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Hurricane Season 2008: Norbert (Eastern Pacific Ocean)
 
Oct. 14, 2008

Holiday Weekend Too Much for Norbert and Odile in Eastern Pacific

There's nothing like a holiday weekend to wear a tropical storm out. At least that's what it seems has happened over the Columbus Day holiday with the storms Norbert and Odile.

Norbert Dissipates in Northern Mexico

On Sunday, Oct. 12, the remnants of Norbert were dissipating over the mountains of northern Mexico. The storm uprooted trees, caused widespread flooding and destroyed roofs from homes and businesses while moving inland from the eastern Pacific Ocean. Mexican authorities reported at least four deaths from flooding in the town of Alamos. By Monday, Oct. 13, Norbert's remnants were dumping moderate rain on west Texas.

Hurricane Norbert made landfall near Puerto Charley on the southwest coast of Baja California around 930 a.m. PDT on Saturday, Oct. 11, with estimated maximum winds of 105 mph or category two strength on the Saffir-Simpson hurricane scale.

Odile Dissipates off the Southwestern Mexico Coast

Tropical Storm Odile weakened to a tropical depression by Monday, Oct. 13 off the southwest coast of Mexico. The National Hurricane Center's last advisory on the storm was on Sunday, Oct. 12. During the morning hours on Oct. 12, Odile was about 100 kilometers (62 miles) south-southwest of Manzanillo, Mexico with winds near 65 kilometers per hour (40 mph). According to the Associated Press, Odile flooded about 200 homes in the Acapulco area before fading away.

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



Oct. 10, 2008

Baja California and Mainland Mexico Brace for a Landfall from Norbert

Satellite image of Norbert Credit: NASA/Jeff Schmaltz, MODIS Rapid Response Team
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Over the Columbus Day weekend Hurricane Norbert is forecast to make landfall in Baja California and then make its final landfall in northwestern Mexico's mainland. Norbert is forecast to cross over the Baja on Saturday, Oct. 11, and hit the mainland on Oct. 12.

This image of Norbert was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite on October 9. Near the time of this image, the storm had weakened to Category 1 strength, with maximum sustained winds near 90 mph.

At 2 p.m. EDT on Oct. 10, Norbert was centered near latitude 20.8 north and longitude 113.4 west or about 265 miles west-southwest of the southern tip of Baja California. Maximum sustained winds are near 100 mph making Norbert a category two hurricane on the Saffir-Simpson Scale. Some weakening is forecast during the next 24 hours before Norbert reaches the Baja California coast. The estimated minimum central pressure was 973 millibars.

Norbert was moving toward the north near 10 mph and will turn toward the north-northeast with an increase in forward speed by early morning Oct. 11. On this track Norbert's center will be very near the southern Baja California peninsula Saturday morning the 11th.

Satellite image of Norbert Credit: NASA/JPL/Colorado State University/Naval Research Laboratory-Monterey
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The National Hurricane Center says that Norbert is expected to produce rainfall accumulations of 4 to 6 Inches over southern Baja California as well as portions of northwestern Mexico with possible isolated amounts of 10 inches. Storm surge flooding of 2 to 5 feet above normal tide level along with large and dangerous battering waves are expected along the west coast of the southern Baja peninsula near and to the southeast of where Norbert makes landfall.

CloudSat Slices Norbert in Half

NASA's CloudSat satellite's Cloud Profiling Radar captured a sideways view of Norbert on Oct. 8 at 21:00 UTC (5:00 p.m. EDT). For comparison, the top image is from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite (GOES-11) around the same time.

The red line through the GOES satellite image shows the vertical cross section of radar, basically what Norbert's clouds looked like sideways. The colors indicate the intensity of the reflected radar energy. The top of Norbert's clouds are almost 15 kilometers (9.3 miles) high.

The blue areas along the top of the clouds indicate cloud ice, while the wavy blue lines on the bottom center of the image indicate intense rainfall. Notice that the solid line along the bottom of the panel, which is the ground, disappears in this area of intense precipitation. It is likely that in the area the precipitation rate exceeds 30mm/hr (1.18 inches/hour) based on previous studies.

