Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 348 PM EDT Wed Apr 24 2024 Day 2 Valid 12Z Thu Apr 25 2024 - 12Z Fri Apr 26 2024 ...A SLIGHT RISK OF EXCESSIVE RAINFALL EXISTS ACROSS PORTIONS OF THE SOUTHERN AND CENTRAL PLAINS... A mid-level trough over the southwestern U.S. is forecast to eject out across the central and southern High Plains by Friday morning, spurring development of a surface cyclone across the High Plains. Winds at 850 mb will be south to south-southwest across the Great Plains but with increased magnitude -- up to 50-60 kt -- and moisture transport will allow precipitable water values to exceed 1.5" across portions of the Plains and Midwest. A broad area of instability east of a forming central High Plains surface low and attendant cold front/dryline, with values of 1000 to 3000 J/kg from northern TX/southern OK into KS and NE. Initially, some convection may be ongoing at the start of the period over OK/AR along a warm front lifting northward, but additional storm development is anticipated to occur during Thursday afternoon ahead of the cold front/dryline in KS/OK with thunderstorm development expanding through the evening and early overnight across TX and northern locations including NE and IA. Strong to severe thunderstorms are likely, ramping up the precipitation potential, despite decently fast cell motions. Deep layer south- southwest flow supports training of cells with rains up to 2.5" in an hour and local amounts up to 6". Models continue to show good agreement for the slight risk across portions of KS/OK/AR/MO which portions of could overlap with some heavy rainfall potential tonight into Thursday morning. The surrounding marginal risk was extended slightly from the overnight issuance southward along the cold front into central TX, eastward along the warm front into the Tennessee Valley, and westward more into Nebraska/South Dakota to the north and west of the surface low. Santorelli/Roth