Nov. 19, 2020 – NASA Aids Disaster Response after Eta and Iota Hit Central America
With up to 155-mph winds, Hurricane Iota smashed record books on Nov. 16 as the strongest hurricane ever recorded to make landfall in Nicaragua. Iota reached Category 5 strength before making landfall as a Category 4 storm near the town of Haulover, Nicaragua.
The onslaught of destructive winds and heavy rainfall was unfortunately familiar to a region that recently suffered another Category 4 landfalling storm – Hurricane Eta – just two weeks earlier. Eta was a Category 4 storm with 140-mph winds when it landed in Nicaragua on Nov. 3 before ripping a wide path of destruction through Honduras and Guatemala.
Heavy rainfall from these two storm systems brought widespread flooding to the region, triggered large and numerous landslides in Guatemala and Honduras, and was responsible for numerous casualties.
NASA’s Earth Applied Sciences Disasters Program supports disaster response and risk reduction efforts throughout the world — before, during, and after disasters strike – and is working to aid Central America with the impacts from these storms.
In the case of Eta and Iota, the Program is using imagery and data from Earth-observing satellites to provide scientific analysis to Guatemala’s National Coordinator for Disaster Reduction and is working with the Coordination Center for Disaster Prevention in Central America. The multi-agency collaboration is assisting local governments in Nicaragua, Honduras and Guatemala, El Salvador, Belize, Costa Rica, and Panama. The Program is also working with U.S. Southern Command to provide situational awareness for potential emergency humanitarian assistance.
The interactive map above shows some highlights of key data products the Disasters Program is using. Specifically, the Program is sharing products such as those (and others in the NASA Disasters Mapping Portal) in frequent coordination meetings to help quantify flood and landslide risk in the region.
One example is the landslide detection maps from the Semi-Automatic Landslide Detection (SALaD) project, which use machine learning to analyze data from commercial Planet Labs satellites and the European Space Agency (ESA) Copernicus Sentinel-2 satellite. ESA Sentinel-2 data was also used to detect likely flooded areas at Honduras’ San Pedro Sula airport. The Program can take the landslide and flood detection data, then combine it with openly available population data and road maps, and deliver actionable guidance to local decision makers on where to best direct their response efforts.
Nov. 17, 2020 – Dangerous Hurricane Iota Sets Late-Season Records
Less than two weeks after being hit by category 4 Hurricane Eta, several Central American countries braced for the arrival of category 5 Hurricane Iota. NASA and NOAA covered the storm with an array of Earth-observing instruments.
The National Oceanic and Atmospheric Administration (NOAA) GOES-16 satellite (one of many geostationary NOAA satellites developed and launched by NASA) captured a natural-color image on Nov. 16 at 10 a.m. local time when the storm was at its peak strength. Iota’s eye was visible and surrounded by powerful thunderstorms. Credit: NOAA/NESDIS, Joshua Stevens, NASA Earth Observatory
Iota is the strongest hurricane and 30th named storm of the 2020 Atlantic season, the most since modern record keeping began (breaking the previous record of 28 set in 2005.) It also marked the first time that two hurricanes have formed in the Atlantic in any November. Iota is the 13th storm to reach hurricane strength this year; the average hurricane year brings six hurricanes.
On November 16 at 1 p.m. EDT, NOAA’s National Hurricane Center (NHC) issued hurricane warnings for large portions of coastal Nicaragua and Honduras as the storm approached landfall. Iota had strengthened to a category 5 storm with sustained winds of 260 kilometers (160 miles) per hour.
Iota made landfall at 10:40 p.m. EDT as a Category 4 hurricane with maximum sustained winds near 155 mph (250 kph) along the northeastern coast of Nicaragua near the town of Haulover, about 30 miles (45 km) south of Puerto Cabezas. Hurricane Iota’s landfall location was approximately 15 miles (25 km) south of where Category 4 Hurricane Eta made landfall on November 3.
