Hurricane Willa

Hurricane Willa

A potent storm is poised to hit Mexico. In this nighttime image acquired at 3:50 a.m. local time (08:50 Universal Time) on October 22, 2018, Hurricane Willa appears off of the country’s Pacific Coast. The image was acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite.

At the time, Willa was a category 4 storm with sustained peak winds of 250 kilometers (155 miles) per hour. The storm was located about 475 kilometers southwest of Guadalajara and 375 kilometers south of the Islas Marías; it was moving slowly to the north. Forecasters expect the storm to reach mainland Mexico late on October 23 or early on October 24.

The VIIRS “day-night band” detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe signals such as city lights, auroras, wildfires, and reflected moonlight. In this case, the clouds were lit by the nearly full Moon. The image is a composite, showing real-time VIIRS storm imagery overlaid on a “black marble” nighttime map.

NASA Earth Observatory image by Joshua Stevens, using VIIRS day-night band data from the Suomi National Polar-orbiting Partnership. Text by Kathryn Hansen.

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