High Profile Vehicles are basically vehicles that sit up higher in the air than a car would.
For example a pickup truck, van, semi and trailer or SUV would all be high profile vehicles.
The wind makes it difficult for any vehicle to drive safely but it's harder for high profile vehicles to drive in the high winds because the wind gusts can get underneath the high profile vehicle much easier than say a car and then could easily push around the high profile vehicle or even flip it over onto the road.
So if you're driving a high profile vehicle you really need to take more caution when driving in the wind and sometimes may have to park the high profile vehicle and wait out the wind until it's gone.