Project Description | Algorithms | Verification | Data | Updates | Evaluations

About the Project

The Precipitation-Type Algorithm Experiment is a collaborative project between NWS/Hydrometeorological Prediction Center, NWS/Storm Prediction Center, OU/Cooperative Institute for Mesoscale Meteorological Studies, and the National Severe Storms Laboratory. It is funded by COMET.

Experiment Dates

The experiment will take place from June 1, 2000 through May 30, 2002.

Preliminary verification results from the first season are now available.

Goals

• determine the quality of six precipitation-type algorithms using observations and mesoscale model output;
• determine if the quality of several precipitation-type algorithms can be improved by modifications based on surface and rawinsonde observations;
• develop a high-quality (in the statistical sense) technique for making probabilistic forecasts of precipitation type with numerical model output and an ensemble of precipitation-type algorithms from one or more models;
• identify efficient methods of displaying probabilistic forecast output of precipitation type for forecasters at the HPC and the SPC;
• help EMC incorporate the algorithms into their model output processing routines in order to distribute the precipitation-type output to all NWS offices;
• familiarize forecasters with the meteorological processes that are associated with the formation of various precipitation types.

Publications

Creation, Evaluation and Implementation of a Precipitation-Type Forecasting System
John V. Cortinas, Jr., Keith F. Brill, and Michael E. Baldwin http://www.spc.noaa.gov/exper/ptax/cometproposal.pdf

Abstract

This COMET proposal describes a two-year project, beginning on 6/1/00, that will create, evaluate, and implement the first precipitation-type probabilistic forecast system, using ensemble forecasting and consensus forecasting concepts, at the Hydrometeorological Prediction Center (HPC) and the Storm Prediction Center (SPC). The research component of this project will evaluate the quality of various precipitation-type algorithms and investigate various ensemble forecasting concepts in applying the collection of algorithms. The operational component of the project will create probabilistic forecasts of each precipitation type diagnosed by the algorithms and consensus forecasts of the most probable precipitation type. After sufficient development and testing at the HPC and the SPC, these forecasts will be made available routinely to all National Weather Service (NWS) offices within two years, provided approval is granted by the NWS.

National Weather Association Annual Meeting, October 2001

The Precipitation-Type Algorithm Experiment at the HPC and the SPC

The16th Conf. on Probability and Statistics in the Atmospheric Sciences, January 2002

Probabilistic Forecasts of Precipitation Ttype
John V. Cortinas, Jr., Keith F. Brill, Michael E. Baldwin
http://www.spc.noaa.gov/exper/ptax/prob3.13.pdf

The presentation is online here.

Forecaster Evaluation Form

Forecasters at the HPC and SPC are assisting in evaluation of the precipitation-type products while making routine forecast products. Archives of evaluations as well as HPC and SPC products for which the precipitation-type algorithm output was used are linked below.

Contact Info

Webmaster:
Daphne Zaras, OU/CIMMS and NSSL
zaras@nssl.noaa.gov