Spring 2018 Flood Outlook

Winter/Spring Flood Potential Outlook
National Weather Service Columbia SC
300 PM EST Thu Jan 18 2018


...Spring Flood Potential Outlook...

...Expect below normal to near normal potential of river flooding
across the Midlands and Central Savannah River Area...

This Spring Flood Potential Outlook is for rivers and tributaries
of the Central Savannah River Basin...East-Central Georgia and
Central South Carolina including the following:

Savannah River Basin Downstream of R. B. Russell Reservoir and
upstream from Burtons Ferry...

The Edisto River basin upstream of the Bamberg and Orangeburg
County line in South Carolina...

The Santee River Basin upstream of the Clarendon and Berkeley
County line and downstream on the Saluda and Broad Rivers at the
Greenwood/Saluda...Laurens/Newberry...Union/Fairfield and the
Chester/Fairfield County lines in South Carolina...

The Wateree River System downstream of Great Falls South
Carolina...

The Great Pee Dee River Basin in Chesterfield County in South
Carolina...

           ...Summary of Recent Weather Events...

Over the last 14 days ending January 18 2018...the hydrologic
area received rainfall amounts that ranged from 0.5 to 1.0 inches
across the Central Savannah River Area and Midlands. This is
approximately 50 to 70 percent of normal for the 14 day period.

          ...Soul Moisture-Drought Conditions...

Here is a breakdown of the current conditions across the Midlands
and CSRA.

D1...Moderate Drought covers the western Midlands and northern
Midlands. This includes the counties of Saluda, Newberry,
Fairfield, Lancaster, Chesterfield and the northern half of
Fairfield.

D0...Abnormally Dry conditions covered much of the remainder of
the Midlands and CSRA. Only a narrow swath that extends from
Barnwell county northeast across Barnwell, Calhoun, Clarendon and
Sumter counties remain under normal conditions.


Go to www.drought.gov for more details.


             ...River and Stream Flow...

Looking at the 14 day stream flow average compared to historical
streamflows for January 17 2018 show most of the stream basins
across the Midlands and CSRA at much below normal to below normal
flows. This includes the Savannah River Basin, Saluda River
Basin, Catawba/Wateree River Basin, Lynches River Basin and the
Edisto River Basin.


                ...Reservoir Levels...

Many of the area reservoirs pools have increased their storage
over the past couple of weeks. Areas along the Savannah River
Basin are below normal for their Spring target pool/guide curves.
The Saluda and Santee Basins remain near or just above their
Spring target pool/guide curves.

Lake Thurmond (FP 330.0 Feet)...
Jan 04 2018 322.03 Feet
Jan 18 2018 322.12 Feet
Difference Plus 0.09 Feet

Lake Greenwood (FP 440.0 Feet)...
Jan 04 2018    435.17 Feet
Jan 18 2018    434.70 Feet
Difference Minus 0.53 Feet

Lake Murray (FP 360.0 Feet)...
Jan 04 2018    354.13 Feet
Jan 18 2018    353.87 Feet
Difference Minus 0.26 Feet

Lake Marion (FP 76.8 Feet)...
Jan 04 2018     73.65 Feet
Jan 18 2018     73.31 Feet
Difference Minus 0.34 Feet

Lake Wateree (FP 100.00 Feet)...
Jan 04 2018     96.52 Feet
Jan 18 2018     96.45 Feet
Difference Minus 0.07 Feet

Data for this segment was gathered from the United States
Geological Survey...the United States Army Corps of
Engineers...Duke Energy...South Carolina Electric and
Gas...Greenwood County and Santee Cooper.


      ...Precipitation and Temperature Outlooks...

Near Term...High pressure will dominate the weather through the
weekend. A cold front will approach the region on Monday bringing
with it a chance for showers Monday night into Tuesday morning.
Rainfall amounts are expected to be around 0.25 inch or less.

Please see the Gridded Forecasts for the chance of rain over the
next 7 days at weather.gov/cae.

The 8 to 14 Day Outlook for the period January 25 to 31 calls for
a 40 percent chance of above normal temperatures along with a 40
percent chance of above normal precipitation through the period.

The 30-Day Outlook for February 2018 indicates 40 percent chance
of above normal temperatures with around a 40 percent chance of
below normal precipitation for the month.

The 3-Month Outlook for February, March and April calls for a 33
to 40 percent chance of above normal temperatures along with a 33
to 40 percent chance with equal chances of above...below and near
normal precipitation.


Go to the Climate Prediction Center webpage at
www.cpc.ncep.noaa.gov for more details and the latest outlooks.

                   ...Summary/Outlook...

The Spring Flood Outlook calls for below normal potential of
river flooding across Central South Carolina and East-Central
Georgia. This is mainly due to La Nina conditions that are
expected to persist for the remainder of the Winter into the early
Spring.

Historically...the River Flood Season begins in early to mid
January with the number of river flood events increasing through
late Winter into early Spring. The peak occurs in early to mid
March then begins to end in late April for the region.

The medium to long range precipitation guidance indicates little
confidence in the region receiving above normal precipitation
through the Spring season. Stream flows have continued to be below
normal to much below normal across much of the region through the
Fall and Winter. The area Reservoirs along the Savannah River are
running below target pool or guide curves. The Santee and Catawba
River Reservoirs are running near or just above normal for their
target pool/guide curves for the middle of January. Overall...the
relative risk of river flooding downstream from these projects is
below normal.

The next schedule Winter/Spring Flood Outlook is scheduled for
Thursday February 01 2018.



                ...Questions and Comments...

If you have any questions or comments about this outlook please
contact...

The National Weather Service
2909 Aviation Way
West Columbia SC 29170
Phone: 803-822-8135
Internet Address: caewx@noaa.gov
Senior Service Hydrologist:
Leonard.Vaughan@noaa.gov



$$

Vaughan