The Blob that Ate New York

An animation of infrared images from the GOES-13 satellite shows a massive system of convective clouds approaching and then enveloping the New York area on the morning of May 8. (Source: Cooperative Institute for Meteorological Satellite Studies.) Lately, I get the impression that New York City's weather is more akin to the tropics than the Northeastern United States. And Wednesday's torrential rain, accompanied by flooding, didn't disabuse me of that idea. Much of the United States has felt the effects of a storm that lumbered slowly eastward the past week, and on Wednesday morning it reached New York. Feeding on water vapor streaming from the tropical Atlantic, the storm caused lots of flooding in the city. In an echo of Hurricane Sandy, water poured into the subway system in places. The animation above, from the Cooperative Institute for Meteorological Satellite Studies (where would ImaGeo be without these awesome folks?), consists of infrared images from the GOES-13 satellite. It shows what happened when the storm moving in from the west entrained the moisture from the Atlantic. Massive convective clouds formed and moved ashore, temporarily turning New York into something resembling the Amazon rain forest. Technically speaking, images in the infrared show the temperature of cloud tops, as well as of the land and surface of the ocean. As clouds blossom in the atmosphere, the rising mass of moisture cools. In infrared images and animations like the one above, these colder temperatures are shown in the redder tones. The angrier and darker the red, the colder the temperature, and therefore the taller — and more massive — the cloud.