The system includes the ability to export the actual, forecast or both actual and forecast wind band data in an ArcInfo™ GIS importable format. This allows the user to do further analysis with that tool. The export format is generic enough so that it could easily be converted to other GIS tool formats by the user. The default wind bands are 34, 50 and 64 knots however this can be easily changed in the general options to any set of values (up to 10) desired.

When this option is selected from the FILE menu the system plots the wind bands desired over a "blank map" and then processes this data.  The entire process takes anywhere from 20 seconds to several minutes depending on processor speed.  During processing, 2 files are written out to the directory specified in the general options.   If no location was specified it will be written to the applications temp directory.

The 2 files that are written are:

filename.att - This file contains the wind band attributes information.

An example of the data is shown below.  In this example the file indicates 3 wind areas of 34, 50 and 64 knots

1,34

2,50

3,64

filename.dat - This file contains the latitude & longitude boundaries for each attribute.

example data

1,auto

-83.37891,28.85417

-83.37891,28.80859

-83.37891,28.76302

-83.37891,28.71745

-83.37891,28.67188

..

.

where filename is a variable with the following naming convention.

filename= stormname + advisory number + type

where type = F (forecast), A (actual) or B (both actual and forecast)

e.g. FLOYD20F indicates this analysis is done for storm Floyd, advisory 20, forecast data only.

While we do not utilize the ArcInfo™ software, instructions on how to import this data that have been passed on to us are shown below.

Data Files:

filename.dat - A text filed formatted to be used by the Arc/Info "GENERATE" command.

filename.att - A text file of attribute information for populating the Arc/Info coverage generated by the "GENERATE" command.

Process:

1. Create an Arc/Info coverage from the filename.att file.

2. Establish topology for the coverage using BUILD

3. Load xport.att into INFO table

4. Join coverage with INFO table (attribute data).

5. Result - a coverage with topology and attribute data that can be used in Arc/Info, ArcView, or loaded into SDE.

Steps:

* Use the "GENERATE" command in Arc to create an Arc/Info polygon Coverage.

* To create topology, you will need to then use the Arc/Info "BUILD" command with the "POLY" option. This will separate the overlaying wind band areas in to distinct, spatially related polygons.

** After this process, the "USER-ID" (in the INFO table) of the first two polygons (surrounding polygons) become zero. You will need to re-assign the "USER-ID" in TABLES or INFO in order to match its attribute table. The "USER-ID" is the key to correctly join the polygon information with the attribute information.

* Use TABLES or INFO to create the database file for loading filename.att. The DEFINE command is used to create the table structure. After the structure is created, use the "ADD FROM" command to add the records from the filename.att file.

* After the table and coverage are created, join the two by using the Arc/Info "JOINITEM" command.

If you have any suggested additions or changes to this process, please contact us at support@pcwp.com.