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Hurricane Season 2009: Tropical Storm Neki (Central Pacific Ocean)
10.27.09
 
October 27, 2009

GOES image of Neki> View larger image
GOES-11 captured Neki's remnants on October 27 at 8 a.m. EDT. Neki appeared as a small, elongated swirl of clouds. The large bank of clouds to Neki's west is a cold front, and Hawaii lies to the east. Credit: NASA GOES Project

AIRS image of Neki> View larger image
NASA's Aqua satellite AIRS instrument captured an infrared image of Tropical Depression Neki's clouds on October 26 at 8:35 a.m. EDT. Neki, appears as a round area of clouds (blue), was devoid of any strong convection. Credit: NASA JPL, Ed Olsen
Tropical Depression Neki Nulled by Cool Waters and Wind Shear

Two ingredients that don't mix well with tropical cyclones are waters cooler than 80 degrees Fahrenheit and wind shear. Those two ingredients were added into Tropical Depression Neki's mix late yesterday, and caused Neki to dissipate.

The Geostationary Operational Environmental Satellite called GOES-11 captured a look at Neki's remnants this morning, October 27 at 8 a.m. EDT. Neki appeared as an ill-defined, elongated swirl of low clouds. The Central Pacific Hurricane Center (CPHC) noted that Neki "Appears to be just a surface trough in satellite imagery."

Last night, October 26 at 5 p.m. HST (11 p.m. EDT) the Central Pacific Hurricane Center issued their final advisory on Neki. At that time, Neki was a depression with maximum sustained winds near 35 mph. Neki's last location was 450 miles north of French Frigate Shoals, or 665 miles north-northwest of Lihue, Hawaii, near 30.3 North and 164.9 West. The depression had a minimum central pressure of 1010 millibars and was speeding north-northeast near 36 mph!

NASA's Aqua satellite AIRS instrument captured an infrared image of Neki's clouds on October 26 at 8:35 a.m. EDT. Neki appeared as a round area of clouds on infrared imagery, was devoid of any strong convection.

The CPHC said that "Decreasing sea surface temperatures along [Neki's northeastern] track and increasing vertical [wind] shear should prevent redevelopment as a tropical cyclone."

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









October 26, 2009

This 3-D image of Tropical Storm Neki's clouds show that some of the thunderstorms actually top out near 16 kilometers (~9 miles). > View larger image
This 3-D image of Tropical Storm Neki's clouds on October 26 at 0647 UTC show that some of the thunderstorms actually top out near 16 kilometers (~9 miles), indicating some strong convection remains.
Credit: NASA/SSAI, Hal Pierce
Neki was showing some areas of moderate rainfall when the TRMM satellite passed overhead on October 26. > View larger image
Neki was showing some areas of moderate rainfall (4 small red areas in the center) when the Tropical Rainfall Measuring Mission (TRMM) satellite passed overhead on October 26.
Credit: NASA/SSAI, Hal Pierce
A visible image from AIRS of Neki, which appears as a tight round circle of clouds. > View larger image
NASA's Aqua satellite also passed over Neki from space and captured a visible image of the storm, which appears as a tight round circle of clouds.
Credit: NASA/JPL, Ed Olsen
NASA Gets a 3-D Look at Neki Becoming Extra-Tropical

NASA's Aqua and Tropical Rainfall Measuring Mission (TRMM) satellites are watching Tropical Storm Neki become extra-tropical, and TRMM data was used to create a three-dimensional image of the storm.

A 3-D image was created from the TRMM Precipitation Radar (PR) instrument on the satellite. It showed Neki still had a small area where potent thunderstorms reached to heights of about 16 kilometers (~52,493 feet) early this morning, October 26.

TRMM images are made at NASA's Goddard Space Flight Center in Greenbelt, Md. and take some ingenuity to create. A typical TRMM rainfall image combines the infrared and visible channels overlaid with a precipitation analysis from the TRMM Microwave Imager and PR instruments.

