October 2025 Discussion and Obs

[Jersey Andrew]

7 minutes ago, bluewave said:

Most storms over the last seven years have been falling into the cutter, I-78 to I-84 hugger and suppressed Southern stream. Strong benchmark storm tracks have been missing. This very strong Northern stream of the Pacific Jet has been leading to these groupings.

One group of storms gets suppressed to the south as kicker lows in the fast Pacific flow come into Western North America. This was the case last winter with the big Gulf snowstorm which went OTS to our south instead of coming up the coast.

The second group is the Great Lakes cutter like we got in mid-February during the -5 SD Greenland block. The jet was so strong and the SSTs to our east so warm that it forced a Southeast ridge rather then getting a benchmark track. Instead Toronto got the historic snows. Enough room between the shortwaves so one system can really amplify and cut to our west like later this week. That was originally forecast to be a coastal storm.

Then the third track is the hugger which can produce some lighter snow events like we got last February. But there was still too much Southeast ridging for NYC Metro so the heaviest totals were to our NW. Plus the there are often too many shortwaves in the fast Pacific flow leading to poor wavelength spacing.

It would be great in the coming winters if we can at least see a few very deep benchmark tracks. But the last time we were able to pull this off was in January 2022 and February 2021. 

If I remember correctly, January 2016 was originally forecast suppressed to south hitting DC area and only within 48 hours was NYC region in bullseye. Don’t know if it was PDO but we had a ridiculous number of blockbuster storms 2009-2011 of 20 inch plus variety.

[bluewave]

30 minutes ago, Jersey Andrew said:

If I remember correctly, January 2016 was originally forecast suppressed to south hitting DC area and only within 48 hours was NYC region in bullseye. Don’t know if it was PDO but we had a ridiculous number of blockbuster storms 2009-2011 of 20 inch plus variety.

Yes that’s true. All the models except the NAM were too surpassed with the system so the snowfall forecasts from the globals were way too low. 

We really had an epic run of benchmark storm tracks from 93-94 all the way up to 17-18. Both under -PDO and +PDO regimes. The -PDOs were defined by the cold ring off the West Coast. With the +PDOs by the warm ring. So the Pacific Jet was much weaker during the best seasons for benchmark storm tracks during that era. 

Since 2018-2019 we have need a new type of -PDO defined more by the warm pool to the east of Japan and south of the Aleutians. This combined with the cold over Siberia leads to a faster Pacific Jet and these three prime storm tracks over the last seven winters leading to the record low snowfall.

The last reprieve for us was during January 2022 when a solid MJO 8 lead to a weakening of the Pacific Jet and the snowy benchmark pattern from ACY to ISP and BOS.  It was the last time we had both a cold and really snowy month. But it was bookmarked by a very warm December and a milder February and March with little to no snow. 

I am really hoping we can find some periods in this coming winter and others where we can see at least a brief return to benchmark tracks. But the overall pattern since 2018-2019 has been working against that.
 

[Brian5671]

bust of a forecast today-it's overcast and 49 vs the mostly sunny and 59 predicted

[SACRUS]

Just now, Brian5671 said:

bust of a forecast today-it's overcast and 49 vs the mostly sunny and 59 predicted

 

Been a lot of those of late , sunny calls and its partly - mostly cloudy.

 

 

[Sundog]

57 minutes ago, Brian5671 said:

bust of a forecast today-it's overcast and 49 vs the mostly sunny and 59 predicted

Looks like the clouds are getting shoved to the SW in your area, you might be getting more sun soon.

[SnoSki14]

Feels like mid November. Cool & cloudy, only 53F right now

[nycwinter]

been very blustery and chilly for days now feels like late november..almost tempted to wear a coat..

[Sundog]

It looks like if it wasn't for that barely 70 degree high on the 19th, Central Park would have gone the entire second half of October without any days in the 70s of higher. 

In fact it was the only day with a high of 70 or higher since the 8th, when our mini torch ended. That's actually really impressive, especially when considering the background state we have to deal with.

[Brian5671]

47 minutes ago, Sundog said:

It looks like if it wasn't for that barely 70 degree high on the 19th, Central Park would have gone the entire second half of October without any days in the 70s of higher. 

In fact it was the only day with a high of 70 or higher since the 8th, when our mini torch ended. That's actually really impressive, especially when considering the background state we have to deal with.

very different from last year where we torched into early Nov with bone dry conditions and temps in the 80's a few days

[qg_omega]

Zzzzzz nothing going on at all locally on the horizon

[MANDA]

Working in the yard the last few days and the top soil is dust.  Bone dry.

October rainfall to date at my location is 1.56".  That is FAR better than last October when the entire month had just a Trace.

Still need rain badly.  Think reasonable expectation for my area is 1" from the coming event based on current guidance.

Anything more will be a gift and anything less will be a disappointment.

[donsutherland1]

A strong NAO blocking regime is in place and will persist into early November. As a result, an extended period of cooler than normal weather will prevail through the end of the month. 

Tomorrow will be another cool day. Temperatures will top out in the lower and middle 50s across much of the region. The unseasonably cool weather will continue through at least the middle of the week before it turns a bit milder. 

