## Background

This is level 4 of 5 and continues the work of the earlier levels. The new files for this level are in `workspace/t4/`. The records from the start are in `workspace/t1/`, and the earlier results are in `workspace/t1/results/` to `workspace/t3/results/`.

## Task

Subject: PJM forecaster for go-live

Time to see whether we can beat PJM. Please build our PJM day-ahead forecaster so Tomas can put it on the scheduler like the other BA models; the runbook in forecasting/pipeline/ has the model contract. Train it on what we had before 2026, then run it for every operating day from January to September 2026 the way it would have run each morning under the product spec, and score it against PJM's own forecast and our standard baseline on the same hours, the way you have been scoring PJM.

Tomas has fetched some of Catalyst's archived copies of EIA's files from this year into eia930/pudl-raw-archive/; his note is in mail/.

In workspace/t4/results/:
- the forecaster, as a folder pjm_forecaster/ with run_forecast.py and whatever it needs;
- the January to September 2026 forecasts as a CSV, one row per delivery hour;
- a short report in Word: the scores by month, how we compare with PJM, and anything in the set-up that could make us look better than we are.

Maren

## Input

- `workspace/t1/`: the records supplied with the work (`company/`, `eia861/`, `eia930/`, `forecasting/`, `github/`, `mail/`, `meetings/`, `projects/`, `reading/`, `weather/`).
- `workspace/t2/`: the files that came with level t2 (`ferc714/`, `mail/`, `pudl/`).
- `workspace/t3/`: the files that came with level t3 (`notes/`, `weather/`).
- `workspace/t4/`: the files that came with level t4 (`eia930/`, `mail/`).
- `workspace/t1/results/`: the results of level t1.
- `workspace/t2/results/`: the results of level t2.
- `workspace/t3/results/`: the results of level t3.

## Output

- `workspace/t4/results/pjm_forecaster`
- `workspace/t4/results/pjm_backtest_2026.csv`
- `workspace/t4/results/pjm_golive_report.docx`