This map shows sea surface temperatures on Nov. 15 near or above 27° Celsius/80.6 Fahrenheit (deep orange and red) in the Caribbean Sea and Gulf of Mexico. The warm water provided the fuel for both Hurricane Iota and Hurricane Eta (tracks overlaid on the map). Credit: NASA JPL MUR SST/Joshua Stevens, NASA’s Earth Observatory
Iota developed on Nov. 13 and strengthened to a hurricane two days later. Iota rapidly intensified in the warm waters of the Caribbean Sea. Within a day and a half, Iota’s wind speeds increased by 160 kilometers (100 miles) per hour.
Ocean temperatures must be near or above 27° Celsius (80.6 Fahrenheit) to sustain a tropical cyclone. Using data from NASA’s Multiscale Ultrahigh Resolution Sea Surface Temperature (MUR SST) project, NASA created a temperature map that showed sea surfaces in the Caribbean Sea and Gulf of Mexico at least that warm or warmer, which allowed for support and strengthening Hurricanes Iota and Eta. MUR incorporates temperature data from multiple NASA, NOAA, and international satellites, as well as ship and buoy observations.
By Michael Carlowicz, with scientific interpretation from Timothy Hall of the NASA Goddard Institute for Space Studies. For a more detailed version of this story, check out NASA’s Earth Observatory website.
Hurricane Eta (a Category 1) over Nicaragua on 11/4/2020 at approximately 5:25Z. This visualization focuses on the high precipitation southwest of Eta’s eye. Credit: NASA’s Scientific Visualization Studio
The Global Precipitation Measurement (GPM) Core Observatory satellite flew over Hurricane Eta at 11:41 p.m. CT on Tuesday, Nov. 3 (0541 UTC Wednesday, Nov. 4). GPM observed the storm’s rainfall with its two unique science instruments: the GPM Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR). As the visualization shows, the instruments observed a large swath of heavy precipitation extending to the north and east of the hurricane’s center, which matched earlier forecasts that called for particularly heavy rainfall across the storm’s path.
These two- and three-dimensional observations of precipitation structure are the hallmark of the GPM mission – managed jointly by NASA and the Japan Aerospace Exploration Agency (JAXA) — which aims improve our understanding of the water cycle and extreme weather events, and contributes to improved climate modeling and weather forecasting around the world.
These visualizations depict the GPM satellite pass about seven hours after Hurricane Eta made landfall on the coast of Nicaragua as a category 4 storm. Current NHC forecasts indicate Eta will move northwest over Central America then head northeast across the Caribbean Sea, threatening Cuba and Florida early next week.
Eta is the 28th named storm of 2020 which beats the 2005 record for the most named storms in a single hurricane season. (See 27 Storms: Arlene to Zeta for a summary of the 2005 hurricane season).
Hurricane Eta (a Category 1) on 11/4/2020 at approximately 5:25Z. This visualization focuses on the disperse outer bands northeast of the eye. Credit: NASA’s Scientific Visualization Studio
Color bar for frozen precipitation rates (ie, snow rates). Shades of cyan represent low amounts of frozen precipitation, whereas shades of purple represent high amounts of precipitation.Color bar for liquid precipitation rates (ie, rain rates). Shades of green represent low amounts of liquid precipitation, whereas shades of red represent high amounts of precipitation.
A natural-color image of Hurricane Zeta (above) was acquired in the late morning on October 28, 2020, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Cameras mounted on the International Space Station captured video footage of the storm (below) just before 1 p.m. that day. Credit: NASA’s Earth Observatory
By Jacob Reed, NASA Earth Applied Sciences Disaster Program
As Tropical Storm Zeta makes landfall on the U.S. Gulf Coast, NASA has eyes on the storm with an array of Earth-observing instruments and stands ready to aid affected communities with critical data and analysis.
