Spring Flood Outlook

...ADVANCED HYDROLOGIC PREDICTION SERVICES (AHPS) ENABLE THE
NATIONAL WEATHER SERVICE TO PROVIDE LONG-RANGE PROBABILISTIC RIVER
OUTLOOKS...

THIS OUTLOOK IS VALID FROM MAR 16 2009 - JUN 14 2009

THE FOLLOWING TABLE GIVES THE CHANCE OF REACHING DIFFERENT
FLOOD LEVELS AT THE GAGES DURING THE VALID PERIOD. THE ONLY AREA
CURRENTLY SHOWING A 50% OR GREATER CHANCE OF MODERATE FLOODING
IS THE JAMES RIVER.


                                         APPROXIMATE CHANCE OF
                 FLOOD LEVELS (FT)       REACHING FLOOD LEVELS
LOCATION         MINOR MODRT MAJOR       MINOR  MODRT  MAJOR
--------         ----- ----- -----       -----  -----  -----
JAMES RIVER
HURON SD        11.0  13.0  15.0        80%    55%    35%
FORESTBURG SD   12.0  14.0  16.0        75%    50%    25%
MITCHELL SD     17.0  20.0  22.0        80%    50%    25%
SCOTLAND SD     13.0  14.0  16.0        70%    60%    35%


FIRESTEEL CREEK
MT VERNON SD     8.0  13.0  15.0        35%    10%    < 10%

W FK VERMILLION RIVER
PARKER SD        9.0  10.0  11.0        < 10%  < 10%  < 10%

E FK VERMILLION RIVER
PARKER SD       12.0  15.0  16.0        15%    < 10%  < 10%

VERMILLION RIVER
DAVIS SD        11.0  13.0  15.0        35%    15%    < 10%
WAKONDA SD      14.0  15.5  17.0        45%    35%    20%
VERMILLION SD   21.0  22.0  30.0        20%    15%    < 10%

BIG SIOUX RIVER
BROOKINGS SD     9.0  10.5  12.0        50%    35%    15%
DELL RAPIDS SD  12.0  14.0  15.0        25%    10%    < 10%
S FALLS 60TH ST 12.0  14.0  16.0        50%    20%    < 10%
SF CLIFF AVE    16.0  18.0  31.0        20%    10%    < 10%
HAWARDEN IA     15.0  20.0  23.0        60%    30%    10%
AKRON IA        16.0  18.0  20.0        65%    45%    35%
SIOUX CITY IA   99.0 105.0 108.0        < 10%  < 10%  < 10%

SKUNK CREEK
SIOUX FALLS SD  11.5  15.0  17.0        < 10%  < 10%  < 10%

SPLIT ROCK CREEK
CORSON SD        8.5  11.0  14.0        30%    15%    < 10%

ROCK RIVER
LUVERNE MN      10.0  12.0  14.0        20%    < 10%  < 10%
ROCK RAPIDS IA  13.0  16.0  19.0        50%    30%    20%
ROCK VALLEY IA  16.0  17.0  19.0        20%    10%    < 10%

FLOYD RIVER
SHELDON IA      12.0  14.0  16.0        35%    20%    < 10%
ALTON IA        12.0  16.0  18.0        30%    10%    < 10%
LEMARS IA       20.0  21.0  24.0        10%    < 10%  < 10%
STRUBLE IA      14.0  15.0  16.0        < 10%  < 10%  < 10%
MERRILL IA      12.0  14.0  16.0        < 10%  < 10%  < 10%
JAMES IA        26.0  30.0  34.0        < 10%  < 10%  < 10%

PERRY CREEK
SIOUX CITY IA   24.0  26.0  28.0        < 10%  < 10%  < 10%

LITTLE SIOUX RIVER
SPENCER IA      10.0  14.0  16.0        70%    25%    < 10%
LINN GROVE IA   18.0  19.5  21.0        60%    40%    15%
CHEROKEE IA     17.0  21.0  24.0        40%    10%    < 10%
CORRECTIONVILLE 19.0  20.0  21.0        15%    10%    < 10%

WEST FORK DITCH
HORNICK IA      20.0  22.0  27.0        15%    10%    < 10%

REDWOOD RIVER
MARSHALL MN     14.0  15.0  16.5      < 10%    < 10   < 10%

DES MOINES RIVER
JACKSON MN      12.0  14.0  16.0        20%    < 10%  < 10%


IN THE TABLE BELOW...THE 90 THROUGH 10 PERCENT COLUMNS INDICATE THE
CHANCE THE RIVER COULD RISE ABOVE THE LISTED STAGE LEVELS IN THE
NEXT 90 DAYS. EXAMPLE: THE JAMES RIVER NEAR SCOTLAND HAS A FLOOD
STAGE OF 13 FEET. THERE IS A 30 PERCENT CHANCE THAT THE RIVER WILL
RISE ABOVE 16.6 FEET IN THE NEXT 90 DAYS.


