Flood Potential Outlook
Issued by NWS Aberdeen, SD

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000
FGUS73 KABR 202134
ESFABR
MNC011-155-SDC013-017-021-025-029-031-037-039-041-045-049-051-057-
059-065-069-075-085-089-091-107-109-115-117-119-129-202100-

PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE ABERDEEN SD
330 PM CST THU FEB 20 2014

IN TABLE 1 BELOW...THE CURRENT (CS) AND HISTORICAL (HS) OR NORMAL
PROBABILITIES OF EXCEEDING MINOR...MODERATE...AND MAJOR FLOOD STAGES
ARE LISTED FOR THE VALID TIME PERIOD.

CS VALUES INDICATE THE PROBABILITY OF REACHING A FLOOD CATEGORY
BASED ON CURRENT CONDITIONS.

HS VALUES INDICATE THE PROBABILITY OF REACHING A FLOOD CATEGORY
BASED ON HISTORICAL OR NORMAL CONDITIONS.

WHEN THE VALUE OF CS IS MORE THAN HS...THE PROBABILITY OF
EXCEEDING THAT LEVEL IS HIGHER THAN NORMAL. WHEN THE VALUE OF CS IS
LESS THAN HS...THE PROBABILITY OF EXCEEDING THAT LEVEL IS LOWER
THAN NORMAL.


...TABLE 1--PROBABILITIES FOR MINOR...MODERATE AND MAJOR FLOODING...
                    VALID PERIOD:  2/22/2014 - 5/23/2014

                                       :    CURRENT AND HISTORICAL
                                       :     CHANCES OF EXCEEDING
                                       :       FLOOD CATEGORIES
                                       :      AS A PERCENTAGE (%)
                      CATEGORICAL      :
                   FLOOD STAGES (FT)   :   MINOR    MODERATE   MAJOR
LOCATION           MINOR   MOD   MAJOR :  CS   HS   CS   HS   CS   HS
--------           -----  -----  ----- : ---  ---  ---  ---  ---  ---
:ELM RIVER
WESTPORT            14.0   16.0   19.0 :  13   15    8    8   <5    5
:JAMES RIVER
COLUMBIA            13.0   16.0   18.0 :  42   40   27   26   17   18
STRATFORD           14.0   17.0   18.5 :  52   48   32   29    9   20
ASHTON              13.0   14.0   16.0 :  38   31   36   30   25   24
:TURTLE CREEK
REDFIELD             7.0   10.0   15.0 :  32   39   17   14    5    8
:JAMES RIVER
REDFIELD            20.0   22.0   25.0 :  21   18   13   15   11   14
:BIG SIOUX RIVER
WATERTOWN           10.0   11.0   12.0 :  39   27   10   11   <5   <5
WATERTOWN            8.0   10.0   12.0 :  78   53   40   24   <5   <5
WATERTOWN - BROAD   11.0   14.0   16.0 :  62   43   <5   <5   <5   <5
CASTLEWOOD           9.0   11.0   16.0 :  67   48   36   27   <5   <5
:GRAND RIVER
LITTLE EAGLE        15.0   17.0   21.0 :  29    8   21    6   13   <5
:MOREAU RIVER
WHITEHORSE          21.0   23.0   25.0 :  11    8    9    7    8    5
:BAD RIVER
FORT PIERRE         21.0   25.0   27.0 :  12   18    7   <5    7   <5
:LITTLE MINNESOTA RIVER
PEEVER              17.0   22.0   24.0 :  35   26   <5   <5   <5   <5
:MINNESOTA RIVER
BIG STONE LAKE     971.5  973.0  975.0 :  <5    7   <5   <5   <5   <5

LEGEND
CS = CONDITIONAL SIMULATION (CURRENT OUTLOOK)
HS = HISTORICAL SIMULATION
FT = FEET

IN TABLE 2 BELOW...THE 95 THROUGH 5 PERCENT COLUMNS INDICATE THE
PROBABILITY OF EXCEEDING THE LISTED STAGE LEVELS (FT) FOR THE VALID
TIME PERIOD.