TRMM flew over Tropical Storm Neki when it was west-northwest of the Hawaiian Islands at 0647 UTC (2:47 a.m. EDT) this morning. TRMM confirmed that the low-level center of circulation was removed from the heaviest convection and precipitation. When the precipitation and circulation of a storm start separating, that's an indication of a weakening tropical cyclone.

At 5 a.m. HST (11 a.m. EDT) on October 26, Tropical Storm Neki had maximum sustained winds near 40 mph. Neki's center was located about 480 miles northwest of Lihue, Hawaii, and 220 miles north-northeast of French Frigate Shoals. That's near latitude 26.8 north and longitude 164.9 west. Neki is moving toward the north near 18 mph and is expected to speed up and shift in track toward the north-northeast over the next 48 hours. Estimated minimum central pressure is 1009 millibars.

NASA's Aqua satellite flew over Tropical Storm Neki on October 26 at 0023 UTC (Oct. 25 at 8:23 p.m. EDT) and the Atmospheric Infrared Sounder instrument onboard captured a visible, infrared and microwave image of the storm. In the visible image, Neki appeared as a tight round circle of clouds. The infrared image showed some high thunderstorm cloud tops, as cold as -63F, indicating that there was still some punch left in the tropical storm.

Neki is Forecast to become extratropical by Tuesday. A conversion to "extratropical" status means that the tropical storm eventually loses its warm core and becomes a cold-core system. During the time it is becoming extratropical the cyclone's primary energy source changes from the release of latent heat from condensation (from thunderstorms near the storm's center) to baroclinic (temperature and air pressure) processes. When a cyclone becomes extratropical it will usually connect with nearby fronts and or troughs (extended areas of low pressure) consistent with a baroclinic (pressure) system. When that happens it appears the system grows larger while the core weakens.

Neki is moving north and moving into cooler waters. Its transition into an extra-tropical cyclone will occur tomorrow.

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



October 23, 2009

TRMM's analysis of rainfall within Neki on Oct. 23 showed areas of heavy rainfall, about 2 inches per hour (red). > View larger image
TRMM's analysis of rainfall within Neki on Oct. 23 at 0124 UTC showed areas of heavy rainfall, about 2 inches per hour (red). The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. Neki was moving into the French Frigate Shoals (west-northwest of the Hawaiian Islands) at the time of this image.
Credit: NASA/SSAI, Hal Pierce
Infrared imagery revealed the deep convection in Neki's center and in the northeast quadrant of the storm. > View larger image
The Atmospheric Infrared Sounder instrument on NASA's Aqua satellite captured an infrared image of Hurricane Neki on October 22 at 2:59 a.m. local time. Infrared imagery revealed the deep convection in Neki's center and in the northeast quadrant of the storm. The coldest cloud tops are cold as or colder than 220K (Kelvin) or minus 63F. The blue areas are around 240K, or minus 27F.
Credit: NASA/JPL, Ed Olsen
NASA Satellite Still Sees Heavy Rainfall in Tropical Storm Neki

Tropical Storm Neki continues moving north and over the weekend it will be in open waters in the Central Pacific. NASA's Tropical Rainfall Measuring Mission (TRMM) satellite passed over Neki early on October 23 and noticed some intense areas of rainfall, even though it is not a hurricane anymore.

On Friday afternoon, October 23, a Tropical Storm warning was still effect for The Papahanaumokuakea National Monument from Nihoa Island to French Frigate Shoals to Maro Reef.

On October 23 at 11 a.m. EDT (5 a.m. HST), Neki had maximum sustained winds near 70 mph. It was moving north-northeast near 7 mph, and had a minimum central pressure of 995 millibars. Its center was about 90 miles south-southeast of French Frigate Shoals and 400 miles west of Lihue, Hawaii near 22.8 North and 165.6 West.

The French Frigate Shoals is the largest atoll in the northwestern Hawaiian Islands. It got its mane name from the French explorer Jean-François de La Pérouse, who almost lost two frigates when attempting to navigate the shoals.

