Hurricanes and Space, a Give-and-Take Affair

As tropical storm Emily takes aim at Puerto Rico and the Dominican Republic, news outlets are aflutter over the possibility that the tempest will soon bring foul weather to Florida, hampering Friday’s launch of the Juno mission to Jupiter.

—The Juno spacecraft sits partially enclosed by the payload portion of an Atlas rocket at a processing facility near Kennedy Space Center on July 18. Picture courtesy NASA/Kim Shiflett

As of 2 p.m. today, the storm began picking up steam and moving westward through the Caribbean, packing winds of about 45 miles (72 kilometers) an hour.

For now Emily isn’t expected to grow into a hurricane, but even as a tropical storm it could bring higher than normal winds, rain, and waves to the Panhandle around Juno’s slated launch time of 11:34 a.m. ET on August 5.

For now, though, NASA is predicting a 70 percent chance of acceptable weather conditions for Juno’s liftoff, noting that the current storm track has Emily reaching Cape Canaveral by Friday night at the earliest.

And hey, even if the storm somehow botches the first attempt, NASA has 21 more days in their launch window to get Juno flying.

Of course, much of our prowess in monitoring hurricanes and predicting their behavior is built on previous successes getting craft into space.

One suite of orbiters in particular—NOAA’s Geostationary Operations Environmental Satellites, or GOES—has been especially helpful in providing data for storm forecasts.

As an example, I give you the latest release from GOES-11, aka GOES West. This “full disk” image of Earth shows Hurricane Eugene off the western coast of Mexico at 11 a.m. ET today.

The GOES program provides continuous monitoring of Earth from what’s known as geosynchronous orbit.

Each craft is about 22,300 miles (35,800 kilometers) above the planet’s surface over the equatorial plane. They move fast enough to match the speed of Earth’s rotation about its axis, allowing each craft to hover continuously over a given position on the surface.

Because they stay over fixed spots, GOES can quickly see the atmospheric “triggers” for severe weather conditions such as hurricanes. The satellites can then monitor storm development, track their movements, and estimate rainfall.

GOES-11 is set up to monitor the western side of North America, which means it sees the Eastern Pacific family of hurricanes as they pop up and then die back down.

On July 31, GOES-11 had spotted the low-pressure area more than 400 miles (643 kilometers) south of Acapulco that grew into tropical depression number 5E and eventually swelled to become Eugene.

The storm is now a Category 2 hurricane, with winds near a hundred miles (160 kilometers) an hour.

Tropical storm-force winds extend 140 miles (225 kilometers) from Eugene’s eye, which means the whole storm is about 280 miles (450 kilometers) wide. So if the system could be picked up and plopped down on the Eastern Seaboard, it would stretch from Philly to Boston (map)—a looming size that’s made very apparent in the GOES-11 image.

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