Featured Images

Text Size

Hurricane Season 2008: Tropical Storm Lowell (Eastern Pacific)
 
Sept. 11, 2008

Tropical Depression Lowell Headed to Mainland Mexico

On Thursday, September 11, at 11:00 a.m. EDT Tropical Depression Lowell was still packing maximum sustained winds near 30 mph, and was moving over the southern Gulf of California and creating locally heavy rainfall over southern Baja California. Lowell is on a track to the mainland of Mexico.

QuikSCAT Watching Tropical Depression Lowell's Winds

NASA's Quick Scatterometer satellite (QuikScat) has been watching Lowell's winds decrease, by using microwaves to peer into the clouds. QuikScat can determine the speed of the rotating winds. This image from QuikScat shows Lowell's 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), but as this image shows, the winds are simply not that strong. The strongest winds are represented in the center of circulation, depicted in blue in this image. This image was captured on Sept. 10 at 13:42 UTC (9:42 p.m. EDT).

Quikscat image of Ike from Sept. 11, 2008
> Larger image
Credit: NASA/JPL At 11:00 a.m. EDT (8 a.m. PDT) Lowell's center was about 75 miles northeast of Cabo San Lucas, Mexico and about 140 miles south of Los Mochis, Mexico, that's near latitude 23.8 north and longitude 109.2 west. Lowell was moving northeast near 10 mph and will continue for another day. The estimated minimum central pressure is 1001 millibars.

Heavy rainfall will still be possible across portions of southern Baja and mainland Mexico; up to 1 to 3 inches across southern Baja California today and 2 to 4 inches (up to 6 in isolated areas) over portions of the states of Sinaloa and Sonora on the mainland. Lowell is expected to dissipate sometime on Saturday, Sept. 13 over mainland Mexico. Text credit: Rob Gutro/Goddard Space Flight Center

Sept. 9, 2008

Tropical Depression Lowell Fading into a Remnant Low

Lowell fades into a Remnant Low Credit: NASA JPL
> Larger image A "Remnant Low" or low pressure system is what tropical depressions degrade to in its dissipation stages, and that's what Tropical Depression Lowell is expected to become by Thursday, Sept. 11.

On Sept. 10, at 2:00 p.m. EDT, Lowell had sustained winds near 35 mph, and was weakening in the eastern Pacific Ocean. Lowell's center was located 130 miles west-southwest of the southern top of Baja California, near 22.6 north and 112.0 west.

Lowell was moving northeast near 7 mph and will continue in that direction for another 12 hours, moving across the southern Baja California peninsula during the overnight hours into Thursday, Sept. 11. The minimum central pressure was 1005 millibars.

Lowell is expected to produce 1 to 3 inches of rainfall through Thursday across southern Baja California. Moisture from Lowell could spread into the adjacent portions of the states of Sinaloa and Sonora in mainland Mexico and produce 1 to 3 inches of rain during the next couple of days.

This infrared image of Lowell was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on September 8 at 9:29 UTC (5:29 a.m. EDT).

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest cloud temperatures, usually visualized in purple, are nowhere to be seen in Lowell, indicating that the storm is fading. The second coldest temperatures that are associated with highest, coldest cloud tops that make up the top of Lowell appear in blue. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

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 surface of the ocean waters, revealing warmer temperatures in orange and red.

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



Sept. 9, 2008

Tropical Storm Lowell Weakening, But Still Headed to Baja California

QuickSCAT image showing Lowell's winds Credit: NASA JPL
> Larger image The National Hurricane Center urged residents of the southern Baja California to keep an eye out for Tropical Storm Lowell.

At 8:00 a.m. EDT on Sept. 9, Tropical Storm Lowell's maximum sustained winds have decreased to near 45 mph. and will likely continue weakening. Tropical Storm Lowell was about 265 miles west-southwest of the southern tip of Baja California and about 275 miles south-southwest of Cabo San Lazaro, Mexico. That's near latitude 21.0 north and longitude 113.5 west.

Lowell is moving toward the northwest near 7 mph and should turn northward. Lowell's center forecast to approach the west coast of southern Baja California late Wednesday or early Thursday. The estimated minimum central pressure is 1002 millibars.

QuikSCAT Watching Lowell's Winds

NASA's Quick Scatterometer satellite (QuikScat) has been watching Lowell's winds by using microwaves to peer into the clouds. QuikScat can determine the speed of the rotating winds, and its data is used by forecasters at the National Hurricane Center.

This image from QuikScat shows Lowell's 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 around Lowell's eye, and are shown in purple which indicate winds over 40 knots (46 mph). This image was captured on Sept. 9 at 1:19 UTC (Sept. 8, 9:11 p.m. EDT).

AIRS image of Lowell near Baja, California Credit: NASA JPL
> Larger image NASA's Aqua Satellite Captures a Shot of Lowell's Cold Clouds

This infrared image of Lowell was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on Sept. 8 at 20:41 UTC (4:41 p.m. EDT).

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The coldest cloud temperatures are in purple located around Lowell's center. The second coolest temperatures are in blue, which make up the clouds outside of Lowell's eye. Those areas in purple have some of the strongest storms.

Scientists use the AIRS data to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters. AIRS' infrared signal doesn't penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

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


Sept. 8, 2008

Two NASA Satellites Analyze Lowell's Clouds; Headed to the Baja

Satellite image of Lowell Credit: NASA/JPL
> Larger image Tropical Storm Lowell is churning in the eastern Pacific Ocean southwest of the Baja California, and two NASA satellites are giving scientists different views of his clouds. CloudSat can tell how high and wide the storm is, and an instrument on NASA's Aqua satellite can see the temperatures in the clouds, to help determine the storm's strength.

While scientists are watching Lowell's strength, because he's a strong tropical storm, the forecasters at the National Hurricane Center are also watching his possible track. On Monday, Sept. 8, the forecast track calls for Lowell to make a right hook and make landfall in Baja California by Sept. 11, Thursday.

As of 5:00 a.m. EDT (2:00 a.m. PDT) on Sept. 8, however, Lowell was located near latitude 18.2 north and longitude 110.6 west or about 50 miles south-southeast of Socorro Island and about 330 miles south of the southern tip of Baja California. Lowell is moving toward the west-northwest near 10 mph.

Maximum sustained winds are near 60 mph with higher gusts. Some slight strengthening is forecast today or tonight and little change in strength expected on Tuesday, Sept. 9. Estimated minimum central pressure is 998 millibars.

NASA's Aqua Satellite Checks Lowell's Temperature

This infrared image of Lowell was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on September 7 at 9:05 UTC (5:05 a.m. EDT).

The AIRS images show the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the tropical cyclone. The AIRS data creates an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters.

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 surface of the ocean waters, revealing warmer temperatures in orange and red.

CloudSat's Sideways View of Lowell Hints at His Strength

Satellite image of Lowell Credit: NASA/JPL/Colorado State University/Naval Research Laboratory-Monterey
> Larger image NASA's CloudSat satellite's Cloud Profiling Radar captured a sideways look across Lowell on Sept. 7 at 8:45 UTC (4:45 a.m. EDT). For comparison, the top image is from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite (GOES-12) around the same time.

The red line through the GOES satellite image shows the vertical cross section of radar, basically what the storm's clouds looked like sideways. The colors indicate the intensity of the reflected radar energy. The top of Lowell's clouds are over 14 kilometers (8.7 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
 
› Back To Top