The Tropical Rainfall Measuring Mission (TRMM) satellite, managed by NASA and the Japanese Space Agency (JAXA) passed over Tropical Storm Neki on October 23 at 0124 UTC (9:24 a.m. EDT Oct. 22) and captured a look at Neki's rainfall. TRMM found that areas of heavy rainfall continued to fall in the northeast and the northern quadrants of the storm. Rainfall rates were very intense, around 2 inches (50 millimeters) per hour in those areas of Neki. Because rainfall is so intense, the Central Pacific Hurricane Center is calling for rainfall amounts between 8 and 12 inches in Neki's path over the weekend.

Rain rates are created from different instruments aboard TRMM. The rain rates in the center of TRMM images are derived from the TRMM Precipitation Radar, the only spaceborne radar of its kind, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are then overlaid on infrared data from the TRMM Visible Infrared Scanner to create the entire image. The images are created at NASA's Goddard Space Flight Center, in Greenbelt, Md.

Hal Pierce of NASA's TRMM Team at NASA Goddard also created an animation of rainfall laid over cloud cover, http://trmm.gsfc.nasa.gov/trmm_rain/Events/neki_23oct09_0124_utc_blend.mpg.

High seas and large surf will continue to impact portions of the Papahanaumokuakea National Monument Friday and Friday night.

Neki and is expected to continue weakening while moving toward the north-northeast over the weekend.

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



October 22, 2009

NASA's Terra satellite passed over Neki and the MODIS instrument captured an image that clearly shows an eye. > View larger image
NASA's Terra satellite passed over Neki and the MODIS instrument captured an image that clearly shows an eye, on October 21 at 11:45 a.m. HST local time.
Credit: NASA MODIS Rapid Response Team
This satellite image on October 22 from NASA Aqua's AIRS instrument shows some high thunderstorm tops (purple) in Neki. > View larger image
This satellite image on October 22 from NASA Aqua's AIRS instrument shows some high thunderstorm tops (purple) in Neki, indicating heavy rainfall and strong convection. Those cloud temperatures were colder than minus 63F. The orange color indicates warm sea surface temperatures near 80F.
Credit: NASA/JPL, Ed Olsen
Papahanaumokuakea National Monument Facing Hurricane Neki

A hurricane warning is in force for the Papahanaumokuakea National Monument from Nihoa Island to French Frigate Shoals to Maro Reef. Hurricane conditions likely there by 5 a.m. HST on Friday, October 23.

The Papahānaumokuākea Marine National Monument is the single largest conservation area under the U.S. flag, and one of the largest marine conservation areas in the world. It encompasses 139,797 square miles of the Pacific Ocean (105,564 square nautical miles) - an area larger than all the country's national parks combined.

Many of the islands and shallow water environments in the National Monument are important habitats for rare species such as the threatened green sea turtle and the endangered Hawaiian monk seal.

As Hurricane Neki nears, the storm had maximum sustained winds near 115 mph at 5 a.m. HST (11 a.m. EDT) today, October 22. It was located about 245 miles south of French frigate shoals and 525 miles west of Honolulu, Hawaii, near 20.4 North and 166.0 West. Neki was moving north-northeast near 10 mph, and had a minimum central pressure of 965 millibars.

Neki's hurricane force winds extend outward up to 60 miles from the center, and tropical storm force winds extend outward up to 205 miles.

NASA's Terra satellite passed over Neki and captured an image of the large storm using the Moderate Imaging Spectroradiometer (MODIS) instrument on October 21 at 2145 UTC (5:45 p.m. EDT/11:45 a.m. HST local time).

NASA Aqua satellite also took a look at Neki, and measured the storm's thunderstorm cloud-top temperatures using infrared imagery. The Atmospheric Infrared Sounder (AIRS) instrument showed some high thunderstorm tops in Neki indicating heavy rainfall and strong convection. Those cloud temperatures were colder than minus 63F.

High seas are a concern with Neki. Neki is creating high seas of 15 to 20 feet that will build up across the smaller islands of the Papahanaumokuakea National Monument. For more information about the Papahanaumokuakea National Monument, visit: http://papahanaumokuakea.gov/.

