Satellites See Ups and Downs of Two Tropical Eastern Pacific Systems
[image-126]There are two tropical cyclones in the Eastern Pacific Ocean on July 5 and one is powering up and one is powering down. NOAA’s GOES-15 satellite captured Tropical Depression Dalila and Tropical Storm Erick, both off the western coast of Mexico. Because Erick is strengthening and is close to the coast, tropical storm warnings have gone into effect for Mexico.
Tropical Depression Dalila has weakened from a Category 1 hurricane status and is expected to dissipate in the next day or two. Meanwhile, Tropical Storm Erick grew from a low pressure area called System 97E into the fifth tropical depression on July 4 and then into a tropical storm later in the day.
NOAA’s GOES-15 satellite captured an image of the two tropical cyclones just before daylight reached the Pacific coast on July 5 at 1200 UTC (8 a.m. EDT/5 a.m. PDT). In the GOES-15 infrared image, Tropical Storm Erick is 550 nautical miles east of the much smaller Tropical Depression Dalila. Because of the close proximity of the storms, the National Hurricane Center bulletin of July 5 at 11 a.m. EDT noted Tropical Depression Dalila does not have much of a future as a tropical cyclone due to moderate southeasterly vertical wind shear being created by the outflow from Tropical Storm Erick.
NOAA manages the GOES-15 satellite, and the NASA GOES Project at NASA’s Goddard Space Flight Center in Greenbelt, Md. created the image.
Tropical Depression Dalila
At 11 a.m. EDT on July 4, Dalila was a tropical storm with maximum sustained winds near 40 mph (65 kph). It was centered near 17.4 north and 109.8 west, about 380 miles (610 km) south of the southern tip of Baja California.
Twenty-four hours later at 11 a.m. EDT on July 5, Dalila had weakened further and was a tropical depression. At that time, Dalila’s maximum sustained winds were near 35 mph (55 kph). It had moved to 17.1 north and 111.7 west, about 415 miles (670 km) south-southwest of the southern tip of Baja California. Dalila was still moving to the west, but had slowed to 3 mph (6 kph) and had a minimum central pressure of 1006 millibars.
There are two things that are forcing Dalila's demise: dry air and wind shear. Wind shear from the east has been battering Dalila and dry air has moved into the storm suppressing formation of thunderstorms. Dalila is expected to become a remnant low in the next day or two.
Tropical Storm Erick
Tropical storm warnings are now in effect for the coast of southwestern Mexico eastward to Zihautanejo and westward to La Fortuna, Mexico. There is also a tropical storm watch now in effect for the coast of southwestern Mexico from west of La Fortuna to Cabo Corrientes.
Those warnings and watches are in effect as of July 5 because Tropical Storm Erick is near the coast and strengthening. The National Hurricane Center expects Erick may strengthen to hurricane force by Saturday, July 6. That would make Erick the fourth hurricane of the Eastern Pacific Hurricane Season out of five storms to form.
At 11 a.m. EDT on July 5, the National Hurricane Center (NHC) noted the Erick was located about 150 miles (245 km) south of Lazaro Cardenas, Mexico, near latitude 15.8 north and longitude 102.1 west. Erick’s maximum sustained winds had grown to 60 mph (95 kph) and strengthening is expected. Erick is moving to the west-northwest near 10 mph (17 kph) and is expected to continue moving in that direction over the next several days.
Tropical-storm-force winds extend outward up to 90 miles (150 km) from the center and the GOES-15 imagery shows that Erick’s cloud cover has a larger extent.
Residents in the warning area can expect3 to 5 inches over southwestern Oaxaca, southern Guerrero, southern Michoaca, Colima, and southern Jalisco, Mexico. The NHC noted that isolated totals could reach up to 8 inches in those areas. Tropical-storm-force winds are expected in the warning area today, July 5 and on July 6. Coastal areas can also expect rough surf as Erick moves up the coast.
Text credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, Md.
July 3, 2013: NASA Satellite Sees Dalila Become a Hurricane in Eastern Pacific
[image-94]The tropical storm that has been hugging the southwestern coast of Mexico moved toward open ocean and strengthened into a hurricane on July 2. NASA’s Aqua satellite passed over Dalila after moving away from the coast and strengthening into a hurricane. Dalila has become the third hurricane of the Eastern Pacific Ocean hurricane season after Barbara and Cosme. As Dalila starts to weaken, a new tropical low appears to be developing to the southeast.
On July 2 at 20:55 UTC (4:55 p.m. EDT) flew over Dalila after the storm became a hurricane. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard Aqua took a visible image of Dalila west of the Mexican state of Jalisco. The MODIS image showed strong thunderstorms around the center of circulation and bands of thunderstorms streaming into the center from the northern and southern quadrants. Infrared data from NASA’s Atmospheric Infrared Sounder or AIRS instrument that also flies aboard Aqua showed that cloud top temperatures are as cold as -80 Celsius or -112 Fahrenheit.[image-110]
At 5 a.m. EDT (0900 UTC) on July 3, Dalila had maximum sustained winds near 75 mph (120 kph) making it a Category 1 hurricane. Dalila’s center was near latitude 18.1 north and longitude 107.5 west, about 220 miles (350 km) west-southwest of Manzanillo, Mexico. Dalila is moving toward the southwest near 2 mph (4 kph) and the National Hurricane Center expects a slow west-southwestward or southwestward motion over the next day or two, then a turn to the west on July 4, after which time the storm is expected to weaken. The estimated minimum central pressure is 987 millibars.