Zeta is following a path similar to Hurricane Delta, which after crossing the Yucatan Peninsula made its way across the Gulf of Mexico and struck the Louisiana coast as a Category 2 hurricane on October 9. As Zeta makes landfall along the northern Gulf Coast, it’s the 7th named storm to do so in this record-breaking season, following Tropical Storm Cristobal, Hurricane Laura, Tropical Storm Marco, Hurricane Sally, Tropical Storm Beta, and Hurricane Delta.
Tropical Storm Zeta is the 27th named storm of 2020, which ties the record with 2005 for the most named storms. The 2020 season is also only the second time in recorded history (the other being 2005) that the Greek alphabet has been used because the number of named storms has exceeded the number of regular names on the list. With several weeks still left in the 2020 hurricane season, 2020 is expected to surpass this previous record for most named storms in one season.
Mapping Rainfall Rates and Structure
Zeta originated in the western Caribbean from a broad area of low pressure. Originally inhibited by changes in wind speeds and directions – also known as wind shear – the system was slow to develop. But by the late afternoon of Saturday October 24, the National Hurricane Center (NHC) reported that a tropical depression had formed, the 28th of the season. Nine hours later the system was upgraded to a tropical storm and given the name Zeta. Over the next twelve hours, Zeta remained nearly stationary and unable to intensify further. It was at about this time that the Global Precipitation Measurement Mission (GPM) Core Observatory satellite flew over Zeta at 2:15pm CDT (19:15 UTC), as shown in the animation.
GPM overpass of Tropical Storm Zeta on October 25 at approximately 2:15pm CDT (19:15 UTC). Half-hourly rainfall estimates from NASA’s multi-satellite IMERG dataset are shown in 2D on the ground, while rainfall rates from GPM’s DPR instrument are shown as a 3D point cloud, with liquid precipitation shown in green, yellow and red, and frozen precipitation shown in blue and purple. Credit: NASA Goddard Scientific Visualization Studio
Here, rainfall rates derived from the GPM Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR) instruments provide a detailed look at Zeta. While broad bands of rain circle the storm, GPM shows that the center itself is ragged and the eye of the storm is asymmetric. Warm, moist air rising up through the atmosphere (shown by the blue surface indicating the top heights of rain clouds) is producing very heavy rainfall (shown in dark red and magenta) near the center. These processes release heat near the center of the circulating storm, helping to consolidate it. At the time of the overpass, Zeta was still classified as a weak tropical storm with maximum sustained winds reported at 40 mph by the National Hurricane Center.
Zeta began to slowly but steadily strengthen, becoming a strong tropical storm overnight with sustained winds just below hurricane intensity early the next morning. Finally, at 2:10pm CDT on the October 26, Zeta reached hurricane intensity.
At this time Zeta was about 105 miles southeast of Cozumel, Mexico and moving northwest. Zeta would go on to make landfall near Tulum at 11:10pm CDT as a Category 1 storm with maximum sustained winds reported at 80 mph by the National Hurricane Center. After crossing the Yucatan Peninsula, Zeta weakened back down to a tropical storm, but re-emerged over the southern Gulf of Mexico. Surface water temperatures were running slightly above normal in this area – still at or above ~82.4 F (28 C), which is well above the ~78.8 F (26 C) typically needed to allow for intensification.
GPM Core Observatory overpass of Tropical Storm Zeta on October 28 at approximately 3:25am CDT (8:25 UTC). Credit: NASA Goddard Scientific Visualization Studio
GPM flew over Zeta again early the morning of October 28, around 3:25am CDT (8:25 UTC) as it was strengthening in the Gulf of Mexico and headed for landfall in southeastern Louisiana. Data captured by the DPR show a symmetric storm, with a clear eye surrounded by tall thunderstorms—an indicator that the storm was strengthening after encountering the Yucatan Peninsula a day earlier.
