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AGUS74 KWCO 191512

HMDNWC



National Hydrologic Discussion - EXPERIMENTAL

NWS National Water Center - Tuscaloosa AL

1015 AM CDT FRI APR 19 2024



.Synopsis...

Potential for renewed river flooding and isolated flooding impacts in  

Eastern Texas and the Lower Mississippi Valley... Continued threat of  

flooding in Puerto Rico... Localized flooding impacts possible in portions  

of Alaska...



.Discussion...



.Eastern Texas and the Lower Mississippi Valley...

Heavy rainfall (2 - 4") across eastern portions of TX and along the AR/LA  

border on day 2 (Sat) will bring a threat for new and renewed river  

flooding as well as isolated flash, urban, and small stream flooding  

impacts. Top layer soils across eastern TX have dried somewhat (50-65% 0-10  

cm RSM, NASA SPoRT), but heavy rainfall yesterday across portions of the  

AR/LA border has wetted those top layer soils (70-90% RSM). Mid-layer soils  

look similar to the top layer soils as far as saturation levels. Some  

rivers in the area, like the Neches (TX) and the Sabine (TX/LA), remain in  

minor to moderate flood stage, and streamflows across the area are much  

above normal (USGS).



Considering the antecedent soil conditions, all flooding modes will be  

possible. Renewed minor river flooding is possible in upper portions of the  

Trinity (TX), Neches, and Sabine river basins, but the rainfall should not  

significantly affect the ongoing river flooding on the lower portions of  

the Neches and Sabine rivers in southeast TX. Flash and urban flooding will  

also be a concern across these regions, especially if training convection  

occurs, and small stream flooding will become more likely as the event  

progresses late into day 2 (Sat) and possibly early into day 3 (Sun).  

Significant rainfall is not expected in these areas beyond early on day 3  

(Sun), which should allow for recessions on rivers to begin or continue  

early next week.



.Puerto Rico...

Flooding in urban areas, on roads, along small streams and rivers, and  

along washes will remain possible at least through day 2 (Sat) as periods  

of heavy rainfall continue over Puerto Rico. Isolated instances of flash  

flooding and mudslides also remain possible in steep terrain.



.Alaska...

Significant rises on small streams and rivers are possible on Kodiak Island  

through day 2 (Sat) as 2 - 3" of rainfall affects the area. Saturated soils  

on the island from rainfall earlier this week indicate that landslides are  

also possible, especially in areas of steep terrain.



//Watson



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