Missouri and James Basins Flood Outlook...updated March 5th

Missouri and James Basins
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE BISMARCK ND
0855 AM CST FRI MAR 5 2010

...FLOOD AND WATER RESOURCES OUTLOOK FOR THE MISSOURIS AND JAMES
RIVER BASINS OF WESTERN AND CENTRAL NORTH DAKOTA...

THIS OUTLOOK CONTAINS QUALITATIVE TEXT AND DETAILED PROBABILITY
TABLES WHICH DESCRIBE THE POTENTIAL FOR FLOODING IN THE MISSOURI
RIVER AND JAMES RIVER BASINS DURING 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 7 MARCH - 5 JUNE 2010

THE THREE MONTH CLIMATE OUTLOOKS COVERING MARCH...APRIL...AND MAY
SHOW NO STRONG INDICATION OF ABOVE OR BELOW NORMAL CONDITIONS FOR
TEMPERATURE AND PRECIPITATION. THESE OUTLOOKS CAN BE VIEWED ON THE
INTERNET AT:

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

AT THIS POINT...ALL RIVER AND STREAMS REMAIN UNDER NORMAL WINTER
CONDITIONS...AND SHOULD REMAIN THAT WAY UNTIL AT LEAST SOME TIME
DURING THE SECOND WEEK OF MARCH BEFORE ANY SUBSTANTIVE RUNOFF
BEGINS.  HOWEVER...AS WE NEAR THE MIDDLE OF MARCH...THESE
CONDITIONS CAN CHANGE VERY RAPIDLY AS THIS PERIOD HISTORICALLY
MARKS THE BEGINNING OF THE SPRING MELT SEASON IN SOUTHERN AND
SOUTHWESTERN NORTH DAKOTA.

THE GOOD NEWS FOR MOST OF WESTERN NORTH DAKOTA HAS BEEN THE
UNUSUALLY DRY WEATHER FROM EARLY FEBRUARY THROUGH EARLY MARCH. 
THIS DRY WEATHER IS REFLECTED IN THE MOST RECENT MODEL RUNS
WHICH TEND TO SHOW SLIGHTLY LOWER PROBABILITIES FOR MODERATE TO
MAJOR FLOODING AT SEVERAL LOCATIONS.  WHILE THE PROBABILITIES
IN THIS OUTLOOK TEND TO BE SLIGHTLY LOWER...SIGNIFICANT RISK
REMAINS BASED UPON EXISTING WATER CONTENT IN THE SNOWPACK WHICH
CAN BE SIGNIFICANTLY ENHANCED BY PRECIPITATION RECEIVED IN MARCH.

TO ILLUSTRATE THE EFFECT OF TIMING AND AMOUNT OF PRECIPITATION
ON FLOODING IN WESTERN NORTH DAKOTA...ONE CAN REFLECT UPON THE
2009 FLOODING WHERE SOME OF THE MORE PROBLEMATIC AREAS OF
WESTERN NORTH DAKOTA RECEIVED UNUSUALLY HIGH AMOUNTS OF
PRECIPITATION AT THE WORST POSSIBLE TIME.  FOR EXAMPLE...
BISMARCK RECEIVED 2.73 INCHES OF MOISTURE IN MARCH 2009 AND
RANKED FIFTH OUT OF 135 YEARS OF HISTORICAL DATA.  JAMESTOWN
RECEIVED 2.41 INCHES OF MOISTURE IN MARCH LAST YEAR WHICH WAS
THE FOURTH WETTEST ON RECORD...AND A NATIONAL WEATHER SERVICE
OBSERVER IN GRANT COUNTY REPORTED 3.07 INCHES OF MOISTURE...
THE MOST SINCE ESTABLISHMENT OF THAT SITE IN 1949.
CONVERSELY...MINOT WAS SLIGHTLY ABOVE NORMAL AND RANKED
THIRTIETH OVERALL WHILE ONE OF THE LEAST FLOOD AFFECTED AREAS
WAS WILLISTON...AND THAT LOCATION WAS UNUSUALLY DRY WITH THE THIRD
LOWEST ON RECORD AT 0.06 INCHES.

THE PROBABILITIES OF FLOODING CONTAINED IN THIS HYDROLOGIC OUTLOOK
WERE DEVELOPED USING SNOWFALL AND SNOW WATER EQUIVALENT DATA CURRENT
THROUGH 2 MARCH 2010.  IN GENERAL...AT LEAST SOME MINOR TO MODERATE
FLOODING REMAINS A NEAR CERTAINTY IN ALL BASINS AND THE RISK OF
MODERATE TO MAJOR FLOODING IS SUBSTANTIAL. EVEN THOUGH THE
PROBABILITY OF MAJOR FLOODING HAS SLIGHTLY LESSENED AGAIN IN THE
MODEL FOR APPLE CREEK AND THE KNIFE RIVER AT HAZEN...THESE TWO SITES
ALONG WITH THE UPPER JAMES RIVER BASIN CONTINUE TO BE THE MOST AT
RISK OF MAJOR 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 ASSOCIATED WITH BRIDGES...MEANDERS IN
CHANNEL...OR OTHER FEATURES THAT IMPEDE FLOW.

OVERLAND FLOODING AND FLOODING ASSOCIATED WITH SMALL...UNGAGED
STREAMS ARE ALSO NOT INCLUDED IN THE PROBABILITY TABLES OF THIS
OUTLOOK.  HOWEVER...SMALL STREAMS ARE VERY LIKELY TO BE PROBLEMATIC
THROUGHOUT MUCH OF WESTERN NORTH DAKOTA...ESPECIALLY WHERE TOWNSHIP
AND COUNTY ROADS CROSS THEM.