Cameras outside the International Space Station captured dramatic views of Hurricane Zeta at 12:50 pm ET October 28, as it churned 200 miles south-southwest of New Orleans packing winds of 90 miles an hour. Credit: NASA
Aiding Risk Reduction, Response and Recovery
To aid local communities in preparing for and recovering from hurricanes and other disasters, the NASA Earth Applied Sciences Disasters Program coordinates a team of experts across NASA centers to provide vital Earth-observing data and analysis. For Hurricanes Laura, Sally, and Delta, the program worked closely with stakeholders from the Federal Emergency Management Agency (FEMA), the Louisiana National Guard, and the Alabama Emergency Management Agency to provide guidance and analysis both in meetings and through data distributed on the NASA Disasters Mapping Portal. Near real-time data for tracking the storm is also made available on the portal’s Tropical Cyclone Dashboard. The program stands ready to continue to work with these agencies and provide assistance for Hurricane Zeta should the need arise.
Combining multiple datasets and tools allows NASA to see the big picture of a storm and its impacts, and helps answer broader questions about how communities can better prepare for, and recover from, the storms of the future. For Hurricane Zeta, researchers will have a unique opportunity to gauge the vulnerability or resilience of a region that was recently impacted by several destructive storms, and to study their compounding effects. Attempting to determine what damage was caused by which storm will be a challenging task on its own. However, attempting to answer these tough questions can provide critical guidance to help communities build back better and strengthen them for the disasters and challenges that lie ahead.
Tropical Storm Nangka made landfall south of Haiphong, Vietnam and began to weaken. NASA’s Aqua satellite revealed wind shear was affecting the storm as it continued to push inland.
On Oct. 14, 2020 at 2:25 a.m. EDT (0625 UTC), NASA’s Aqua satellite provided a visible image of Tropical Storm Nangka after it made landfall in northeastern Vietnam. Credit: NASA/NRL
The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite captured a visible image of Tropical Storm Nangka on Oct. 14, 2020 at 2:25 a.m. EDT (0625 UTC) that revealed after the storm made landfall it began weaken. In the imagery, strong storms continued to circle the center and were in the northern quadrant.
On Oct 14 at 5 a.m. EDT (0900 UTC), Nangka was centered near latitude 20.2 degrees north and longitude 106.1 degrees east, about 59 nautical miles southeast of Hanoi, Vietnam. Nangka tracked west-northwestward and further inland and was being affected by vertical wind shear.
In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels. Once a tropical cyclone makes landfall, the topography contributes to wind shear that weakens a storm’s circulation.
Nangka is forecast to move further inland while dissipating over the mountainous terrain of northwest Vietnam and northern Laos over the next day and a half.
About NASA’s Worldview and Aqua Satellite
NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”
NASA’s Aqua satellite is one in a fleet of NASA satellites that provide data for hurricane research.
Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
Oct. 14, 2020 – NASA Rainfall Imagery Reveals Norbert Regains Tropical Storm Status
Norbert has been meandering around in the Eastern Pacific Ocean for several days as a tropical depression. A NASA satellite rainfall product that incorporates data from satellites and observations revealed that Norbert has regained tropical storm status after showing increased organization and deep convection.
On Oct. 14 at 4:30 a.m. EDT (0830 UTC), NASA’s IMERG estimated Tropical Storm Norbert was generating as much as 30 mm(1.18 inches of rain [dark pink]) near the center of circulation. Rainfall throughout most of the storm was occurring between 5 and 15 mm (0.2 to 0.6 inches/yellow and green colors) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRLAt 11 p.m. EDT on Oct.13, Norbert regained tropical storm strength. At that time, the National Hurricane Center noted that Norbert had increased in organization during the evening hours and satellite data showed a tightly curved band of convection wrapping about halfway around the low-level center.
