Science and Exploration

The View From Orbit: Danielle and Earl

By Keith Cowing
May 24, 2013
Filed under

Danielle and Earl are both spinning around in the Atlantic Ocean and NASA’s Terra satellite captured one image of both storms at the same time, one in the Caribbean and the other approaching the North Atlantic Ocean. Both are expected to impact land.

Danielle and Earl are both spinning around in the Atlantic Ocean and NASA’s Terra satellite captured one image of both storms at the same time, one in the Caribbean and the other approaching the North Atlantic Ocean. Both are expected to impact land.

Danielle is transitioning to an extra-tropical storm in the northern Atlantic and may impact southern Greenland. Before Earl reached hurricane status NASA’s GRIP Hurricane Mission researchers flew out to analyze the storm. Earl is now threatening the U.S. east coast and earlier today, August 30, he became a major hurricane.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument that flies aboard NASA’s Terra satellite captured a stunning image of the large Hurricane Danielle and the smaller, less organized Hurricane Earl, far to Danielle’s south. In the image, Danielle’s eye can be seen, despite some high clouds filling in most of it. An eye is not visible in Earl, however. The image shows the western edge of Earl affecting the Leeward Islands when this image was captured on August 29 at 10:20 a.m. EDT.

Danielle started causing problems for U.S. east coast residents this weekend with large waves and dangerous surf conditions. News reports indicated that more than 100 people were rescued from dangerous currents in beaches from Maryland to New Jersey over the weekend. Large waves and dangerous surf conditions are diminishing around Bermuda today, and will gradually subside along the U.S. east coast over the next couple of days. Waves near 10 feet however are expected to develop this afternoon along parts of Newfoundland, Canada as Danielle tracks northward.

At 11 a.m. EDT on August 30, Danielle’s maximum sustained winds were near 75 mph, and it is expected to weaken in the next 48 hours and become extratropical. The center of Hurricane Danielle was located near latitude 40.9 north and longitude 50.7 west. Danielle is moving toward the northeast near 16 mph and is expected to speed up in this direction. The National Hurricane Center noted that Danielle will still remain a large and powerful cyclone over the far north Atlantic for the next two days. Tropical Storm force winds extend out from Danielle’s center up to 310 miles, making this monster storm up to 620 miles in diameter!

As Danielle continues north and heads toward Greenland, Hurricane Earl has the residents of the U.S. East coast on watch. Earl reached hurricane strength as it approached the northern Leeward Islands on August 29 and NASA researchers were there collecting data.

NASA’s Genesis and Rapid Intensification Processes (GRIP) experiment is a NASA Earth science field mission that’s happening now out of Fort Lauderdale, Florida using three aircraft, 15 instruments and NASA satellites to better understand how tropical storms form and develop into major hurricanes.

NASA’s DC-8 aircraft left Fort Lauderdale at 10:05 a.m. EDT on Saturday heading for St. Croix for a multi-day deployment that targeted (at that time) Tropical Storm Earl. Science missions to Earl were planned for Sunday and Monday in close support of operations being flown by NOAA aircraft. On Sunday, August 29, the DC-8 completed an 8.5-hour science flight over (then) Hurricane Earl west of St. Croix. The research aircraft flew at altitudes of 33,000 feet and 37,000 feet and descended to 7,000 feet northwest of the storm area to collect measurements of atmospheric aerosols. The flight originated in St. Croix but diverted to land in Fort Lauderdale, Fla., due to the degrading weather forecast for St. Croix associated with the approaching hurricane.

Early on August 30 at 0535 UTC (1:35 a.m. EDT), NASA’s Atmospheric Infrared Sounder (AIRS) that flies on the Aqua satellite captured an infrared image that showed a very large area of powerful convection and strong, high thunderstorms (as cold as -63 Fahrenheit) that take up most of Hurricane Earl’s center as it was moving through the Northern Leeward Islands and headed to Puerto Rico.

Later in the morning after NASA’s Aqua satellite passed over Earl, it became a major hurricane (Category 3) with maximum sustained winds near 120 mph. Hurricane Earl was already impacting many islands and hurricane warnings are in effect. Earl’s center was about 95 miles east-northeast of St. Thomas and 165 miles east of San Juan, Puerto Rico near 18.7 North and 63.6 West. It was moving west-northwest near 15 mph, and had a minimum central pressure of 960 millibars.

A hurricane warning is in effect for Anguilla, Saint Martin and Saint Barthelemy, St. Maarten, Saba, and St. Eustatius, the British Virgin Islands, the U.S. Virgin Islands and the Puerto Rican Islands of Culebra and Vieques. A Hurricane Watch is in effect for Puerto Rico. A tropical storm warning is in effect for Antigua, Barbuda, Montserrat, St. Kitts, and Nevis and Puerto Rico. A tropical storm watch is in effect for Turks and Caicos Islands.

The National Hurricane Center noted this morning, “Hurricane conditions will be spreading across the northern Virgin Islands during the next few hours. Tropical storm conditions will spread over portions of Puerto Rico this afternoon with Hurricane conditions possible this evening and tonight. Storm surge will raise water levels by as much as 3 to 5 feet above ground level primarily near the coast in areas of onshore wind within the hurricane warning area…and 1 to 3 feet in the tropical storm warning area. The surge will be accompanied by large and dangerous battering waves. Earl is expected to produce total rainfall accumulations of 4 to 8 inches over the Leeward Islands, The Virgin Islands and Puerto Rico with possible isolated maximum amounts of 12 inches especially over higher elevations.”

Interests along the U.S. East coast should closely monitor the approach of Hurricane Earl. Beachgoers should be aware of dangerous surf and riptides developing as Earl approaches the U.S. coast later this week.

Text credit: Rob Gutro, NASA’s Goddard Space Flight Center, Greenbelt, Md.

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