Tag: Willa 2018

Oct. 26, 2018 – NASA’s IMERG Reveals Hurricane Willa’s Rainfall

NASA uses satellite data to calculate the amount of rainfall generated from tropical cyclones, and used that capability for the Eastern Pacific Ocean’s Hurricane Willa.

Tropical Depression 24E formed on October 20, 2018 and later in the day became tropical storm Willa. The tropical depression rapidly intensified and was a category five hurricane with winds of over 161 mph (140 knots) on October 22. Willa had weakened to category three intensity when it made landfall in Sinaloa, Mexico on October 24, 2018. Moisture streaming from Willa’s remnants added to the soaking of the already water logged state of Texas. Moisture from Willa’s remnants contributed to storms over the Southeast and to the developing Nor’easter moving over the East Coast.

At NASA’s Goddard Space Flight Center in Greenbelt, Maryland a rainfall accumulation analysis was generated by totaling Integrated Multi-satellitE Retrievals for GPM (IMERG) data for the period from October 20 to 26, 2018.  The IMERG rainfall accumulation data indicated that Willa produced rainfall totals greater than 20 inches (508 mm) in the Pacific Ocean off Mexico’s coast. IMERG data also indicated that rainfall accumulations of over 15 inches (381 mm) occurred in parts of Mexico and Southeastern Texas.

A rainfall accumulation analysis was generated by totaling Integrated Multi-satellitE Retrievals for GPM (IMERG) data for the period from October 20 to 26, 2018. Hurricane Willa’s approximate 0000Z and 1200Z locations are shown on this analysis. Willa produced rainfall totals greater than 20 inches (508 mm) in the Pacific Ocean off Mexico’s coast. IMERG data also indicated that rainfall accumulations of over 15 inches (381 mm) occurred in parts of Mexico and Southeastern Texas. Credit: NASA/JAXA, Hal Pierce

IMERG data are generated every half hour by NASA’s Precipitation Processing System by merging data from the satellites in the GPM Constellation, and calibrating those data with measurements from the GPM Core Observatory as well as rain gauge networks around the world. IMERG data are provided for much of the globe. Full coverage is calculated over latitudes from 60 degrees north to 60 degrees south with the remaining areas of the globe being partially covered.

The Integrated Multi-satellitE Retrievals for GPM (IMERG) creates a merged precipitation product from the GPM constellation of satellites. These satellites include DMSPs from the U.S. Department of Defense, GCOM-W from the Japan Aerospace Exploration Agency (JAXA), Megha-Tropiques from the Centre National D’etudies Spatiales (CNES) and Indian Space Research Organization (ISRO), NOAA series from the National Oceanic and Atmospheric Administration (NOAA), Suomi-NPP from NOAA-NASA, and MetOps from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).  All of the instruments (radiometers) onboard the constellation partners are intercalibrated with information from the GPM Core Observatory’s GPM Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR).

GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

By Hal Pierce
NASA’s Goddard Space Flight Center

Oct. 24, 2018 – Satellite Imagery Shows Willa Dissipated Over Mexico

Satellite data showed a shapeless area of clouds over northeastern Mexico on Oct. 24 where former hurricane Willa has dissipated. NOAA’s GOES-West satellite captured a visible image of Willa’s remnant clouds.

On Oct. 24 at 12 p.m. EDT (1600 UTC), NOAA’s GOES-West satellite provided a visible image of Willa’s remnant clouds. Satellite images and surface observations indicate that Willa’s surface circulation has dissipated over northeastern Mexico.

At 11 a.m. EDT (1500 UTC), the remnants of Willa were located near latitude 25.5 degrees north and longitude 101.5 degrees west. That’s about 75 miles (120 km) west of Monterrey Mexico. The remnants are moving toward the northeast near 28 mph (44 kph) and this general motion is expected to continue today. Maximum sustained winds had decreased to near 25 mph (35 kph) with higher gusts. The estimated minimum central pressure is 1008 millibars.

The National Hurricane Center noted “A non-tropical cyclone that is forecast to move from the Gulf of Mexico to the northeastern United States over the next few days is a separate system, and not directly associated with Willa’s remnants.”

By Rob Gutro
NASA’s Goddard Space Flight Center

Oct. 23, 2018 – NASA Eyes Powerful Hurricane Willa Affecting Western Mexico

NASA’s Aqua satellite provided an infrared view of Hurricane Willa as it continued moving toward landfall in western Mexico on Oct. 23. NASA-NOAA’s Suomi NPP satellite provided a visible look at the extent and structure of the storm. Willa is expected to bring life-threatening storm surge, wind, and rainfall to portions of west-central and southwestern Mexico.

NASA Satellite Imagery Reveal

On Oct. 22, NASA-NOAA’s Suomi NPP satellite captured a visible image of Hurricane Willa when it was battering western Mexico with heavy rainfall, rough surf and strong winds. The image showed powerful thunderstorms circling a cloud-filled eye and the storm stretched from Sinaloa state south to Michoacan state.

NASA’s Aqua satellite passed over Hurricane Willa on Oct. 23 at 4:47 a.m. EDT (0847 UTC) and the Atmospheric Infrared Sounder or AIRS instrument aboard analyzed cloud top temperatures using infrared light. Coldest cloud top temperatures were as cold as or colder than 208 Kelvin or minus 85.2 degrees Fahrenheit (minus 65.1 Celsius). Cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

Watches and Warnings on Oct. 23, 2018

A Hurricane Warning is in effect for San Blas to Mazatlan, including Las Islas Marias. A Tropical Storm Warning is in effect for Playa Perula to San Blas and north of Mazatlan to Bahia Tempehuaya.