...TABLE 2--EXCEEDANCE PROBABILITIES...

                               CHANCE OF EXCEEDING STAGES
                                  AT SPECIFIC LOCATIONS
                          VALID PERIOD: 2/22/2014 - 5/23/2014
LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:ELM RIVER
WESTPORT              5.3    5.4    6.2    8.7   11.0   14.5   16.6
:JAMES RIVER
COLUMBIA              5.0    5.1    6.9   11.2   16.6   19.3   19.9
STRATFORD             7.8    8.2    9.4   14.3   17.3   18.4   19.5
ASHTON                4.0    4.4    5.3   10.2   15.9   20.4   23.9
:TURTLE CREEK
REDFIELD              3.1    3.2    3.5    5.6    9.4   11.1   14.5
:JAMES RIVER
REDFIELD              3.7    4.4    5.5   10.0   16.9   25.8   29.8
:BIG SIOUX RIVER
WATERTOWN             5.7    6.1    8.5    9.7   10.4   11.0   11.5
WATERTOWN             5.5    6.6    8.2    9.8   10.3   10.9   11.4
WATERTOWN - BROAD     6.3    7.0    9.3   11.4   12.5   13.0   13.4
CASTLEWOOD            5.4    5.8    8.1   10.2   11.4   12.2   13.7
:GRAND RIVER
LITTLE EAGLE          7.3    8.0    9.1   12.6   15.2   21.9   23.2
:MOREAU RIVER
WHITEHORSE            6.1    6.2    7.9    9.3   15.2   21.9   26.3
:BAD RIVER
FORT PIERRE           3.4    4.3    6.8    9.4   13.7   22.2   31.0
:LITTLE MINNESOTA RIVER
PEEVER               13.5   13.8   14.6   16.1   18.0   20.1   21.1

IN TABLE 3 BELOW...THE 95 THROUGH 5 PERCENT COLUMNS INDICATE THE
PROBABILITY OF FALLING BELOW THE LISTED STAGE LEVELS (FT) FOR THE
VALID TIME PERIOD.

...TABLE 3--NONEXCEEDANCE PROBABILITIES...

                            CHANCE OF FALLING BELOW STAGES
                                 AT SPECIFIC LOCATIONS
                          VALID PERIOD: 2/22/2014 - 5/23/2014
LOCATION              95%    90%    75%    50%    25%    10%     5%
--------            ------ ------ ------ ------ ------ ------ ------
:LITTLE MINNESOTA RIVER
PEEVER               10.2   10.2   10.2   10.1    9.7    9.7    9.7


SUMMARY OF THE PROBABILISTIC OUTLOOKS...
THE CONDITIONAL SIMULATIONS BASED ON THE CURRENT CONDITIONS INDICATE
THAT THERE IS A LOWER THAN NORMAL CHANCE OF SEEING MINOR...
MODERATE...OR MAJOR FLOODING FOR NEARLY THE ENTIRE REGION. THE ONLY
EXCEPTIONS ARE NEAR NORMAL CHANCES OF MINOR FLOODING ON THE MIDDLE
PORTIONS OF THE JAMES RIVER NEAR STRATFORD...AND FOR PORTIONS OF THE
BIG SIOUX RIVER AROUND WATERTOWN AND CASTLEWOOD.

CURRENT SNOW CONDITIONS...
AREAS WEST OF A LINE FROM ABERDEEN TO REDFIELD IOWA HAVE LITTLE TO
NO SNOW REMAINING ON THE GROUND. EAST OF THAT LINE...SNOW DEPTHS
ARE STILL IN THE 4 TO 8 INCH RANGE...WITH POCKETS OF 9 TO 14 INCHES
REMAINING AROUND VICTOR AND CLEAR LAKE. THE WATER CONTENT OF THE
REMAINING SNOW PACK IS GENERALLY IN THE 1 TO 3 INCH RANGE. THE SNOW
PACK DENSITY IS GENERALLY 15 TO 25 PERCENT. SIGNIFICANT MELTING AND
RUNOFF WILL OCCUR WHEN THE SNOW DENSITY GETS OVER 30 TO 40 PERCENT.

