Correct Snow precipitation

[MostafaGomaa93]

Description

close #279
close #280

Checklist

• Add a reference to related issues.
• @mentions of the person or team responsible for reviewing proposed changes.
• This pull request has a descriptive title.
• Code is written according to the guidelines.
• The checks by MISS_HIT style checker and
  linter, below the pull request, are
  successful (green).
• Documentation is available.
• Add changes to the changelog file under section Unreleased.
• Model runs successfully, see tests.
• Ask a meinatainer to re-generate exe file if matlab codes are changed. About how to create an exe file, see exe readme.

[MostafaGomaa93]

I made a small mistake and added all files using (git add --all), so the pull request recognises all the files as changed. But the actual changes are in 11 files only

[Crystal-szj]

I made a small mistake and added all files using (git add --all), so the pull request recognises all the files as changed. But the actual changes are in 11 files only

Hi @MostafaGomaa93, thanks for your efforts. Let's try to fix it by following these steps:

# 1. Create a new branch 
git checkout -b correct_precip_snow_backup

# 2. Go back to the version before running 'git add --all'
git reset --soft 8d3ef7532577b8b2a31d9565999641b11194e4af

# 3. Modify git config file: set 'core.fileMode' to false
git config --global core.fileMode false

# 4. Check the status of changes
git status

When completing the above 4 steps, check if the 'mode changes' are still listed in the modified files,

• If yes, we just keep it as they are for now.
• if no, run git diff to confirm the changes you made to correct the calculation of precipitation, and stage and commit the changes

git add <files> 
git commit -m <commit message>

[Crystal-szj]

To remove the changes caused by 'mode change', a new PR #282 is created based on Mostafa's changes in this RP.