Even if you are threatened with being fired, your life is more important than your job. If your employer tries to fire you for refusing to come in during dangerous weather conditions, you can consider suing them for unfair dismissal.
The severe storm is a legitimate threat to life and safety, and it is unreasonable for companies to expect staff to disregard government safety warnings. It would be extremely risky for employees to try to travel and work in such hazardous conditions, putting themselves and others in danger.
This is a unique situation where workers may be able to successfully challenge employers who try to force them to come in. Your safety should be the top priority.
If your employer is putting profits over people's wellbeing, you can consider naming and shaming them publicly to hold them accountable. Remember, your life is worth more than any shift or job. Stay safe and don't risk your safety, even if your employer tries to threaten you.