Discussion: WeatherCat Integration Forum
AppleScripts: Edouard Lagache has made available various AppleScripts that work with WeatherCat (extensive documentation is provided) - the latest release is 27th October 2013. As of this time, the facilities provided include:
- WC ET Reporter - An AppleScript tool for computing and reporting Evapotranspiration data from WeatherCat. This AppleScript can compute evapotranspiration using the Blaney-Criddle equation. Owners of Davis Vantage Pro-2 stations fitted with a solar radiation sensor can also use the script to compile data using the more accurate Penman-Monteith equation. Data can be displayed via Growl or email.
- WC Status Growler - An AppleScript tool for reporting the status of various WeatherCat subsystems via Growl.
- WC Storm Monitor - An AppleScript tool for generating wind, rainfall, and barometric pressure change alerts from WeatherCat. Alerts can be displayed via Growl or email.
- WC temperature rising and WC temperature falling - Two AppleScripts to create Growl notifications from WeatherCat temperature alerts.
- WC Twitter Uploader - An AppleScript extension to WeatherCat to upload data to Twitter.
- WC Web Data Uploader - An AppleScript extension to WeatherCat to upload data to several weather upload Websites. This AppleScript is deprecated since WeatherCat provides superior facilities to upload data to all the services supported by this AppleScript. However, it is still included as it could be a useful starting point for a custom upload script to some other service.
- WC Zambretti Forecaster - An AppleScript to generate forecasts from WeatherCat current conditions. It uses the methodology developed by Negretti and Zambra in their mechanical "slide rule" forecast calculator of 1915.
- WC AppleScript Tags Processor - An AppleScript that processes pseudo web-tags of the same sort as used by WeatherCat. This AppleScript allows one to incorporate data from many of the AppleScripts in this collection into web pages generated by WeatherCat such as cumulative evapotranspiration data and Zambretti forecasts.
- Start WeatherCat Scripts - An AppleScript that can be used to start some or all of the AppleScripts above that run continuously. Can be used with WeatherCat's startup action feature to launch all the desired AppleScripts automatically.
- Stop WeatherCat Scripts - An AppleScript to shutdown some or all of the AppleScripts above that run continuously. Can be used with WeatherCat's shutdown action feature to stop all the desired AppleScripts automatically when WeatherCat quits.
See WeatherCat Scripts of 2013-12-01 for more details and download.
Tips and tricks for using the WeatherCat Scripts
- Disabling Growl notifications when not desired (such as on vacation)
- Forwarding Growl notifications to an iOS device using Prowl
Delta T Synthetic Channel AppleScript
MikeGF has graciously continued AppleScript synthetic channel to compute Delta T. Delta T is the difference between wet bulb and dry bulb, and it is indicative of evaporation rate. The higher the Delta T the higher the evaporation rate. When spraying pesticides/herbicides, if the Delta T is too high the evaporation rate will also be too high, reducing the droplet life and therefore reducing the effectiveness of the spray. The preferred conditions for spraying are with a Delta T between 2 and 8 - if it is higher then for the same effectiveness you may need to increase application rates - with the resultant cost as well as potential environmental side effects. A short intro on weather effects for spraying is available in this pamphlet from the Australian Bureau of Meteorology Weather for Pesticide Spraying.
In the "old days," Delta T was easy to measure by comparing the two standard thermometers. Modern instruments require that the Delta T be computed from temperature and humidity. The NOAA algorithm uses an iterative process to estimate wet bulb based on temperature, relative humidity and atmospheric pressure.
More information about it and a link to download it can be found here on the WeatherCat forum: