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Hurricane Season 2009: Tropical Storm Guillermo (Eastern Pacific)
08.20.09
 
August 19, 2009

AIRS image of Guillermo> View larger image
NASA's AIRS instrument captured this visible image of Tropical Storm Guillermo on August 19 at 7:53 p.m. EDT fizzling out. The weak swirl North of Hawaii is all that is left of this storm. Credit: NASA JPL, Ed Olsen
Bidding Guillermo Goodbye

Guillermo is weakening to a remnant low pressure system in the central Pacific Ocean, and NASA satellite data has shown that the storm looks like a weak swirl north of Hawaii.

NASA's Aqua satellite flew over Guillermo on Aug. 19 at 7:53 p.m. EDT, and its Atmospheric Infrared Sounder (AIRS) instrument captured a visible image of the storm.

The Central Pacific Hurricane Center issued their final warning for Guillermo today, August 20. Guillermo's last position was 720 nautical miles north of Honolulu, Hawaii, near 31.7 degrees north latitude and 157.0 west longitude. His minimum central pressure was estimated near 1012 millibars.

It was moving northwest near 15 mph, and sustained winds near 46 mph, but fading. Guillermo will weaken as he continues to travel at sea in a northwesterly then northerly direction.

By Saturday, August 22, Guillermo is forecast to have dissipated.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



August 19, 2009

Guillermo Turns Away from Hawaii, Heads Northwest

QuikScat caught most of Tropical Storm Guillermo in a satellite image from 12:04 a.m. EDT on August 19 > Larger image
QuikScat caught most of Tropical Storm Guillermo in a satellite image from 12:04 a.m. EDT on August 19 (his western side was out of range of the satellite as it tracked over the storm from space). Different colors and wind direction are indicated by small barbs. White barbs point to areas of heavy rain. The highest wind speeds appear in purple and are over 46 mph. Credit: NASA/JPL
Residents of the Hawaiian Islands and the islands that form the chain to the northwest of the Big Island are breathing a sigh of relief as Tropical Storm Guillermo has changed course and is headed far away from them.

On Wednesday, August 19 at 5 a.m. Hawaii local time (11 a.m. EDT), Guillermo was still packing sustained winds near 40 mph. He was located about 635 miles north-northwest of Honolulu, Hawaii and moving northwest near 18 mph. Minimum central pressure was 1010 millibars.

Guillermo has held onto tropical storm force winds despite battling wind shear (winds that can tear a storm apart). Because the winds that are battering Guillermo are expected to strengthen as he moves northwest, he's expected to dissipate by the weekend.

QuikScat caught most of Tropical Storm Guillermo in a satellite image from August 19 at 12:04 a.m. EDT as it passed overhead. Guillermo's western side was out of range of the satellite as it tracked over the storm from space, but the strongest winds in the storm's center were captured on the satellite imagery. The highest wind speeds appear in purple and are over 46 mph. Since then, sustained winds have dropped to 40 mph and Guillermo continues moving away from the Hawaiian Islands.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



GOES image of Guillermo on August 18, 2009> Larger image
This image of Guillermo was captured by NOAA's GOES-11 satellite on August 18 at 2:30 p.m. EDT when his maximum sustained winds were near 40 knots (46 mph). It was losing the signature "comma shape" of a tropical storm. Credit: NRL/NOAA
Guillermo has run into cooler waters and winds that are starting to batter and weaken him, and he's expected to continue on that course over the next couple of days around Hawaii. Satellite imagery from the GOES-11 satellite revealed that the storm is losing its signature "comma shape."

On Tuesday, August 18, Guillermo's maximum sustained winds were down to 40 knots (xxx mph), and the ocean temperatures below 80 degrees Fahrenheit that he's running into are sapping his strength. Tropical cyclones need sea surface temperatures of at least 80F to maintain power.

Guillermo continued tracking north of the Hawaiian islands, but by the end of the week is expected to make a left turn and rain on Midway Island. He was located about 490 miles northeast of Hilo, Hawaii at 5 a.m. EDT on August 18, near 23.9 north and 148.9 west. Guillermo was moving northwest near 19 knots.

Guillermo was captured in an image by NOAA's (Geostationary Operational Environmental Satellite) GOES-11 satellite on August 18 at 2:30 p.m. EDT when his maximum sustained winds were near 40 knots (46 mph) and minimum central pressure was 1007 millibars. At that time, Guillermo was located near 26.5 north and 150.4 west.

Tropical Storm Guillermo is expected to continue weakening as it continues to track north of the Hawaiian Islands. If it survives until the weekend, it could bring rains and gusty winds to Midway Island, and the Pearl and Hermes Atolls, which are part of the Northwestern Hawaiian Islands.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



August 17, 2009

Hurricane Guillermo's winds using its microwave imagery to peer through its clouds on August 16. > View larger image
NASA's QuikScat satellite captured Hurricane Guillermo's winds using its microwave imagery to peer through its clouds on August 16 at 11:18 p.m. EDT. The highest wind speeds are normally shown in purple, which indicate winds over 40 knots. The strongest winds are represented in the center of circulation.
Credit: NASA/JPL, Peter Falcon
Guillermo when it was still a well-organized tropical storm. > View larger image
NASA's Aqua satellite captured Guillermo on August 13 at 5:15 p.m. EDT from the Moderate Imaging Spectroradiometer (MODIS) instrument when it was still a well-organized tropical storm. It strengthened into a hurricane the next day.
Credit: NASA/MODIS Rapid Response
Tropical Storm Guillermo Hitting a Wall, Passing North of Hawaii's Big Island

Over the next couple of days, Tropical Storm Guillermo will pass far north of the big island of Hawaii, and continue weakening because of winds, and an exposed center. It's basically hitting a wall of resistance in the atmosphere.

According to the Central Pacific Hurricane Center, who is now forecasting for Guillermo since he exited the eastern Pacific and entered their realm, "Tropical storm Guillermo continues to weaken. Most of the colder cloud tops have now been sheared off and the deep convection has completely dissipated. The low level center is now completely exposed on the southwest side of the system. Guillermo is clearly continuing to weaken rather quickly due to strong west-southwest wind shear."

At 5 a.m. HST (11 a.m. EDT) on Monday, August 17, Guillermo had maximum sustained winds near 60 mph, but those are expected to wane with the wind shear battering the storm. His center was about 695 miles east-northeast of Hilo, Hawaii and 860 miles east of Honolulu. That's near 21.5 north and 144.5 west. Guillermo is moving west-northwest near 18 mph and will turn to the northwest in the next 2 days. Minimum central pressure is near 1000 millibars.

NASA's Aqua satellite captured Hurricane Guillermo on August 13 at 5:15 p.m. EDT from the Moderate Imaging Spectroradiometer (MODIS) instrument, and the image showed a well-organized tropical storm at the time that became a hurricane the next day.

NASA's QuikScat satellite captured Hurricane Guillermo's winds using its microwave imagery to peer through its clouds on August 17 at 3:18 UTC (August 16 at 11:18 p.m. EDT). QuikScat can determine the speed of the rotating winds. QuikScat shows wind speeds in different colors and wind direction are indicated by small barbs. White barbs point to areas of heavy rain. The highest wind speeds are normally shown in purple, which indicate winds over 40 knots (46 mph). The strongest winds are represented in the center of circulation.

The good news is that Guillermo's winds are expected to wane and it's going far north of the big island of Hawaii

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



August 14, 2009

AIRS image of Hurricane Guillermo in the eastern Pacific Ocean > View larger image
he Aqua satellite's AIRS instrument is actually able to measure a cloud's temperatures from space, and on Aug. 13 at 5:11 p.m. EDT, AIRS captured revealed very high clouds, towering thunderstorms with very cold temperatures and a visible eye in the storm.
Credit: NASA JPL, Ed Olsen
Guillermo Strengthens to Hurricane on NASA Infrared Satellite Imagery

When NASA's Aqua satellite flew over Guillermo in the Eastern Pacific Ocean late at night on August 13, the infrared instrument that captures cloud temperatures showed an eye the storm's center, indicating a strengthening storm. Guillermo became a hurricane shortly afterward.

Aqua's Atmospheric Infrared Sounder (AIRS) is actually able to measure a cloud's temperatures from space, and on Aug. 13 at 5:11 p.m. EDT (21:11 UTC) the image AIRS captured revealed very high clouds, towering thunderstorms with very cold temperatures. Both very high clouds and very cold temperatures indicate strong tropical cyclones, because storms are made up of hundreds of thunderstorms.

