Flood Potential Outlook
Issued by NWS Bismarck, ND

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FGUS73 KBIS 291904
ESFBIS
NDC009-013-023-049-061-069-075-079-101-021800-

PROBABILISTIC HYDROLOGIC OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE BISMARCK ND
1235 PM CST FRI JAN 29 2010

THIS PRODUCT IS BEING REISSUED TO CORRECT A FORMAT PROBLEM IN TABLE 1.

THIS OUTLOOK IS FOR FLOOD POTENTIAL IN THE SOURIS (MOUSE) RIVER
BASIN OF NORTH CENTRAL NORTH DAKOTA OVER THE NEXT 90 DAYS.

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

                 LONG-RANGE PROBABILISTIC OUTLOOK
               VALID 02 FEBRUARY 2010 - 03 MAY 2010

THE THREE MONTH CLIMATE OUTLOOK...FEBRUARY...MARCH...AND APRIL SHOWS
WESTERN NORTH DAKOTA WITH A 38 PERCENT PROBABILITY OF ABOVE AVERAGE
TEMPERATURES...34 PERCENT PROBABILITY OF AVERAGE TEMPERATURES...AND
A 28 PERCENT PROBABILITY OF BELOW NORMAL TEMPERATURES. THE THREE
MONTH OUTLOOK ALSO SHOWS AN EQUAL CHANCE FOR ABOVE NORMAL...
NORMAL...OR LOWER THAN NORMAL PRECIPITATION. THESE OUTLOOKS CAN BE
VIEWED ON THE INTERNET AT:

                   HTTP://WWW.CPC.NCEP.NOAA.GOV

ALL RIVERS AND STREAMS ARE UNDER NORMAL WINTER CONDITIONS WITH NO
RIVER OR STREAM IN THE BASIN CURRENTLY ABOVE FLOOD STAGE.

THE PROBABILITIES OF FLOODING CONTAINED IN THIS HYDROLOGIC OUTLOOK
WERE DEVELOPED USING SNOWFALL AND SNOW WATER EQUIVALENT DATA CURRENT
THROUGH 25 JANUARY 2010.  AS SHOULD BE EXPECTED...THE RISKS FOR
FLOODING HAVE SIGNIFICANTLY RISEN IN MANY AREAS BECAUSE OF THE SNOW
RECEIVED OVER CHRISTMAS...RIGHT AFTER THE LAST HYDROLOGIC MODEL
RUN...AND THE PRECIPITATION RECEIVED IN JANUARY.

THE SOURIS BASIN APPEARS TO HAVE LARGELY BEEN SPARED SIGNIFICANT
RAIN DURING THE JANUARY STORMS.  HOWEVER...SNOWFALL IN DECEMBER AND
AGAIN IN JANUARY HAS CREATED A VERY HIGH WATER EQUIVALENT CENTERED
AROUND THE MINOT AREA.  THE AREAS NORTH AND WEST OF MINOT TEND TO
HOLD LESS SNOW AND WATER EQUIVALENT OVERALL AND CONTINUES TO
DECREASE UPSTREAM OF LAKE DARLING.  PARTLY BECAUSE OF THE AMOUNT OF
WATER IN THE SNOW...AND LOCATION OF THE HIGHEST WATER
CONTENT...PROBABILITIES FOR REACHING AT LEAST MINOR FLOODING ARE
HIGHEST FOR THE SOURIS RIVER AT FOXHOLM AND AREAS DOWNSTREAM OF
MINOT. SOME DOWNSTREAM AREAS CURRENTLY HAVE A GREATER THAN 90
PERCENT CHANCE OF MINOR FLOODING WITH TOWNER AND BANTRY HAVING A
GREATER THAN AN 80 PERCENT CHANCE OF MODERATE FLOODING.  THE WILLOW
CREEK AND WINTERING RIVER SITES OF WILLOW CITY AND KARLSRUHE ALSO
HAVE A GREATER THAN 50 PERCENT PROBABILITY OF MINOR FLOODING.

THE RECENT WARM WEATHER HAS COMPACTED THE SNOW IN MANY AREAS AND CAN
LEAD TO PUBLIC UNDERESTIMATION OF FLOOD RISK...ESPECIALLY BASED UPON
VISUAL COMPARISONS BETWEEN CURRENT SNOWPACK AND THAT OF LAST YEAR.

ONE SHOULD NOTE THOUGH THAT WHILE THE SOURIS RIVER BASIN AS A WHOLE
CURRENTLY HAS A SNOWPACK CAPABLE OF GENERATING FLOODING...THERE ARE
OTHER FACTORS WHICH WILL WEIGH HEAVILY IN SPRING FLOODING. THE
AMOUNT OF MOISTURE RECEIVED IN FEBRUARY AND MARCH ALONG WITH
EVENTUAL WEATHER CONDITIONS DURING THE SPRING MELT ARE UNFORESEEABLE
AND WILL LARGELY CONTROL THE LOCATION AND SEVERITY OF FLOODING.

