Another storm is expected to hit Israel on Tuesday.
Rescue services are standing by in case of floods.
Ayman Jaber has been missing since the floods last week.
The students drowned in flash floods, and amid questions into why the trip went ahead despite the severe weather conditions, police arrested Kahan and two other staffers.
Rescue workers extricate hikers trapped in floods, remove downed tree limbs, Kinneret rises 7 cm.
"The best thing we can do right now is respond to each appeal as it comes. Time is against us but we will do whatever we can to help."
Jerusalem schools to close at noon ahead of expected flurries.