Little change in Neki's strength is forecast over the next 24 hours, but Neki is expected weaken as the storm heads into cooler waters and wind shear. Neki is forecast to continue moving northeast and then weaken to a depression by early next week.

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



October 21, 2009

Neki's rainfall; the red areas indicate rainfall of about 2 inches per hour. > View larger image
TRMM captured an image of Neki's rainfall when it was about 817 Kilometers (441 miles) southwest of the Hawaiian Islands. The red areas indicate rainfall of about 2 inches per hour. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour.
Credit: NASA/SSAI, Hal Pierce
NASA's AIRS instrument captured Neki's high thunderstorm cloud temperatures (-63F) on October 21. > View larger image
NASA's AIRS instrument captured Neki's (purple and blue) high thunderstorm cloud temperatures (-63F) at 1:24 a.m. EDT on October 21. Neki is a large storm, as evidenced by the size of the Hawaiian Islands to the northeast in this image.
Credit: NASA/JPL, Ed Olsen
Two NASA Satellites See Neki Become a Category Two Central Pacific Hurricane

Tropical storm Neki was upgraded to a hurricane on October 20, 2009, and is now a Category 2 hurricane. It is expected to continue strengthening to a Category 3 hurricane as it passes well to the southwest of the Hawaiian Islands. NASA's Tropical Rainfall Measuring Mission (TRMM) satellite and Aqua satellite have measured its cloud temperatures and rainfall while flying overhead, and have seen indications of an intensifying storm.

A tropical storm watch is in force for Johnston Island, meaning that tropical storm conditions are possible within the next 48 hours. A hurricane watch is in force for the Papahanaumokuakea National Monument from French Frigate Shoals to Lisianski. That means that hurricane conditions possible within 48 hours. Large swells from the southeast may reach the monument as early as Thursday.

The TRMM satellite passed over Neki when it was about 441 miles (817 kilometers) southwest of the Hawaiian Islands. Sustained wind speeds at that time had increased to over 75 knots (~86 mph) making it a strong category 1 hurricane. Since then, its winds have increased by 19 mph. TRMM noticed that there were some areas of heavy rainfall within Neki.

At 5:00 a.m. HST (11 a.m. EDT) on October 21, Hurricane Neki's maximum sustained winds were near 105 mph with higher gusts. Neki is a category 2 hurricane on the saffir-simpson scale. The hurricane is expected to intensify to category 3 strength over the next 48 hours. Neki's center was near latitude 17.0 north and .longitude 166.6 west or about 640 miles west-southwest of Honolulu, Hawaii And about 195 miles east of Johnston Island. Neki is moving toward the north-northwest near 6 mph. Neki is expected continue north-northwestward for the next 36 hours then gradual turn toward the north. Estimated minimum central pressure is 970 millibars.

NASA Aqua satellite also flew over Neki. Aqua's Atmospheric Infrared Sounder (AIRS) instrument captured Neki's high thunderstorm cloud temperatures at 1:24 a.m. EDT on October 21. The thunderstorm tops were colder than minus 63 Fahrenheit, indicating a strong or strengthening storm.

Neki is predicted to move toward the uninhabited Island of Laysan and pass within about 152 miles, to the northeast of Johnston Island.

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



October 20, 2009

TRMM's analysis of rainfall within Neki showed areas of heavy rainfall. > View larger image
TRMM's analysis of rainfall within Neki showed areas of heavy rainfall. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. Red areas are heavy rainfall at almost 2 inches per hour.
Credit: NASA/SSAI, Hal Pierce
NASA's TRMM Sees Some Heavy Rains in Neki as it Heads Toward Johnston Island

The Tropical Rainfall Measuring Mission, or TRMM satellite has been flying over Tropical Storm Neki in the Central Pacific Ocean and providing scientists with an idea of how much rainfall Johnston Island can expect from it.

A Hurricane Watch is already in effect for Johnston Island. That means hurricane conditions are possible within the next 48 hours. A Hurricane Warning may be issued later today, meaning hurricane conditions are happening.

Johnston Island is the main island in the Johnston Atoll, a 50-square-mile atoll in the North Pacific Ocean. It's located 750 nautical miles west of Hawaii. The Atoll consists of four islands: Johnston, Sand, North Island and East Island.

