Feature request


Would it be possible to tell wxsim somewhere that there isn’t going to be any tornadoes and snow in western norway? 8O

I mean, it IS possible to have a tornado here, but there is a much higher chance of severe blizzards and freezing conditions in hawaii in july than tornadoes in western norway… :wink:

Sunday: Dense overcast. Rain likely in the morning, then a mix of rain and snow
likely in the afternoon. High risk of severe thunderstorms and possible
High 5. Wind west around 11 mps, gusting to 17 mps, in the morning,
becoming northwest around 15 mps, gusting to 21 mps, in the afternoon. Chance of
precipitation 80 percent. Precipitation (liquid equivalent) mostly between 5 and
10 mm. No snow accumulation expected.

I have a feeling that the thunderstorm forecast graph was climbing way off the chart today…

So, back to my future feature request:
a checkbox that will forecast tornadoes or not.

In the same go, I would very much appreciate some option box’es to account for local weather, for example:
if wind is westerly : add 20% to forecasted percipitation
if wind is easterly : subtract 20% from forecasted percipitation
if wind is southly : add 0% to forecasted percipitation


I hope that made sense, and the 20% would off course be a user configured value…

You can turn off the severe weather comments, under preferences. I don’t recall whether or not that will omit them from the text forecast (I think it will - give it a try). Also, I’m not sure if the Northwest European severe weather indices really work that well or not. One of them is the Boyden index, mainly for England. This may just not be the time of year to have that feature activated.

Regarding precip chances, that’s an interesting suggestion. I’m reluctant to do it without further study, though, because the GFS model, which is the source of most of the precip info, supposedly “knows” your topography already, though perhaps with too crude a resolution to get the really local effects in there. Keep your eye on it and I’ll think about it.



Hi Tom,
I seem to be experiencing similar problems regarding % precipitation and wind direction, albeit that mine is for different diections for obvious reasons. The Moray Firth area of Scotland has a quite distinct mountain shadow from rain for South, West, and to a slightly lesser extent the SW where rain funnels up the Great Glen. Those forecasts that WxSim have been giving for those directions I believe could well be enhanced by some additional user tweaking with such a suggestion, as has been proposed by “Rush”. :slight_smile:

I’m not very confident in the NW European severe weather indices WXSIM is using (such as the Boyden index), or at least I’m not sure under what circumstances they are useful, so I am not totally surprised by this. I do wonder what circumstances made it get THAT far off, though! :frowning:

Try going under Preferences, and turn OFF the convective bulletins. This will definitely omit such things from the alphanumeric output, and I think I’ve got it so they will be omitted from the plain text output, too (though actually I’m not sure and need to check).

Hope that helps!


My website is first off a lightning detector site and turning off convective bulletins is not good since then it will never mention thunder in the forecasts… Are the tornado part of it downloaded from a noaa or similar server or is it generated based on values in the convective graphs wich I thought? If the latter is the case it should be possible to display thunder but not tornado warnings ?

Are you saying I should select US instead of northwestern europe advection thingie? (or where should I change the nw europe severe indicies?)
I only have shwrs/thunder selected on my output graph, none of the other cape’s like boyden or ko, total totals etc…

You might want to try the North American setting, to see if the output is more realistic. One problem with tornados is that they require more than just unstable air. I’m far from being an expert in severe weather, but my understanding is that helicity, wind shear, etc. play in, and maybe even really unstable air doesn’t on its own make tornados in Norway.

Oddly (to me anyway!) I’ve read that England and the Netherlands have some of the highest tornado frequencies per unit area in the world. I think they’re mostly weak tornados, though. Do you ever get them in Norway?