Hodhodata@statistics

Statistical Data Analyst , Statistical programmer, Applied statistician & Bio-statistician. ⛔No Private messages 👉 🚫📩❌.

[Hodhodata@statistics @Statisticizer]

How would you rate the accuracy and practical usefulness of my long-range forecasts for Autumn 2025 and Winter 2026 so far?
(Rating Scale):
(5🌟) Excellent (Highly accurate & very useful)
(4🌟) Good (Mostly accurate & useful)
(3🌟) Moderate (Mixed performance)
(2🌟) Low accuracy (Limited usefulness )
(1🌟) Not useful / Missed expectations

Your feedback helps refine future outlooks and improve regional targeting.

Please also mention your country/region in the comments so I can prioritize areas of highest relevance and usability .

[Hodhodata@statistics @Statisticizer]

@UUUnnnz @yd1109461450125 🫶🙏

[Hodhodata@statistics @Statisticizer]

@UUUnnnz @yd1109461450125 احترار شهر نوفمبر الجاري و هو نادر جدا بالارشيف توقتعه حسابيا بشهر ستة الماضي بعز ام الصيف -قبل 5 شهور تقريبا- بتيسير الله و ثم بالطرق الاحصائية. https://t.co/WogsuUXpxZ

https://t.co/urbV5Y1Us9

[Hodhodata@statistics @Statisticizer]

🚨#HeadsUp: Early Polar SSW & Vortex Weakening Signal — Autumn 2026 .

Last year, I highlighted the potential for an unusually early and (rare occurrence) November Polar Vortex disruption and Sudden Stratospheric Warming events, months before it became widely discussed by forecasting centers and analysts .

🔗 See the 2025 early SSW forecast:
https://t.co/yBrHRW9iNT
This year, a multivariable framework incorporating solar, planetary, space-atmospheric weather, and stratospheric factors has been used to assess the upcoming season’s polar behavior .

After examining the latest analog composites (n=20, with additional supporting cases) and stratospheric diagnostics for November 2026, a SSW event signal is again emerging that warrants attention.

🔷 Key Signals

🔹 10 hPa temperatures indicate developing polar warming during the second half of November, with persistent anomalies extending across North America, Alaska, and parts of southern Europe between ~15–30 November.

🔹 30–100 hPa geopotential height anomalies show strong upward-propagating wave activity into the polar stratosphere, with indications of zonal wind deceleration and partial reversal above ~65–70°N.

🔹 The vortex appears increasingly susceptible to displacement and deformation, particularly during the 15–25 November window.

🔹 A coherent Rossby wave train is evident across multiple atmospheric layers, suggesting active troposphere–stratosphere coupling.

🔷 Interpretation

The current signal supports:

✔ Elevated probability of early-season vortex weakening
✔ Increased likelihood of a displacement-type warming event
✔ Enhanced planetary wave activity

⚠️ Moderate probability of vortex stretch / partial split
🔷 Key Uncertainty
I am not yet concluding a major SSW, but signals from this early outlook do support it.

The decisive factor remains:

Whether warming intensifies enough to produce a full zonal wind reversal at 10 hPa near 60°N. Yet this early analyses do point for definite reversal of wind. see comment.

🔷 Bottom Line

A dynamically active stratospheric regime is likely during late autumn 2026, with a credible signal for early vortex disturbance.
However, confirmation of a major SSW or full split remains conditional.

📊 The attached maps summarize the evolving signal.
More diagnostics (geopotential heights, wind anomalies, and vertical structure) are included in the thread.

⚠️ This forecast is probabilistic, not deterministic, based on composite analysis, AI-assisted downscaling, and advanced statistical methods.

Statistical Analog Model
By M. @Statisticizer
Chief Data Scientist — https://t.co/4PftHqD0mL

[Hodhodata@statistics @Statisticizer]

@UUUnnnz @yd1109461450125 يوجد تحديثات حاليا بتتوافق مع التوقعات الاحصائية الان , حول 20-30 نوفمبر و ممكن تعدلها التماذج مرة او مرتين قبل الثلث الاخير ,
و اجمالا اخوي البرق انا ما اصقعها من راسي :) , فعليا بعملها بطرق حسابية ,
توقع الاحترار بالقبة القطبية كمثال من قبل اربع اشهر هي اقرب مثال انها جيدة.

[Hodhodata@statistics @Statisticizer]

@gregporter_wx No, unfortunately, I haven't published it and have no plans to submit it to a journal. I may eventually make it freely available through GitHub, alongside other extended monthly climate oscillation indices I have independently calibrated or reconstructed, but not just yet.

