OKLAHOMA CITY - This week's winter weather blast has dealt a heavy blow to the Oklahoma Blood Institute. 

OBI staff are reporting that over the past three icy days, they've only seen about half the donors they need to maintain their supply.

Now, that puts them in a position where they need to pull themselves out of the slump while maintaining regular levels.

Their doors are open for extended hours while they ask for more donations.

All donor centers will be open until 6 p.m. on Friday and until 4 p.m. Saturday at OBI locations statewide.

Your blood donation goes to more than 160 hospitals medical facilities and air ambulances statewide.

"If we don't replace the missing units from this week, we won't be able to respond to that increased need next week," OBI CEO Dr. John Armitage said.

On top of that, the metro and western Oklahoma is expecting freezing fog and wet roads which many hope will not further inhibit donations.