Norbert’s Status on Oct. 14
At 5 a.m. EDT (0900 UTC), the center of Tropical Storm Norbert was located near latitude 22.1 degrees north and longitude 113.3 degrees west. Norbert is moving toward the northwest near 15 mph (24 kph). A northwestward motion with a gradual decrease in forward speed is expected through tonight. Maximum sustained winds remain near 40 mph (65 kph) with higher gusts. Little change in strength is expected this morning, but the tropical storm is forecast to begin weakening by later today. Norbert is forecast to become a remnant low tonight or early Thursday, and dissipate by Thursday night.
Estimating Norbert’s Rainfall Rates from Space
NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated on Oct. 14 at 4:30 a.m. EDT (0830 UTC), Norbert was generating as much as 30 mm (1.18 inches) of rain per hour near the center of circulation. The National Hurricane Center noted that the exact location has been difficult to pinpoint in the area of deep convection.
Rainfall throughout most of the storm was estimated as falling at a rate between 5 and 15 mm (0.2 to 0.6 inches) per hour. At the U.S. Naval Laboratory in Washington, D.C., the IMERG rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite to provide a full extent of the storm.
What Does IMERG Do?
This near-real time rainfall estimate comes from the NASA’s IMERG, which combines observations from a fleet of satellites, in near-real time, to provide near-global estimates of precipitation every 30 minutes. By combining NASA precipitation estimates with other data sources, we can gain a greater understanding of major storms that affect our planet.
What the IMERG does is “morph” high-quality satellite observations along the direction of the steering winds to deliver information about rain at times and places where such satellite overflights did not occur. Information morphing is particularly important over the majority of the world’s surface that lacks ground-radar coverage. Basically, IMERG fills in the blanks between weather observation stations.
NASA Researches Tropical Cyclones
Hurricanes/tropical cyclones are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Oct. 13, 2020 – NASA Animation Tracks the End of Tropical Storm Delta
NASA’s Terra satellite obtained visible imagery as Tropical Storm Delta made landfall in Louisiana and moved northeastward soaking the U.S. southeast and Mid-Atlantic states.
NASA’s Terra satellite provided a visible image to forecasters of Tropical Storm Delta moving through the southeastern U.S. on Oct. 11 at 1:30 p.m. EDT. At the time of the image, the storm was centered over northern Alabama. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).
NASA Satellite View: Delta’s Organization
The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Delta on Oct. 11 at 1:30 p.m. EDT. The storm still appeared circular in imagery. At the time, it was centered over northern Alabama. At the time Terra passed overhead, Delta had weakened to a tropical depression with maximum sustained winds near 25 mph (35 kph).
Visible imagery from NASA’s Terra satellite captured from Oct. 9 to Oct. 12 were compiled into an animation. The animation showed the landfall and movement of Tropical Storm Delta. Delta dissipated over the southeastern U.S. and its remnants moved into the Atlantic states. The animation was created using NASA’s Worldview product at NASA’s Goddard Space Flight Center in Greenbelt, Md.
This animation of visible imagery from NASA Terra satellite shows the landfall and movement of Tropical Storm Delta from Oct. 9 to Oct. 12. Delta dissipated over the southeastern U.S. and its remnants moved into the Atlantic states. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).
Delta’s Landfall on Oct. 9
National Weather Service Doppler radar imagery, Air Force Reserve Hurricane Hunter aircraft data, and surface observations indicated on Oct. 9 that Delta made landfall near Creole, Louisiana, around 7 p.m. EDT with estimated maximum sustained winds of 100 mph (155 kph). Delta was a category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale.
Delta’s Final Advisory
The National Hurricane Center (NHC) issued the final advisory on Delta at 11 p.m. EDT on Oct. 11 (Oct. 12 at 0300 UTC). At that time, the center of Post-Tropical Cyclone Delta was located near latitude 34.5 degrees north and longitude 84.1 degrees west. It was just 60 miles (95 km) north-northeast of Atlanta, Georgia. The post-tropical cyclone was moving toward the east near 15 mph. Maximum sustained winds were near 15 mph (30 kph) with higher gusts.
