Build an ERA5 Wildfire Atmospheric Drying Index Assessor — implementation

## Build
Model severe wildfire weather potential by querying ERA5 temperature and relative humidity pressure level grids. Detect persistent atmospheric drying windows to quantify parametric forest protection trigger uncertainty.

## User
Wildfire Parametric Underwriter

## Workflow
1. Formulate cdsapi retrieve parameters for ERA5 atmospheric temperature and relative humidity.
2. Ingest simulated pressure level grids and calculate Vapor Pressure Deficit (VPD) metrics.
3. Track cumulative days with extreme drying anomalies exceeding regional wildfire danger thresholds.
4. Evaluate trigger sensitivity and basis risk against synthetic timberland fire damage inventories.

## Interface
Streamlit analytical app plotting time-series VPD curves, reanalysis grids, and trigger activations.

## Data
Execute cdsapi test retrieval scripts configured with simulated local NetCDF or GRIB files.
Starter examples below are synthetic. They are not downloaded records.

## Source
[Copernicus Climate Data Store client](https://raw.githubusercontent.com/ecmwf/cdsapi/master/README.rst)
Specify ERA5 pressure-levels dataset parameters in cdsapi retrieve calls per README.

## Tools
mlflow, cdsapi, xarray, scipy.
MLflow tracks parametric model experiments, trigger threshold parameters, and basis risk metrics.
Local computation environment with API access to hosted LLM for model explanation.

## Deliverables
Submit runnable source, pinned dependencies, setup commands, a working interface, example outputs, and a recorded end-to-end demo. Include tests and an action log.

## Acceptance
- Constructs CDS API calls with pressure level and product type fields.
- Calculates Vapor Pressure Deficit within 0.1 kPa numerical precision.
- Tracks parametric index simulation metrics and run parameters in MLflow.

## Starter Examples
```json
[
  {
    "input": {
      "forest_tract_id": "TIMBER-OR-7",
      "vpd_threshold_kpa": 2.8,
      "min_consecutive_days": 5,
      "daily_vpd_series": [
        1.5,
        2.9,
        3.1,
        3,
        3.2,
        3.4,
        2.1,
        1.8
      ]
    },
    "expected_output": {
      "forest_tract_id": "TIMBER-OR-7",
      "max_drying_streak_days": 5,
      "parametric_trigger_fired": true,
      "payout_tier_percentage": 75,
      "experiment_logged": true
    }
  },
  {
    "input": {
      "forest_tract_id": "TIMBER-WA-3",
      "vpd_threshold_kpa": 2.8,
      "min_consecutive_days": 5,
      "daily_vpd_series": [
        2.9,
        3,
        2.2,
        3.1,
        3.2,
        2.5
      ]
    },
    "expected_output": {
      "forest_tract_id": "TIMBER-WA-3",
      "max_drying_streak_days": 2,
      "parametric_trigger_fired": false,
      "payout_tier_percentage": 0,
      "experiment_logged": true
    }
  }
]
```

## Safety
Index assessments serve only as actuarial simulations without initiating financial capital movements.
Use mock external writes. Require human review before any real deployment.