normal .bil files no longer available

[rabutler-usbr]

Normals are no longer available in .bil. I'm pretty sure the ftp site only has them in Geo Tif format:

https://data.prism.oregonstate.edu/normals/us/4km/ppt/monthly/

@ran-codes - does this match you're current understanding? I may need to update some of the changes you made in #135

[ran-codes]

Correct normals no longer in .bil. For the changes in #135, i revert to FTP to get .bil for normals (just to make sure thigns don't break) see details here ran-codes#11

But this is definitely a tempeorary solution - I think in the overall shift twoards Geotiff this hack can be removed.

[rabutler-usbr]

I'm not even seeing .bil files on the ftp site anymore

[rabutler-usbr]

They are available at https://prism.oregonstate.edu/request/normals/1991-2020_BIL