> For the complete documentation index, see [llms.txt](https://docs.rootcause.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rootcause.ai/more-details/digital-twin/temporal-simulations/forecast.md).

# Forecast

Forecast projects selected variables forward in time, returning a trajectory for each with a confidence band that widens further into the future. It is the temporal counterpart of [Prediction](/more-details/digital-twin/simulation-types/prediction.md): where Prediction answers "what outcome is most likely for this input?", Forecast answers "how will these variables evolve over the next *n* steps?"

Forecast is available on **temporal** Digital Twins — those built on time-series data. The system auto-detects a time column and sets the twin's type to Temporal when you [create it](/user-guide/creating-digital-twin.md); no separate setup is needed. For the workflow that produces a twin in the first place, see [Step 5: Build Digital Twin](/user-guide/creating-digital-twin.md).

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## Starting a simulation

Open a temporal Digital Twin, open the **Simulations** tab, then click **New Simulation**. The type picker for a temporal twin differs from the static one: it offers time-aware simulations, with **Forecast**, **Temporal Intervention**, and **Causal Health Monitor** available today and the rest of the temporal family rolling out (see [Temporal Simulations](/more-details/digital-twin/temporal-simulations.md)).

<figure><img src="/files/zgIrv08ehK09gfGmiNbG" alt="The New Simulation screen for a temporal Digital Twin, with Quick Start suggestions and the temporal type cards — Forecast, Temporal Intervention, Temporal Optimization"><figcaption><p>The temporal twin's simulation menu, with generated Quick Start suggestions above the type cards. Choose <strong>Forecast</strong> to project variables forward in time.</p></figcaption></figure>

Choose **Forecast** to open the setup.

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## Step 1: Select forecast targets

The forecast targets are the time-series variables you want projected forward. Each selected target is forecast independently across the horizon. Pick as many as you need — every target appears as its own chart in the result.

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## Step 2: Forecast horizon

The horizon sets how many time steps ahead the simulation covers. The bar shows your training range against the forecast range, so you can see how far past the data you are projecting. A horizon of 60 days on a model trained over 364 days, for example, extends two months beyond the last observation.

Forecasting far beyond the training range is possible, but the confidence band widens the further out you go — the model is honest about growing uncertainty.

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## Step 3: Forecast from *(optional)*

By default the forecast begins at the last date in the training data. Set a start time here — relative to the last training date, or a custom date — to begin the projection earlier or later.

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## Step 4: Confidence level

The default of 0.95 means the model is 95% confident the actual value will fall within the shown band. Higher confidence widens the band; lower narrows it. Leave the default unless you have a specific reason to change it.

<figure><img src="/files/CvToz9ukwauGxUdISoJz" alt="The Forecast setup: selecting forecast targets from the twin&#x27;s time-series variables, with the optional Forecast from section below"><figcaption><p>The start of the Forecast setup: pick the targets to project — each selected target becomes its own chart in the result.</p></figcaption></figure>

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## Running the forecast

Select the twin versions to run on, review the configuration summary, and click **Run Simulation**. **Validate** checks the setup without running it.

<figure><img src="/files/5QmPiinhElt9j8u4b1xr" alt="The end of the Forecast setup: confidence level 0.95, the version selector, the Configuration Summary, and the Run Simulation button"><figcaption><p>The configuration summary confirms what is being forecast, over what horizon, at what confidence — the last check before running.</p></figcaption></figure>

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## Reading the result

The result page opens with an AI summary of the forecast, a per-target summary of net change, and one chart per target.

<figure><img src="/files/OH2Ioq6aad10FoGgExTq" alt="A completed Forecast run over a 1-week horizon at 95% confidence: AI summary, forecast summary table, and a confidence-banded chart for the target variable"><figcaption><p>A completed Forecast. Each target gets its own chart with the projected trajectory and its confidence band; the summary table reports the net change over the horizon.</p></figcaption></figure>

Each chart plots the variable's history up to the forecast start, then the projected trajectory with its confidence band shaded around it. The band widens with the horizon, reflecting accumulating uncertainty. Per-chart controls surface the underlying reasoning:

* **Changepoints** — the points where the trajectory shifts direction or slope.
* **Why** — the causal drivers behind the projected movement.
* **Bounds** — toggle the confidence band on and off.

The **Forecast Summary** reports the net change for each target over the horizon, and the **Forecast Results Table** holds the underlying values for export. The whole run exports as PDF.

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## Other Simulation Types

Forecast is the temporal analogue of [Prediction](/more-details/digital-twin/simulation-types/prediction.md); a temporal twin's menu offers time-aware versions of the other types too — see [Temporal Simulations](/more-details/digital-twin/temporal-simulations.md). The static types are:

* [Prediction](/more-details/digital-twin/simulation-types/prediction.md) — the most likely outcome for a specific input.
* [Intervention](/more-details/digital-twin/simulation-types/intervention.md) — change a variable and observe propagation.
* [Optimization](/more-details/digital-twin/simulation-types/optimization.md) — find the input combination that best meets a goal.
* [Best Action](/more-details/digital-twin/simulation-types/best-action.md) — the minimum change needed to reach a target.
* [Explanation](/more-details/digital-twin/simulation-types/explanation.md) — the drivers and impacts behind an outcome.

See [Simulation Types](/more-details/digital-twin/simulation-types.md) for the full picture and [Step 6: Run Simulations](/user-guide/simulations.md) for the general overview.