LOCATION        FS(FT) 90%  80%  70%  60%  50%  40%  30%  20%  10%
-----------     ----   ---  ---  ---  ---  ---  ---  ---  ---  ---
JAMES RIVER
HURON           11.0  10.8 11.0 11.3 12.6 13.4 14.6 15.9 17.7 20.1
FORESTBURG      12.0  10.3 11.3 12.9 13.5 14.0 14.5 15.2 16.6 19.6
MITCHELL        17.0  16.2 17.0 18.5 19.4 20.1 20.5 21.2 23.4 26.1
SCOTLAND        13.0   9.4 11.0 12.8 13.8 14.9 15.3 16.6 18.2 19.8

FIRESTEEL CREEK
MOUNT VERNON     8.0   2.5  3.5  4.5  5.2  6.1  7.1  8.5  8.9 13.3

WEST FORK VERMILLION RIVER
PARKER           9.0   1.6  1.6  2.3  2.7  2.9  3.2  3.9  4.3  5.4

EAST FORK VERMILLION RIVER
PARKER          12.0   5.1  5.4  6.8  7.5  8.3  9.5 10.4 11.1 12.4

VERMILLION RIVER
DAVIS           11.0   4.6  6.8  7.1  8.7  9.7 10.6 11.6 12.3 14.0
WAKONDA         14.0   6.6  8.2 10.3 11.4 13.6 14.5 16.1 17.0 17.3
VERMILLION      21.0   6.7  8.3 10.2 11.7 13.5 14.6 17.3 19.9 24.5

BIG SIOUX RIVER
BROOKINGS        9.0   4.6  5.6  7.3  8.3  9.1  9.8 10.9 11.5 12.3
DELL RAPIDS     12.0   5.2  6.1  7.5  8.6  9.5 10.4 11.6 13.1 13.7
60TH STREET     12.0   9.9 10.3 10.9 11.6 12.0 12.4 12.9 13.9 14.5
NORTH CLIFF     16.0   7.4  8.4  9.0 10.5 11.6 13.1 14.2 16.0 17.9
HAWARDEN        15.0  10.1 12.1 14.0 15.6 16.7 18.6 20.3 21.6 23.3
AKRON           16.0  11.3 13.4 15.2 16.8 17.7 19.5 20.7 21.8 23.2
SIOUX CITY      99.0  86.7 87.1 88.5 89.3 90.3 92.2 93.6 95.2 97.2

SKUNK CREEK
SIOUX FALLS     11.5   5.3  5.5  5.7  6.2  6.7  7.2  7.6  8.4 10.2

SPLIT ROCK CREEK
CORSON           8.5   4.0  4.4  4.9  5.2  6.2  7.0  8.6 10.4 13.2

ROCK RIVER
LUVERNE         10.0   4.1  4.2  4.4  4.6  4.9  5.6  6.7  9.7 11.2
ROCK RAPIDS     13.0   9.9 10.3 11.0 11.9 13.1 14.5 16.4 18.7 20.0
ROCK VALLEY     16.0   7.6  8.1  8.6  9.3 10.4 12.0 14.1 15.9 17.4

FLOYD RIVER
SHELDON         12.0   6.6  7.1  7.5  8.2  8.8  9.4 12.6 14.1 14.7
ALTON           12.0   7.2  7.6  8.3  8.9  9.1 10.2 11.9 13.0 15.9
LE MARS         20.0  11.9 12.4 12.7 12.9 13.9 15.0 16.3 19.0 19.6
MERRILL         20.0   1.2  1.9  2.2  2.7  3.2  4.1  5.7  6.8  9.8
JAMES           26.0  10.7 11.2 11.6 12.1 12.7 13.5 14.8 16.0 18.7

WEST BRANCH FLOYD RIVER
STRUBLE         14.0   4.7  5.3  5.5  5.8  6.4  7.2  8.2  8.9 12.0

PERRY CREEK
SIOUX CITY      24.0   8.0  8.3  8.8  9.2  9.8 10.9 11.9 12.6 14.9

LITTLE SIOUX RIVER
SPENCER         10.0   8.0  9.6 10.1 11.3 12.3 13.1 13.7 14.5 15.2
LINN GROVE      18.0  16.9 17.2 17.6 18.1 18.9 19.3 20.1 20.6 21.4
CHEROKEE        17.0   8.7  9.9 11.5 12.7 15.4 16.7 18.5 19.9 21.0
CORRECTIONVILLE 19.0   7.2  7.8  8.9 10.8 12.0 13.2 15.1 18.5 20.0

WEST FORK DITCH
HORNICK         20.0   9.0 10.4 11.5 12.8 14.1 16.5 17.2 18.6 21.9

REDWOOD RIVER
MARSHALL        14.0   8.8  8.9  9.2  9.4  9.7 10.8 11.0 11.9 13.1

DES MOINES RIVER
JACKSON         12.0   7.3  7.8  8.2  8.8  9.4 10.2 11.0 11.8 13.4

FOR THE FLOOD OUTLOOK FOR NORTHEAST SOUTH DAKOTA GO TO http://www.weather.gov/water/textprods/view.php?wfo=abr&prod=ESF

FOR THE FLOOD OUTLOOK FOR CENTRAL IOWA GO TO
http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=dmx&storyid=21071&source=0

CURRENT CONDITIONS: THIS SPRING FLOOD OUTLOOK IS BASED ON CONDITIONS
AS OF FRIDAY MORNING...MARCH 13.

