NOAA’s National Weather Service National Digital Forecast Database: Status Update LeRoy Spayd Chief, Meteorological Services Division Unidata Policy Committee February 5-6, 2004

Unidata Policy Committee National Digital Forecast Database (NDFD) Accomplishments Since 9/11/03  Establishment of Digital Services Program in Office of Climate, Water, and Weather Services  NWS Instruction , Digital Data Products/Services Specification   Effective on January 2, 2004  Update to Instruction in draft form, New or Enhanced Products and Services  Includes proposed criteria for implementation of new official NDFD products

Unidata Policy Committee NWSI Highlights  Provides a framework for products and services generated from the digital forecast database prepared by the NWS  Specifies definitions, collaboration thresholds, and minimum grid production times for digital forecast elements  Establishes collaboration responsibilities to achieve forecast consistency  Defines and describes the National Digital Forecast Database (NDFD)

Unidata Policy Committee Draft NWSI Highlights  Proposed criteria for transition of products from internal to experimental and then to official  Objective Quality Assessment  Spatial consistency  Inter element consistency  Objective verification  Operational Readiness  Availability  Timeliness  Completeness  Service product retention  Continuity of operations

Unidata Policy Committee NDFD Plans for Product Implementation  Period of public comment on these elements ended December 2003:  Maximum Temperature  Minimum Temperature  Probability of Precipitation (12 hr forecast)  Weather  Wind speed and direction  Significant wave height  Public comments on NDFD graphics 95% positive  Decision on implementation of these elements will be made by March 31, 2004

Unidata Policy Committee NDFD Plans for Product Implementation (continued)  Public comment period on these elements continues until March 2004  Temperature  Dewpoint  Quantitative precipitation (QPF)  Snow Amount  Decision on implementation of these elements will be made by June 30, 2004  Will continue this 3-6 month process with additional experimental NDFD elements

Unidata Policy Committee NDFD Verification Activities  Prototyping NDFD verification capabilities  Comparison to point observations  Metar  Comparison to point based guidance  Global Forecast System MOS  Comparison to gridded analyses  Rapid Update Cycle (RUC)

Unidata Policy Committee National Digital Forecast Database Point Based Verification

Unidata Policy Committee National Digital Forecast Database Point Based Verification

Unidata Policy Committee National Digital Forecast Database Gridded Verification

Unidata Policy Committee NDFD Verification Trend by Forecast Period

Unidata Policy Committee NDFD Weather Elements Over Marine Zones Some parameters such as maximum temperature may not be required by mariners Complexity of preparation of products over marine zones -limited observational sites for validation of skill

Unidata Policy Committee NDFD Issues of Concern to NWS Customers and Partners  Limited feedback from customers on use of gridded data  Need for customer and partner feedback on requirements for criteria to make NDFD grids elements operational  Gridded Elements over Marine Zones may have separate implementation time frames

Unidata Policy Committee NWS Partner Comments for NDFD January 2004  Majority of respondents prefer: 1. Data formats in addition to GRIB 2:  XML  netCDF 2.Additional dissemination system  NOAA’s Operational Model Archive and Distribution System (NOMADS) 3.Additional protocols  Non-ftp access  Open Source Project for a Network Data Access Protocol (OPeNDAP)  Unanimous request for NDFD Verification Statistics to be made available on public web site