Text credit: Rob Gutro (from NHC reports), NASA's Goddard Space Flight Center



Oct. 9, 2008

Norbert Now a Powerful Hurricane, Headed to Baja

Well-defined AIRS image of Norbert, showing its power Credit: NASA JPL
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See such a large and well-defined eye on the false-colored satellite image of Hurricane Norbert is enough to send shivers down your spine. That's in indication of a well-developed and very powerful storm, and that's what Hurricane Norbert is on Thursday, October 9, 2008.

Late Wednesday, at 11:00 p.m. EDT, Norbert reached category four hurricane status on the Saffir-Simpson scale, when his sustained winds were measured at 135 mph. By 5:00 a.m. EDT on Oct. 10, Hurricane Norbert's winds decreased a little to 125 mph making it a dangerous category three hurricane. However, the National Hurricane Center warns that storms of this power fluctuate in intensity.

At 5 a.m. Oct. 10, Norbert was moving northwestward near 7 mph in the open waters of the eastern Pacific Ocean. Norbert was about 410 miles south-southwest of the southern tip of Baja California. That's near latitude 17.5 degrees north and longitude 112.5 degrees west. Minimum central pressure was 954 millibars.

Norbert is a bigger storm than last week'sTropical Storm Marco that made landfall in east central Mexico. Norbert's tropical storm force winds extend up to 140 miles from its center.

AIRS visible image of Norbert Credit: NASA JPL
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NASA's Aqua Satellite Provides Visible and Temperature Views of Norbert

These infrared and visible images were created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. They were taken October 8 at 20:53 UTC (4:53 p.m. EDT).

The infrared image shows a huge temperature difference between the tops of the clouds in the tropical cyclone and the warm ocean waters that power it. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the area of low pressure. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the ocean and land surfaces, revealing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength.

The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

Where is Norbert Headed?

The National Hurricane Center (NHC) noted "Interests in the southern Baja California peninsula should monitor the progress of Norbert." Currently, forecast models call for a northeast turn which will carry Norbert over the Baja late Friday, Oct. 11 into early morning Saturday, Oct. 12.

The NHC discussion on Oct. 10 at 5 a.m. PDT says that Norbert "will be over warmer waters in the next 12-24 hours with a light shear environment (that means light winds that will allow the storm to maintain strength) and some fluctuations in the intensity are likely due to changes in the eyewall structure." After a day, the wind shear should increase and the storm should weaken. However, the NHC forecasts Norbert to be a Category 2 hurricane when it makes landfall and crosses the Baja.

Text credit: Rob Gutro (from NHC reports) NASA's Goddard Space Flight Center



Oct. 8, 2008

Norbert Becomes a Major Eastern Pacific Hurricane

Satellite image of Norbert Credit: Hal Pierce, SSAI/NASA
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Hurricane Norbert has continued to strengthen, and has now become a major hurricane with sustained winds near 115 mph. Norbert is in the open waters of the eastern Pacific, but forecast models take Norbert into Baja California late Friday as a hurricane.

Maximum sustained winds have increased to near 115 mph with higher gusts making Norbert a category three hurricane on the Saffir-Simpson scale. Additional strengthening is forecast during the next 24 hours.

At 5:00 a.m. EDT Norbert's center was located about 470 miles south of the southern tip of Baja California. That's near latitude 16.1 north and longitude 110.0 west. Norbert is moving toward the west-northwest near 10 mph and will continue in that direction before turning northward on Oct. 9. Estimated minimum central pressure is 960 millibars.

NASA's TRMM Satellite Analyzes Rainfall from Space

The image above was made from data captured by the Tropical Rainfall Measuring Mission (TRMM) satellite on October 8 at 5:59 UTC (1:59 a.m. EDT). This TRMM image shows the horizontal pattern of rain intensity within Norbert. The center is located near the yellow, green and red areas, which indicate rainfall between 20 and 40 millimeters (.78 to 1.57 inches) per hour. The red area is considered moderate rainfall.

The National Hurricane Center forecasters use TRMM data in their forecasts. As noted in the Hurricane Norbert discussion on Oct. 7, "Recent TRMM and AMSU (Advanced Microwave Sounding Unitm an instrument on NASA's Aqua satellite) microwave data show that Norbert has a well-defined 20-25 nautical mile wide eye and a closed eyewall. The eye has occasionally appeared in visible and infrared imagery and is gradually becoming more distinct with time. The eyewall cloud top [temperatures] exceed -80 Celsius in some areas."