[Hodhodata@statistics @Statisticizer]

Very informative post. I extensively use GLAAM in long-range forecasting,and it makes sense to include it in statistical models.Its close link to spaceweather parameters is particularly relevant.I have personally reconstructed an extended AAM dataset spanning 300 years & it works

[Met4Cast - UK Weather @Met4CastUK]

Let's learn No. 3: Atmospheric Angular Momentum (AAM)

The AAM is a very complicated topic & an area of science that is relatively new in terms of research and understanding. I'll try my best to explain the broader outline as simply as I can, but please feel free to ask questions!

The AAM forms part of the Global Synoptic Diagnostic Model (GSDM), a model designed to apply a diagnostic approach to medium range weather forecasting, whilst it can't tell you specific weather on specific days it's instrumental in predicting broad-scale weather patterns in the 2-3 week range & sometimes a little beyond that.

Today, i'll focus solely on the AAM. Atmospheric angular momentum (AAM) is a measure of how fast the atmosphere rotates around the Earth's axis.

A faster atmospheric rotation = a positive AAM, a slower atmospheric rotation = negative AAM. It's essentially a measurement of momentum within the atmosphere when averaged across the globe.

Various weather events can either add or remove westerly momentum from the atmosphere and the MJO (previously discussed) is a big player in this, when the MJO progresses eastwards through the Maritime Continent frictional torque generated against earths surface acts to slow down earths rotation, energy must be conserved however so this momentum transfers into the atmosphere and the result is we see an increase in atmospheric momentum.

The largest player in adding or removing momentum however is mountain torque. During a positive mountain torque event, large mountain ranges are "bumping" into areas of higher pressure, this slows down earths rotation and that transfers momentum into the atmosphere. (please see linked tweet thread in the reply to this for a more detailed explanation on mountain torque) Mountain torque always proceeds frictional torque.

The opposite to the above is also true, the MJO returning to the Indian Ocean sees a return to negative frictional torque with negative mountain torque following, this does the opposite to a positive event and removes westerly momentum, transferring that momentum back into earths rotation and out of the atmosphere.

During La Nina, AAM is typically negative due to an increase in the easterly trade winds across the Pacific (less westerly momentum), the opposite is true for El Nino, weaker easterly trade winds tend to produce positive AAM.

You can however see positive AAM during La Nina, or negative AAM during El Nino, these are often called "mini ENSO cycles" and are more broadly driven by the MJO.

Complicated. How does this tie into weather patterns?

A very rough rule of thumb is that a positive AAM (increased westerlies) tends to produce a more wavey/amplified jet stream which increases areas of blocking high pressure in the mid/high latitudes, a negative AAM does the opposite and produces a flatter, more zonal jet stream.

The direction of travel is often more important than the total. For example; total AAM could be negative but certain events are adding westerly momentum to that atmosphere & thus AAM tendency (direction of travel) is positive.

You also need to account for "where" those positive or negative anomalies are heading. Are they moving towards the equator? In which case this tends to enhance sub-tropical highs and we see a stronger Azores high and often milder weather, or are those anomalies moving towards the poles? In which case blocking in the higher latitudes is more likely. I've annotated the AAM tendency chart (2nd image) to try and show this.

You also need to account for phasing of the MJO, does this align with the current direction of travel with the AAM? For example; let's say the MJO is in phase 6, this typically correlates to high latitude blocking, but AAM anomalies are moving towards the equator, this goes against the idea of high latitude blocking.

Two opposing signals make the medium range forecast more uncertain. Looking at the MJO alone, you'd expect blocked patterns but the AAM is telling a different story, this is why it's important not to take the MJO in isolation.

When both of these drivers are in alignment however, you can be far more confident in the medium range forecasting space in terms of the broader pattern, often being able to flag the potential for "high impact weather" far earlier, albeit on a broader scale, specific details of when/where/how bad will always be reserved for shorter range forecasting & models.

I hope this explanation makes at least some sense & explains why AAM plays an important role in medium range forecasting. Any questions please feel free to ask.

Next time: Frictional Torque & Mountain Torque.

[Hodhodata@statistics @Statisticizer]

@gregporter_wx My independently reconstructed monthly angular momentum index has proven valuable for long-range forecasting, with strong independent correlation with the QBO. It is a computed estimate, not an observed AAM index.

[Hodhodata@statistics @Statisticizer]

@AironJaquer @AEMET_Esp @pyreweather 🙏🙏

[Hodhodata@statistics @Statisticizer]

🎯🚨The forecast has materialized as expected.

Atlantic Storm Claudia and Charles are heading towards Spain, with @AEMET_Esp warning of potentially imminent severe rainfall episodes across parts of Spain and Portugal.

[Hodhodata@statistics @Statisticizer]

🌦️🌐🚨 November 1–12 Synoptic Outlook | Mediterranean Region.

🗺️ Attached are my preliminary synoptic outlook maps for the first 12 days of November, highlighting expected troughing patterns, precipitation potential, cloud-cover distribution (new maps 🆕), and estimated snowfall probabilities (new maps 🆕❄️) across the Mediterranean region.

