going to have an event this strong and not effect the tropical forcing patterns, especially in the early part of met winter 

What are you saying this very strong Oct -IOD is going to cause in December in the E US? What’s your prediction?

[snowman19]

10 minutes ago, GaWx said:

What are you saying this very strong Oct -IOD is going to cause in December in the E US?

@GaWx I’m not sure exactly what it’s going to do, but my educated guess is that it affects MJO behavior, actual specifics? I’m not sure yet. I also think it is going to constructively interfere with the La Niña and enhance atmospheric coupling

[FPizz]

1 hour ago, GaWx said:

Bump: I don’t think it’s my imagination. I’ll start from the main page:

https://www.americanwx.com/bb/
 

 This is what I see, which is a change from how it had been for years:

———————

  What is different is seeing “General Forecasting and Discussion” instead of seeing the following below “Tropical HQ”. 

 

——————

 So, now one has to click on “General Forecasting and Discussion” as an extra step before only after that being able to click on “Weather Forecasting and Discussion”, which then leads to seeing this thread.

 Are any others seeing this change?

Hasn't changed for me, odd

 

[GaWx]

4 minutes ago, FPizz said:

Hasn't changed for me, odd

 

Very strange!

 When you go to https://www.americanwx.com/bb/

do you see what the first screenshot I posted shows with “General Forecasting and Discussion” showing and not “Weather Forecasting and Discussion”?

[bncho]

20 minutes ago, GaWx said:

Very strange!

 When you go to https://www.americanwx.com/bb/

do you see what the first screenshot I posted shows with “General Forecasting and Discussion” showing and not “Weather Forecasting and Discussion”?

something changed for me as well. it could still see the original "General Forecasting and Discussion" tab, but I couldn't see anything at all for the "Regional Weather Discussion" tab at all (on mobile), making it more difficult to access threads there.

[anthonymm]

On 10/29/2025 at 12:04 PM, snowman19 said:

Apparently this looks like a ton of snowcover in Canada to our north lol

The complete and utter lack of any semblance of snow as far north as northern Quebec is disturbing indeed. Should be the kiss of death for us.

[anthonymm]

On 10/30/2025 at 6:54 AM, donsutherland1 said:

Some Washington, DC winter forecasts: https://wapo.st/3JxBxBT

 

Hah DC would be lucky to get more than 3" with the type of pattern that will unfold.

[FPizz]

1 hour ago, bncho said:

something changed for me as well. it could still see the original "General Forecasting and Discussion" tab, but I couldn't see anything at all for the "Regional Weather Discussion" tab at all (on mobile), making it more difficult to access threads there.

I'm on a laptop, maybe that is why. Mobile is one more click for me as well now

[FPizz]

43 minutes ago, anthonymm said:

The complete and utter lack of any semblance of snow as far north as northern Quebec is disturbing indeed. Should be the kiss of death for us.

If you believe any 15 day model output, a lot of canada gets covered, especially the eastern half.  If that came to be, would it really matter that it is Nov 15th vs Oct 31?

[snowman19]

2 hours ago, GaWx said:

What are you saying this very strong Oct -IOD is going to cause in December in the E US? What’s your prediction?

To answer your question more specifically, this was literally just posted on X 15 min ago:

“The question many people ask is: is MJO good? Does it propagate in the CPAC?
Not an easy answer since there are many factors that influence atmospheric circulation, first of all the IOD and secondly the ENSO.
A strongly negative phase of the IOD increases tropical convection, enhancing it on the maritime continent with strong WWB, while a negative ENSO with colder SST over the central Pacific (La Nina CP) favors strong EWB on the international date line (180°).

This situation sees strong diverging trade winds in the equatorial area.
A strong propagation above the CPAC (upward converging heat fluxes) is excluded, if not a rapid phase but with a weak magnitude, there could still be some weak effect even in the mid-latitudes to be evaluated later. The Hovmoller diagram at 850hpa shows this rapid passage of WWB over the CPAC due to the support of a gravitational kelvin wave.

The PV could remain weak at the moment due to the eQBO with a probable Canadian Warming whose effects will affect America and less Europe.

