Final answer:
The weather played a crucial role in Washington's plan, as the miserably icy conditions caught the Hessian forces by surprise and made it difficult for them to defend their position.
Step-by-step explanation:
During the river crossing as part of Washington's plan, the weather played a crucial role. The weather was described as miserably icy, with terrible conditions that made it difficult for all the American troops to make the crossing. The bad weather actually worked to Washington's advantage, as it caught the Hessian forces by surprise and made it harder for them to defend their position. The icy river also added to the element of surprise, as the Hessians didn't expect an attack in such challenging weather conditions.