During the 150 days of the flood, Pangaea split. This involved violent volcanic and seismic activity, and huge amounts of lava being dumped into the oceans, which warmed the earth's oceans. Warm oceans produce increased levels of precipitation, which creates a thick cloud cover and results in cool land masses. The temperature difference between the ocean and land masses would have made for intense weather patterns, super-storms that raged for weeks across half a continent. The nearly non-stop precipitation (plus high amounts of volcanic ash in the atmosphere), would bring about the Ice Age, slowly at first, and then snowballing towards the end.
Then the frozen land masses of the Ice Age would in turn cool the oceans. At that point the oceans were likely cooler than they are today, with ice caps creeping far southward, and the level of precipitation for most of the globe would drop to drought level. In addition to the drought, it would be a time of intense wind and dust storms, and large amounts of "dirty snow" would be heaped up in moving drifts by the wind. (Which accounts for the mammoth buried with buttercups in his stomach, and the loess deposits covering huge areas of the northern latitudes.) This period is called the “glacial maximum.” After a pause, the glaciers, now exposed to the sun without proper cloud cover, would melt in a catastrophically short period, perhaps less than a hundred years.