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 BISMARCK HYDROLOGIC SERVICE AREA.


                  VALID 7 MARCH - 5 JUNE 2010

                                                           DEPARTURE
                                                             FROM
                        ---------FLOOD STAGES---------      NORMAL
                         MINOR     MODERATE    MAJOR     OF REACHING
 LOCATION               STG  PCT   STG  PCT   STG  PCT   FLOOD STAGE
---------------------------------------------------------------------
LITTLE MUDDY RIVER
 WILLISTON 10NE          10  80%    12  29%    14  13%    16% GREATER
LITTLE MISSOURI RIVER
 MARMARTH                18  11%    23   5%    30  ---     8% GREATER
 MEDORA                  15  86%    18  15%    20   6%    75% GREATER
 WATFORD CITY            20   7%    24  ---    30  ---            N A
SPRING CREEK
 ZAP                     14 >98%    18  87%    20  69%            N A
KNIFE RIVER
 MANNING                 15  84%    17   9%    20  ---    71% GREATER
 HAZEN 1S                21 >98%    24  98%    25  90%            N A
HEART RIVER
 MANDAN 3W               17  80%    23  13%    28   2%    76% GREATER
APPLE CREEK
 MENOKEN 6W              15 >98%    16  96%    17  52%            N A
JAMES RIVER
 GRACE CITY 3W           12  93%    14  81%    15  64%    86% GREATER
 LAMOURE                 14 >98%    16  94%    18  25%            N A
 LUDDEN 5SW              12 >98%    14 >98%    17  39%            N A
PIPESTEM CREEK
 PINGREE 3W               9 >98%    11  87%    13  ---            N A
CANNONBALL RIVER
 REGENT                  22  10%    24   7%    26   6%            N A
 BREIEN                  10 >98%    20  44%    23   8%            N A
CEDAR CREEK
 RALEIGH 19S             12  67%    14  38%    16  18%    64% GREATER
BEAVER CREEK
 LINTON 1W                9  95%    11  82%    13  69%    83% GREATER

NA = NOT APPLICABLE
NN = NEAR NORMAL


IN TABLE 2 BELOW...THE 90 THROUGH 10 PERCENT COLUMNS GIVE THE
PROBABILITY OF THE RIVER AT A GIVEN LOCATION RISING TO THE INDICATED
STAGE LEVELS WITHIN THE NEXT THREE MONTHS.

EXAMPLE: LITTLE MUDDY CREEK NEAR WILLISTON HAS A FLOOD STAGE OF 10
FEET. IN THE NEXT THREE MONTHS THERE IS ONLY A 10 PERCENT CHANCE
THAT THE CREEK WILL RISE TO 14.2 FEET...BUT A 60 PERCENT CHANCE THAT
IT WILL RISE TO AT LEAST 11.1 FEET.

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

                CHANCE OF EXCEEDING STAGES AT SPECIFIC LOCATIONS
                           ALL STAGES ARE IN FEET
                        VALID 7 MARCH - 5 JUNE 2010

LOCATION   FS (FT)   90%    80%    70%    60%    50%    40%    30%    20%   10%
_______    ______    ___    ___    ___    ___    ___    ___    ___    ___   ___
LITTLE MUDDY RIVER
WILLISTON 10NE 10    9.1   10.0   10.7   11.1   11.4   11.6   12.0   13.1   14.2

LITTLE MISSOURI RIVER
MARMARTH ND    18   12.0   12.5   13.0   13.7   14.4   14.7   15.2   16.1   18.1
MEDORA ND      15   14.5   15.2   15.8   16.3   16.6   16.9   17.1   17.6   18.5
WATFORD CITY   20   12.3   13.6   14.1   14.5   14.9   15.1   15.6   16.0   16.8

SPRING CREEK
ZAP ND         14   16.9   19.2   19.8   20.4   21.2   23.0   23.6   24.2   27.4

KNIFE RIVER
MANNING        15   14.3   15.6   15.7   15.8   16.1   16.2   16.4   16.7   17.0
HAZEN ND 1S    21   25.0   25.4   25.9   26.0   26.4   26.6   26.8   27.2   28.5

HEART RIVER
MANDAN 3W      17   16.2   17.1   17.6   18.8   19.4   20.5   21.2   21.8   25.4

APPLE CREEK
MENOKEN 6W     15   16.3   16.5   16.7   16.9   17.2   17.4   17.6   17.7   18.0

JAMES RIVER
GRACE CITY 3W  12   13.4   14.1   14.6   15.3   16.0   16.2   16.5   17.3   18.4
LAMOURE        14   16.1   16.3   16.5   17.0   17.2   17.4   17.8   18.5   18.9
LUDDEN 5SW     12   16.1   16.2   16.6   16.7   16.8   17.0   17.4   17.8   18.4

PIPESTEM CREEK
PINGREE 3W      9   10.8   11.2   11.3   11.4   11.5   11.6   11.9   11.9   12.1

CANNONBALL RIVER
REGENT         22   13.1   14.0   14.2   14.4   14.9   15.7   16.7   18.5   22.2
BREIEN         10   16.6   17.6   18.8   19.0   19.6   20.7   21.1   21.5   22.4

CEDAR CREEK
RALEIGH 19S    12   10.1   11.1   11.8   12.1   12.4   13.8   14.8   15.8   16.6

BEAVER CREEK
LINTON 1W       9    9.6   11.4   12.9   13.9   15.4   16.2   17.1   18.3   21.4

THE NUMBERS CONTAINED IN THIS LONG-RANGE PROBABILISTIC OUTLOOK 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 17 RIVER FORECAST POINTS IN THE MISSOURI
AND JAMES RIVER BASINS 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 MARCH 2010. 

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

$$
 
 


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