Spring Flood Outlook Missouri River Basin

The National Weather Service has released its update of the Spring Flood Outlook maps. Values are not given for the mainstem Lower Missouri River, but gives good information on tributaries. These maps reflect snowpack, soil moisture and existing runoff, but don't take into account precipitation. Some sources are predicting a wet spring so that will definitely affect the Missouri River.

Here's the link to the report, with probability maps

Here's an analysis for North Dakota tributaries.

Here's the text from the NWS report:

THIS SNOWMELT OUTLOOK IS FOR THE MISSOURI RIVER DRAINAGE WHICH
INCLUDES RIVERS IN MONTANA, WYOMING, COLORADO, NORTH DAKOTA, SOUTH
DAKOTA, MINNESOTA, NEBRASKA, KANSAS, IOWA, AND MISSOURI.

SIGNIFICANT SNOWPACK EXISTS ON THE MISSOURI RIVER BASIN PLAINS FROM
EASTERN MONTANA THROUGH NORTHWESTERN IOWA. SNOWMELT, COUPLED WITH
ABOVE NORMAL SOIL MOISTURE CONDITIONS AND CLIMATOLOGICAL RAINFALL
THIS SPRING, IS LIKELY TO RAISE MANY RIVERS ABOVE FLOOD STAGE DURING
THE NEXT FEW MONTHS AND CAUSE MAJOR FLOODING AT MANY LOCATIONS.

SOME MINOR ICE JAM FLOODING IS ALREADY OCCURRING OR HAS RECENTLY
OCCURRED ON THE MISSOURI AND JEFFERSON RIVERS IN MONTANA, THE PLATTE,
ELKHORN, LOUP AND NIOBRARA RIVER BASINS IN NEBRASKA, AND THE WHITE
RIVER BASIN IN SOUTH DAKOTA.  ADDITIONAL FLOODING RESULTING FROM ICE
JAMS IS LIKELY THROUGHOUT THE LATE WINTER AND EARLY SPRING.  THIS
WOULD ADD TO THE FLOODING DESCRIBED IN THESE OUTLOOKS.

THERE IS POTENTIAL FOR MODERATE TO MAJOR FLOODING DUE TO SNOWMELT
THROUGHOUT THE BIG SIOUX RIVER BASIN IN SOUTH DAKOTA AND NORTHWEST
IOWA WITH POTENTIAL FOR NEAR RECORD FLOODING AT SOME LOCATIONS.

THERE IS POTENTIAL FOR MODERATE TO MAJOR FLOODING DUE TO SNOWMELT
THROUGHOUT THE JAMES RIVER BASIN IN BOTH NORTH AND SOUTH DAKOTA,
ALONG THE KNIFE RIVER IN NORTH DAKOTA, IN THE LOWER MILK RIVER BASIN
IN MONTANA, AND IN THE VERMILLION RIVER BASIN IN SOUTHEAST SOUTH DAKOTA.

MODERATE FLOODING DUE TO SNOWMELT IS LIKELY IN THE APPLE AND LITTLE
MUDDY BASINS IN NORTH DAKOTA, AND IN THE GRAND AND CHEYENNE RIVER BASINS
IN SOUTH DAKOTA. THERE IS THE POTENTIAL FOR MINOR TO MODERATE FLOODING
IN THE NORTH PLATTE BASIN IN WESTERN NEBRASKA, THE MOREAU AND WHITE
RIVER BASINS IN SOUTH DAKOTA, AND THE LITTLE SIOUX RIVER BASIN IN IOWA. 

MINOR FLOODING DUE TO SNOWMELT IS MORE LIKELY IN THE LITTLE MISSOURI
BASIN IN NORTH AND SOUTH DAKOTA, AND THE BEAVER AND CANNONBALL BASINS
IN NORTH DAKOTA.

BASED ON THE CURRENT SNOWPACK IN THE MOUNTAINS OF MONTANA, WYOMING
AND COLORADO, THE UPPER NORTH PLATTE IN WYOMING HAS THE POTENTIAL FOR
MINOR TO MODERATE FLOODING DUE TO SNOWMELT WHILE THE LARAMIE RIVER IN
WYOMING, AND THE GALLATIN, BIG HOLE, AND UPPER YELLOWSTONE BASINS IN
MONTANA HAVE POTENTIAL FOR MINOR FLOODING DUE TO SNOWMELT.  
  
IN THE SOUTHEASTERN THIRD OF THE MISSOURI RIVER BASIN, WITHIN THE
STATES OF NEBRASKA, WESTERN IOWA, EASTERN KANSAS, AND MISSOURI, THE
SOILS ARE NEARLY SATURATED AND THERE IS SOME SPOTTY SNOW COVERAGE.
IN THIS AREA IT IS LIKELY THAT SPRING FLOODING WILL HAPPEN IF
TYPICAL RAINFALL EVENTS OCCUR. LONG LEAD-TIME OUTLOOKS FOR THESE TYPES
OF EVENTS ARE NOT POSSIBLE. HOWEVER, AHPS PROBABILISTIC FORECASTS ARE
AVAILABLE FOR SOME OF THESE AREAS. THESE FORECASTS INDICATE THAT MINOR
TO MODERATE FLOODING IS LIKELY WITH NORMAL OCCURRENCES OF HEAVY
RAINFALL EVENTS.

