Cumulus

Cumulus is a gridded meteorological data repository that serves the Corps Water Management and Hydrologic and Hydraulic Communities of Practice.  Cumulus is a web service that provides on-demand data access through its primary website https://www.cumulus.corps.cloud as well as its Application Programming Interface (API) connections supported in HEC-RTS and HEC-MetVue.  

Cumulus access requires CAC authentication and is currently available only through CorpsNet.  Cumulus access via HEC-RTS and HEC-MetVue is possible through the following URLs:

• https://cumulus-api.corps.cloud/ (Primary AWS Commercial URL, will be retired in 2026)
• https://cumulus.cwbi.mil/api (Secondary AWS GovCloud URL, will become primary in 2026)

The Cumulus Website and API provide means to select the following information for a desired dataset(s) download:

• Product – Provides a list of all available historic, real-time, and forecast meteorological parameters
• Corps Office – Filter the applicable watersheds for the selected office
• Watershed – Determines the clipping extents for the dataset download
• Time Window – Defines the start and end dates and times for the dataset download

  • For forecast datasets, Cumulus archives all forecast versions based on the issuance date and time. The end time for the download time window is used by Cumulus to return the forecast version issued closest to or at that time.

New products and extents can be created if requested.  The process for requesting these can be found here: Submitting Cumulus Issues or Requests

The CAVI supports direct connections to Cumulus for obtaining gridded meteorological data and driving forecast simulations.   Primary access to Cumulus is through the CAVI Extract Editor.  Refer to the following tutorial on how to Setting Up a Cumulus Extract.

For release notes on changes to Cumulus and CDA that impact CWMS, please Visit:

• Cumulus and CWMS Data API (CDA)