Sunday, September 2, 2012

Record low averted for the moment

Yesterday I paddled for 60 minutes on a river that registered -9.8 feet on the Memphis gauge.  That's within a foot of the record low of -10.7 feet, but it looks like we won't be breaking that for at least the next week, as the forecast has the river rising at least two feet in the next few days.

The remnants of Hurricane Isaac apparently have dropped enough precipitation in the Tennessee and Ohio valleys to send some water down here to Memphis.  We have gotten relatively little rain here at Memphis, but rain here does not affect the Mississippi's level at Memphis.  Nor does rain in Arkansas and southern Missouri, because those watersheds drain into the St. Francis, White, and Arkansas Rivers, which enter the Mississippi downstream of Memphis, and the Red River, which feeds the Atchafalaya.

To make the Mississippi rise at Memphis, rain must fall in the Tennessee valley, the Midwest, and the upper Great Plains.  That's where the tributaries are that feed the Mississippi upriver from Memphis--tributaries like the Tennessee River, the Cumberland River, the Ohio River, the Missouri River, and, of course, the upper Mississippi River.

For a while, I wasn't sure Isaac was going to send any rain up into those regions.  It sounded like its remnants were mostly affecting northern Louisiana, Arkansas, and central Mississippi.  Here at Memphis we got a lot of wind but not much rain besides a couple of heavy thundershowers.  But now it appears that some rain is falling up in places that will send some water our way.

Yesterday's paddling session certainly was a windy one.  I did some balance drills on the procession of waves moving from south to north in the harbor.

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