NHC said, “Some further weakening is possible tonight as a new surface low develops in the Carolinas, and Delta’s surface low is expected to be absorbed by this new low pressure area on Monday, Oct. 12.”
About NASA’s Worldview and Terra Satellite
NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”
NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.
Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
Oct. 13, 2020 – NASA Sees Tropical Storm Nangka Soaking Hainan Island
Using a NASA satellite rainfall product that incorporates data from satellites and observations, NASA estimated Nangka’s rainfall rates as the storm soaked Hainan Island, China early on Oct. 13 (EDT).
On Oct. 13 at 8 a.m. EDT (1200 UTC), NASA’s IMERG estimated Tropical Storm Nangka was generating as much as 30 mm (1.18 inches of rain [dark pink]) around the center of circulation. Rainfall throughout most of the storm and in fragmented bands of thunderstorms to the north and east of the center, was occurring between 5 and 15 mm (0.2 to 0.6 inches/yellow and green colors) per hour. The rainfall data was overlaid on infrared imagery from Japan’s Himawari-8 satellite. Credit: NASA/NOAA/NRLNangka formed in the South China Sea and moved in a westerly direction over the last couple of days.
Nangka’s Status on Oct. 13
At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Nangka was located near latitude 19.1 degrees north and longitude 110.0 degrees east just over Hainan Island, China. It is about 286 nautical miles east-southeast of Hanoi, Vietnam. Nangka is moving toward the west-northwest.
Maximum sustained winds are near 50 knots (58 mph/93 kph) with higher gusts. Nangka is forecast to strengthen slightly in the Gulf of Tonkin (the body of water between Hainan Island, China and Vietnam) and then weaken as it moves toward Vietnam.
Estimating Nangka’s Rainfall Rates from Space
NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product estimated on Oct. 13 at 8 a.m. EDT (1200 UTC) that Nangka was generating as much as 30 mm (1.18 inches) of rain per hour around the center of circulation.
Rainfall throughout most of the storm and in fragmented bands of thunderstorms north and east of the center was estimated as falling at a rate between 5 and 15 mm (0.2 to 0.6 inches) per hour. At the U.S. Naval Laboratory in Washington, D.C., the IMERG rainfall data was overlaid on infrared imagery from Japan’s Himawari-8 satellite to provide a full extent of the storm.
What Does IMERG Do?
This near-real time rainfall estimate comes from the NASA’s IMERG, which combines observations from a fleet of satellites in near-real time to provide near-global estimates of precipitation every 30 minutes. By combining NASA precipitation estimates with other data sources, we can gain a greater understanding of major storms that affect our planet.
What the IMERG does is “morph” high-quality satellite observations along the direction of the steering winds to deliver information about rain at times and places where such satellite overflights did not occur. Information morphing is particularly important over the majority of the world’s surface that lacks ground-radar coverage. Basically, IMERG fills in the blanks between weather observation stations.
NASA Researches Tropical Cyclones
Hurricanes/tropical cyclones are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
Oct. 09, 2020 – GPM Captures Hurricane Delta on Approach to the Gulf Coast
The NASA / JAXA GPM Core Observatory satellite passed over Hurricane Delta Thursday October 8, 2020 at approximately 7:40pm CT (00:40 UTC on 10/9/2020), capturing data on the intensity of precipitation within the storm as it approached the Gulf Coast.
Credit: NASA
Hurricane Delta is the 25th named Atlantic storm of the 2020 hurricane season. After exhausting a list of prepared names, the World Meteorological Organization turns to the Greek alphabet to name storms. Delta marks the strongest Greek-named storm on record.
Hurricanes typically get a massive boost of energy when they pass over warm waters. Hurricane Delta rapidly intensified from a tropical depression to Category 4 storm in about 30 hours.
