GaWx

Latest Arctic ice falling back closer to the mean as the Arctic N of 80N anoms have warmed considerably:

 Feb in the E US will likely be heavily affected by the Feb NAO. The CFSv2 is implying a strong -NAO in Feb ‘27.

-These Ninos had a strong +NAO in Feb: 1992, 2016, 2024

 Here’s the Feb temp anom composite:

-These Ninos had a strong -NAO in Feb: 1958, 1966, 2010

Here’s the Feb temp anom composite:

1 hour ago, LakePaste25 said:

As @bluewave has shown, much of the seasonal guidance has verified too cold for +ENSO episodes. 

-2016: much less E based Nino

In the E US, the mid-Oct ‘15 forecast mean CFSv2 for Feb ‘16 actually verified slightly too warm overall in the E US!

Verification of Feb ‘16 (vs 1981-2010):

-2024, much weaker and less E based Nino:

The mid-Oct ‘23 mean CFSv2 forecast for Feb ‘24 verified too cold NE but wasn’t too far off in the SE and was very close deep SE:

Verification of Feb ‘24 (vs 1991-2020):

 How will it do for Feb ‘27? We’ll see! Yes, although I’m not at all trusting any model, I’m excited about the Feb potential (not Dec at all and not much for Jan though that could very well be transitioning):

40 minutes ago, LakePaste25 said:

I question this because if you aren’t skewing heavily +PNA/-EPO in the mean, how do you end up with heavily negative anomalies in the South?

 That’s still a moderate +PNA since SE US H5 anomalies are much lower than those for W Can. Then combine that with an off the charts E Can/W -NAO block diverting cold down into the SE. H5 anomalies are lowest in the SE US of anywhere on the globe in CFSv2 Feb fcast with -8 to -10 dam. Also, cold in SE, especially deep SE, has at most a modest correlation with -EPO:

 

Edit: Also note that climo used by TT here is 1984-2009, which is colder than 1991-2020. So, had 1991-2020 been used instead, H5 anomalies over the E US would be even lower since mean H5 has warmed.

 Latest CFSv2 10 day mean 850 mb fcast anomalies for Feb of 2027: note that >75% of Conus BN, including ~1/3 of Conus 2-4 C BN, along with the extreme warmth in E Canada that is consistent with strong blocking there allowing the diverting of dominant Arctic cold into much of Conus:

——————
In stark contrast, mid-Oct forecast for Feb ‘24: 85% AN in Conus/no block in E Canada in that much weaker/much less E based Nino vs 26-7:

—————
In sharp contrast to mid-Oct forecast for Feb ‘16: only <15% BN, none sub -2C, and less extreme Canadian warmth centered >1,000 miles W of the Feb ‘27 forecast in that much less E based Nino vs 26-7:

Latest CFSv2 10 day mean 850 mb fcast anomalies for Feb of 2027: note that >75% of Conus BN, including ~1/3 of Conus 2-4 C BN, along with the extreme warmth in E Canada that is consistent with strong blocking there allowing the diverting of dominant Arctic cold into much of Conus:

——————
In stark contrast, mid-Oct forecast for Feb ‘24: 85% AN in Conus/no block in E Canada in that much weaker/much less E based Nino vs 26-7:

—————
In sharp contrast to mid-Oct forecast for Feb ‘16: only <15% BN, none sub -2C, and less extreme Canadian warmth centered >1,000 miles W of the Feb ‘27 forecast in that much less E based Nino vs 26-7:

Today’s CFSv2 GLAAM forecast (see top image below): currently extremely high at +3 SD; though very high, Oct is not as high as record-breaking Sep (keep in mind that it amazingly exceeded +4 SD for a 6 day period (within 9/17-23), which may not happen again for decades):

By latitude: similar pattern that has dominated for awhile with the strongest positive anomalies S of 20N:

In contrast, 2023-4 was nothing of the sort:

On 10/20/2026 at 7:57 PM, Chinook said:

Anybody reading this from Arizona? There's a rare enhanced risk for severe storms in Arizona, with 5% risk of tornadoes.

 I just read that part of AZ on Wednesday had a tornado watch for the first time in 15 years!

