Computer model simulation of surface winds and atmospheric moisture, showing the long plume of water vapor extending from the equator to Canada.
It's raining, but on the wrong coast. In California, an intense drought has reached a new milestone, with 100% of the state in severe to exceptional drought. No significant rain is expected there until the fall, and the fire season — which typically doesn't kick into high gear until early fall — has already proven destructive.
But on the East Coast, the problem is too much rain. A storm with a direct connection to the tropics has dumped up to nearly 9 inches of rain in the Southeast and Mid-Atlantic states, and what appears to be a wall of heavy rain is headed right for New York City. Flash floods have occurred in several states, including New York, Virginia and North Carolina.
According to the National Weather Service, up to three inches of rain could fall in New York City during a short period on Friday night, prompting a flash flood watch for the area. The moisture feed for this storm extends all the way to the equator, like a temporary highway for water vapor.
This heavy rain episode comes soon after Pensacola, Florida, broke its all-time 24-hour rainfall record, with nearly two feet of rain. It also comes soon after a major scientific report was released, which found that rain is coming in increasingly heavy doses throughout the U.S. The biggest increase in extreme precipitation events — 71% — was seen in the Northeast, the report found.
Scientists have long postulated that a warmer atmosphere would lead to heavier rain and snowstorms, since warm air holds more water vapor, and warmer seas lead to more evaporation. These trends help put the atmosphere on steroids, favoring extreme precipitation events.