849
FGUS73 KBIS 281840
ESFBIS
NDC009-013-023-049-069-075-079-101-301845-
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE BISMARCK ND
140 PM CDT THU MAR 28 2024
THIS FLOOD AND WATER RESOURCES OUTLOOK IS FOR THE SOURIS RIVER BASIN
OF NORTH DAKOTA, COVERING THE PERIOD OF 1 APRIL THROUGH 30 JUNE,
2024. THIS IS A ROUTINE MONTHLY ISSUANCE OF FLOOD PROBABILITIES FOR
NWS FORECAST LOCATIONS. THESE PROBABILITIES ARE ISSUED ON, OR
AROUND, THE FOURTH THURSDAY OF EVERY MONTH.
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
NORMAL/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 SNOWPACK ACROSS THE SOURIS RIVER BASIN HAS BEEN IN THE PROCESS
OF MELTING ITS SNOWPACK ON AND OFF AGAIN OVER THE PAST SEVERAL
WEEKS. IN GENERAL THOUGH, THE NORTH DAKOTA PORTION OF THE BASIN IS
LARGELY SNOW FREE WITH THE EXCEPTION OF MODEST SNOW COVERAGE IN THE
TURTLE MOUNTAIN AREA, AND AGAIN IN THE WESTERN PART OF THE BASIN
ALONG THE MISSOURI COTEAU AND PART OF THE LONG CREEK WATERSHED. IN
GENERAL THOUGH, THERE IS NOT ENOUGH SNOW TO REALLY ENHANCE THE RISK
OF WIDESPREAD FLOODING. ACCORDINGLY, THE VAST MAJORITY OF THE RISK
OF FLOODING FOUND IN THE BELOW TABLES IS PROPORTIONAL TO THE RISK OF
HEAVY SPRING RAINS AND THE REGION'S ENTRY INTO ITS SEVERE
THUNDERSTORM SEASON.
OVERALL THOUGH, WIDESPREAD FLOODING AT THIS POINT DOES NOT APPEAR TO
BE A SIGNIFICANT CONCERN WITHOUT REMARKABLY LARGE AMOUNTS OF SPRING
RAIN.
..SNOWPACK CONDITIONS
SNOW CONTINUES TO COME AND GO WITH NO SIGNIFICANT ACCUMULATION OF
WATER ON TOP OF THE GROUND. WHERE SNOW DOES EXIST IN THE TURTLE
MOUNTAIN, MISSOURI COTEAU, AND LONG CREEK AREAS, SNOW-WATER
EQUIVALENT IN THE SNOWPACK LIKELY RANGES FROM A TRACE UP TO MAYBE
ONE-HALF OF AN INCH OF WATER.
..SOIL CONDITIONS
SOIL MOISTURE VALUES ACROSS THE SOURIS RIVER BASIN IN NORTH DAKOTA
ARE NOW CONSIDERED TO BE NEAR NORMAL ACROSS THE REGION WITH THE
EXCEPTION OF A SOMEWHAT BELOW NORMAL PORTION NORTH AND EAST OF MINOT.
FROST DEPTH REMAINS HIGHLY VARIABLE THIS YEAR AND IS NOW EVEN MORE
COMPLICATED AS RECENT WARM WEATHER HAD STARTED THAWING THE GROUND
SURFACE BEFORE COLD WEATHER ONCE AGAIN MOVED INTO THE REGION. THIS
LEAVES AT LEAST A PART OF THE AREA WITH A FROZEN GROUND SURFACE ON
TOP OF MAYBE A FEW INCHES OF THAWED SOIL BEFORE IT ONCE AGAIN COOLS
TO BELOW FREEZING AT DEPTH. WHAT THIS SUGGESTS IT THAT ALTHOUGH
OVERALL FROST DEPTH MAY BE GREATER THAN 30 INCHES IN SOME AREAS,
ONCE WARM WEATHER AGAIN ENTERS THIS PART OF NORTH DAKOTA, THE SOILS
MAY QUICKLY THAW AND ONCE AGAIN BECOME PERMEABLE TO INFILTRATION OF
RAIN AND MELTWATER.
..CURRENT DROUGHT CONDITIONS
THE U.S. DROUGHT MONITOR REFLECTS D0 (ABNORMALLY DRY) TO D1
(MODERATE DROUGHT) ACROSS MOST OF THE SOURIS RIVER BASIN IN NORTH
DAKOTA. ONLY A PORTION OF WESTERN WARD AND EASTERN MOUNTRAIL
COUNTIES ARE NOT UNDER A CURRENT DROUGHT DESIGNATION.
GIVEN THE TIME OF YEAR, NO SIGNIFICANT IMPACTS ARE NOTED WITH THE
CURRENT DROUGHT DESIGNATIONS. HOWEVER, CONCERNS WITH INCREASED
DROUGHT DESIGNATIONS GOING INTO SPRING ARE WARRANTED, ESPECIALLY
SINCE CLIMATE OUTLOOKS AND NEAR-TERM FORECASTS DO NOT TEND TO FAVOR
A CHANGE IN EXISTING TRENDS ANYTIME SOON.
..RESERVOIRS AND NATURAL WETLANDS
LAKE DARLING ABOVE MINOT ALONG WITH THE CANADIAN RESERVOIRS BEHIND
GRANT DEVINE AND RAFFERTY DAMS HAVE CAPTURED WHAT THEY COULD THUS
FAR IN TRYING TO REACH THEIR FULL SUPPLY LEVEL BEFORE THE END OF
SPRING. IN GENERAL THOUGH, THEY ALL STILL RETAIN SIGNIFICANT
CAPACITY TO TEMPER RUNOFF FROM ANY CURRENTLY UNFORESEEN HEAVY SPRING
RAINS.