Although the storm is off the coast of Mexico, coastal areas can expect very rough surf for the next couple of days as the storm continues moving westward. The National Hurricane Center noted that swells generated by Dalila are affecting portions of the southwestern coast of Mexico from near Zihuatanejo to Cabo Corrientes. These swells could cause life-threatening surf and rip current conditions.
Meanwhile, southwest of Dalila, the broad low pressure area called System 97E continues developing several hundred miles south of the Gulf of Tehuantepec. According to NHC, environmental conditions are expected to gradually become more conducive for development over the next couple of days, so System 97E has a medium chance...50 percent...of becoming a tropical cyclone in the next two days as it moves in a westerly direction at about 10 mph.
NASA’s Goddard Space Flight Center
July 02, 2013 - NASA Sees Tropical Storm Dalila Weaken, New Low Pressure Area Form
NOAA’s GOES-15 satellite captured an infrared image of the Eastern Pacific Ocean during the pre-dawn hours on July 2 and noticed Tropical Storm Dalila weakening near the southwestern Mexico coast, while further southwest a new tropical low pressure area called System 97E, had formed.[image-78]
Dalila’s maximum sustained winds appeared to peak on July 1 at 11 p.m. EDT when they hit 70 mph (110 kph). By 5 a.m. EDT on July 2, Dalila’s maximum sustained winds dropped to 65 mph (100 kph). Dalila was also moving away from the southwestern coast of Mexico and headed into the open waters of the Eastern Pacific Ocean.
At 5 a.m. EDT on July 2, Dalila was located near 17.7 north latitude and 106.8 west longitude, about 185 miles (300 km) west-southwest of Manzanillo, Mexico. Dalila was moving to the west at 5 mph (7 kph) and had a minimum central pressure of 994 millibars.
The National Hurricane Center (NHC) expects Dalila to keep moving in a westerly direction with a little change in strength over the next couple of days.
NOAA’s GOES-15 satellite captured an infrared image of Dalila as it was pulling away from the coast on July 2 at 1200 UTC (8 a.m. EDT/5 a.m. PDT). In the imagery, the line of daylight is apparent just east of the System 97E. NOAA manages the GOES-15 satellite, and NASA's GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Md. created the image using the GOES-15 satellite data.
Satellite imagery has shown that the bands of thunderstorms appear to have decreased around the center. NHC forecasters noted that decrease is possibly due to a combination of moderate vertical wind shear from the southeast and dry air working its way into the storm. Microwave satellite imagery has helped place the center southeast of the previous NHC advisory position.
System 97E has formed off the coasts of southwestern Mexico and southwestern Guatemala. The low stretches for several hundred miles from the Gulf of Tehuantepec to southwestern Guatemala. The NHC noted that environmental conditions will become favorable for slow development, and System 97E has a medium chance (near 30 percent) of becoming a tropical depression over the next two days. The low is moving to the west to west-northwest at 10 mph (16 kph).
NASA’s Goddard Space Flight Center
July 1, 2012 - Satellite Shows Tropical Storm Dalila Hugging Mexico’s Southwestern Coast
System 96E became a tropical depression and quickly grew into Tropical Storm Dalila on June 30. Dalila has been hugging the coast of southwestern Mexico practically since it formed, and continues to do so on satellite imagery taken on July 1.[image-51]
Because of its close proximity to the coast, there's a tropical storm warning in effect for the southwestern coast of Mexico from Punta San Telmo to La Fortuna, and a Tropical Storm Watch from north of La Fortuna. That means 1 to 3 inches of rainfall expected over coastal areas of the Mexican states of Micohcan, Colima and Jaliso, and tropical storm force winds, today, July 1.
On Sunday, June 30, Dalila’s maximum sustained winds were near 40 mph (65 kph). By Monday, July 1 at 11 a.m. EDT, Dalila’s maximum sustained winds increased to 60 mph (95 kph). The National Hurricane Center expects Dalila to reach hurricane force over the next couple of days.
The storm was moving to the northwest at 9 mph (15 kph) and is expected to turn west-northwest and head out to sea. It was centered near 17.8 north and 105.8 west, about 130 miles (205 km) south-southeast of Manzanillo, Mexico. Minimum central pressure dropped from 1003 millibars on June 30 to 998 millibars on July 1, indicating intensification was occurring over that time.
NOAA’s GOES-15 satellite captured an infrared image of Tropical Depression Dalila on July 1 at 12:00 UTC (8 a.m. EDT) that showed how close to the southwestern coast of Mexico that Dalila is tracking. The image also showed strong thunderstorms were firing up around the center of circulation. The NOAA GOES image was created by the NASA GOES Project at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Two different computer models are presenting two different scenarios with Dalila, according to the National Hurricane Center (NHC). According to the latest NHC bulletin on the Dalila, the GFS model is forecasting a stronger storm that will move farther north, while the ECMWF model is forecasting a weaker storm that will move slowly southwest. The NHC forecast splits the difference on the intensity and calls for a westward motion in the next two days.
NASA’s Goddard Space Flight Center