Add XY points to raster map generated by levelplot

Question

I have raster maps which are generated using the raster package in R. These raster layers can be visualized using the rasterVis package\'s

Answer 1

So I had a dataframe with xy cordinates and so many z columns. This is the final answer to get points added to my map thanks to @jbaums:

s <- stack(raster1,raster2)
coordinates(SITES...TTEST) <- ~x+y # SpatialPointsDataFrame
levelplot(s, layout=c(1, 2), 
          col.regions=colorRampPalette(c("darkred", "red3", 
                                         "orange", "yellow", "lightskyblue", "royalblue3", 
                                         "darkblue")),
          at=seq(floor(39.15945) ,ceiling(51.85068), length.out=30), 
          par.strip.text=list(cex=0),scales=list(alternating=FALSE))+
  layer(sp.points(SITES...TTEST, pch=ifelse(SITES...TTEST$Precip_DJF6 < 0.05, 2, 3), cex=2, col=1), rows=1) +
  layer(sp.points(SITES...TTEST, pch=ifelse(SITES...TTEST$Precip_DJF6 < 0.05, 2, 3), cex=2, col=1), rows=2)