IMPORTANTLY...THE PROBABILITIES FOR FLOODING IN THIS HYDROLOGIC
OUTLOOK DO NOT INCLUDE RISK ASSOCIATED WITH ICE JAM RELATED
FLOODING.  TIMING AND SEVERITY OF ICE JAMS DEFY STATISTICAL
FORECASTING METHODS ALTHOUGH ICE JAMS DO TEND TO FORM IN
HISTORICALLY KNOWN LOCATIONS TYPICALLY ASSOCIATED WITH BRIDGES...
MEANDERS IN CHANNEL...OR OTHER FEATURES THAT IMPEDE FLOW.


TABLE 1 SHOWS THE PROBABILITY OF EXCEEDING THE DEFINED FLOOD STAGES.
FOR MORE DETAILS SUCH AS CHANCES OF EXCEEDING CERTAIN STAGES AT
SPECIFIC LOCATIONS REFER TO TABLE 2.



    TABLE 1. CHANCES OF EXCEEDING FLOOD STAGE AT SPECIFIC
             LOCATIONS IN THE SOURIS RIVER BASIN.


             VALID 02 FEBRUARY 2010 - 03 MAY 2010

                                                          DEPARTURE
                         ---------FLOOD STAGES---------   FROM NORMAL
                         MINOR     MODERATE    MAJOR      OF REACHING
LOCATION                 STG  PCT   STG  PCT   STG  PCT   FLOOD STAGE
---------------------------------------------------------------------
-DES LACS RIVER
  FOXHOLM                16   6%    18   4%    19   3%    NEAR NORMAL
SOURIS RIVER
  SHERWOOD 15W           18  36%    20  26%    25  ---     7% GREATER
  FOXHOLM 3E             10  65%    13  52%    15   6%    13% GREATER
  MINOT 4NW              14  34%    17   9%    22   4%    14% GREATER
  MINOT-BRDWY BRDG     1549   8%  1551   8%  1555   3%    NEAR NORMAL
  LOGAN                  34  50%    36  24%    38   1%    28% GREATER
  SAWYER                 22  42%    24  24%    26   8%    20% GREATER
  VELVA                1505  47%  1510   4%  1515  ---    25% GREATER
WINTERING RIVER
  KARLSRUHE 6N            7  60%     9   3%    10  ---    52% GREATER
SOURIS RIVER
  TOWNER                 52 >98%    54  80%    56  13%            NA
  BANTRY 8E              11 >98%    12  83%    14  11%            NA
WILLOW CREEK
  WILLOW CITY 7W         10  77%    14  37%    16   6%    43% GREATER
SOURIS RIVER
WESTHOPE 7NNE            10  96%    14  45%    16  18%    57% GREATER

FS  = FLOOD STAGE
--- = STATISTICAL DISTRIBUTION COMPLETELY BELOW THIS STAGE
NA  = NOT APPLICABLE

IN TABLE 2 BELOW...THE 90 THROUGH 10 PERCENT COLUMNS GIVE THE CHANCE THE
RIVER AT THE GIVEN LOCATION WOULD RISE ABOVE THE INDICATED STAGE LEVELS
WITHIN THE NEXT 90 DAYS.

EXAMPLE: DES LACS RIVER AT FOXHOLM HAS A FLOOD STAGE OF 16 FEET. IN
THE NEXT THREE MONTHS THERE IS A 90 PERCENT CHANCE THAT THE RIVER
WILL RISE TO 7.8 FEET...BUT ONLY A 10 PERCENT CHANCE THAT IT
WILL RISE ABOVE 13.3 FEET.

     TABLE 2. CHANCES OF EXCEEDING STAGES AT SPECIFIC LOCATIONS IN THE
     BISMARCK HYDROLOGIC SERVICE AREA.

                            ALL STAGES ARE IN FEET
                       VALID 02 FEB 2010 - 03 MAY 2010

LOCATION   FS (FT)   90%    80%    70%    60%    50%    40%    30%    20%    10%
________   ______    ___    ___    ___    ___    ___    ___    ___    ___    ___
DES LACS RIVER
FOXHOLM       16     7.8    8.1    8.4    9.0    9.5   10.3   11.2   12.0   13.3

SOURIS RIVER
SHERWOOD 15W  18     8.3    9.7   11.3   12.3   14.2   17.5   18.6   21.2   23.1
FOXHOLM 3E    10     8.0    8.6    9.2   11.2   13.1   13.6   14.1   14.4   14.4
MINOT 4NW     14     7.5    9.1    9.6   10.8   12.1   13.1   14.4   15.0   17.4
MINOT BWY BR 1549 1542.0 1542.7 1543.1 1543.7 1544.3 1544.9 1545.6 1546.1 1548.0
LOGAN         36    27.5   29.6   31.1   32.0   34.4   35.4   35.9   36.4   37.5
SAWYER        22    16.0   17.5   19.0   20.4   21.4   23.0   23.5   24.3   25.7
VELVA        1505 1498.6 1500.8 1502.1 1503.9 1504.8 1506.1 1506.6 1507.1 1508.9
TOWNER 1NW    52    53.7   54.0   54.4   54.8   55.1   55.3   55.5   55.8   56.4
BANTRY 8E     11    11.8   12.2   12.5   12.7   12.9   13.2   13.3   13.5   14.2
WESTHOPE 7NNE 10    10.5   10.9   11.5   12.8   13.8   14.3   15.3   16.0   17.7