SNOW DEPTH...THERE ARE STILL 1 TO 4 INCHES OF SNOW ON THE GROUND
ALONG AND NORTH OF HIGHWAY 14. SOUTH OF THERE...THERE IS AN INCH OR
LESS OF SNOW COVER REMAINING...WITH A FEW AREAS STILL HAVING SOME
SNOW IN DRIFTS...DITCHES...AND SHELTERBELTS.

SNOW WATER EQUIVALENT...THERE IS 0.5 TO 1.0 INCH OF WATER IN THE
REMAINING SNOWPACK IN THE EXTREME NORTHERN AREAS. FOR THE REST OF
THE REGION...THERE IS AT MOST 0.25 INCH OF WATER STILL BEING HELD
IN THE SNOW PACK WHEN AVERAGED OUT OVER THE ENTIRE AREA OF THE
RIVER BASINS.

SOIL MOISTURE...NEAR NORMAL SOIL MOISTURE CONDITIONS EXIST TO THE
EAST OF INTERSTATE 29. AREAS TO THE WEST ARE 1 TO 2 INCHES ABOVE
NORMAL.

CURRENT STREAMFLOW/ICE CONDITIONS...STREAMFLOWS ARE GENERALLY
ABOVE NORMAL ON ALL OF THE RIVERS DUE TO THE RAIN AND SNOWMELT
THAT OCCURRED IN FEBRUARY. THERE IS STILL A CONSIDERABLE AMOUNT
OF ICE ON THE RIVERS...MAINLY NORTH OF INTERSTATE 90. THE ICE
THICKNESS IS STILL 1 FOOT OR GREATER IN SOME OF THE
NORTHERN-MOST AREAS.

30 AND 90 DAY OUTLOOKS...THE LASTEST OUTLOOKS FROM THE CLIMATE
PREDICTION CENTER CALL FOR EQUAL CHANCES OF BELOW NORMAL...
NORMAL...AND ABOVE NORMAL TEMPERATURES FOR THE REMAINDER OF
MARCH...AND ABOVE NORMAL PRECIPITATION FOR THE REST OF THE MONTH.
THE 90 DAY OUTLOOK FOR MARCH THROUGH MAY SHOWS EQUAL CHANCES OF
ABOVE NORMAL...NORMAL...AND BELOW NORMAL TEMPERATURES AND
PRECIPITATION FOR THE 3 MONTH PERIOD OF MARCH THROUGH MAY.
EXPERIMENTAL LOCAL OUTLOOKS DONE AT THE SIOUX FALLS
WEATHER SERVICE OFFICE INDICATE A HIGHER CHANCE OF NORMAL TO
ABOVE NORMAL TEMPERATURES AND NORMAL TO BELOW NORMAL
PRECIPITATION FOR MARCH THROUGH MAY.

THE NUMBERS CONTAINED IN THIS LONG-RANGE PROBABILISTIC OUTLOOK
REPRESENT NATURAL FLOWS. THAT IS...FLOWS UNAFFECTED BY MAN-MADE
STRUCTURES IN THE BASIN SUCH AS DIVERSION DAMS AND RESERVOIRS.

THIS LONG-RANGE PROBABILISTIC OUTLOOK CONTAINS FORECAST VALUES THAT
ARE CALCULATED USING MULTIPLE SEASON SCENARIOS FROM 30 OR MORE YEARS
OF CLIMATOLOGICAL DATA INCLUDING CURRENT CONDITIONS OF THE
RIVER...SNOW COVER...AND SOIL MOISTURE...AND THE 30 TO 90 DAY
LONG-RANGE OUTLOOKS OF TEMPERATURE AND PRECIPITATION. BY PROVIDING
THE COMPLETE RANGE OF PROBABILITIES...THE LEVEL OF RISK ASSOCIATED
WITH LONG-RANGE PLANNING DECISIONS CAN BE DETERMINED. THESE
PROBABILISTIC FORECASTS ARE PART OF THE NATIONAL WEATHER SERVICE`S
ADVANCED HYDROLOGIC PREDICTION SERVICES (AHPS).

LONG-RANGE PROBABILISTIC OUTLOOKS WILL BE ISSUED TOWARD THE END OF
THE MONTH THROUGHOUT THE YEAR. THE NEXT SCHEDULED OUTLOOK FOR THESE
SITES WILL BE ISSUED ON MARCH 27 2009.

VISIT OUR WEB SITE AT WWW.WEATHER.GOV/FSD FOR MORE WEATHER AND RIVER
INFORMATION INCLUDING GRAPHS OF PROBABILISTIC RIVER OUTLOOKS.



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