It appears per models that due to a combo of a large Tahiti SLP rise/smaller Darwin fall and despite it being way down at -43 today, it should break the very long current -SOI streak and go positive by ~Oct 25th. That means that the current -SOI streak would end near 74 days.

23 minutes ago, LongBeachSurfFreak said:

Absolutely. You can see the fronts are gone in Josephine. But the convention is not particularly deep near the center. It also has a relatively large area of tropical storm force winds in the northern quadrant (gradient driven)


.

1. For you: How’s the surf in your area?

2. For all: Can a subtropical cyclone attain hurricane force winds but still not be classified as tropical? We know there are ST depressions and storms, but I’ve never heard of a subtropical H. Why not?

1 hour ago, NorthHillsWx said:

93L looks subtropical. Looks much more tropical in nature than the last nor Easter everyone was freaking out over on social media. This one is actually maintaining convection over the center, has highest winds in central convection, and is over the Gulf Stream 

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
340 PM EDT Wed Oct 21 2026

For the North Atlantic...Caribbean Sea and the Gulf of America:

Special Outlook issued to raise formation probabilities for AL93

Offshore of the East Coast of the United States (AL93):
Updated: Shower and thunderstorm activity has become better
organized in association with a storm-force low pressure area
located a few hundred miles off the mid-Atlantic United States
coast. The system has continued to acquire subtropical
characteristics today and has become separated from fronts. If
these trends continue, a subtropical storm could form later this
afternoon or tonight while it accelerates northeastward.

Regardless of the status of the system, high winds, coastal
flooding, and dangerous surf are expected along portions of the U.S.
East Coast during the next few days. For more information, including
hurricane-force extratropical wind warnings, please consult
statements and warnings from local National Weather Service offices
and the Weather Prediction Center, along with the High Seas
Forecasts and the Storm Warnings issued by the National Weather
Service.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 7 days...high...70 percent.

Evidently, this was already declared STS Josephine just a few minutes ago.

————————

12Z UKMET was still another having run it even though the text technically called it a TS (I don’t think it is capable of distinguishing T from ST):

TROPICAL STORM 93L ANALYSED POSITION : 36.7N 69.0W

ATCF IDENTIFIER : AL932026

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 21.10.2026 0 36.7N 69.0W 995 44
0000UTC 22.10.2026 12 37.5N 69.4W 991 47
1200UTC 22.10.2026 24 38.8N 68.4W 985 49
0000UTC 23.10.2026 36 39.9N 65.1W 984 66
1200UTC 23.10.2026 48 41.4N 59.5W 982 61
0000UTC 24.10.2026 60 43.0N 56.6W 986 51
1200UTC 24.10.2026 72 43.0N 54.8W 990 46
0000UTC 25.10.2026 84 42.8N 51.4W 994 41
1200UTC 25.10.2026 96 41.7N 45.7W 1004 38
0000UTC 26.10.2026 108 CEASED TRACKING

 The GEFS NAO prog continues to correct to more positive. Check out how much it has risen over the last 8 forecast days:

Oct. 13th fcast mean had it never getting >+1 and that on Oct. 15th with it later down to sub -0.8 for 6 days with it continuing through end of forecast period; It had Oct. 27th down at -0.9:

 Today’s forecast is so much more positive: it actually peaked way up at +1.73 on Oct 19th and with forecast now dipping only to -0.7 on Oct 22nd followed by a sharp rise to +0.8 on Oct 27th (vs the  Oct 13th run having it down at -0.9):

 Per @Stormchaserchuck1this solidly +NAO in Oct. is actually a good sign if one wants the chance for a -NAO domination in winter to increase. I’m just passing that along as it isn’t my own idea. Forecast models are suggesting a good chance of a -NAO in Feb, regardless. Before that will be tough imho due to at least solar but we’ll see.

6 minutes ago, BlizzardWx said:

What could be interesting is if el nino forcing indeed is summarily shoved eastward could the typical warm anomaly that sits over the Great Lakes be pushed far enough east that we get more cold air into the US like the CFS is showing? We could also get the moisture from having an active storm track into the south like you would expect in strong el nino. So I am not saying I am buying it, but just wondering out loud on what it will actually mean. Does shifting the forcing east linearly shift the pattern? That isn't always the case either. 