For more information about how TRMM looks at rainfall, visit NASA's TRMM Web site at: http://trmm.gsfc.nasa.gov/. TRMM is a joint mission between NASA and the Japanese space agency JAXA.

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



Oct. 7, 2008

A 3-Day Satellite Look at Norbert: Growing from a Depression to a Hurricane

AIRS images of Norbert going from a tropical depression, to a tropical storm, to a hurricane. Credit: NASA JPL
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Watching a tropical depression strengthen into a tropical storm and then into a hurricane is something that fascinates meteorologists and weather watchers. That's exactly what NASA's Aqua satellite was able to do with a time series of images of Norbert taken over three days.

These infrared images were created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. They were taken October 5 at 20:17 UTC (4:17 p.m. EDT), October 6 at 8:35 UTC (4:35 a.m. EDT) and Oct. 7 at 5:17am EDT.

On October 5 at 5 p.m. EDT, Norbert was still a depression with sustained winds near 35 mph. On October 6 at 4 a.m. EDT, Norbert had just become a tropical storm and received its name. Sustained winds at that time were near 65 mph. Norbert was classified a hurricane on Tuesday, October 7 in the 5:00 a.m. EDT advisory from the National Hurricane Center when its sustained winds were near 75 mph.

The infrared images show a huge temperature difference between the tops of the clouds in the tropical cyclone and the warm ocean waters that power it. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the area of low pressure. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

The infrared signal of the AIRS instrument can't see through clouds, so where there aren't any AIRS reads the infrared signal (temperature) from the ocean and land surfaces, showing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength. These data are also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

Where is Hurricane Norbert on October 7?

At 11:00 a.m. EDT on Oct. 7, Hurricane Norbert's winds increased from 75 mph to 80 mph, and he was moving west-northwestward near 8 mph in the open waters of the eastern Pacific Ocean. Norbert was about 555 miles south-southeast of the southern tip of Baja California. That's near latitude 15.3 degrees north and longitude 107.1 degrees west. Minimum central pressure was 987 millibars.

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



Oct. 6, 2008

Tropical Storm Norbert May Become an Eastern Pacific Hurricane

Satellite image of Norbert Credit: NASA/Hal Pierce
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The weekend of October 4-5 was busy in the eastern Pacific. Tropical Storm Marie was in the open waters and headed west, while Tropical Depression 15-E (as in "Eastern" Pacific), formed about 230 miles south of Acapulco, Mexico around 8 p.m. PDT on Friday, Oct. 3. The fifteenth tropical depression of the eastern Pacific Ocean hurricane season then strengthened into Tropical Storm Norbert over the weekend.

On Monday, October 6 at 5:00 a.m. EDT (2:00 a.m. PDT), forecasters at the National Hurricane Center were watching Norbert, because his winds were already sustained near 65 mph, and strengthening into a hurricane is expected later in the day or on Oct. 7. Computer models also have Norbert taking a turn toward the Baja California and approaching that area by the end of the week.

Meanwhile on Oct. 6, Norbert was still sitting in the waters of the Eastern Pacific Ocean, about 340 miles south of Manzanillo, Mexico, near latitude 14.1 north and longitude 103.9 west. Norbert is moving west near 7 mph and will continue west-northwestward over the next couple of days. The estimated minimum central pressure was 993 millibars.

TRMM Checks Norbert's Rainfall from Space

The image above was made from data captured by the Tropical Rainfall Measuring Mission (TRMM) satellite on October 5 at 22:02 UTC (2:22 p.m. EDT). This TRMM image shows the horizontal pattern of rain intensity within Norbert. The center is to the lower right of the red line that bisects the storm. Most of the rainfall is located on the southwest and west sides of the storm in the yellow, green and red areas, which indicate rainfall between 20 and 40 millimeters (.78 to 1.57 inches) per hour. The very tiny red areas are considered moderate rainfall.

For more information about how TRMM looks at rainfall, visit NASA's TRMM website at: http://trmm.gsfc.nasa.gov/. TRMM is a joint mission between NASA and the Japanese space agency JAXA.

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