By nightfall, after several inches of rain fell on a deep spring snowpack, there were record-shattering floods.

Torrents of water poured off the mountains. Swollen rivers carrying boulders and trees smashed through Montana towns over the next several days. The flooding swept away houses, wiped out bridges and forced the evacuation of more than 10,000 tourists, park employees and residents near the park.

As a cleanup expected to last months grinds on, climate experts and meteorologists say the gap between the destruction and what was forecast underscores a troublesome aspect of climate change: Models used to predict storm impacts do not always keep up with increasingly devastating rainstorms, hurricanes, heat waves and other events.

"Those rivers had never reached those levels. We literally were flying blind not even knowing what the impacts would be," said Arin Peters, a senior hydrologist with the National Weather Service.

Hydrologic models used to predict flooding are based on long-term, historical records. But they do not reflect changes to the climate that emerged over the past decade, said meteorologist and Weather Underground founder Jeff Masters.

"Those models are going to be inadequate to deal with a new climate," Masters said.

Another extreme weather event where the models came up short was Hurricane Ida, which slammed Louisiana last summer and then stalled over the Eastern Seaboard—deluging parts of Pennsylvania, New Jersey and New York with unprecedented rainfall that caused massive flooding.