I have figured it out. This is what I did (in case it may be helpful to someone else).
In order to use scatterm(lat,lon,z*10,z,'filled') I had to create a matrix with the specific models coordinates. I then extracted the latitudes and longitudes into their own vectors to use in the scatterm. I also transposed the data,z, into vector to match the size of lat and lon.
I hope this was clear, but the main idea for my case was to have the latitude and longitude as its own vector to supply in the scatterm function for the projection to be correct. Initially I had extracted the position of the data in the matrix so I was supplying rows,columns not lat,lon of my data.
Thank you for the help :)