Flood Potential Outlook
Issued by NWS Bismarck, ND
Issued by NWS Bismarck, ND
Versions:
1
2
979 FGUS73 KBIS 301853 ESFBIS NDC009-013-023-049-069-075-079-101-011900- Probabilistic Hydrologic Outlook National Weather Service Bismarck ND 153 PM CDT Thu May 30 2024 This Flood and Water Resources Outlook is for the Souris River Basin of North Dakota, covering the period of 27 May through 25 August, 2024. This is a monthly issuance of the 90-day flood risks for the Souris River Basin of North Dakota. These probabilities are updated 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... Despite several decent sized storm events over the past few weeks, overall flood risk within the Souris River Basin of North Dakota remains near normal to below normal. ...Snowpack Conditions... Despite a recent late offering of snow in and around the Turtle Mountain area, there is no appreciable snow remain in North Dakota at this point in time. ...Soil Conditions... Soil moisture values across the Souris River Basin are mostly surplus to near normal according to the latest remote sensing represented in the SPoRT-LIS maps. ...Current Drought Conditions... Due to recent generous and widespread rainfall, all drought designations have been removed from the Souris River Basin of North Dakota. This is a welcome reflection of the improvement seen over the past few weeks, but keeping drought at bay will require timely rains over the coming month with growing season hitting its stride. ...Reservoirs and Natural Wetlands... The majority of natural wetlands and lakes also are at, or near normal water levels going into spring. Man-made structures, such as Lake Darling and the upstream Canadian reservoirs of Grant Devine and Rafferty are faring well given the recent moisture. ...Weather Outlook... Near term, in the next few days, an above normal expectation for temperature along with below normal precipitation is favored to retain the above normal temperature and transition to an equal chances designation for above normal, near normal, or below normal precipitation. Looking longer term, the one and three-month outlooks place the entire state in the equal chances designation for above normal, near normal, or below normal temperature and precipitation. This pretty much depicts the Upper Great Plains as an island of uncertainty whereas the rest of the continental 48 states is generally favored for above normal temperatures. ...Ice Conditions... No ice exists along the Souris River and its tributaries in North Dakota. 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: 05/27/2024 - 08/25/2024 : 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 <5 <5 <5 <5 <5 Foxholm 1573.0 1576.0 1578.0 : <5 18 <5 <5 <5 <5 Minot 1562.0 1565.0 1570.0 : <5 <5 <5 <5 <5 <5 Minot 1551.0 1553.0 1557.0 : <5 <5 <5 <5 <5 <5 Logan 1536.0 1538.0 1540.0 : <5 <5 <5 <5 <5 <5 Sawyer 1524.0 1526.0 1528.0 : <5 <5 <5 <5 <5 <5 Velva 1507.0 1512.0 1517.0 : <5 <5 <5 <5 <5 <5 :Wintering Karlsruhe 1509.0 1511.0 1512.0 : <5 <5 <5 <5 <5 <5 :Souris Towner 1454.0 1456.0 1458.0 : 14 28 <5 8 <5 <5 Bantry 1440.0 1441.0 1443.0 : 14 31 6 20 <5 <5 :Willow Creek Willow City 1442.0 1446.0 1448.0 : 10 8 <5 <5 <5 <5 :Souris Westhope 1414.0 1418.0 1420.0 : 9 27 <5 6 <5 <5 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: 05/27/2024 - 08/25/2024 Location 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Des Lacs Foxholm 1639.2 1639.2 1639.2 1640.4 1641.3 1643.1 1643.6 :Souris Sherwood 1606.4 1606.4 1607.0 1609.2 1611.9 1615.8 1619.2 Foxholm 1566.5 1566.5 1566.5 1567.4 1570.9 1571.3 1572.1 Minot 1550.9 1550.9 1550.9 1551.7 1554.2 1555.1 1555.7 Minot 1541.3 1541.3 1541.3 1541.6 1542.8 1543.3 1543.8 Logan 1520.1 1520.1 1520.4 1523.1 1526.7 1527.8 1529.6 Sawyer 1507.1 1507.1 1507.7 1509.8 1512.2 1513.4 1515.9 Velva 1490.6 1490.6 1491.6 1493.0 1496.3 1498.9 1500.6 :Wintering Karlsruhe 1504.7 1504.7 1504.7 1504.7 1505.0 1507.7 1508.6 :Souris Towner 1448.4 1448.4 1448.4 1449.0 1453.0 1454.4 1455.4 Bantry 1434.2 1434.2 1434.2 1434.4 1438.8 1440.4 1441.3 :Willow Creek Willow City 1438.3 1438.3 1438.3 1438.3 1438.3 1442.1 1445.3 :Souris Westhope 1411.8 1411.8 1411.8 1411.8 1412.5 1413.5 1415.1 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: 05/27/2024 - 08/25/2024 LOCATION 95% 90% 75% 50% 25% 10% 5% -------- ------ ------ ------ ------ ------ ------ ------ :Des Lacs Foxholm 1639.2 1639.1 1638.9 1638.9 1638.8 1638.8 1638.8 :Souris Sherwood 1606.4 1606.3 1606.1 1605.8 1605.8 1605.8 1605.8 Foxholm 1566.5 1566.5 1566.5 1566.5 1566.5 1566.5 1566.5 Minot 1550.9 1550.9 1550.8 1550.7 1550.6 1550.6 1550.6 Minot 1541.3 1541.3 1541.2 1541.1 1541.1 1541.1 1541.1 Logan 1520.1 1520.0 1520.0 1519.8 1519.8 1519.8 1519.8 Sawyer 1507.0 1506.9 1506.7 1506.6 1506.6 1506.6 1506.6 Velva 1490.4 1490.3 1490.2 1490.2 1490.2 1490.2 1490.2 :Wintering Karlsruhe 1503.6 1503.3 1503.0 1503.0 1503.0 1503.0 1503.0 :Souris Towner 1446.5 1446.2 1445.6 1445.2 1445.2 1445.2 1445.2 Bantry 1432.4 1432.1 1431.4 1431.1 1431.0 1431.0 1431.0 :Willow Creek Willow City 1436.9 1436.8 1436.1 1436.1 1436.1 1436.1 1436.1 :Souris Westhope 1411.2 1411.0 1410.3 1410.0 1409.9 1409.9 1409.9 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 June. $$ Schlag