563
FGUS73 KBIS 261708
ESFBIS
NDC009-013-023-049-069-075-079-101-270115-
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE BISMARCK ND
1208 PM CDT THU MAR 26 2026
..FLOOD AND WATER RESOURCES OUTLOOK
THIS FLOOD AND WATER RESOURCES OUTLOOK IS FOR THE SOURIS RIVER BASIN
OF NORTH DAKOTA, COVERING THE PERIOD OF MARCH 30TH THROUGH JUNE
28TH, 2026.
THE FOLLOWING MESSAGE HAS FOUR SECTIONS. THE FIRST PROVIDES SOME
TEXT ON THE HIGHLIGHTS OF THIS OUTLOOK AND CONDITIONS AFFECTING THE
LOCAL HYDROLOGY. THE SECOND SECTION GIVES THE CURRENT AND HISTORICAL
RISKS OF FLOODING AS DETERMINED BY THE ENSEMBLE STREAMFLOW FORECAST
MODEL OF THE NATIONAL WEATHER SERVICE. THE THIRD SECTION GIVES THE
CURRENT PROBABILITIES FOR REACHING FLOOD STAGE AT THE LISTED
FORECAST LOCATIONS. AND FINALLY, THE FOURTH SECTION COVERS THE RISK
OF THE RIVER SITES FALLING BELOW THE LISTED STAGES.
..FLOOD OUTLOOK HIGHLIGHTS
THE OVERALL FLOOD RISK FOR FORECAST LOCATIONS FROM THE SOURIS RIVER
RIVER AT SHERWOOD ALL THE WAY DOWN THROUGH THE SOURIS RIVER AT MINOT
AND VELVA IS NEAR TO BELOW NORMAL FOR THIS TIME OF THE YEAR. THAT
REFLECTS A LACK OF SNOWCOVER IN THE UPPER AND MIDDLE REACHES OF THE
BASIN, AND A FAVORABLE MELT CYCLE TO WHAT SNOWPACK PREVIOUSLY
EXISTED. THERE IS A HIGHER THAN NORMAL RISK OF MINOR FLOODING AT
BANTRY ON THE SOURIS RIVER AND ON WILLOW CREEK AT WILLOW CITY, WHERE
ENOUGH COLLECTIVE RUNOFF HAS ALREADY BEEN GENERATED TO RESULT IN
INCREASED FLOWS INTO EARLY APRIL. THERE ALSO REMAINS 1 TO 2 INCHES
OF ADDITIONAL SNOW-WATER EQUIVALENT (SWE) YET TO MELT IN PARTS OF
THE TURTLE MOUNTAIN REGION. COLLECTIVELY, THE RUNOFF CURRENTLY
WORKING ITS WAY THROUGH THE SYSTEM AND ADDITIONAL SNOWMELT IN THE
TURTLE MOUNTAIN REGION IS ENOUGH TO CAUSE THE HIGHER THAN NORMAL
PROBABILITIES OF MINOR FLOODING AT THE BANTRY AND WILLOW CITY
FORECAST POINTS, AND NEAR NORMAL ODDS OF MINOR FLOODING FROM TOWNER
ON THE SOURIS RIVER DOWNSTREAM THROUGH THE SOURIS RIVER AT WESTHOPE.
HOWEVER, THE GENTLE MELT CYCLE AND LACK OF MORE SIGNIFICANT SWE
MEANS THAT THE ODDS OF ANYTHING MORE THAN MINOR FLOODING ARE IN THE
NORMAL RANGE FOR THIS TIME OF THE YEAR, EVEN AT THOSE LOCATIONS.