Absolutely that can happen with how E based it is progged to be! This is especially the case for Feb as the CFS has been showing. I’m expecting a very mild Dec and a mild to NN first half of Jan. Then the fun times could really get going starting late in Jan and especially in Feb and possibly continuing through early March.

 The CFSv2 for the last 2 months worth of daily 10 day mean runs has been persistent in showing Feb ‘27 to have an extreme couplet of a much warmer than normal E Canada and a cold dominant CONUS. No other mid-Oct. 10 day CFSv2 mean (back to 2012, its first one) has shown anything anywhere close to this, which has not only 80% of Conus BN but also a very mild E Canada acting as a very strong block:

 In this post in the main forum, I compared this mid-Oct CFSv2 forecast to all other CFSv2 mid-Oct forecasts for Feb (back to first one for Feb ‘12) and its implications regarding what may actually happen in Feb ‘27:

Aside: @buckeyefan1would you mind pinning this winter outlook thread? It is getting relatively little viewing and thus few posts (only 50 in 6 months) due to being so far down on the topics list even after a recent post since 5 other threads have already been pinned.

12 hours ago, MJO812 said:

Great video. This El Nino might screw up the warm forecasts.

https://youtu.be/4gP_R1OGeQ8?is=EA6MCfhV6sw9i-6k

Anthony,

 Maybe this person saw this latest 10 day CFSv2 mean for Feb ‘27 (Nino): 80% of CONUS BN; much AN E Canada:

 No other mid Oct 10 day mean for Feb back to 2012 has had anything even closely resembling this extreme couplet, and a cold dominant Feb US/much warmer than normal E Can have been on EVERY 10 day mean since they started going out that far in mid August! 
 
 Check out how much Feb of ‘27 differs from all other 10 day mean forecasts made in mid-Oct for other Febs back to the start of the CFSv2:

2026: 1% of CONUS BN; BN E Can:

2025: 0% of CONUS BN; BN E Can

2024 (Nino): 0% of CONUS BN; AN E Can

2023: 33% of CONUS BN; BN E Can

2022: 6% of CONUS BN; BN E Can

2021: 20% of CONUS BN; BN E Can

2020: 1% of CONUS BN; BN E Can

2019 (Nino): 5% of CONUS BN; BN E Can

2018: 20% of CONUS BN; BN E Can

2017: 3% of CONUS BN; BN E Can

2016 (Nino): 4% of CONUS BN; AN E Can

2015 (Nino): 0% of CONUS BN; BN E Can

2014: 4% of CONUS BN; BN E Can

2013: 1% of CONUS BN; BN E Can

2012: 15% of CONUS BN; BN E Can

 Feb: % BN Conus; E Can anom

‘27 (Nino): 80% BN US; much AN E Can

’26: 1% BN US; BN E Can

’25: 0% BN US; BN E Can

’24 (Nino): 0% BN US; AN E Can

’23: 33% BN US; BN E Can

’22: 6% BN US; BN E Can

’21: 20% BN US; BN E Can

’20: 1% BN US; BN E Can

’19 (Nino) 5% BN US; BN E Can

’18: 20% BN US; BN E Can

’17: 3% BN US; BN E Can

’16 (Nino): 4% BN US; AN E Can

’15 (Nino): 0% BN US; BN E Can

’14: 4% BN US; BN E Can

’13: 1% BN US; BN E Can

’12: 15% BN US; BN E Can

—————————————

Analysis of above: 

-Feb of ‘27 80% BN US vs only 33% (‘23) for next closest! Avg of only 7.5% BN US for 2012-26 and a mere 2% BN for the four El Niño cases!

-The other 4 Nino Febs had no more than 5% BN US! The two strongest Nino Febs had US BN of 0% (‘24) and 4% (‘16)! So, there’s virtually no resemblance to ‘27.

-BN in the SE US virtually nonexistent on any of 2012-2026 with most of them mild. But in stark contrast, 2027 has a very cold SE!

-Feb of ‘27 has by far the warmest E Can. Only 2 others had any degree of AN (much less intense than ‘27) and they were the 2 strongest El Niños (‘24 and ‘16).

——————

 In closing, Feb of ‘27 has been very persistently (for 2 months!) showing on the CFSv2 a highly unique (among all Febs on record) extreme couplet of a cold dominant CONUS and extreme blocking/very warm E Canada. The CFSv2 has been trying to tell us something it never has and though I’m not at all saying to trust it, I am suggesting that it not be dismissed.

The latest CFSv2 10 day mean prog for RONI for Oct is +2.5 and for Nov is +2.75. The current record high for any month since 1950 is the +2.5 of Jan of 1983. Judging by the blue lines all being at or below +2.75, this graph’s +2.75 mean for Nov is likely heading down in future 10 day runs. @40/70 Benchmark’s prediction for RONI is looking pretty good:

https://www.cpc.ncep.noaa.gov/data/indices/Rnino34.ascii.txt

23 hours ago, GaWx said:

Indeed as it on today’s Euro Weeklies gets down to +14 in early Nov, weakest run yet. Nothing earth shatteringly weak but interesting, regardless:

Today’s Euro Weeklies 10 mb zonal mean wind prog is even weaker than yesterdays, which had its lowest at 14 m/s, with it down to 12 m/s:

Today’s GEFS NAO forecast is even more positive than yesterdays, which itself was much more + than last week’s GEFS: 

Today: gets down to only -0.6 and then quickly rises to +0.5 followed by drop back to 0:

Yesterday:

Last week: 

23 minutes ago, roardog said:

Beating that record is not a slam dunk yet then. 

Agreed

 The most similar that I found to what the Euro Weeklies are forecasting late Oct-late Nov were 2016-7, 2009-10, and 1979-80 with the last two being El Niños:

2016 La Niña: similar late Oct/early Nov though late Nov weaker

2009 El Niño: not as weak late Oct/early Nov and weaker mid Nov vs 2026 (dip ~2 weeks later than 2026)

1979 El Niño: not as weak late Oct but early to mid Nov similar to 2026 although late Nov much weaker vs 2026

16 minutes ago, roardog said:

What’s the record RONI? I forgot now.

Are you asking for the record relative trimonthly 3.4? Or the record relative weekly 3.4?

Weekly record of relative 3.4 is +2.9 (12/29/1982)

Trimonthly RONI record is +2.40 in DJF 1982-3.

Yesterday’s NOAA official relative weekly SSTa update for last week had this: note the 0.3 cooling in Nino 4 to -0.1 and that 3.4 stayed at +2.4:

07OCT2026         4.4        3.4        2.4        0.2
 14OCT2026         4.4        3.5        2.4       -0.1

https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt

This is now Invest 93L.

 0Z UKMET almost gets to H strength:

TROPICAL STORM 93L ANALYSED POSITION : 35.0N 70.7W

ATCF IDENTIFIER : AL932026

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 20.10.2026 0 35.0N 70.7W 1004 37
1200UTC 20.10.2026 12 35.2N 70.5W 998 40
0000UTC 21.10.2026 24 35.5N 69.8W 998 45
1200UTC 21.10.2026 36 36.2N 69.5W 995 40
0000UTC 22.10.2026 48 36.9N 69.7W 989 51
1200UTC 22.10.2026 60 38.1N 68.1W 982 52
0000UTC 23.10.2026 72 39.4N 63.9W 975 63
1200UTC 23.10.2026 84 42.8N 56.7W 975 57
0000UTC 24.10.2026 96 45.9N 51.6W 986 54
1200UTC 24.10.2026 108 46.7N 48.5W 992 45
0000UTC 25.10.2026 120 48.0N 42.4W 991 45
1200UTC 25.10.2026 132 54.1N 32.9W 980 40
0000UTC 26.10.2026 144 CEASED TRACKING

3 hours ago, MJO812 said:

Euro shows a stretched PV in the long range. We never had a very strong El Nino like this so no one knows what wil happen.

Indeed as it on today’s Euro Weeklies gets down to +14 in early Nov, weakest run yet. Nothing earth shatteringly weak but interesting, regardless: