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:

-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):

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:

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.

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?

Subtropical Storm Josephine Advisory Number 1 NWS National Hurricane Center Miami FL AL102026 500 PM AST Wed Oct 21 2026 ...SUBTROPICAL STORM JOSEPHINE FORMS... ...FORECAST TO MOVE NORTHEASTWARD AWAY FROM THE UNITED STATES... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...37.4N 69.5W ABOUT 265 MI...425 KM S OF NANTUCKET MASSACHUSETTS ABOUT 585 MI...940 KM SW OF HALIFAX NOVA SCOTIA MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...N OR 10 DEGREES AT 6 MPH...9 KM/H MINIMUM CENTRAL PRESSURE...990 MB...29.24 INCHES Subtropical Storm Josephine Discussion Number 1 NWS National Hurricane Center Miami FL AL102026 500 PM AST Wed Oct 21 2026 The non-tropical area of low pressure (Invest AL93) that we have been monitoring this week has acquired enough subtropical characteristics to be considered a subtropical storm. Scatterometer data showed that fronts near the cyclone had dissipated, with a smaller radius-of-maximum wind than yesterday. Additionally moderate-to-deep convection has been organizing near and west of the warm-core center. Thus, advisories have been initiated on a subtropical storm, and 55 kt is shown as the initial intensity based on the scatterometer data. Josephine has been moving slowly northward today as a shortwave ridge passes across the northeastern United States. The storm should accelerate northeastward tomorrow as a mid-latitude trough digs into the Great Lakes and Northeastern United States, taking the system away from the US. By Friday, the low should turn eastward, to the south of Newfoundland. Model guidance is in good agreement on this path, and the new forecast is close to a blend of the global model consensus and the NOAA corrected-consensus aid HCCA. The subtropical storm will likely intensify during the next day or so through a favorable trough interaction while it remains near the north wall of the Gulf Stream. Global models are in good agreement on a band of hurricane-force winds developing tomorrow on the back side of the low as it undergoes extratropical transition. A slow weakening is anticipated by late Friday with the loss of forcing from the trough while the system moves over cold water. The NHC intensity forecast is similar to a blend of the GFS/ECMWF global model solutions. The cyclone should become absorbed in about 4 days within a much larger low over the North Atlantic. Since the coastal wind hazards with this system have been covered for the last several days through non-tropical products issued by local National Weather Service offices, and the system is forecast to move away from the coast, those products will remain in effect until the threat diminishes. FORECAST POSITIONS AND MAX WINDS INIT 21/2100Z 37.4N 69.5W 55 KT 65 MPH...SUBTROPICAL 12H 22/0600Z 38.1N 69.0W 60 KT 70 MPH...SUBTROPICAL 24H 22/1800Z 39.6N 66.2W 65 KT 75 MPH...POST-TROP/EXTRATROP 36H 23/0600Z 41.4N 61.6W 70 KT 80 MPH...POST-TROP/EXTRATROP 48H 23/1800Z 43.3N 56.9W 60 KT 70 MPH...POST-TROP/EXTRATROP 60H 24/0600Z 44.1N 53.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 24/1800Z 44.4N 50.4W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 25/1800Z 43.5N 37.5W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 26/1800Z...DISSIPATED

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.

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.