How to plot/calculate the Cone of Uncertainty for WP cyclone

[phweather]

Hi all,

Newbie here. This is my first post but I'd been following threads esp on Western Pacific weather forums. I'm a mobile app developer/software engineer from the Philippines. I'm very interested about weather and wanted to create solutions/app that can solve/help weather-related problems. I have already create an Android app focus for Philippine (and partly Western Pacific) called PHWeather (please see: https://play.google.com/store/apps/deta ... .phweather)

Now I want to create new app that will focus more on cyclones in a wider scope. Starting with North Western Pacific Basin (where Philippines belong). I already researched/studied some cyclone/meteorology stuffs but I'm still don't get it all. My question is (stated in the title): "How to plot/calculate the Cone of Uncertainty for WP cyclones?". JTWC and JMA have stated wind radi on each of their forecast tracks but I could not see the uncertainty values. Also, NHC has published about Track Forecast Cone (see here: http://www.nhc.noaa.gov/aboutcone.shtml) but only for Atlantic and Eastern North Pacific Basins.

Can anyone (esp. meteorologist) tell/teach me how to plot the Cone of Uncertainty for WP cyclones? and where to get those values? Any help will be appreciated.

Thanks.

[brunota2003]

First off, welcome to Storm2K! I'm not a met, but yes, the NHC definitely seems to be more forthcoming to the general public than anyone else; with how they forecast/asking for opinions of any new products they would like to start issuing. I'm not too certain about other RMSCs, and would actually be interested in this answer as well. I'll take a look around tomorrow, if it hasn't been answered by then, and see if I can dig anything up!

[phweather]

First off, welcome to Storm2K! I'm not a met, but yes, the NHC definitely seems to be more forthcoming to the general public than anyone else; with how they forecast/asking for opinions of any new products they would like to start issuing. I'm not too certain about other RMSCs, and would actually be interested in this answer as well. I'll take a look around tomorrow, if it hasn't been answered by then, and see if I can dig anything up!

Thanks @brunota2003.

I just reviewed JMA's forecast tracks and YES, they include "Radius of probability circle" values. (please see: http://www.jma.go.jp/en/typh/). However, still want to know how they came up with those values.

[brunota2003]

I would imagine they use errors similar to the NHC, but not sure. There are some mets here that deal with that area, you could PM them and see if they know? You should be able to find their names by looking through the threads in the WestPAC forum.

[theavocado]

Hi all,

Can anyone (esp. meteorologist) tell/teach me how to plot the Cone of Uncertainty for WP cyclones? and where to get those values? Any help will be appreciated.

I can partially answer your question. The JTWC cone is the 5 year running mean error added to the 34kt wind radii, with the full description on thier FAQ page. The annual mean error can be found in their annual reports found here.