IN GENERAL, MELTING OF THE SNOWPACK HAS RESULTED IN RUNOFF AT ALL
POINTS IN THE SOURIS RIVER BASIN OF NORTH DAKOTA IN THE LAST FEW
WEEKS. IN MOST CASES, THE COMBINATION OF A FAVORABLY-SLOW MELT AND
RELATIVELY LOW SWE VALUES HAS GENERALLY PREVENTED PROBLEMATIC HIGH
WATER. DESPITE THE LACK OF SNOWCOVER, SOILS ARE WET ACROSS MUCH OF
THE SOURIS RIVER BASIN, AND SOILS ARE ONLY SLOWLY THAWING. AS A
RESULT, IF A HEAVY SNOW OR HEAVY RAIN EVENT WAS TO OCCUR, IT COULD
GENERATE ENOUGH RUNOFF TO CAUSE INCREASED FLOWS ON CREEKS AND
STREAMS. HOWEVER, THE OUTLOOK PROBABILITIES ALREADY ACCOUNT FOR BOTH
CURRENT SOIL CONDITIONS AND THE HISTORICAL FREQUENCY OF SPRINGTIME
RAIN AND SNOW EVENTS.
..SNOWPACK CONDITIONS
THE SNOWPACK HAS MELTED OVER MOST OF THE SOUTHERN AND WESTERN PARTS
PARTS OF THE SOURIS RIVER BASIN, WITH NO SNOWCOVER PRESENT AS OF
LATE MARCH FROM SHERWOOD DOWN THROUGH THE MINOT, VELVA, AND TOWNER
AREAS. THERE REMAINS A MODEST SNOWPACK IN THE UPPER REACHES OF THE
SOURIS RIVER BASIN IN SOUTHERN SASKATCHEWAN, WHERE SNOW-WATER
EQUIVALENT (SWE) VALUES OF A TRACE TO TO 1 INCH ARE PRESENT IN SOME
AREAS. THAT IS WELL WITHIN THE NORMAL TO BELOW-NORMAL RANGE OF SWE
VALUES FOR THE UPPER REACHES OF THE BASIN AT THIS TIME OF THE YEAR.
THE ONE PORTION OF THE SOURIS RIVER BASIN THAT CONTINUES TO HAVE A
MORE NOTABLE, ALBEIT MELTING SNOWPACK IS IN THE TURTLE MOUNTAIN
REGION. RECENT WARM WEATHER HAS MELTED SOME OF THAT SNOWPACK IN THE
LAST WEEK, WHICH IS CURRENTLY RESULTING IN NOTEWORTHY RUNOFF INTO
THE LOWER PORTIONS OF THE SOURIS RIVER BASIN. SWE VALUES IN THE
TURTLE MOUNTAIN AREA REMAIN IN THE 1 TO 2 INCH RANGE, SUGGESTING
THERE IS STILL SOME WATER AVAILABLE TO MELT AND PRODUCE ADDITIONAL
RUNOFF. HOWEVER, THE MELT CYCLE HAS BEEN RELATIVELY GENTLE, AND THE
AMOUNT OF REMAINING SWE IN THE TURTLE MOUNTAIN AREA IS GENERALLY
LOWER THAN PAST YEARS THAT HAD SIGNIFICANT FLOODING. HOWEVER, GIVEN
THE WET AND STILL THAWING SOILS, UNDER THE RIGHT CONDITIONS, THIS
COULD STILL PRODUCE SURPRISING AMOUNTS OF RUNOFF, SUCH AS IF HEAVY
RAIN WERE TO OCCUR.
..CURRENT DROUGHT CONDITIONS
THERE ARE NO DROUGHT DESIGNATIONS WITHIN THE SOURIS RIVER BASIN OF
NORTH DAKOTA.
..RESERVOIRS AND NATURAL WETLANDS
RESERVOIRS AND NATURAL WETLANDS ARE GENERALLY WELL WITHIN THE NORMAL
RANGE OF THEIR LONG-TERM TRENDS FOR THIS TIME OF YEAR. ALL FLOOD
CONTROL PROJECTS ARE AT, OR BELOW, THEIR DESIRED EARLY SPRING LEVELS.
..SOIL CONDITIONS
EARLIER WIDESPREAD MELTING OF THE SNOWPACK OVER MUCH OF THE SOURIS
RIVER BASIN HAS RESULTED IN VERY HIGH NEAR SURFACE SOIL MOISTURE
VALUES. THE TURTLE MOUNTAIN AREA RETAINED MORE OF ITS SNOWPACK AND
AS A RESULT THE SOIL MOISTURE VALUES IN THAT PART OF THE BASIN ARE
CLOSER TO NORMAL.
SOILS HAVE BEGUN TO WARM, BUT SOIL TEMPERATURES VARY CONSIDERABLY
ACROSS THE BASIN. THE TOP FEW INCHES OF THE SOIL HAVE WARMED TO
NEAR FREEZING IN MOST PARTS OF THE BASIN AS THE THAWING PROCESS
HAS PROGRESSED THE LAST WEEK OR TWO. HOWEVER, DEEPER LAYERS OF
THE SOILS CONTINUE TO BE BELOW FREEZING ACROSS MUCH OF THE BASIN.
IN FACT, IN THE TURTLE MOUNTAIN AREA, THE FROST DEPTH REMAINS AS
DEEP AS AROUND 30 INCHES IN SOME AREAS WHERE SNOWCOVER HAS LASTED
THE LONGEST.
..WEATHER OUTLOOK
THE SHORT TERM WEATHER FORECAST CALLS FOR WARM AND MAINLY DRY WEATHER
TO CLOSE OUT THE MONTH OF MARCH, BUT THE 6-10 AND 8-14 DAY OUTLOOKS
FAVOR ABOVE NORMAL PRECIPITATION PROBABILITIES FOR NORTH DAKOTA IN
EARLY APRIL. THE OVERALL WEATHER PATTERN WILL BEGIN TO FAVOR COOLER
TEMPERATURES, AS WELL, ESPECIALLY IN NORTHERN PARTS OF THE STATE IN
THE 6-10 AND 8-14 DAY PERIOD. LOOKING FURTHER OUT, WHEN CONSIDERING
THE OUTLOOK FOR THE FULL MONTH OF APRIL, THERE ARE EQUAL CHANCES OF
ABOVE-NORMAL, NEAR-NORMAL, OR BELOW-NORMAL TEMPERATURES AND
PRECIPITATION. THIS ULTIMATELY SUGGESTS THAT A RELATIVELY NORMAL
SPRING WEATHER PATTERN FEATURING LARGE VARIABILITY IS HIGHLY
PROBABLE THE NEXT FEW WEEKS. THAT INCLUDES THE AFOREMENTIONED
POTENTIAL FOR A WETTER AND COOLER START TO APRIL.
LOOKING EVEN LONGER TERM, THE 3-MONTH OUTLOOK COVERING APRIL, MAY,
AND JUNE HAS ALMOST ALL OF THE MISSOURI AND JAMES RIVER BASINS IN
EQUAL CHANCES FOR ABOVE-NORMAL, NEAR-NORMAL, OR BELOW-NORMAL
TEMPERATURES AND PRECIPITATION. THE EXCEPTION IS THE SOUTHWESTERN
CORNER OF NORTH DAKOTA, WHICH FAVORS ABOVE-NORMAL TEMPERATURES IN
THAT 3-MONTH PERIOD. THIS IS CONSISTENT WITH HISTORICAL TRENDS FOR
THE AREA AS A LA NINA PATTERN FADES THROUGH THE SPRING.
