How do I time urea top dressing using the rain forecast to avoid losing it?

Apply urea when the soil is moist but heavy rain is not expected right after, because a light shower or moist soil helps the urea dissolve and reach the roots, while a downpour soon after washes it away or runs it off. The best window is when the forecast shows light rain coming or the soil is already moist, with no heavy rain in the next day or two. If you apply on bone dry soil with no rain or irrigation to follow, much of the nitrogen is lost to the air as gas before the crop can use it. If you apply just before a heavy downpour, it washes off the field. So check the 3 day forecast. If light rain is expected, apply just before it and let it carry the urea in. If no rain is coming, apply and give a light irrigation to wash it into the soil. Avoid top dressing right before a forecast heavy storm. Split the nitrogen into doses at the right crop stages and time each split with the forecast, which both saves fertiliser and feeds the crop better.