..WEATHER OUTLOOK
THE CLIMATE PREDICTION CENTER 6-10 DAY OUTLOOK FAVORS NEAR NORMAL
TEMPERATURE AND PRECIPITATION. THIS EVOLVES INTO A NEAR NORMAL
TEMPERATURE WITH ABOVE NORMAL PRECIPITATION FOR THE 8-14 DAY
OUTLOOKS. LOOKING OUT EVEN FARTHER, THE WEEKS 3-4, ONE-MONTH, AND
THREE MONTH OUTLOOKS FOR APRIL, MAY AND JUNE GENERALLY FAVOR ABOVE
NORMAL TEMPERATURES WITH EQUAL CHANCES FOR ABOVE NORMAL, NEAR
NORMAL, OR BELOW NORMAL PRECIPITATION.
..ICE CONDITIONS
ICE IS QUICKLY WANING ACROSS MOST OF NORTH DAKOTA WITH MOST RIVERS
NOW BEING AT LEAST MOSTLY ICE FREE AFTER THOSE STREAMS EXPERIENCED
RUNOFF IN LATE WINTER. WETLANDS, PONDS, LAKES, AND LARGER RESERVOIRS
ARE STILL LARGELY COVERED IN ICE OF VARYING THICKNESS AND QUALITY.
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: 04/01/2024 - 06/30/2024
: 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 : 10 35 <5 16 <5 <5
MINOT 1562.0 1565.0 1570.0 : 6 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 : 7 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 : 11 16 <5 <5 <5 <5
:SOURIS
TOWNER 1454.0 1456.0 1458.0 : 39 61 13 26 <5 <5
BANTRY 1440.0 1441.0 1443.0 : 39 62 23 41 <5 8
:WILLOW CREEK
WILLOW CITY 1442.0 1446.0 1448.0 : 27 48 6 20 <5 <5
:SOURIS
WESTHOPE 1414.0 1418.0 1420.0 : 19 52 <5 22 <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: 04/01/2024 - 06/30/2024
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:DES LACS
FOXHOLM 1639.3 1639.4 1640.7 1641.8 1643.3 1644.6 1646.2
:SOURIS
SHERWOOD 1608.9 1609.2 1610.1 1611.9 1614.8 1618.8 1620.3
FOXHOLM 1571.0 1571.0 1571.0 1571.0 1571.0 1573.1 1576.0
MINOT 1554.1 1554.1 1554.1 1554.3 1555.2 1556.6 1562.8
MINOT 1542.8 1542.8 1542.9 1543.0 1543.5 1544.1 1547.1
LOGAN 1526.6 1526.6 1526.7 1527.1 1528.6 1533.1 1537.1
SAWYER 1512.1 1512.1 1512.2 1512.8 1514.5 1521.1 1523.0
VELVA 1496.1 1496.1 1496.2 1496.7 1499.0 1505.8 1507.5
:WINTERING
KARLSRUHE 1503.7 1503.7 1504.3 1506.0 1507.8 1509.0 1509.3
:SOURIS
TOWNER 1452.3 1452.3 1452.6 1453.4 1454.9 1456.1 1456.7
BANTRY 1437.8 1437.9 1438.2 1439.3 1440.8 1441.8 1442.3
:WILLOW CREEK
WILLOW CITY 1437.2 1437.2 1437.2 1438.2 1442.7 1444.7 1446.6
:SOURIS
WESTHOPE 1411.4 1411.4 1411.5 1412.1 1413.0 1415.7 1417.3
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: 04/01/2024 - 06/30/2024
LOCATION 95% 90% 75% 50% 25% 10% 5%
-------- ------ ------ ------ ------ ------ ------ ------
:DES LACS
FOXHOLM 1639.5 1639.3 1639.3 1639.2 1638.9 1638.8 1638.7
:SOURIS
SHERWOOD 1606.8 1606.5 1606.3 1606.1 1605.8 1605.8 1605.8
FOXHOLM 1566.5 1566.5 1566.5 1566.5 1566.5 1566.5 1566.5
MINOT 1551.3 1551.2 1551.0 1550.9 1550.8 1550.6 1550.6
MINOT 1541.5 1541.5 1541.4 1541.3 1541.2 1541.1 1541.1
LOGAN 1521.9 1521.1 1520.2 1520.1 1520.0 1519.8 1519.8
SAWYER 1508.5 1507.9 1507.6 1507.1 1506.7 1506.6 1506.6
VELVA 1492.3 1491.7 1491.2 1490.5 1490.2 1490.2 1490.2
:WINTERING
KARLSRUHE 1503.6 1503.6 1503.5 1503.0 1503.0 1503.0 1503.0
:SOURIS
TOWNER 1448.0 1446.7 1446.1 1445.3 1445.0 1444.7 1444.7
BANTRY 1433.5 1432.4 1431.9 1431.1 1430.9 1430.7 1430.7
:WILLOW CREEK
WILLOW CITY 1437.0 1436.9 1436.7 1436.1 1436.1 1436.1 1436.1
:SOURIS
WESTHOPE 1410.4 1410.3 1410.3 1409.9 1409.6 1409.5 1409.4
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.
SCHLAG
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