Nephyr Weather

clm-studios/nephyr-weather

Pulls GFS ensemble weather data for 12 cities with a focus on finding edges in prediction markets. You get access to probabilistic forecasts that can reveal when consensus weather predictions might be off, which matters if you're trading on weather-dependent outcomes or trying to spot mispriced contracts on platforms like Polymarket or Kalshi. The server surfaces ensemble spread and model agreement metrics rather than just point forecasts. Reach for this when you need programmatic access to weather uncertainty data for quantitative trading strategies, not for general weather lookups where a standard API would do fine.

tools: 5
transport: STDIO
last updated: Apr 1, 2026

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Tools

5 tools

Public tool metadata for what this MCP can expose to an agent.

get_weather_signalsGet GFS ensemble weather signals for one or more cities on a given date. Returns model probability of daily high exceeding various thresholds, derived from the 31-member GFS ensemble forecast. Requires cities (list of city names) and forecast_date (YYYY-MM-DD). Optional: thres...5 params

Get GFS ensemble weather signals for one or more cities on a given date. Returns model probability of daily high exceeding various thresholds, derived from the 31-member GFS ensemble forecast. Requires cities (list of city names) and forecast_date (YYYY-MM-DD). Optional: thres...

Parameters* required

citiesarray

List of city names e.g. ["NYC", "Chicago"]. Call get_city_info to see supported cities.

directionstring

Direction to evaluate: 'above' or 'below' the threshold.one of above · belowdefault: above

forecast_datestring

Forecast date in YYYY-MM-DD format.

market_typestring

Weather variable: 'high' (daily max), 'low' (daily min), 'rain' (precipitation).one of high · low · raindefault: high

threshold_fnumber

Temperature threshold in Fahrenheit (default 70).default: 70

get_ensemble_forecastFetch the raw GFS 31-member ensemble forecast for a city on a given date. Returns per-member daily high temperatures, low temperatures, and precipitation. Useful for custom probability calculations or verifying signal generation.2 params

Fetch the raw GFS 31-member ensemble forecast for a city on a given date. Returns per-member daily high temperatures, low temperatures, and precipitation. Useful for custom probability calculations or verifying signal generation.

Parameters* required

citystring

City name e.g. 'NYC', 'Chicago', 'London'.

forecast_datestring

Forecast date in YYYY-MM-DD format.

detect_edgesScan weather markets for edges — cases where the GFS model probability differs significantly from the market-implied probability. Requires a list of (signal, market) pairs. Returns all EdgeResults, or only tradeable ones if tradeable_only=True.9 params

Scan weather markets for edges — cases where the GFS model probability differs significantly from the market-implied probability. Requires a list of (signal, market) pairs. Returns all EdgeResults, or only tradeable ones if tradeable_only=True.

Parameters* required

citystring

City name for the signal.

directionstring

Signal direction.one of above · belowdefault: above

forecast_datestring

Forecast date YYYY-MM-DD.

market_pricenumber

Market YES price as probability (0-1).

market_typestring

Market type.one of high · low · raindefault: high

min_edge_pctnumber

Minimum edge in percent to flag tradeable (default 5).default: 5

platformstring

Platform the market is on.one of kalshi · polymarketdefault: kalshi

threshold_fnumber

Temperature threshold in Fahrenheit.

tickerstring

Market ticker (optional, for identification).default:

list_active_marketsList active weather markets on Polymarket or Kalshi. Optionally filter by city. Returns market tickers, prices, volumes, and metadata. Kalshi requires api_key to be provided.3 params

List active weather markets on Polymarket or Kalshi. Optionally filter by city. Returns market tickers, prices, volumes, and metadata. Kalshi requires api_key to be provided.

Parameters* required

citiesarray

Optional city filter.

kalshi_api_keystring

Kalshi API key (required for Kalshi markets).

platformstring

Which platform to query.one of polymarket · kalshi · alldefault: polymarket

get_city_infoGet coordinates and metadata for a supported city, or list all supported cities if no city is provided.1 params

Get coordinates and metadata for a supported city, or list all supported cities if no city is provided.

Parameters* required

citystring

City name or alias. Leave empty to list all cities.