🌧️ 🇪🇸 Iberia & 🇫🇷 France | Potential Atlantic Influence

A low-pressure system over the Bay of Biscay may develop during the first 10 days of November, potentially affecting the Iberian Peninsula and parts of southwestern Europe. This configuration could facilitate a colder-air intrusion into the region.

🌧️ Precipitation anomalies may turn notably positive across Iberia, particularly over inland and southeastern parts of the peninsula, with elevated rainfall potential also extending into parts of France. The magnitude and distribution of precipitation will depend on the eventual positioning and evolution of the low-pressure system.

🌬️ Areas where high- and low-pressure systems interact may experience enhanced rainfall potential, provided the necessary atmospheric ingredients for lifting, moisture convergence, and cloud development are present. This may include parts of North African territory.

❄️🎿 Iberia | Estimated Snowfall Probabilities

The snowfall-risk analysis indicates potential snowfall over the high peaks of the southern and eastern mountain ranges of the Iberian Peninsula. However, these probabilities do not guarantee substantial snowfall or significant snow accumulation. The map represents the likelihood of snowfall rather than the expected amount or depth of snow.

☀️🌍 North Africa & Central Mediterranean | Potential Stability
An anticyclonic influence may prevail or develop over parts of North Africa and the central Mediterranean, favoring atmospheric subsidence, more stable conditions, and reduced precipitation potential in the affected areas.

🔭📅 Second Half of November | Preliminary Outlook

Looking further ahead, Iberia may experience increased atmospheric subsidence and a transition toward more stable conditions during the second half of November. Nevertheless, periods of residual or renewed atmospheric instability cannot yet be ruled out.
⚠️ Forecast Disclaimer: This is a preliminary, long-range probabilistic synoptic outlook, not a deterministic forecast. The projected atmospheric patterns, precipitation distribution, and snowfall probabilities remain subject to refinement as the forecast period approaches and additional analyses become available.

🛰️ Weather maps courtesy of @PyreWeather: https://t.co/AAChjhK20Q.

Climatic statistical analog modelling, Weather Forecasting and downscaling by Mr. M @Statisticizer - https://t.co/4PftHqD0mL .

______
#WeatherOutlook #MediterraneanWeather #SynopticAnalysis #NovemberForecast #Iberia #NorthAfrica #SnowfallPotential #WeatherForecasting

[Hodhodata@statistics @Statisticizer]

@jmabcic @AEMET_Esp @pyreweather 🫶🙏🙏

[Hodhodata@statistics @Statisticizer]

@PlaysSaheb I may share some pre-instrumental historical reconstructions at some point ( later) . IERS provides GLAAM and other geophysical angular momentum datasets from 1948 onward, which I also used to independently validate my estimates.

https://t.co/IprLWwiVDS

[Hodhodata@statistics @Statisticizer]

@luismaiabento @AEMET_Esp Yes, Ah!😅

[Hodhodata@statistics @Statisticizer]

@PlaysSaheb Unfortunately, I do not share my computed data publicly. I have no interest in publishing papers about GLAAM or climate in journals either, it makes no useful sense to me.

[Hodhodata@statistics @Statisticizer]

@KitDelUs 🙏

[Hodhodata@statistics @Statisticizer]

@rmip25 @AEMET_Esp @pyreweather 🙏🫂🫶🫶

[Hodhodata@statistics @Statisticizer]

@luismaiabento @AEMET_Esp Bruna (borrasca Bruna). I think I've confused her name with a friends name whose nickname was Bruna , her real name was Claudia .

[Hodhodata@statistics @Statisticizer]

@IsabelComares @AEMET_Esp @pyreweather 😔

[Hodhodata@statistics @Statisticizer]

@AEMET_Esp Se prevé estabilidad hasta los últimos diez días, aunque el noroeste de España y norte de Portugal podrían mantener lluvias y tormentas atlánticas hasta el 23. Otra fase húmeda podría llegar a finales de noviembre y principios de diciembre, afectando al este peninsular & Balear.

[Hodhodata@statistics @Statisticizer]

@judah47 Just sharing: From a statistical analog perspective, with a possible mild +Ve Greenland Blocking (+GBI) is a possible scenario during 10–17 November. However, the GFS does not indicate Greenland Blocking before 15 November. Thank you for the updates!

[Hodhodata@statistics @Statisticizer]

@AEMET_Esp recede westward into the atlantic* sorry for the typing error.

[Hodhodata@statistics @Statisticizer]

@AEMET_Esp more maps for the same period. and By the way the storm may received westward later on into the Atlantic.

[Hodhodata@statistics @Statisticizer]

@IsabelComares @AEMET_Esp 🫶🙏🙏🙏