Build the application

## Build
Model atmospheric drying extremes using ERA5 surface temperature and dewpoint reanalysis grids. Quantify multi-day vapor pressure deficit anomalies to evaluate parametric wildfire season ignition risk.

## User
Forestry Risk Analyst

## Workflow
1. Extract 2m temperature and 2m dewpoint temperature fields from ERA5 CDS datasets.
2. Compute saturation and actual vapor pressure to derive daily Vapor Pressure Deficit (VPD).
3. Identify prolonged consecutive days exceeding 95th percentile VPD thresholds.
4. Generate a parametric trigger performance report illustrating historical payout distributions.

## Interface
Interactive CLI with ASCII charts and structured JSON outputs detailing VPD anomaly timelines.

## Data
Use cdsapi to retrieve 2m temperature and dewpoint data, or process synthetic multi-day meteorological arrays.
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)
Extracts temperature and dewpoint variables using cdsapi retrieve queries for ERA5 reanalysis single levels.

## Tools
optuna, cdsapi, scipy.
Optuna optimizes trigger thresholds to balance basis risk against historical fire occurrences.
Open-source local LLM or hosted Claude to generate parametric sensitivity summaries.

## 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
- Accurately computes saturation vapor pressure using standard Tetens formula.
- Computes daily maximum vapor pressure deficit (VPD) in kilopascals.
- Identifies periods where continuous extreme drying exceeds defined contract duration.

## Starter Examples
```json
[
  {
    "input": {
      "forest_tract_id": "OR-TIMBER-04",
      "threshold_vpd_kpa": 3,
      "duration_days": 3,
      "vpd_daily_kpa": [
        2.8,
        3.2,
        3.5,
        3.4,
        2.1
      ]
    },
    "expected_output": {
      "forest_tract_id": "OR-TIMBER-04",
      "trigger_met": true,
      "max_consecutive_extreme_days": 3,
      "peak_vpd_kpa": 3.5
    }
  },
  {
    "input": {
      "forest_tract_id": "OR-TIMBER-05",
      "threshold_vpd_kpa": 3.5,
      "duration_days": 3,
      "vpd_daily_kpa": [
        2.8,
        3.2,
        3.4,
        2.1
      ]
    },
    "expected_output": {
      "forest_tract_id": "OR-TIMBER-05",
      "trigger_met": false,
      "max_consecutive_extreme_days": 0,
      "peak_vpd_kpa": 3.4
    }
  }
]
```

## Safety
Outputs represent academic risk models and do not provide real-time forest fire warnings or binding contract payments.
Use mock external writes. Require human review before any real deployment.