NOAA/National Weather Service's Chief Learning Office United States Department of Commerce
Commerce Learning Center

Hydrology Professional Development Series (PDS) 2 : Develop, Implement and Maintain Models and Tools

PDS Statement of Responsibility : Develop and implement hydrological and hydraulic models and tools in support of operations.

Description of the Area of Responsibility : Both RFCs and WFOs are dependent upon effective and well maintained hydrologic and hydraulic models and tools to support operational services.

Prerequisites : Basic fundamental statistics, unit hydrograph theory, general knowledge of water balance accounting, snow hydrology, routing methods, hydraulics, geospatial data manipulation, familiarity with Linux OS and Windows.

Hydro PDS 2 : Develop, Implement and Maintain Models and Tools

Executive Producer - John Bradley (AFS25)

PCU 1 : Calibrate a model

Producers -

NWS hydrologic forecasting requires simulations that are representative of the systems they seek to emulate so that projections of hydrologic conditions in the future can be made with accuracy and confidence.

Hydrologic forecasters, whether at an RFC or WFO, need to understand how the parameters embedded within the structure of existing, vetted hydrologic models affect simulation outcome and calibration. To conduct simulation calibration, hydrologists will need to describe drainage basin topology, assemble quality-controlled historical forcing datasets, characterize the hydraulic routing behavior through usage of unit hydrographs and routing schemes, and configure system simulation architecture and data retrieval. Hydrologists will also need to make the choice of whether to pursue manual or automated means of parameter estimation. Automated methods introduce a new set of control parameters that govern the selection of a non-dominated set of parameter values for the hydrologic model being calibrated.

PCU 2 : Configure operational framework to incorporate models and tools within the specific forecasting system

Producers - Alaina MacFarlane (Mid-Atlantic River Forecast Center, State College, PA) and John Schmidt (Southeast River Forecast Center, Peachtree City, GA)

Test and modify the modeling system so that it can be used to generate real time forecasts or information.

As existing models are improved or additional models are implemented, they must be introduced into the operational forecasting environment. This requires that the models are tested prior to being used for operations forecasts.

PCU 3 : Evaluate the hydrological forecasts and services (Ongoing assessment of model performance, forecast validation & verification)

Producers - Dave Streubel (Alaska-Pacific River Forecast Center, Anchorage, AK), Rick Koehler (Forecast Decision Training Branch, Boulder, CO) and Laura Diamond (North Central RFC, Chanhassen, MN)

Performing a periodic comparison between the forecasts and the conditions which occurred and reviewing forecast justification will enable forecasters to continuously improve the services they provide to our customers and partners.

Accuracy and skill are two performance measures for any hydrologic forecast. To become a better forecaster, it is not enough to simply know that a forecast did not verify based on a specific standard. A forecaster must determine what went into a forecast and identify methods for improvement. This is done through forecaster development that allow assessment of the forecast relative to the inputs and operational environment under which the forecasts were issued and communicated.