Lake Powell Forecast API

Run forecast scenarios programmatically. The engine runs client-side — results are computed in your browser using the same model as the main analyzer.

Interactive Query

Result

Click "Run Forecast" to see results...

URL API

Pass parameters via URL hash to pre-fill and auto-run:

api.html#elev=3529.4&date=2026-03-13&swe=3364&release=1.0&end=2027-06-01

JavaScript Module API

Import the forecast engine directly in your own code:

<script type="module">
import { forecast, findLowPoint, THRESHOLDS } from './forecast.js';

const results = forecast({
  currentElevation: 3529.4,
  currentDate: '2026-03-13',
  sweApr1: 3364,
  releaseMultiplier: 1.0,
  forecastEndDate: '2027-06-01',
});

const low = findLowPoint(results);
console.log('Projected low:', low);
</script>

Parameters

• currentElevation — Lake elevation in ft (NGVD 1929). Get latest from USGS API.
• currentDate — YYYY-MM-DD format.
• sweApr1 — Basin-average April 1 Snow Water Equivalent in tenths of mm. Get from NCEI API.
• releaseMultiplier — Scale factor on baseline decline rates. 1.0 = current Mid-Elevation Tier (~7.48 MAF/yr).
• forecastEndDate — YYYY-MM-DD. Forecast projects monthly to this date.

Response

Returns JSON with monthly projections, the low point, and threshold crossings.

For Claude / LLM Integration

The forecast engine is a pure JavaScript module with zero dependencies. To use in an AI context:

1. Fetch current elevation from USGS: GET https://waterservices.usgs.gov/nwis/dv/?format=json&sites=09379900¶meterCd=62614&period=P1D
2. Fetch current SWE from NCEI (10-station average)
3. Run forecast() with those inputs
4. Interpret results against THRESHOLDS