Status of Hurricane Willa on Oct. 23 at 11 a.m. EDT

At 11 a.m. EDT on Oct. 23, NOAA Hurricane Hunter Aircraft found that the center of Hurricane Willa was passing over Las Islas Marias, Mexico. The center of Hurricane Willa was located near latitude 21.4 degrees north and longitude 106.9 degrees west.  Willa is moving toward the north-northeast near 6 mph (9 kph). A faster motion toward the northeast is expected by this evening. Maximum sustained winds are near 125 mph (205 kph) with higher gusts.  Willa is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.  Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km).

The National Hurricane Center noted “While gradual weakening is forecast today, Willa is expected to be a dangerous hurricane when it reaches the coast of Mexico.  Rapid weakening is expected after landfall tonight and continuing into Wednesday (Oct. 24).

On the forecast track, the center of Willa will make landfall within the hurricane warning area along the west-central coast of mainland Mexico this evening.”

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Oct. 22, 2018 – Dangerous Hurricane Willa Probed By NASA and Japan’s GPM Satellite

Hurricane Willa is a major hurricane threatening western Mexico. Forecasters were able to see the rate of rainfall occurring within the powerful storm when the Global Precipitation Measurement mission or GPM’s core satellite passed overhead and provided that data.

On Oct. 22, the National Hurricane Center or NHC noted that “Will became a potentially catastrophic category 5 hurricane on the Saffir-Simpson hurricane wind scale and is expected to produce life-threatening storm surge, wind, and rainfall over portions of west-central and southwestern Mexico.”

Willa’s Rapid History

Willa formed on Saturday, Oct. 20 and quickly became a tropical storm. By 5 p.m. EDT, Willa strengthened into a major hurricane and continued to strengthen.

Hurricane Willa was a Category 4 hurricane and moving northward toward the western coast of Mexico when the GPM core observatory passed above on October 21, 2018 at 3:51 p.m. EDT (1951 UTC). At that time, the hurricane had maximum sustained winds of about 95 mph (109 knots).

GPM Satellite Provides Rainfall Rates

GPM’s Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments collected data showing that hurricane Willa and feeder bands were producing heavy rainfall over a large area. The location of precipitation in Willa’s well defined eye wall was made evident by GPM’s radar (DPR Ku Band). DPR indicated that a few powerful convective storms within Willa were dropping rain at a rate of over 6.3 inches (160 mm) per hour.

At NASA’s Goddard Space Flight Center in Greenbelt, Md. a simulated 3-D view was created of the storm looking from the south-southeast reveals hurricane Willa’s rainfall structure. It was developed using GPM’s radar data (DPR Ku Band). That DPR data enabled a cross-section view that shows the anatomy of precipitation around hurricane Willa’s eye. Intense radar echoes of up to 57dBZ are shown (dark red) in this slice through the center of the intensifying hurricane. GPM’s radar shows that a few powerful storms in the eye of the hurricane were reaching heights above 8.7 miles (14.0 km). These tall storms referred to as “hot towers” are often an indication of hurricane intensification. These powerful convective storms near the center of the hurricane were releasing energy in the form of latent heat of condensation that powers the hurricane.

GPM is a joint mission between NASA and JAXA, the Japan Aerospace Exploration Agency.

Willa’s Expected Rainfall

The National Hurricane Center said “Willa is expected to produce storm total rainfall accumulations of 6 to 12 inches, with local amounts to 18 inches, across portions of western Jalisco, western Nayarit, and southern Sinaloa in Mexico.  This rainfall will cause life-threatening flash flooding and landslides. Farther inland, Willa is expected to produce rainfall amount of 2 to 4 inches across portions of Zacateca, Durango, southeast Chihuahua, and Coahuila in Mexico, with local amounts to 6 inches possible. This rainfall could cause life-threatening flash flooding.”

Warnings and Watches in Effect on Oct. 22

A Hurricane Warning is in effect for San Blas to Mazatlan, including Las Islas Marias. A Tropical Storm Warning is in effect for Playa Perula to San Blas and north of Mazatlan to Bahia Tempehuaya.

GPM passed above Willa on October 21, 2018 at 3:51 p.m. EDT (1951 UTC). The location of precipitation in Willa’s well defined eye wall was made evident by GPM’s radar (DPR Ku Band). DPR indicated that a few powerful convective storms within Willa were dropping rain at a rate of over 6.3 inches (160 mm) per hour. GPM’s radar shows that a few powerful storms in the eye of the hurricane were reaching heights above 8.7 miles (14.0 km).  Click to see 3-D flyby animation. Credit: NASA/JAXA, Hal Pierce

Status of Willa on Oct. 22

At 11 a.m. (1500 UTC) on Oct. 22 the center of Hurricane Willa was located near latitude 19.1 degrees north, longitude 107.2 degrees west.  About 175 miles (280 km) south-southwest of Las Islas Marias Mexico. Willa is moving toward the north near 7 mph (11 kph), and this general motion is expected to continue today.

Satellite data indicate that the maximum sustained winds have increased to near 160 mph (260 kph) with higher gusts.  Willa is a category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale.

Some strengthening is still possible today.  Slight weakening is forecast to begin on Tuesday, but Willa is expected to be an extremely dangerous major hurricane when it reaches the coast of Mexico. Hurricane-force winds extend outward up to 30 miles (45 km) from the center and tropical-storm-force winds extend outward up to 105 miles (165 km).

The National Hurricane Center (NHC) predicts Willa to accelerate toward the north-northeast and move over or very near the Islas Marias early Tuesday and make landfall along the southwestern coast of mainland Mexico in the hurricane warning area Tuesday afternoon or evening.

For details on Storm Surge, Wind and Surf, visit: www.nhc.noaa.gov.

By Harold F. Pierce / Rob Gutro
NASA Goddard Space Flight Center