Spring of 1944 seems to have been very rainy in general. Here are some fragments from "Report on the supply of the offensive operations of the 1st Guards Tank Army in March-April of 1944":
"The army was carried by Studebakers, which lived up to their expectations. Aside from Studebakers, we had to use tanks that towed cars behind them."
"The Rear Directorate of the 1st Guards Tank Army was faced with great difficulty due to the mud in the Winter of 1943/44. Studebakers could barely move with the speed of 5-6 kph, while all other wheeled vehicles were completely paralyzed."
Sometimes, it doesn't even have to be a particularly muddy spring to ruin your day, all you have to do is find a stream.