[ferret_users] Overlaying location of minimum U wind

[Samrat Rao <samrat.rao@xxxxxxxxx>]

Hi,

I am trying to locate and plot the minimum U wind values on a lat-lon figure. I am attaching the figure generated.

After ploting the U wind contours i use the following:

 repeat/range=0:120:2/name=xpos (  \
   let minval =  uwnd[x=`xpos`e,y=@min,z=`zl`:`zu`@ave,l=7]; \
   let ypos = uwnd[x=`xpos`e,y=@loc:`minval`,z=`zl`:`zu`@ave,l=7]; \
   list ypos; \
   plot/line=14/color=red/thickness=3/size=0.15/symbol=3/vs/nolabel/overlay xpos,ypos  )

As you can see the symbols are being plotted below the location of minimum U wind. I have the following questions:

1) The reason for the incorrect location of the symbols. I am not having this problem with NCEP reanalysis data.

2) I am unable to get the 'line' qualifier connect the different symbols. How to do this?

3) At some locations there is a discontinuity (for example around 55E). To me it looks artificial.

4) In case there is a missing value for 'ypos', then how do i ensure that this does not cause an error and abort in the script execution?

I hope you people will have patience to reduce some of my difficulties.

Thanks,
Samrat Rao.

Attachment: figures.pdf
Description: Adobe PDF document