CURRENT SOIL MOISTURE/FROST CONDITIONS...
THE LATEST MODELED SOIL MOISTURE SHOWS +1 TO -2 INCH ANOMALIES
ACROSS THE AREA. FROST DEPTHS IN THE SOILS ACROSS THE REGION
STILL RANGE FROM AROUND 20 INCHES IN THE WEST TO 40 INCHES IN THE
EAST. SOME OF THE SOUTHERN AREAS HAVE SEEN THE TOP FEW INCHES OF THE
SOILS START TO THAW WITH THE WARM TEMPERATURES AND SNOW MELT EARLIER
THIS WEEK.

CURRENT RIVER/ICE CONDITIONS...
A FEW OF THE MOST SOUTHERN PORTIONS OF THE MAIN RIVERS...AND SEVERAL
OF THE SMALLER STREAMS AND TRIBUTARIES...HAVE STARTED TO SEE SOME
VERY MINIMAL RUNOFF FROM SNOW MELT OVER THE LAST FEW DAYS. MOST OF
THE REST OF THE RECENT SNOWMELT IS EITHER BEING ABSORBED BY THE TOP
FEW INCHES OF THAWED SOILS...OR IS SIMPLY PONDING UP IN FIELDS AND
DITCHES WAITING FOR THE SOILS TO BEGIN THAWING. THE ENTIRE REGION
STILL HAS COMPLETELY ICE COVERED RIVERS AND STREAMS. ICE THICKNESSES
ARE ESTIMATED TO STILL BE AT LEAST ONE TO TWO FEET ACROSS ALL OF
EASTERN SOUTH DAKOTA. DUE TO THIS THICK ICE...ICE JAMS WILL BE A
VERY REAL THREAT AS WE HEAD INTO THE MELT/BREAKUP PERIOD OVER THE
NEXT SEVERAL WEEKS.

TEMPERATURE/PRECIPITATION OUTLOOKS...
FOR THE NEXT 2 WEEKS...TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL
WITH BELOW NORMAL PRECIPITATION. THE LATEST 30 DAY OUTLOOK FOR MARCH
SHOWS THE BEST CHANCES FOR BELOW NORMAL TEMPERATURES ACROSS THE
AREA...WITH EQUAL CHANCES OF ABOVE...NORMAL...OR BELOW
PRECIPITATION. THE 90 DAY OUTLOOK FOR MARCH THROUGH MAY SHOWS
INCREASED CHANCES FOR BELOW NORMAL TEMPERATURES FOR MOST OF THE
AREA...AND EQUAL CHANCES FOR ABOVE...NORMAL...OR BELOW
PRECIPITATION.

THESE LONG-RANGE PROBABILISTIC OUTLOOKS CONTAIN FORECAST VALUES THAT
ARE CALCULATED USING MULTIPLE SEASON SCENARIOS FROM 30 OR MORE YEARS
OF CLIMATOLOGICAL DATA...INCLUDING CURRENT CONDITIONS OF THE
RIVER...SOIL MOISTURE...SNOW COVER...AND 30 TO 90 DAY LONG-RANGE
OUTLOOKS OF TEMPERATURE AND PRECIPITATION. BY PROVIDING A 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
SERVICE.

VISIT OUR WEB SITE WEATHER.GOV/ABR FOR MORE WEATHER AND WATER
INFORMATION.

THE NEXT OUTLOOK WILL BE ISSUED THURSDAY MARCH 6TH.

$$

PARKIN












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