Public Information Statement
Issued by NWS St. Louis, MO
NOUS43 KLSX 042208
Service Change Notice
National Weather Service Saint Louis MO
508 PM CDT Tue Apr 04 2017
TO: Family of Services /FOS/ subscribers...
NOAA Weather Wire Service /NWWS/ subscribers...
Emergency Managers...Weather Information Network
/EMWIN/ subscribers...NOAAPort subscribers...
other National Weather Service /NWS/ users and
partners...and NWS employees.
FROM: Mark Fuchs
SUBJECT: Three new forecast points will be introduced on May 15.
The National Weather Service Office in St. Louis, Missouri will
begin providing new forecast services for three river gaging
locations in Missouri on May 15, 2017.
At the confluence of the Osage and Maries rivers east of Jefferson
City, flood-only forecast services will begin for Mari-Osa
campground. Flood-only means forecast services will only be
provided when forecast or observed stages are above action stage,
typically a couple of feet below flood stage, or higher. At this
site, flood stage is 19 feet. Moderate flooding begins at 22 feet,
while major flooding begins at 25 feet. Flood impacts in this reach
of river include damages to agricultural fields, campgrounds, local
roads, and residences along the riverfront. This area was
significantly impacted last during the flood of late December, 2015,
when the river crested at 30.3 feet.
Along the Meramec River in south St. Louis County, flood-only
forecast services will begin for the new river gage at Fenton,
Missouri. Flood stage at Fenton is 25 feet. Moderate flooding
begins at 29 feet, and major flooding begins at 32 feet. Flood
impacts in the Fenton area are primarily urban, with numerous
streets, businesses, and residences impacted by floodwaters. The
last significant flood at this location was likely the greatest
flood of at least the past century, recorded on New Year`s Eve 2015,
when the Meramec crested at 42.86 feet.
Along the upper Mississippi River between Quincy, Illinois and
Canton, Missouri, daily river forecast servies will begin for the
new river gage at La Grange, Missouri. This gage was installed by
the U.S. Army Corps of Engineers-Rock Island District last summer.
Flood stage is 18 feet. Moderate flooding begins at 23 feet, and
major flooding begins at 25 feet. Signficant urban impacts occur
throughout the town of La Grange along with agricultural impacts
north and south of town. The greatest flood of recent memory
occurred with the flood of 1993, when the river crested near 30
Flood stage is the river level at which minimal human impact from
floodwaters begins, and the level the National Weather Service uses
as a threhold for issuing river flood warnings. Moderate and major
flood stages are levels at which human impact increases noticably.
At moderate levels, numerous secondary roads are often inundated and
some outbuildings may be flooded. At major levels, primary roads
and highways can become flooded along with residences and
In addition to forecasts and observations, impact information, data
on past flood events, and additional information can be found at the
St. Louis Advanced Hydrologic Prediction Service (AHPS) website at
The National Weather Service welcomes public feedback. If you have
any questions or comments regarding these service improvements,
National Weather Service Forecast Office - St. Louis, Missouri
12 Missouri Research Park Drive
St. Charles, MO 63304
Phone: (636) 447-1876 extension 493