In infrared imagery, NASA's false-colored purple clouds are as cold as or colder than 220 Kelvin or minus 63 degrees Fahrenheit (F). The blue colored clouds are about 240 Kelvin, or minus 27F. AIRS visualized most of Guillermo's clouds in purple, meaning they're very cold and very high.

On Friday, August 14 at 5 a.m. EDT, Guillermo had maximum sustained winds near 75 mph and will strengthen a little, but then it's going to run into colder waters. Surface water temperatures colder than 80 degrees Fahrenheit are too cold to provide power to tropical cyclones to keep their strength, so he'll weaken over the weekend.

Hurricane Guillermo was located 1,100 miles west-southwest of the southern tip of Baja California, near 17.6 north latitude and 125.9 west longitude. Guillermo was moving west near 15 mph and will turn west-northwest over the weekend. Estimated minimum central pressure is 987 millibars.

Over the weekend of Aug. 15-16, Guillermo will encounter the colder waters and will drop back to tropical storm status and continue to weaken.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center



August 13, 2009

GOES-11 captured all four tropical areas in the Pacific on August 13 at 8 a.m. EDT. > View larger image
GOES-11 captured all four tropical areas in the Pacific on Aug. 13 at 8 a.m. EDT: from left to right, the remnants of Maka and Felicia, then TD9E and finally,Tropical Storm Guillermo, which looks pretty impressive west of the Mexican coast.
Credit: NASA/GOES Project
GOES-11 captured all four tropical areas in the Pacific on August 13 at 8 a.m. EDT. > View larger image
This is a "full-disk" image of the Earth taken by GOES-11. In the image, north of the equator, you can see where GOES-11 captured all four tropical areas in the Pacific on Aug. 13 at 8 a.m. EDT: from left to right, the remnants of Maka and Felicia, then TD9E and finally,Tropical Storm Guillermo.
Credit: NASA/GOES Project
GOES-11 Sees Tropical Cyclones Fizzling and Forming in the Eastern Pacific!

There are a lot of ups and downs in tropical cyclone formation in the Pacific Ocean this week, and that's keeping NOAA's GOES-11 satellite busy. There are remnants of Maka and Tropical Depression 9E, a fizzled Felicia, and a new Tropical Storm named Guillermo.

The graphics folks that create images from the satellite at the GOES Project at NASA Goddard Space Flight Center in Greenbelt, Md. are posting updated images on the GOES Project website often and forecasters are watching them.

In the Central Pacific Ocean, Maka and Felicia are now a memory. Felicia dissipated before it reached Hawaii, and the remnants of Maka are 1,400 miles west-southwest of Kauai. Maka's remnant clouds and showers are still moving west, and it's unlikely that it will re-organize. That means a quiet Central Pacific Ocean for the next two days.

In the Eastern Pacific, Tropical Depression 9E (TD9E) appears to be fizzling although it may get a second chance at life, while Tropical Depression 10E powered up into Tropical Storm Guillermo.

The remnants of TD9E are weakly spinning to around 30 mph, while it continues moving west-southwest near 9 mph. The center was located about 1,750 miles west-southwest of the southern tip of Baja California, near 13.9 north and 134.1 west. The National Hurricane Center noted that shower and thunderstorm activity has increased this morning, and the environment seems to be a little more conducive to strengthening, so TD9E isn't written off yet. In fact, there's about a 30-50% chance it may strengthen back into a tropical depression.

Meanwhile, Tropical Depression 10E gained strength took the name Guillermo and it's sustained winds whipped up to near 50 mph. Guillermo is moving west-northwest near 16 mph and will continue in that direction. Guillermo is closer to mainland Mexico, but poses no threat as its heading away from land. On Aug. 13 at 5 a.m. EDT the storm was located 805 miles west-southwest of the southern tip of Baja California near 16.9 north and 120.5 west. His minimum central pressure is 999 millibars. Guillermo is moving into a favorable environment, so he's expected to continue strengthening.

Even though the peak of hurricane season in the eastern and central Pacific Oceans are a month away, it seems like we're already there.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center