IN TABLE 1 BELOW, THE CURRENT (CS) AND HISTORICAL (HS) OR NORMAL
PROBABILITIES OF EXCEEDING MINOR...MODERATE...AND MAJOR FLOOD STAGE
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 GREATER 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:
VALID PERIOD: 03/30/2026 - 06/28/2026
: 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
-------- ----- ----- ----- : --- --- --- --- --- ---
:DES LACS
FOXHOLM 1651.0 1653.0 1654.0 : <5 <5 <5 <5 <5 <5
:SOURIS
SHERWOOD 1623.0 1625.0 1630.0 : <5 12 <5 5 <5 <5
FOXHOLM 1573.0 1576.0 1578.0 : 8 33 <5 16 <5 <5
MINOT 1562.0 1565.0 1570.0 : <5 16 <5 6 <5 <5
MINOT 1551.0 1553.0 1557.0 : <5 <5 <5 <5 <5 <5
LOGAN 1536.0 1538.0 1540.0 : 6 19 <5 <5 <5 <5
SAWYER 1524.0 1526.0 1528.0 : <5 7 <5 <5 <5 <5
VELVA 1507.0 1512.0 1517.0 : 5 17 <5 <5 <5 <5
:WINTERING
KARLSRUHE 1509.0 1511.0 1512.0 : 7 16 <5 <5 <5 <5
:SOURIS
TOWNER 1454.0 1456.0 1458.0 : 37 62 17 26 <5 <5
BANTRY 1440.0 1441.0 1443.0 : >95 64 28 43 <5 9
:WILLOW CREEK
WILLOW CITY 1442.0 1446.0 1448.0 : >95 48 23 22 <5 6
:SOURIS
WESTHOPE 1414.0 1418.0 1420.0 : 34 56 7 26 <5 17
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:
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:DES LACS
FOXHOLM 1641.6 1641.6 1641.6 1641.6 1643.1 1644.5 1645.6
:SOURIS
SHERWOOD 1610.3 1610.3 1610.4 1610.7 1614.6 1619.7 1620.4
FOXHOLM 1570.6 1570.6 1570.6 1570.6 1570.9 1572.9 1576.0
MINOT 1554.5 1554.5 1554.5 1554.5 1555.0 1556.7 1561.4
MINOT 1543.1 1543.1 1543.1 1543.1 1543.3 1544.1 1546.2
LOGAN 1527.3 1527.3 1527.3 1527.3 1528.2 1533.8 1536.7
SAWYER 1512.9 1512.9 1512.9 1512.9 1515.2 1521.2 1522.7
VELVA 1497.1 1497.1 1497.1 1497.1 1500.5 1506.4 1507.1
:WINTERING
KARLSRUHE 1505.5 1505.5 1505.5 1505.5 1507.4 1508.4 1509.3
:SOURIS
TOWNER 1454.0 1454.0 1454.0 1454.0 1455.1 1456.6 1456.8
BANTRY 1440.3 1440.3 1440.3 1440.3 1441.1 1442.2 1442.4
:WILLOW CREEK
WILLOW CITY 1443.7 1443.8 1444.3 1444.9 1445.9 1446.7 1447.6
:SOURIS
WESTHOPE 1413.4 1413.4 1413.4 1413.6 1415.0 1416.9 1418.4
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:
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:DES LACS
FOXHOLM 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:SOURIS
SHERWOOD 0.0 0.0 0.0 0.0 0.0 0.0 0.0
FOXHOLM 0.0 0.0 0.0 0.0 0.0 0.0 0.0
MINOT 0.1 0.0 0.0 0.0 0.0 0.0 0.0
MINOT 0.1 0.1 0.0 0.0 0.0 0.0 0.0
LOGAN 0.2 0.1 0.0 0.0 0.0 0.0 0.0
SAWYER 0.2 0.1 0.0 0.0 0.0 0.0 0.0
VELVA 0.2 0.1 0.0 0.0 0.0 0.0 0.0
:WINTERING
KARLSRUHE 0.0 0.0 0.0 0.0 0.0 0.0 0.0
:SOURIS
TOWNER 0.5 0.3 0.2 0.1 0.1 0.1 0.1
BANTRY 0.6 0.3 0.2 0.1 0.1 0.1 0.1
:WILLOW CREEK
WILLOW CITY 0.1 0.0 0.0 0.0 0.0 0.0 0.0
:SOURIS
WESTHOPE 0.8 0.5 0.3 0.2 0.1 0.1 0.1
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/BIS FOR MORE WEATHER AND WATER
INFORMATION.
THE NEXT OUTLOOK WILL BE ISSUED BY THE END OF APRIL.
CJS
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