AORC: Hourly US Weather Grid for Hydrologic Modeling, 1979-Present

Eight hourly weather variables on an 800-meter grid cover the continental US from 1979 and Alaska from 1981 to the near-present. The NOAA Office of Water Prediction created this Analysis of Record for Calibration (AORC) to drive land-surface and hydrologic models, including the National Water Model. Data is provided in a cloud-optimized Zarr format for efficient access.

Use Cases

• Calibrating hydrological model parameters based on the suite of eight driving weather variables.
• Analyzing long-term trends in precipitation and temperature over the continental US and Alaska.
• Running retrospective simulations of the National Water Model using the specified input data.
• Studying spatial patterns of radiation and wind components at a terrain-relevant scale.

Strengths

• Covers a long temporal range, from 1979/1981 to near-present, providing decades of hourly data.
• Includes eight specific variables: precipitation, temperature, humidity, pressure, radiation, and wind components.
• Offers high spatial resolution with a grid mesh length of approximately 800 meters (30 arc seconds).
• Data is post-processed into a cloud-optimized Zarr format, which the description suggests loads significantly faster than the native NetCDF.

Limitations

• An announcement notes a past processing issue that incorrectly masked 0.04% of rows, though corrected data is being regenerated.
• The full grid extent includes outer rows and columns filled with missing values, a remnant of earlier requirements.
• Column-level documentation is absent; field semantics and data structure must be inferred after download.

Provenance

Source

NOAA Office of Water Prediction (OWP).

Collection Method

Gridded record created from reviewing, identifying, and processing multiple large-scale observation and analysis datasets.

Time Range

1979 to near-present (CONUS), 1981 to near-present (Alaska).

Freshness

Data runs with a 10-day lag and is updated to the near-present, but the last update date is unknown.

Geography

Continental United States, Alaska, and their hydrologically contributing areas.