# Presentation: 877283

## Design ReviewClimatology in GFE

- Tom LeFebvre
- November 10, 2005

## Climatology in GFE

- Requirements Review
- Engineer the architecture to add climatology data sets from NCDC to GFE display, smart tools, and formatters.  Allow these data sets to be used as part of the gridded forecast process.

## NCDC Grids

- How are NCDC grids created?
- Start with 1961-1990 atlas grids produced by PRISM
- Create 1971-2000 distance-weighted average grids
- Calculate the difference, preserving the detail in the original PRISM data set

**+**

- =

- 61-90 Atlas

- 71-00 Obs

- 71-00 Climo grid

## Climatology in GFE

- NDCD Gridded Climatology Grids
- Binary
- Projected on a lat/lon grid
- 2 minutes / grid point (nominally 4 km)
- 12 Monthly Normals
- Max Temp.
- Min Temp.
- Precipitation

## Processing NCDC Grids

- To be used in GFE, NCDC grids must be:
- Remapped to local map projection
- Clipped to local spatial domain
- Converted to local spatial resolution
- Solution: Use built in functions in ifpServer
- Convert NCDC grids to “AWIPS model data” format
- ifpServer will remap, clip, and convert resolution automatically

## Processing NCDC Grids

- 010101000101101011110010101010101
- 101010100101010111010101010100010
- 010100011101001010101001010101011
- 010010101010110101010101000101010
- 101001010101011010101010101011101
- 001011011100011010101010101110101
- 101010010101010110101010101010101
- 100101010101010100101010110010100
- 101010100001111010101010111001101
- 101010010101010110101010101010101
- 100101010101010100101010110010100
- 101010100001111010101010111001101
- 100101010101010100101010110010100
- 101010100001111010101010111001101
- 101010010101010110101010101010101
- 100101010101010100101010110010100
- 101010100001111010101010111001101

- netcdf 20050101_0000 {
- dimensions:
- record = UNLIMITED ; // (12 currently)
- n_valtimes = 12 ;
- data_variables = 2 ;
- charsPerLevel = 11 ;
- namelen = 132 ;
- x = 1601 ;
- y = 505 ;
- levels_1 = 1 ;
- variables:
- 	float mnt(record, levels_1, y, x) ;

- NCDC Binary file

- AWIPS model netCDF file

- This processing is done one time at GSD

## Climatology in GFE

- Climatology
- netCDF file

- ifpServer

- ifpServer reads
- Climatology
- netCDF file

- ifpServer makes
- Climatology grids
- available to all GFEs

- Remapping, clipping,
- resolution conversion
- performed inside ifpServer

## Climatology in GFE

- Once netCDF file is installed, one line in the a configuration file makes it available to the ifpServer.
- To install climatology in GFE:
- Install climatology netCDF file
- Add one line to configuration file
- Install smart tool

## Smart Tool – PopulateFromClimo

- User selects:
- Time period on GFE
- User selects element: MinT or MaxT
- User selects data source: (PRISM or NCDC)

## Smart Tool – PopulateFromClimo

- Retrieves grids from ifpServer
- Performs spline calculations at each grid point
- Creates climatology grid for each selected day

## Cubic Spline

- 2 phases
- Calculates coefficients based on monthly grids
- Uses coefficients to calculate grids in between (in time) monthly grids
- All monthly grids are centered on the middle of the month (all months 15th,  February  – 14th)