Rain will likely arrive Wednesday night or Thursday. A general 1"-3" rainfall is likely late Wednesday night through Friday. There remains uncertainty about the area of heaviest rainfall. The storm will be followed by a continuation of cool weather.

The ENSO Region 1+2 anomaly was +0.3°C and the Region 3.4 anomaly was -0.6°C for the week centered around October 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.07°C and the ENSO Region 3.4 anomaly has averaged -0.48°C. La Niña conditions will likely continue through mid-winter.

The SOI was +23.46 today. 

The preliminary Arctic Oscillation (AO) was +0.455 today. The NAO was -1.744. That is the lowest NAO figure since November 22, 2024 when the NAO was -1.823.

Based on sensitivity analysis applied to the latest guidance, there is an implied 78% probability that New York City will have a warmer than normal October (1991-2020 normal). October will likely finish with a mean temperature near 58.3° (0.4° above normal). 

Supplemental Information: The projected mean would be 1.4° above the 1981-2010 normal monthly value.

 

[MJO812]

3 hours ago, qg_omega said:

Zzzzzz nothing going on at all locally on the horizon

Rain

[Sundog]

I can't believe we have to switch clocks back this weekend. I hope all you weirdos that go to sleep at 4PM are happy. 

[psv88]

50 minutes ago, Sundog said:

I can't believe we have to switch clocks back this weekend. I hope all you weirdos that go to sleep at 4PM are happy. 

It’s horrific. Depression sets in 

[MJO812]

13 minutes ago, psv88 said:

It’s horrific. Depression sets in 

No way

Its great

[psv88]

52 minutes ago, MJO812 said:

No way

Its great

Pitch black by 5 pm?

[jm1220]

26 minutes ago, psv88 said:

Pitch black by 5 pm?

Flip side it's light out when I have to wake up for work. 

[psv88]

7 minutes ago, jm1220 said:

Flip side it's light out when I have to wake up for work. 

I wake up at 8:30 am…no thanks 

[SnoSki14]

3 hours ago, Sundog said:

I can't believe we have to switch clocks back this weekend. I hope all you weirdos that go to sleep at 4PM are happy. 

I hate the cold, dark mornings so yes it's fine. Can't imagine it still being dark at 8-830. 

[bluewave]

Most stations on track to finish October warmer than average as this is another month with Canada being so warm that areas to our north will finish warmer again relative to the means.

 

POU…..+0.7

FWN….+1.3

PHL…..+1.7

SMQ….+0.3

NBW….+1.5

EWR….+1.7

NYC…..+0.5

LGA……+0.1

JFK……+1.1

HPN…..+2.2

BDR….-0.3

ISP……+2.4

 

[Sundog]

6 minutes ago, bluewave said:

Most stations on track to finish October warmer than average as this is another month with Canada being so warm that areas to our north will finish warmer again relative to the means.

 

POU…..+0.7

FWN….+1.3

PHL…..+1.7

SMQ….+0.3

NBW….+1.5

EWR….+1.7

NYC…..+0.5

LGA……+0.1

JFK……+1.1

HPN…..+2.2

BDR….-0.3

ISP……+2.4

 

Nobody feels like the October we just had was a warm, above normal month though in the tristate. That four day torch in the first week skewed the averages. 

[Sundog]

Those four days in the 80s added about +1.4 degrees to the monthly average in Central Park, even more in other locations. 

[bluewave]

47 minutes ago, Sundog said:

Nobody feels like the October we just had was a warm, above normal month though in the tristate. That four day torch in the first week skewed the averages. 

What it is feels like is a bit deceptive since October is one of the fastest warming months of the year. So we have been normalizing how warm it has been getting since it only takes a small + departure to rank in the top 15 warmest Octobers.

Sussex NJ is currently  ranked 8th warmest October through the 28th. White Plains is 12th warmest and Islip is 7th warmest.

It would probably make more sense to use an earlier climate era like 1961-1990 or 1951-2000 as a base period so rankings and departures will actually match up. Instead of updating the normals every 10 years in a rapidly warming climate.

This frequent updating leads to the false sense that it isn’t warming as fast as it really is and making the departures less relevant unless they are very high.

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Oct
Click column heading to sort ascending, click again to sort descending.

1	2017	61.9	0
2	2021	61.2	0
3	2007	61.1	0
4	1990	60.9	0
5	1971	59.7	0
6	2023	58.8	0
7	2025	58.6	3
8	1995	58.5	0
9	2024	58.4	0
10	1963	58.3	0
11	2019	57.9	0
-	2013	57.9	0
-	2012	57.9	0

[MJO812]

10 hours ago, psv88 said:

Pitch black by 5 pm?

Yes

[steve392]

3 minutes ago, MJO812 said:

Yes

I second!  Love me 430 sunsets and darkness early and driving to work in darkness.  

[Sundog]

23 minutes ago, bluewave said:

What it is feels like is a bit deceptive since October is one of the fastest warming months of the year. So we have been normalizing how warm it has been getting since it only takes a small + departure to rank in the top 15 warmest Octobers.

