Visitors have been told to stay away from forests across much of northern England after Storm Arwen blew over tens of thousands of trees.
Forestry England will conduct an aerial survey of the damage in the coming days and have sent teams to clear roads for people living in the affected areas.
Some toppled trunks were still held up by neighbouring trees and could fall at any time.
It listed Thrunton Woods, Kidland, Harbottle and Simonside near Rothbury, Kielder, Hamsterley and Chopwell in the North East, plus Grizedale Forest and Gisburn in the North West, as being badly affected by uprooted trees, loose branches, downed power lines and blocked access.
Photos showed hundreds of trees in Kidland Forest in Northumberland that had blown over.
Video by forestry ranger Alex Maclennan at the entrance to Thrunton Woods, also in Northumberland, showed hundreds more flattened pines, causing him to say: “This is why we don’t want the public to come to this area – (it’s) pretty bad.”
Kevin May, forest management director for North England said: “This was a very significant storm and it’s caused a lot of damage.
“Our immediate concern is for people who live and work in the forest and we are working intensively to restore some kind of normality.
“Many of our woodlands will still be dangerous and are simply not safe for visitors at the moment.
“There is also the risk from hanging trees – those that have been blown over, but have been caught on other trees.
“These can fall with little or no warning.
“Our message is to stay clear for the time-being and that will speed the recovery.”
Forestry England said once it is safe, a major clear-up expected to take several months will start.
It will then draw up plans for forest recovery to ensure their future for visitors, wildlife and the economy.