NOAA National Water Model Short-Range Land Forecast

GribStream Code: nwmshortland

Current archive: GribStream indexes compatible source objects beginning January 1, 2025. NOAA describes the AWS source as a rolling four-week archive, so older retained objects should be treated as opportunistic rather than guaranteed permanent history.

Forecast timing: the short-range configuration runs every hour and publishes hourly lead times from 1 through 18 hours. Several model cycles can therefore describe the same valid hour; choose the run and lead-time policy that fits the application.

Land fields only: this dataset contains the fixed 1 km land grid. It does not include the separate channel, reservoir, or higher-resolution terrain-routing outputs.

Availability and open data: operational delays, missing cycles, and future NWM upgrades can create gaps or require compatibility updates. NOAA Open Data are available for public use; attribution is requested and NOAA endorsement must not be implied.

Description

The National Water Model is NOAA's operational continental-scale hydrologic forecasting system. Its land component uses the Noah-MP land-surface model to track exchanges of water and energy between the ground, vegetation, snowpack, and atmosphere.

nwmshortland focuses on the six variables NOAA publishes in each 1 km short-range land file. Together they describe snow amount and state, the fraction of ground covered by snow, accumulated evapotranspiration, and near-surface soil saturation.

This is not the streamflow product most people first associate with NWM. River reaches and reservoirs are point-based source products, while this collection is a regular land grid designed for spatial queries and maps across the broader CONUS+ domain.

The inventory below lists the exact selectors, levels, units, forecast horizons, and currently indexed availability.

Detail

• Archive begins: 2025-01-01
• Official NOAA National Water Model overview: https://water.noaa.gov/about/nwm
• Key features:
  • Six source variables: ACCET, FSNO, SNEQV, SNOWH, SNOWT_AVG, and SOILSAT_TOP.
  • Snow-cover fraction, snow depth, snow water equivalent, and average snow temperature for snowpack monitoring.
  • Accumulated total evapotranspiration and soil saturation in the top two soil layers, representing approximately the upper 0.4 m.
  • Hourly deterministic forecasts through 18 hours on one consistent land-surface grid.
• Resolution: Fixed 4,608 by 3,840 Lambert conformal grid with 1 km spacing over the CONUS+ land domain.
• Temporal coverage: One deterministic cycle every hour, with hourly forecast lead times from 1 through 18 hours.
• Primary uses: Snowpack and melt monitoring, soil-wetness dashboards, agricultural water management, watershed situational awareness, evapotranspiration tracking, winter operations, and short-range hydrologic forecast comparison.

Related datasets

• HRRR for the atmospheric forcing and short-range weather context
• MRMS for radar and multi-sensor precipitation analyses
• NBM for blended weather guidance across the United States

Parameters