copeg wrote: - Stream/creaks and rivers - on average (and in spring) run lower in the AM rather than the PM.
last summer I had a few opportunities to test this - and in each case where I camped near a crossing and then checked water levels in the AM again. Well, in each case the water level was actually higher in the morning. This was mid July at Bear Creek and Evolution Creek. Water levels were high to begin with and in both cases, by morning they were about 2" higher than the evening before. Both days were sunny, no precip for days in advance on both crossings.
I suppose the warm weather could have driven a faster melt and then the water rose anyway, just not as much overnight as it would have over the coming day? Both crossings were at high water level for the season, so I would have expected some slowdown in the morning, but none of that happened. At 7-8am on the morning the water was higher than at 8pm the night before.
Perhaps the key to the water level change is frost in the upper elevations. That's a rather unpredictable thing, even in very early summer. Looking at air temps for Bishop Pass over the season, it can have a minimum temp above 50 starting in May, but can also freeze in late July if the conditions are right. If this is a frost related thing, it'll be a hit and miss with the stream crossings, but I guess if you're lucky and it gets really cold overnight, you can make a sketchy crossing a little easier if you wait for the morning. I just wouldn't abort a hike mid day expecting that the water level will be much lower in the AM. It may actually be higher!