Sussex NJ is currently  ranked 8th warmest October through the 28th. White Plains is 12th warmest and Islip is 7th warmest.

It would probably make more sense to use an earlier climate era like 1961-1990 or 1951-2000 as a base period so rankings and departures will actually match up. Instead of updating the normals every 10 years in a rapidly warming climate.

This frequent updating leads to the false sense that it isn’t warming as fast as it really is and making the departures less relevant unless they are very high.

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Oct
Click column heading to sort ascending, click again to sort descending.

1	2017	61.9	0
2	2021	61.2	0
3	2007	61.1	0
4	1990	60.9	0
5	1971	59.7	0
6	2023	58.8	0
7	2025	58.6	3
8	1995	58.5	0
9	2024	58.4	0
10	1963	58.3	0
11	2019	57.9	0
-	2013	57.9	0
-	2012	57.9	0

If those four torch days didn't happen Central Park would have finished below normal even when going by the 1981-2010 standards. 

When I calculated the 30 year averages going way back, I found the 1931-1960 and 1941-1970 averages for October warmer than today's FYI. 

[donsutherland1]

1 hour ago, bluewave said:

What it is feels like is a bit deceptive since October is one of the fastest warming months of the year. So we have been normalizing how warm it has been getting since it only takes a small + departure to rank in the top 15 warmest Octobers.

Sussex NJ is currently  ranked 8th warmest October through the 28th. White Plains is 12th warmest and Islip is 12th warmest.

It would probably make more sense to use an earlier climate period like 1961-1990 or 1951-2000 as a base period so rankings and departures will actually match up.

Instead of updating the normals every 10 years in a rapidly warming climate. This leads to the sense that it isn’t warming as fast as it really is and making the departures less relevant unless they are very high.

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Oct
Click column heading to sort ascending, click again to sort descending.

1	2017	61.9	0
2	2021	61.2	0
3	2007	61.1	0
4	1990	60.9	0
5	1971	59.7	0
6	2023	58.8	0
7	2025	58.6	3
8	1995	58.5	0
9	2024	58.4	0
10	1963	58.3	0
11	2019	57.9	0
-	2013	57.9	0
-	2012	57.9	0

 

37 minutes ago, Sundog said:

If those four torch days didn't happen Central Park would have finished below normal even when going by the 1981-2010 standards. 

When I calculated the 30 year averages going way back, I found the 1931-1960 and 1941-1970 averages for October warmer than today's FYI. 

This is a perennial debate with multiple perspectives and no single solution.

For longer-term climate perspectives, 1951-1980 (GISS) or 1901-2000 (NOAA) are good baselines. Those baselines allow one to compare the contemporary climate to a longstanding baseline for purposes of assessing how the climate has changed.

The current 30-year figures reflect the current state of the climate, which is warmer than it was when assessed against the longer-term baselines typically used in climate research. The current figures also address the question visitors to locations might ask e.g., "What is it typically like in December in New York City?" That could be important for a visitor from Toronto who wants to know whether she really needs a sweater to view the lighting of the Rockefeller Center Christmas tree.

Although the headline monthly anomaly, which will be slightly positive is typically used to define the monthly outcome, a better picture involves getting into more detail. The month will wind up with 58%-61% of days having been cooler than the 1991-2020 baseline. Moreover, the average anomaly was skewed by October 5-7, all of which averaged 10.5° or more above normal. Excluding those days, the monthly anomaly would be reduced by 1.3°. A trimmed mean, which would drop the three coldest and warmest days relative to normal would still result in a mean that would be 0.6° cooler.

Here's how October looks through October 28th:

[TheClimateChanger]

1 hour ago, bluewave said:

What it is feels like is a bit deceptive since October is one of the fastest warming months of the year. So we have been normalizing how warm it has been getting since it only takes a small + departure to rank in the top 15 warmest Octobers.

Sussex NJ is currently  ranked 8th warmest October through the 28th. White Plains is 12th warmest and Islip is 7th warmest.

It would probably make more sense to use an earlier climate era like 1961-1990 or 1951-2000 as a base period so rankings and departures will actually match up. Instead of updating the normals every 10 years in a rapidly warming climate.

This frequent updating leads to the false sense that it isn’t warming as fast as it really is and making the departures less relevant unless they are very high.

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Oct
Click column heading to sort ascending, click again to sort descending.

1	2017	61.9	0
2	2021	61.2	0
3	2007	61.1	0
4	1990	60.9	0
5	1971	59.7	0
6	2023	58.8	0
7	2025	58.6	3
8	1995	58.5	0
9	2024	58.4	0
10	1963	58.3	0
11	2019	57.9	0
-	2013	57.9	0
-	2012	57.9	0

People might not believe it, but Mother Nature is never fooled. Way more foliage hanging around than usual, at least in my area.

[Brian5671]

13 hours ago, Sundog said:

I can't believe we have to switch clocks back this weekend. I hope all you weirdos that go to sleep at 4PM are happy. 

You can't believe it?   We've been doing it for 75 years, lol