Flood Potential Outlook
Issued by NWS Little Rock, AR

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HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE LITTLE ROCK AR
730 PM CST THU MAR 01 2018

...SPRING FLOOD OUTLOOK FOR MUCH OF ARKANSAS...

The National Weather Service Forecast Office in Little Rock has a
Hydrologic Service Area which is wholly located within the state of
Arkansas. It encompasses an area which includes the White River from
Bull Shoals Dam downstream and the Ouachita River and tributaries
from the headwaters to the upper boundary of the Felsenthal National
Wildlife Refuge. Along with the main stem of these rivers, it also
includes tributaries with forecast locations on the Cache, Black,
Spring, Saline, Petit Jean, Fourche LaFave, Little Missouri,
Buffalo, Little Red, and Eleven Point Rivers.

EXISTING CONDITIONS...

For much of the winter, drought conditions worsened across much of
Arkansas with the Reservoirs well within their Conservation Pool.
However, over the last few weeks, significant rainfall has fallen
across much of the state and dramatically changed conditions.
Temperatures through the late winter have been below normal...and as
a result plants and vegetation have yet to green up.

Rainfall - With record February rainfall, and heavy rainfall during
the fourth week of December, winter rainfall totals at many
locations ended up being some of the highest ever recorded. At 15
locations, winter of 2017-2018 went down as the wettest since
records began. For the state as a whole, it appears that the winter
of 2017-2018 will go down as the wettest winter since 1949-1950, and
the 3rd westtest on record since state averages have been tabulated
(1895).

Snowpack - Snowpack estimates from the National Operational
Hydrologic Remote Sensing Center (NOHRSC) indicate no snowpack in
Arkansas, which is normal. Snow depths of 5 to 20 inches are
confined to portions of Minnesota, Wisconsin, and Iowa. Snow water
equivalents range from 0.5 TO 4 inches over this area. The snow is
not expected to have any significant impacts to the lower
Mississippi River.

Soil Moisture - Soil moisture conditions are well above normal over
the lower Ohio, Mississippi, and Tennessee Valleys due to recent
rainfall.

River Flows and Reservoirs - Storage capacity at the Corps of
Engineer Projects in the White River basin is much greater than this
time last year (1 to 7 feet above normal pool). Reservoirs along the
Arkansas River tributaries in central Arkansas were over 25 feet
above normal pool due to the last few weeks of heavy rainfall in
this area.

White River Basin...

Based on existing soil moisture, streamflows, and normal spring
rainfall patterns; an ABOVE AVERAGE Flood Potential is expected over
the lower White and Black Basins. Percent of available flood control
storage for the Black/White Basin Reservoirs are given below.

                                            2/15   3/1
                      Clearwater Res. MO    100%   78%
                          Beaver Res. AR    100%   87%
                      Table Rock Res. MO    100%   91%
                     Bull Shoals Res. AR    100%   95%
                         Norfork Res. AR    100%  100%

Recent rainfall has allowed streamflows to rise to near and above
seasonal levels. Soil moisture conditions are above normal. Minor to
moderate flooding is occurring on the lower Black River and moderate
to major flooding is occurring on the lower White and Cache Rivers.
Observed daily streamflows as a percent of median are given below.

                                            2/28
White River               Batesville  AR     88%
White River               Newport  AR       245%

ARKANSAS RIVER BASIN...

The potential for flood conditions in western Arkansas will be near
normal this spring. Flooding in western Arkansas usually occurs in
response to specific heavy precipitation events similar to the heavy
rainfall last week. Also, the Arkansas River may flood in response
to upstream conditions. Although upstream reservoirs are currently
well into their flood pools, there are currently no indications
these hydrologic conditions will continue throughout the Spring to
alter the flood potential of the area.

Precipitation totals during the last 90 days for western Arkansas
have been significantly above average. Many areas across the
southwest to central parts of the state have seen more than 150% of
their normal precipitation during this period.

Soil moisture conditions in western Arkansas are significantly above
normal due to recent heavy rainfall. Soil moisture is currently
extremely high along the I-30 corridor from southwest to central
Arkansas.

Corps of Engineers projects in southwestern Arkansas are all
currently well into their flood control capacity available at this
time. Recent heavy rainfall has the reservoirs at high levels.
Streamflows in western Arkansas are all above normal due to the
heavy rain, as well.

The Climate Prediction Center`s (CPC) Seasonal Outlook (MAR-APR-MAY)
indicates there are increased chances (40-50%) for above normal
temperatures across western Arkansas. The outlook indicates equal
chances of above, below, or near median precipitation during the
same time period.

The U.S. Drought Monitor of March 1, 2018 indicates varied drought
conditions across western Arkansas. Southwestern Arkansas is free of
drought. The Arkansas River Valley and Northwest Arkansas are
currently experiencing Abnormally Dry (D0) conditions. CPC`s
Seasonal Drought Outlook of February 15, 2018 calls for improvements
to the drought conditions during the next three months.

OUACHITA RIVER BASIN...

Streamflows and soil moisture content are well above seasonal
averages. Moderate to major flooding is occurring in Arkansas and
minor to moderate is forecast in Louisiana. Observed daily
streamflows as a percent of median are given below.

                                            2/28
Ouachita River                 Camden AR   1188%
Ouachita River                 Monroe LA    127%

Based on existing soil moisture, streamflows, and normal spring
rainfall patterns; an ABOVE AVERAGE Flood Potential is expected over
the Ouachita and Black River Basins.

Percent of available reservoir flood control storage is given below.

                                            3/01
                         Lake Ouachita AR    70%
                              Degray Res. AR 20%

...EXTENDED TEMPERATURE AND PRECIPITATION OUTLOOK...

The 8-14 DAY Outlook issued by the NWS Climate Prediction Center
indicates chances of above normal precipitation and below normal
temperatures.

The 30-DAY Outlook indicates chances of above normal temperatures and
precipitation.

The 90-DAY Outlook issued by the NWS Climate Prediction Center
indicates chances of above normal temperatures and chances of above
normal precipitation over the Tennessee and Ohio Valleys and chances
of below normal precipitation over the gulf coast.

CONCLUSION...

The Spring Potential Outlook is a routine product. Should excessive
rainfall become part of the forecast at any time frame of the year,
a hydrologic outlook will be issued with event specific information.

For the latest river stage information, forecast, and warnings
please visit our website at:

http://www.weather.gov/lzk

River stage and forecast data can be obtained by selecting the
rivers and lakes AHPS link on the front page.

$$

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