in this talk, we will discuss recent results on stable self-similar singularity formation for the 2d boussinesq and singularity formation for the 3d euler equations in the presence of the boundary with $c^{1,alpha}$ initial data for the velocity field that has finite energy. the blowup mechanism is based on the hou-luo scenario of a potential 3d euler singularity. we will also discuss some 1d models for the 3d euler equations that develop stable self-similar singularity in finite time. for these models, the regularity of the initial data can be improved to $c_c^{infty}$. some of the results are joint work with thomas hou and de huang.