Precipitation is the underestimated, unexotic hazard of a tropical storm. No one fears rain. It is familiar, unlike a wind that gusts to 110 miles an hour or a sea that foams and rages.
But floods can be killers, their effects felt far inland. That fact was demonstrated as Irene, a hurricane that on paper had dwindled to a tropical storm, inundated the valleys of Vermont, the farmland of upstate New York and many other places nowhere near the ocean.
"In most people's minds, a hurricane is principally a wind event, and if they have heavy rain — it's incidental, it's too bad," said Kerry Emanuel, an MIT professor of atmospheric science who has studied hurricanes.
The media generally think along the same lines, which is why hurricane coverage typically features a windblown weather reporter standing on a beach, shouting warnings of greater fury to come.
"Rainfall isn't sexy. Everyone went to the coast looking for the wind and the storm surge," said David Vallee, a National Weather Service hydrologist in Taunton, Mass.
Irene didn't meet expectations of wind and storm surge; some said the media had overhyped the storm. But losses from Irene will top $7 billion, according to an analysis cited by the Associated Press. Flooding affected a swath of the eastern United States from New Jersey to northern New England, where 26 rivers set all-time high-water marks.
Irene proved especially rainy on its western flank, as tropical moisture from the south met colder air along the jet stream. The elevated terrain of the Catskills, the Berkshires and the Green Mountains helped wring moisture from the air as the storm traveled.
Vermont was primed for disaster. It had an especially snowy winter, with up to 200 inches recorded in some locations. It suffered floods in March and May. It had typical summer weather, but the soil remained wet, said Andy Nash, a National Weather Service meteorologist in Burlington, Vt.
Nash and his colleagues managed, with help from Vermont news media, to warn people that they were facing floods that would compare with the worst on record, back in 1927 and 1938. Vermont had recorded three flood-related deaths and a missing person as of Wednesday. Nash said that without the warnings, the death toll could have been higher.
Still, he said, a lot of people couldn't imagine the scale of something like Irene, in which the entire state became inundated with 6 to 8 inches of rain.
"Until you've lived through it, I don't think you have an appreciation for it," Nash said.
In New Jersey, the Raritan River swelled 13.9 feet above flood stage. In Vermont, the Winooski River surpassed flood stage by 10.2 feet. Similar figures could be found on the Mad River in Vermont, the Housatonic in Connecticut and the Pompton in New Jersey.
As of Wednesday, the Associated Press has tallied 45 deaths from Irene, at least a dozen from drowning. Many happened with stunning quickness as people encountered swollen creeks.
"If you kill hundreds of people, it's almost always storm surge," said Hugh Willoughby, a Florida International University meteorologist, adding that most don't kill hundreds or even dozens.