I did not say it would freeze at 40 F, I said how much the wind chill would be. I was illustrating this for people who were commenting on the high named winds (Chinook, reverse Chinook, whatever) and how cold they felt. I then said at 20 F ambient temperature what the wind chill would be, and then I said it would then be cold enough for some fast freezing. An ambient temperature of 20 F will freeze water, I assure you.
And unless you mean zero Celsius, it’s 32 F that water freezes at.
Right, Una, sorry, I guess my brain switched off from waffling from C to F and back twenty times in this thread, plus trying to figure out what people were tryig to say when they put a temperature as “±40F” (which is “plus or minus 40 F”)…
More on the Chinook tribe. The tribe is (for the moment, anyway) effectively extinct in that last year the federal government declined to acknowledge a petitioner for federal recognition which calls itself “The Chinook Indian Tribe/Chinook Nation.” The Chinooks continue to live near the mouth of the Columbia River and Shoalwater Bay, definitely on the west side of the Rockies. Other descendents of the various Chinook bands have married into a number of surrounding tribes which still deal directly with the federal government as political entities.
The decision was especially unusual since the Chinooks had received a positive final determination in the waning days of the Clinton Administration. The decision was pulled by the Bush administration and, a year and a half later, completely reversed.
In a rather stunning example of poor planning, the reversal of the decision was announced at the exact same time that Chinook Chairman Harry Johnson was here in Washington, DC as a guest of President Bush to commemorate the bicentennial of the Lewis and Clark expedition. Lewis and Clark wrote extensively about several bands of the Chinook, who aided the explorers during their winter stay on the Pacific coast.
This document, describes the rapid cold-to-warm weather pattern and associates it with the Sioux of the plains, far removed from where the actual Chinook are. My guess–only a guess–would be that the word is from the Lakota language and is probably coincidentally associated with the tribe of the same name.