The Tropical Rainfall Measuring Mission (TRMM) satellite, managed by NASA and the Japanese Space Agency (JAXA) passed over Tropical Storm Neki on October 20 at 1043 UTC (6:43 a.m. EDT/12:43a.m. HST) and captured a look at Neki's rainfall. TRMM found that there were some areas of heavy rainfall in the northeast quadrant of the storm. Rainfall rates were around 2 inches per hour in that part of Neki.

Rain rates are created from different instruments aboard TRMM. The rain rates in the center of TRMM images are derived from the TRMM Precipitation Radar, the only spaceborne radar of its kind, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are then overlaid on infrared data from the TRMM Visible Infrared Scanner to create the entire image. The images are created at NASA's Goddard Space Flight Center, in Greenbelt, Md.

TRMM also has the ability to analyze how high the thunderstorms are in tropical cyclones, and this morning's image indicated there were some "hot towers," that is, towering thunderstorms that are almost 15 kilometers (about 9 miles) high. That's an indication that the storm is strengthening.

At 2 a.m. HST (8 a.m. EDT) on October 20, Tropical Storm Neki's maximum sustained winds had increased from 40 mph to 50 mph, and it is expected to continue intensifying. Neki was located about 515 miles east-southeast of Johnston Island, and 640 miles south-southeast of Honolulu, Hawaii. It was near 13.0 North and 162.8 West. Neki is moving northwest near 18 mph and will continue in that direction for the next two days, although it is forecast to slow down. Estimated minimum central pressure is 1005 millibars.

Neki will continue to strengthen as it moves northwest and could pass Johnston Island as a hurricane. Tropical Storm Neki is headed for a landfall over the tiny island by Thursday, October 22.

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



October 19, 2009

NASA's QuikScat instrument captured an inside look at Tropical Storm Neki's winds on Oct. 19 > View larger image
NASA's QuikScat instrument captured an inside look at Tropical Storm Neki's winds on Oct. 19 at 0425 UTC (12:25 a.m. EDT). White barbs point to areas of heavy rain. The highest wind speeds, are shown in purple, which indicate winds over 40 knots (46 mph).
Credit: NASA JPL, Peter Falcon
NASA's Aqua satellite captured this visible image of Tropical Storm Neki on October 19 > View larger image
NASA's Aqua satellite captured this visible image of Tropical Storm Neki on October 19 at 00:11 UTC in the Central Pacific Ocean.
Credit: NASA JPL, Ed Olsen
Two NASA Satellites See Tropical Storm Neki Form in the Central Pacific

Tropical Storm Neki formed today about 830 miles southeast of Johnston Island in the Central Pacific Ocean. NASA's QuikScat and Aqua satellites quickly captured and analyzed winds and temperatures in Neki, enabling forecasters to see the storm strengthening.

Today, October 19, at 11 a.m. EDT (5 a.m. HST) Neki had maximum sustained winds near 40 mph, and was moving west-northwest near 14 mph. Estimated minimum central pressure is 1006 millibars. It was 825 miles south of Honolulu, Hawaii and about 830 miles southeast of Johnston Island near latitude 9.5 North and longitude 159.6 West. Neki is expected to shift slowly toward the northwest later tonight or Tuesday, at which time it is forecast to strengthen into a hurricane.

NASA's QuikScat instrument captured an inside look at Tropical Storm Neki's surface winds using microwave technology from its vantage point in space on Oct. 19 at 0425 UTC (12:25 a.m. EDT). QuikScat showed highest wind speeds near 40 mph.

NASA's Aqua satellite also flew above Neki and the Atmospheric Infrared Sounder (AIRS) instrument captured a visible, infrared and microwave image of the storm. The visible image showed a storm getting organized and developing the signature tropical storm shape. The infrared and microwave images confirmed some high thunderstorms, indicating some strong convection and a strengthening storm.

Neki is forecast to pass very close to Johnston Island on Wednesday, October 21 as a hurricane.

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