Saturday, April 20, 2013

Water level on the Mississippi River begins its annual spring rise

It's spring and that means the annual water rise on the Mississippi River is underway.  Thanks to rainfall in the middle Mississippi and (mainly) Ohio Rivers and some snow melt upstream, the river gauge at Memphis has begun it's climb.

This morning, the NWS issued a Flood Advisory for Crittenden, and Lee Counties in AR, Shelby County TN, and DeSoto and Tunica Counties in MS as stages on the river at Memphis and Tunica Riverpark are forecast to rise towards flood stage in the coming weeks.  The "hydrograph" below shows the forecast river stages over the next 5 days.  The long-range forecast through May 1 indicates a stage of 32.5' on that date.  Flood stage at Memphis is 34', though affects from high water begin much lower than that.  (For reference, below is a picture of the Wolf River Harbor with the river at 35.6'.)

Wolf River Harbor with the Mississippi River at 35.6', which is higher than currently forecast.

Also, it is important to note that forecasts are based on past/recent rainfall, forecast rainfall for the next 24 hours, and runoff from snow melt upstream.  Any additional rainfall upstream could significantly affect river stage forecasts.


The latest 28 day river stage forecast (released weekly) does not indicate significant flooding, so there is no reason to expect that we'll see the type of water we experienced 2 years ago when the foot of Beale Street went under and national media were wading on Riverside Drive!  The one good thing that should help keep the river stages somewhat in check (unless significant rainfall occurs in the Ohio River Valley in the next 2 weeks) is that there is not a lot of existing snow in the Upper Mississippi River basin.  Snow is confined mainly to the Dakotas, MN, and northern WI.

Existing snow (colored by depth) in the north-central U.S.
Some of the effects that will be felt in the Memphis area based on the current forecast:

  • 25'- Roads along the river south of Shelby Forest are beginning to go under water. Fields begin to flood in extreme southwestern Shelby County near North Horn Lake.
  • 27' - Water is beginning to touch the levee between I-40 and I-55. Much of the land between Memphis and West Memphis is flooded.
  • 30' - Boat Landing on the north end of Mud Island at the mouth of the Wolf River is covered. Recreational vehicle park south of West Memphis starts to flood
  • 32' - Most all land between Memphis and West Memphis is under water. Levee has water on it west of President Island south to Blue Lake.

More information on the river stage, forecast, and effects from flooding at Memphis can be found here.  In addition, the daily river stages can also be found on this page on MemphisWeather.net.

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