Forecasting Guide
How We Build a Long Range Forecast
The three layers of forecasting at dayboro.au, adn the 9-step Inigo Jones process documented from start to finish
What this guide covers
We publish a monthly long range forecast for the Dayboro valley. I've been doing it since 2004 in one form or another, and the method has changed a fair bit over that time. This guide documents the current process, step by step, so you can follow along or build your own version and compare it to mine.
It's not a short read. Nine steps, each with its own page. But if you want to understand where the forecast numbers actually come from, this is the only place we've written it all down.
The three layers of forecasting at dayboro.au
We run three different types of forecasting, and they do different jobs. None of them replaces the others.
Long range (the Inigo Jones method)
Monthly outlooks, published roughly a month in advance. This is the focus of this guide. It's based on the work of Inigo Jones, a Queensland meteorologist who spent his career correlating astronomical cycles with rainfall and temperature patterns. I've reverse engineered his method, built the calculations from scratch, and run it against 20 years of local data. It gives you a sense of what the month is likely to feel like overall, not what happens day to day.
Medium range (the Dayboro Model)
7 to 10 day outlooks, updated daily. This uses data from our Ecowitt weather station on Lyndhurst Hill combined with numerical model output. It's what you check when you're planning the week. BOM's grid for this area is calibrated to Samford, which is lower and gets different airflow off the D'Aguilar Range. Our model uses local data, so it performs better in the valley.
Near term (BOM 1 to 3 day forecasts)
We link to BOM forecast for the short end. We don't replicate it. BOM has resources we don't, and for 24 to 48 hours out their numerical models are hard to beat. Use them.
How they fit together
Inigo Jones tells you the overall character of the month. The Dayboro Model gives you the timing within that. BOM handles the precision of the next day or two. You read them in that order, not as alternatives to each other.
An honest note: these forecasts don't always agree. When they don't, I say so. The skill is in knowing which layer to trust for which question.
The 9 step Inigo Jones process
This is the full documented method. I've split it across nine pages because each step genuinely needs its own space. You can read them in sequence or jump to the part that interests you. Eventually you'll want to read all of them if you're building your own version.
Understanding the Basics
Who Inigo Jones was, the core idea behind the method, and the astronomical cycles he tracked.
Data Collection and Preparation
The four data categories you need, where to get them, and how to organise them before you start.
Collecting Your Data
Specific datasets, exact URLs, file formats, and what quality checks to run before you trust the numbers.
Setting Up Your Forecast Model
Building the spreadsheet framework, defining the cycle columns, and running your first position calculations.
Moisture Chart Creation
How lunar phases map to moisture periods, and how to construct the monthly moisture chart from scratch.
Pattern Recognition
Matching current cycle positions against historical analogues and deciding which years to weight.
Forecasting with Astronomical Calculations
Translating cycle positions and analogue patterns into an actual monthly forecast statement.
Verification and Calibration
Scoring the forecast against observed data and adjusting your weightings based on what the record shows.
Continuous Verification
Running the scorecard over time, tracking skill, and knowing when the method is drifting.
Why we publish the method
We publish the forecast before the period it covers. Then, once the month is done, we open the forecast to everyone and post the observed data next to it so anyone can check the result. That's the deal.
I won't hand over the raw data files. That's not about hiding anything. It's about keeping the focus on the process rather than arguments about whether my spreadsheet is manipulated. If you build your own dataset from the public sources we document in Step 2 and Step 3, you'll reach the same starting point. From there you can audit every number.
Some people find the method controversial. The idea that Jupiter's orbital position influences Queensland rainfall is not mainstream meteorology, and I understand why that's a hard sell. That's fine. Build your own version using the same process, run it against the historical record, and see what you get. That's more useful than arguing about it.
The people who get the most out of a monthly outlook are those making decisions weeks in advance. Gardeners timing plantings around moisture cycles. Graziers planning stock moves. Growers on irrigation who need to read the season rather than just the week. If that describes you, the planting guides at Garden Buddy are worth pairing with these forecasts.
Where to see the forecasts
The actual monthly forecasts are at our long range forecasts page. Members can see the current month's forecast before it's published to everyone. Past months and the accuracy scorecard are open to all.
The technical cycle positions we used for 2026 are documented separately at our 2026 methodology page. That's where you'll find the actual planetary positions, the analogue years selected, and the reasoning behind each monthly call.
If you're new to the valley or just exploring the D'Aguilar hinterland, Local Buddy has the community directory and events guide for Dayboro and surrounds. The Tawny Trails covers the arts circuit through the hinterland if that's more your pace.