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Pennsylvania State Univ.: "Mean Areal Precipitation (MAP) forecast project"

Final Report

1.1 Introduction
The purpose of this project was to use historical mean areal precipitation data from the Middle Atlantic River Forecast Center to determine the range and length of precipitation events over their forecast domain; to generate a casebook of examples, both printed and on-line, and to provide the distribution of casebook information to forecasters as a training aid to improve the quantitative precipitation estimates used by the river forecast center. The training will include a precipitation forecasting workshop via teleconferencing from the CTP Office at the conclusion of the project.

This partnership was a joint effort of MARFC Senior HAS forecaster Patricia Wnek along with CTP forecaster Ernest Ostuno and State Climatologist and Penn State instructor Paul Knight. The contributions were MAP and WFO quantitative precipitation forecast data (maps and tables) and hydrologic summaries from MARFC. Radar estimates of rainfall from CTP and surrounding Doppler radar sites were provided by Ernest Ostuno, NWS. Cooperative precipitation data, model grid-point forecasts, casebook captions and design of the on-line project were the task of Paul Knight and Penn State meteorology students.

1.2 Description of Accomplishments

The MAP Project created an operational reference containing a MAP Climatology with accompanying case studies and test cases in a web page and hard-copy format.

The basin climatology illustrates for QPF forecasters how basin average precipitation usually occurs for common daily weather events as well as for seasons, months and even by time of day. The forecasters have a quick reference to see the usual duration of precipitation and the most typical amount, which occurs.

The accompanying case studies and test cases can be used as the forecaster has time to learn more about the most common forecaster biases and how to correct for these errors and create more accurate and useful QPFS. The case studies also illustrate the likely synoptic conditions, which produce excessive precipitation.


There were several important exchanges, which took place during this project. The most significant exchanges were the informal learning, which occurred during our bi-weekly meetings. A wide range of QPF issues were discussed along with techniques and recent publications on the subject. This helped to shape the direction of the project and gave each member a greater appreciation of the challenges of quantitative precipitation forecasting.

There was a training workshop for NWS CTP and MARFC forecasters to introduce the page and show how it could be used operationally. This was presented on October 16, 1998. A lively discussion ensued that helped the team to improve the design of the online part of the project.

A seminar for Penn State meteorology students and Professor J.M. Fritsch's (METEO 579) class was given on November 10, 1998.

Teletraining sessions are being scheduled for all WFO offices serving MARFC: (Wakefield, Binghamton, Brookhaven, Mount Holly, Sterling, Blacksburg, as well as NCEP. NWS Regional office staff, NWS headquarters Office of Hydrology and other neighboring RFCs and WFOS).

Several Penn State students associated with the MAP Project became more familiar with NWS operations and were introduced to hydrology career opportunities.


There have been two formal presentations to date. The first was a summary of the project to the CTP and MARFC offices and invited Penn State-Faculty on October 16, 1998 at the CTP conference room. The second presentation was given to the Special Topics class (Meteo 579) on November 10, 1998.

The Website is the primary source of the data and case studies. A paper copy of this web site will be sent along to each NWS Office and the COMET headquarters within the next week.

Teletraining presentations for each of the forecast offices in the Eastern Region of the NWS are being scheduled for this spring and early summer.


A few problems arose that set back the deadlines that we had hoped to achieve. We received word of funding late relative to the spring 1998 semester. This limited the work of one of our students since she was scheduled to graduate in May.

There were some difficulties in processing the database, some software and a few hardware problems that caused further delays. The size of MAP data set made use of spreadsheet analysis a challenge. Perhaps the most common problem we encountered was scheduling routine meetings for those involved in the project. The shift work at the NWS and the constraints of the academic calendar made regular meeting times nearly impossible.

The benefits of this project were many. The most obvious benefit was to the participants who became acquainted with the challenging details of short-range precipitation predictions. The project encouraged discussion and presentations to the MAP project group by PSU grad students and faculty, which helped to direct our attention to future projects.

The MAP project brought the Penn State University and CTP participants to become more aware of the operational impact of QPF to river forecasting. The case studies allowed the group to review previous work done by Penn State students, the CTP SOO Rich Grumm and lead forecaster Mike Evans.

The expertise of Penn State students in the web page creation (Tom Owens) and the design of the casebook (Alex Cadman) along with the analysis of large volumes of data (Paula Miano) made the project a first-class learning experience.

It is our hope that the foremost benefit will be to the Eastern Region forecasters who will use the online pages and the casebook to make even better predictions on the quantity of precipitation in their forecast domain.