Above normal streamflows are expected in the month of March.
March begins with above normal streamflows in the western Ohio valley and near normal streamflows elsewhere. Within the first week or two of March, the weather pattern will become more active with generous amounts of precipitation expected. This should result in better chances of above normal streamflows, especially in areas that received so much rainfall in February (such as Kentucky, Tennessee and West Virginia).
Hydrologic Flood and Drought Potential
Flooding in the lower Green River will continue as March begins and should persist through at least the first week of the month. Elsewhere, the potential for new flooding is low during the first week of March.
One weather system will affect the entire Ohio Valley by the end of the first week of March. Then by mid-month, outlooks call for the weather to become more active. This will raise the likelihood of flooding through the end of March in areas with lingering high moisture from February's rains and flooding--areas such as Kentucky, Tennessee, and southern West Virginia.
Drought improvement is expected to continue in March.
Drought conditions have generally ended across the Ohio Valley. The main exception is an axis from central Illinois, across northern Indiana and into northwestern Ohio. These areas have received below normal amounts of precipitation through the winter. A more active weather pattern by mid-March is expected to improve these dry conditions in the northwest Ohio Valley.
Past 30 Day Hydrological and Meteorological Review
Rainfall Departures
In contrast to the cool, dry conditions in January, February brought periods of warmer southwesterly flow to the region. This brought several significant precipitation events to the basin. Rainfall was especially above normal (ranging from 10-15 inches) in middle Tennessee, most of Kentucky, and southern West Virginia. The only area featuring below normal precipitation was in east central Illinois, northern Indiana, and northwestern Ohio.
30 day observed precipitation for the OHRFC basin.
Soil moisture near the end of February was above normal for most areas south of the Ohio River. To the north, conditions transitioned from normal to below normal. The driest soils were found in central Illinois, northern Indiana and much of Ohio.
Streamflows near the end of February were in the normal range across most of the Ohio Valley. Elevated streamflows were persisting in northern Ohio and northern Pennsylvania due to recent melting snowpack and ice running off into area rivers.
Atmospheric Teleconnection and Oscillation Forecasts
By the beginning of March the Ohio Valley was generally draining out from the wet conditions and flooding of mid-February. The lower Ohio river had crested and was in recession. Water remained high in the lower Green Watershed of western Kentucky due to high reservoirs draining to return their winter pools down to normal levels. Some of the snow and ice in the northern Ohio Valley finally started melting out as temperatures warmed during the last week of February.
During the first week of March precipitation is expected to be modest, but by the end of the first week a first significant weather system of the month will pass through the region. This will keep rivers at elevated levels and soils moist. By mid-March a more persistent active weather pattern is expected to result in some flooding. Areas most vulnerable will be to the south of the Ohio River where conditions were so wet in February. This will also be dependent on which locations of heaviest rains.