OUTLOOK NUMBERS FOR LOCATIONS NOT REPRESENTED IN AHPS PRODUCTS ARE
NOT BEING ISSUED WITH THIS TEXT PRODUCT.  HOWEVER, THOSE LOCATIONS IN
EASTERN NEBRASKA, EASTERN KANSAS AND ALL OF MISSOURI NOT INCLUDED IN
THE AHPS PRODUCTS THAT NORMALLY FLOOD NEARLY EVERY SPRING WILL LIKELY
HAVE SLIGHTLY ABOVE NORMAL CHANCE TO FLOOD THIS YEAR BECAUSE OF WET
SOILS.  IN ADDITION, MINOR FLOODING IS LIKELY ON THE MISSOURI
RIVER DURING THE SNOWMELT SEASON WITH THE ADDITION OF HEAVY SPRING
RAINS DUE TO INCREASED FLOW FROM UPSTREAM SNOWMELT RUNOFF.

THIS OUTLOOK CONTAINS A GENERALIZED SUMMARY OF SPRING FLOOD POTENTIAL.
ABOVE NORMAL FUTURE SNOW, COMBINED WITH SIGNIFICANT RAINS AND RAPID
MELT, WILL INCREASE THE CURRENT FLOOD POTENTIAL WHILE BELOW NORMAL
FUTURE PRECIPITATION AND GRADUAL OR INTERMITTENT FREEZING AND THAWING
WILL DECREASE THE MAGNITUDE OF THE CURRENT ASSESSMENT. IN ADDITION,
WHEN MANY OF THE FROZEN RIVERS AND STREAMS THAW, ICE JAMS CAN OCCUR
CAUSING HIGHER RIVER LEVELS AND POSSIBLE FLOODING.

THESE PROJECTIONS OF RIVER STAGES AND RESERVOIR LEVELS ARE BASED
ON CURRENT OBSERVED OR ESTIMATED STATES OF STREAMFLOW, SOIL MOISTURE,
AND SNOW PACK. THESE ANTECEDENT CONDITIONS ARE COUPLED WITH FUTURE
PRECIPITATION AND TEMPERATURE PATTERNS AND ANTICIPATED OPERATIONAL
HYDROLOGIC CHANGES, SUCH AS RESERVOIR RELEASES AND CANAL DIVERSIONS,
TO COMPILE THE OUTLOOK. "OUTLOOKS" ARE PROVIDED FOR LONG-RANGE (WEEKS
TO MONTHS) PROJECTIONS BASED ON CLIMATOLOGICAL PATTERNS OF
PRECIPITATION AND TEMPERATURE. "FORECASTS" ARE PROVIDED FOR
SHORT-TERM(DAYS) PROJECTIONS BASED ON FUTURE FORECASTED PATTERNS OF
PRECIPITATION AND TEMPERATURE. THE UNCERTAINTY OF THESE PRODUCTS
VARIES FROM SEASON TO SEASON AND SITE TO SITE. IN RECENT YEARS,
OUTLOOK CRESTS HAVE BEEN ABOVE THE OBSERVED CREST ABOUT AS OFTEN AS
THEY HAVE BEEN BELOW THE OBSERVED CREST.  THE UNCERTAINTY OF
FORECASTS TEND TO BE LESS THAN THE UNCERTAINTY OF OUTLOOKS DUE TO
THEIR SHORTER LEAD TIME. USERS OF THESE PRODUCTS ARE ENCOURAGED TO
CONTACT THEIR NEAREST NATIONAL WEATHER SERVICE FORECAST OFFICE FOR
CONTINUED UPDATES OF METEOROLOGICAL CONDITIONS WHICH CAN HAVE
SIGNIFICANT IMPACTS ON FLOOD PLANNING AND FLOOD MITIGATION ACTIVITIES.

FOR ADDITIONAL QUANTITATIVE INFORMATION PLEASE REFER TO AHPS PRODUCTS
FOR PROBABILISTIC FORECASTS OF POTENTIAL FLOODING.  REFER TO FLOOD
FORECASTS, IF ANY ARE CURRENTLY ISSUED, FOR INFORMATION ABOUT ONGOING
OR ANTICIPATED FLOODING.

IF CONDITIONS CHANGE, ANOTHER OUTLOOK WILL BE ISSUED ON MARCH 9TH. 
OTHERWISE, ANOTHER OUTLOOK COULD BE ISSUED MARCH 23RD IF SIGNIFICANT
MELT IS NOT ALREADY OCCURRING.

ADDITIONAL RIVER INFORMATION CAN BE FOUND IN THE DAILY HYDROLOGIC
ACTIVITIES DISCUSSION, FLOOD FORECASTS FOR RIVERS NEAR OR ABOVE
FLOOD STAGE, DAILY RIVER FORECASTS, AHPS PRODUCTS AND THE MONTHLY
WATER SUPPLY OUTLOOK, ALL ISSUED BY THIS OFFICE.