With these variables, the atmospheric circulation will remain blocked with a tropical convection that will remain on the maritime continent with difficulty in propagating over the Pacific”

 

 

 

 

[GaWx]

13 minutes ago, snowman19 said:

To answer your question more specifically, this was literally just posted on X 15 min ago:

“The question many people ask is: is MJO good? Does it propagate in the CPAC?
Not an easy answer since there are many factors that influence atmospheric circulation, first of all the IOD and secondly the ENSO.
A strongly negative phase of the IOD increases tropical convection, enhancing it on the maritime continent with strong WWB, while a negative ENSO with colder SST over the central Pacific (La Nina CP) favors strong EWB on the international date line (180°).

This situation sees strong diverging trade winds in the equatorial area.
A strong propagation above the CPAC (upward converging heat fluxes) is excluded, if not a rapid phase but with a weak magnitude, there could still be some weak effect even in the mid-latitudes to be evaluated later. The Hovmoller diagram at 850hpa shows this rapid passage of WWB over the CPAC due to the support of a gravitational kelvin wave.

The PV could remain weak at the moment due to the eQBO with a probable Canadian Warming whose effects will affect America and less Europe.

With these variables, the atmospheric circulation will remain blocked with a tropical convection that will remain on the maritime continent with difficulty in propagating over the Pacific”

 

 

 

 

Thank you, snowman.

 Y’all may find this interesting. Eric Webb just posted this at another BB after I asked him the same Q:

There's lots of co-variability between ENSO and the IOD, and there's a positive correlation between ENSO & IOD intensity. Oth, when you try to isolate the influence of the IOD alone here in the context of weak to moderate La Ninas, this is what happens:

The Nov-Dec 500mb & SLP difference composite of +IOD & -IOD years with weak to moderate La Niña captures some of the things we're currently seeing like the very extended Pacific Jet/+EPO, +PNA, and even perhaps the -SAM/-AAO. The NAO is completely different this year though.
 

 Then he posted this:

This is what happens if you take that difference composite through the winter. 

The big takeaway I glean from this is the transition from an early winter +PNA type pattern to a canonical Nina look w/ a +NAM/AO is much sharper in these winters with a bigger -IOD in the preceding fall. 

Also, the classic Seasonal Footprinting Mechanism (SFM) pattern is more prominent in Feb-Mar in the -IOD years, which would hasten the development of +PMM in the spring and be more favorable for El Niño development later next year.

————

So, Webb and you may be in agreement at least to an extent.

[michsnowfreak]

For those worried about what they perceive as not enough cold/snow in Canada in late October...and of course the now favorite starting phrase on amwx "since 2016..." I thought this was very interesting.

The chart below shows snow at Detroit the past 10 years and then the previous 10 years. The bottom line is the period of record average. The past 10 years have shown a very unusual trend of snowier than average Novembers and below average snowfall in Decembers. Even more interesting is the lower November snow the previous 10 years in what were fantastic winters.

[WestMichigan]

2013-2014 stands out like a sore thumb in the middle of that data.  Makes you realize just how much of an anomaly it was.

[TheClimateChanger]

On 10/29/2025 at 3:11 PM, TheClimateChanger said:

Good post. I realize this is in regard to the 2014-15 winter, but I think a lot of people here are just getting old and don't realize how old some of these winters are. We are as far removed from 2013-2014, as we were from the winter of 1981-1982 (which UPI reports left an indelible mark on weather history - see link at end) in the winter of 1993-1994. I don't know about you, but in 1993/94, I would've considered 1981/82 to be ancient history.  But some of these people would have you believe it was just yesterday.

Link: Winter 1982 rewrites weather history - UPI Archives

 

[MJO812]

4 hours ago, anthonymm said:

The complete and utter lack of any semblance of snow as far north as northern Quebec is disturbing indeed. Should be the kiss of death for us.

We are in October, not December. Saying should be the kiss of death for us is a weenie statement. 

[George001]

1 hour ago, MJO812 said:

We are in October, not December. Saying should be the kiss of death for us is a weenie statement. 

Yeah it takes time to build snowpack. Right now it is slowly building over western Canada, and is beginning to expand south and east. This process will continue until the snow arrives in New England by mid-late December.