NDFDClimate: A Computer Application for the National Digital Forecast Database Christopher Mello WFO Cleveland

NDFDClimate NDFDClimate is a computer application that creates images of forecast and climatological parameters for the U.S. from two different digital data sets. NDFDClimate is a computer application that creates images of forecast and climatological parameters for the U.S. from two different digital data sets. NDFD (National Digital Forecast Database) weather forecast grids produced by the NWS and PRISM data (Parameter-elevation Regressions on Independent Slopes Model), an expert system that uses point climatological temperature data and a digital elevation model (DEM) to generate gridded estimates of climate parameters. NDFD (National Digital Forecast Database) weather forecast grids produced by the NWS and PRISM data (Parameter-elevation Regressions on Independent Slopes Model), an expert system that uses point climatological temperature data and a digital elevation model (DEM) to generate gridded estimates of climate parameters.

PRISM Data Parameter-elevation Regressions on Independent Slopes Model PRISM system determines climate elements (temp, or rainfall) values at grid cells by calculating linear regression relationships between the climate element and elevation PRISM system determines climate elements (temp, or rainfall) values at grid cells by calculating linear regression relationships between the climate element and elevation Each grid cell estimate is determined from a separate multiple linear regression using data from nearby climate stations Each grid cell estimate is determined from a separate multiple linear regression using data from nearby climate stations Each station in the regression is weighted based on five factors: distance, elevation, vertical layer (helps identify temp inversions in high mountain valleys), topographic orientation, coastal proximity Each station in the regression is weighted based on five factors: distance, elevation, vertical layer (helps identify temp inversions in high mountain valleys), topographic orientation, coastal proximity

PRISM Data Parameter-elevation Regressions on Independent Slopes Model Temperature data from PRISM consist of daily maximum and minimum temp fields for 1971 – 2000 at 5 km resolution Temperature data from PRISM consist of daily maximum and minimum temp fields for 1971 – 2000 at 5 km resolution PRISM derived daily normal max & min temperature grids were compared to official data from the NCDC for CLE, TOL, ERI, YNG, SYR, RIC, & GSP PRISM derived daily normal max & min temperature grids were compared to official data from the NCDC for CLE, TOL, ERI, YNG, SYR, RIC, & GSP Each site had a MAE near 0.25 ° F for both max and min temp with the highest daily error < 1 ° F Each site had a MAE near 0.25 ° F for both max and min temp with the highest daily error < 1 ° F

NDFD Data National Digital Forecast Database NDFD consists of digital forecast data that are produced by the WFOs across the U.S. and merged into a single image or file for each parameter and projection. NDFD consists of digital forecast data that are produced by the WFOs across the U.S. and merged into a single image or file for each parameter and projection. Forecast grids are produced for Days 1-7 with 5 km resolution Forecast grids are produced for Days 1-7 with 5 km resolution NDFD grids include max and min temp, POP, temp, water equivalent, snow amount NDFD grids include max and min temp, POP, temp, water equivalent, snow amount

NDFDClimate NDFDClimate uses the GRADS software to create images that utilize information from both the NDFD and PRISM data NDFDClimate uses the GRADS software to create images that utilize information from both the NDFD and PRISM data GRADS has the ability to add, subtract, or manipulate fields using many formulas. Users can specify the domain and contour interval of images. GRADS has the ability to add, subtract, or manipulate fields using many formulas. Users can specify the domain and contour interval of images.

NDFDClimate NDFDClimate produces temperature anomaly grids by subtracting NDFD grids from PRISM derived daily climate grids NDFDClimate produces temperature anomaly grids by subtracting NDFD grids from PRISM derived daily climate grids NDFDClimate combines some NDFD fields to generate 5 day totals of heating and cooling degree days and 60 hour QPF NDFDClimate combines some NDFD fields to generate 5 day totals of heating and cooling degree days and 60 hour QPF

NDFD Low Temp Fcst

Normal Low Temp 0909

Min Temp Anomaly 0909

Max Temp Anomaly

NDFD 5day Total CDD ° F

NDFDClimate Uses Processes NDFD data for users with 5 day HDD & CDD totals temp changes Processes NDFD data for users with 5 day HDD & CDD totals temp changes Educate users on current temperatures anomalies where point data may be inadequate Educate users on current temperatures anomalies where point data may be inadequate

NDFDClimate References References Berman, F., A. Chien, K. Cooper, J. Dogarra, I. Foster, D. Gannon, L. Johnson, K. Kennedy, C. Kesselman, J. Mellor-Crummey, D. Reed, L. Torczon, and R. Wolski., The GRADS Project: Software Support for High-Level Grid Application Development. International Journal of High Performance Computing Applications, Daly, C., R.P. Neilson, and D. L. Phillips, A Statistical- Topographic Model for Mapping Climatological Precipitation over Mountainous Terrain. J. Appl. Meteor., 33,