MET/MODE QPF Verification

MODE, the Method for Object-Based Diagnostic Evaluation, provides an object-based verification for comparing gridded forecasts to gridded observations. MODE is used here by defining a precipitation object as an area greater than approximately 50 km x 50 km that has more precipitation per day than the given threshold (13mm, 25mm, or 50mm). For more information on MODE click here.

Click here to view MODE verification applied to integrated water vapor transport (IVT) in an effort to identify atmospheric rivers.

Valid Date

Model

Lead Time

Threshold

Forecasted

Observed

Object Verification

MODE Overview

MODE, the Method for Object-Based Diagnostic Evaluation, provides an object-based verification for comparing gridded forecasts to gridded observations. MODE may be used in a generalized way to compare data from which objects may be well defined. It has most commonly been applied to precipitation fields and radar reflectivity. The steps performed in MODE consist of:

  • Define objects in the forecast and observation fields based on user-defined parameters.
  • Compute attributes for each of those objects: such as area, centroid, axis angle, and intensity.
  • For each forecast/observation object pair, compute differences between their attributes: such as area ratio, centroid distance, angle difference, and intensity ratio.
  • Use fuzzy logic to compute a total interest value for each forecast/observation object pair based on user-defined weights.
  • Based on the computed interest values, match objects across fields and merge objects within the same field.
  • Write output statistics summarizing the characteristics of the single objects, the pairs of objects, and the matched/merged objects.
  • MODE may be configured to use a few different sets of logic with which to perform matching and merging.