####018002799#### AGUS74 KWCO 161522 HMDNWC National Hydrologic Discussion - EXPERIMENTAL NWS National Water Center - Tuscaloosa AL 1015 AM CDT TUE APR 16 2024 .Synopsis... Flooding impacts possible in the Upper Midwest and Puerto Rico and USVI... River flooding continues in East Texas, the Lower Mississippi Valley, and Southeast and the Ohio Valley... .Discussion... .Upper Midwest... Localized flooding impacts are possible today from portions of northeastern NE and northern IA to southern MN and southwestern WI in response to expected locally heavy rainfall (1 - 3"). Ahead of this event, antecedent soil conditions are relatively dry (less than 55% 0 - 10 cm RSM, NASA SPoRT). While this does suggest ample soil infiltration capacity at least initially, the lack of available evapotranspiration (dormant vegetation), coupled with the potential for enhanced rainfall rates, may locally overwhelm infiltration capacity and lead to runoff into nearby streams and urban areas. The GFS-forced National Water Model (NWM) is indicating low end rapid onset flooding signals throughout the region (26 - 50%) with associated Annual Exceedance Probabilities (AEPs) mostly greater than 50%. However, localized AEPs of 20 - 2% in areas of northern IA and southern WI suggests small stream responses are possible. .Puerto Rico and USVI... Periods of heavy rainfall will continue the threat of flooding on small streams and in urban areas through day 2 (Wed). Isolated flash flooding is ongoing and landslides are possible, especially in areas of steep terrain. .Ohio Valley... Minor to isolated moderate river flooding continues across portions of IN and IL, though most points have crested. With that, additional rainfall today through day 2 (Wed) may elicit renewed rises and/or stalled recessions along portions of the White (IN) and Wabash (IN) rivers, though this will be heavily dependent on where convection trains or persists. .East Texas, Lower Mississippi Valley, and Southeast... Widespread minor to moderate river flooding will continue throughout these regions through at least the end of the week as runoff from recent heavy rainfall routes through the systems. With no significant rainfall expected over the next several days, crests and subsequent recessions will continue unimpeded for now, minimizing the risk of any additional river flooding impacts. Additional rainfall may return to the region this weekend (days 5 - 6), potentially bringing renewed rises and delaying recessions. However, confidence is low and the exact location of impacts is unknown due to the extended nature of the event. //Kirkpatrick $$