On October 22, 2012, the MODIS instrument captured this exceptionally clear view of the Mid-Atlantic. Cooling temperatures had splashed fall colors across the Appalachian Mountains.

Meanwhile, our colleague Rob Gutro—the force behind NASA's Hurricane Resources Page—noted that Tropical Depression 18 had strengthened into Tropical Storm Sandy.

On the same day, Jeff Schmaltz from the MODIS Rapid Response system put out this image of Tropical Storm Sandy churning in the Caribbean.

Our first Natural Hazards image of Sandy shows the storm off the coast of Columbia on October 23, 2012.  At that point, weather forecasters had already begun to express serious concerns that this storm could hit the Mid-Atlantic and Northeast.

On the 23rd, Rob Gutro pointed to data from NASA's TRMM satellite highlighting the fact that "hot towers" contributed to Sandy's intensification.  There's more info about hot towers in this blog post we published in September. 

Sandy proved a force to be reckoned with as it passed through the Caribbean. Sandy caused significant damage in the Bahamas, Cuba, Jamaica, Puerto Rico, the Dominican Republic, and Haiti; at least 65 lives were lost to the storm as it passed.

Over the next few days, it began to look ever more likely that Sandy would hit the Mid-Atlantic due to unusual meteorological conditions that caused the storm to veer to the west toward land rather than staying over the ocean.  We published this time-lapse animation of the storm off the coast of Florida as light from the setting sun highlighted the structure of the clouds on October 26, 2012. The “super rapid scan” images—one every minute from 7:15 a.m. until 6:30 p.m. EDT—revealed intricate details of the storm’s motion. Web users flooded to our YouTube page and within hours the video has received more than 100,000 views.

Many began calling Sandy "Frankenstorm" — partly because the storm was going to hit close to Halloween, but also because this was an unusual storm that had features of both a tropical cyclone and an extratropical cyclone.  On Climate Central, guest blogger Adam Sobel wrote an excellent post that explained how the process of morphing from one storm type to the other—extratropical transition—works. A Harvard website had some informative background information that explained the difference between the two types of storms. And Discovery News had a piece that explained why the storm was so large.

Meanwhile, our team was updating our Natural Hazards section as fast as we could. The new Suomi NPP satellite, which was launched one year ago, captured stunning views of the massive, swirling storm both during the day and the night. The main reason this storm was so large was the progression of the extratropical transition mentioned above. Rather than having a tight, circular cloud structure with an eye, extratropical cyclones tend to be sprawling and look like giant commas when viewed from space.

As the storm got closer to making landfall, an interesting discussion about climate change and storms started to appear on the web.