WINTERING RIVER
KARLSRUHE 5NE  7     6.4    6.7    6.8    7.2    7.4    7.5    7.7    8.0    8.6

WILLOW CREEK
WILLOW CITY 7W 10    7.5    9.0   11.6   12.5   13.1   13.7   14.3   15.1   15.7


TABLE 3 PROVIDES PROBABILISTIC FORECASTS FOR "HOW LOW COULD THE RIVER GO?"
THIS FEATURE IS INCLUDED ON OUR AHPS WEB PAGES FOR EACH FORECAST POINT IN
THE SOURIS RIVER BASIN THAT HAS PROBABILISTIC GRAPHICS PRODUCED FOR THEM.
PROBABILISTIC LOW FLOW INFORMATION WILL PROVIDE USEFUL INFORMATION DURING
DROUGHTS...AND FOR RIVER USERS INTERESTED IN FISHERIES...INDUSTRIAL
DISCHARGES...DILUTION RATIOS...RECREATION...IRRIGATION...AND NAVIGATION.
IT WILL AID IN RISK ASSESSMENT DURING SITUATIONS WHERE LOW FLOWS MAY BE
CRITICAL TO OPERATIONS.

TABLE 3. CHANCES OF FALLING BELOW INDICATED STAGE AT SPECIFIC LOCATIONS IN THE
BISMARCK HYDROLOGIC SERVICE AREA.

                           ALL STAGES ARE IN FEET
                    VALID 02 FEB 2010 - 03 MAY 2010

LOCATION    FS (FT)  10%    20%    30%    40%    50%    60%    70%    80%    90%
________    _______  ___    ___    ___    ___    ___    ___    ___    ___    ___

DES LACS RIVER
FOXHOLM       16     4.5    4.5    4.5    4.5    4.5    4.5    4.5    4.5    4.5

SOURIS RIVER
SHERWOOD 15W  18     1.1    1.1    1.1    1.1    1.2    1.2    1.2    1.2    1.2
FOXHOLM 3E    10     4.5    4.5    4.5    4.5    4.5    4.5    4.5    4.5    4.5
MINOT 4NW     14     3.8    3.8    3.8    3.8    3.8    3.8    3.8    3.8    3.8
MINOT BWY BR 1549 1532.0 1532.0 1532.0 1532.0 1532.0 1532.0 1532.0 1532.0 1532.0
LOGAN         36    18.8   18.8   18.8   18.8   18.8   18.8   18.8   18.8   18.9
SAWYER        22     5.4    5.4    5.4    5.4    5.4    5.4    5.4    5.4    5.4
VELVA        1505 1489.0 1489.0 1489.0 1489.0 1489.0 1489.0 1489.0 1489.0 1489.0
TOWNER 1NW    52    43.2   43.2   43.2   43.2   43.2   43.2   43.2   43.2   43.2
BANTRY 8E     11     1.4    1.4    1.4    1.4    1.4    1.4    1.5    1.6    1.6
WESTHOPE 7NNE 10     5.4    5.5    5.6    5.8    5.8    5.8    5.8    5.8    5.8


WINTERING RIVER
KARLSRUHE 5NE  7     2.7    2.7    2.7    2.7    2.7    2.7    2.7    2.7    2.7

WILLOW CREEK
WILLOW CITY 7W 10    4.9    4.9    4.9    4.9    4.9    4.9    4.9    4.9    5.0


THE NUMBERS CONTAINED IN TABLE 3 REPRESENT NATURAL FLOWS. THAT
IS...FLOW 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 HISTORICAL WEATHER PATTERNS FROM 30 OR MORE
YEARS OF CLIMATOLOGICAL DATA WITH CURRENT CONDITIONS OF THE
RIVER...SNOWPACK...AND SOIL MOISTURE. 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 SERVICE.

THIS OUTLOOK IN GRAPHICAL FORM ALONG WITH GRAPHS OF STAGE...FLOW...
AND VOLUME ARE AVAILABLE ON THE NATIONAL WEATHER SERVICE WEBSITE.
OTHER USEFUL LINKS INCLUDING EXPLANATIONS OF THIS PRODUCT AND
CURRENT INFORMATION FOR ALL 13 RIVER FORECAST POINTS IN THE SOURIS
RIVER BASIN ARE AVAILABLE ON OUR WEB SITE. FIVE-DAY FORECASTS ARE
ALSO AVAILABLE WHEN THE RIVER AT A FORECAST POINT IS NEAR OR ABOVE
FLOOD STAGE.

VISIT OUR HOME PAGE AT: HTTP://WWW.WEATHER.GOV/BIS FOR MORE WEATHER
AND FLOOD INFORMATION.

THE NEXT AHPS FORECAST WILL BE ISSUED 19 FEBRUARY 2010.

IF YOU HAVE ANY QUESTIONS...CONTACT THE NWS AT 701-250-4495.

$$
AJS
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