Oct. 09, 2020 – NASA Finds Hurricane Delta Packing Heavy Rainfall
NASA’s satellite rainfall product that incorporates data from satellites and observations found that Hurricane Delta was bringing along heavy rainfall as it headed to the U.S. Gulf Coast on Oct. 9.
On Oct. 9 at 5:30 a.m. EDT (0930 UTC), NASA’s IMERG estimated Delta was generating as much as 50 mm(~2 inches of rain [dark red]) around the center of circulation. Rainfall rates in storms surrounding those areas of heaviest rainfall (green, pink, red) were estimated as falling at a rate between 10 and 40 mm (0.4 to 1.6 inches) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRLWarnings and Watches in Effect on Oct. 9
There are many warnings in effect, as Delta approaches the U.S. Gulf coast. A Storm Surge Warning is in effect from High Island, Texas to Mouth of the Pearl River, Louisiana including Calcasieu Lake, Vermilion Bay, and Lake Borgne.
A Hurricane Warning is in effect from High Island, Texas to Morgan City, Louisiana. A Tropical Storm Warning is in effect from west of High Island to Sargent, Texas and east of Morgan City, Louisiana to the mouth of the Pearl River, including New Orleans and Lake Pontchartrain and Lake Maurepas.
Delta’s Status on Oct. 9
At 11 a.m. (1500 UTC), the center of Hurricane Delta was located near latitude 28.0 degrees north and longitude 93.8 degrees west. That is about 130 miles (205 km) south-southwest of Cameron, Louisiana.
Delta is moving toward the north near 13 mph (20 kph). A turn toward the north- northeast is expected this afternoon, followed by a northeastward motion during the day Saturday. Maximum sustained winds are near 115 mph (185 kph) with higher gusts. Delta is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. The latest minimum central pressure estimated from NOAA Hurricane Hunter aircraft data is 962 millibars.
Estimating Delta’s Rainfall Rates from Space
NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated Delta’s rainfall rates.
On Oct. 9 at 5:30 a.m. EDT (0930 UTC), NASA’s IMERG estimated Delta was generating as much as 50 mm (~2 inches of rain) around the center of circulation. Rainfall rates in storms surrounding those areas of heaviest rainfall were estimated as falling at a rate between 10 and 40 mm (0.4 to 1.6 inches) per hour.
At the U.S. Naval Laboratory in Washington, D.C., the IMERG rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite to provide a full extent of the storm.
What Does IMERG Do?
This near-real time rainfall estimate comes from the NASA’s IMERG, which combines observations from a fleet of satellites, in near-real time, to provide near-global estimates of precipitation every 30 minutes. By combining NASA precipitation estimates with other data sources, we can gain a greater understanding of major storms that affect our planet.
What the IMERG does is “morph” high-quality satellite observations along the direction of the steering winds to deliver information about rain at times and places where such satellite overflights did not occur. Information morphing is particularly important over the majority of the world’s surface that lacks ground-radar coverage. IMERG fills in the blanks between weather observation stations.
Delta’s Heavy Rainfall Forecast
NASA’s rainfall data is provided to forecasters at the National Hurricane Center and is reflected in one of the key messages.
NHC said, “Today through Saturday, Delta is expected to produce 5 to 10 inches of rain, with isolated maximum totals of 15 inches, from southwest into central Louisiana. These rainfall amounts will lead to significant flash, urban, small stream flooding, along with minor to major river flooding.
For extreme east Texas into northern Louisiana, southern Arkansas, and western Mississippi, Delta is expected to produce 3 to 6 inches of rain, with isolated maximum totals of 10 inches. These rainfall amounts will lead to flash, urban, small stream, and isolated minor river flooding.
As the remnants of Delta move further inland 1 to 3 inches of rain, with locally higher amounts, are expected in the Tennessee Valley and Mid- Atlantic this weekend. There is a potential for 3 to 6 inches in the Southern Appalachians, which could lead to isolated flash, urban, and small stream flooding.”
Additional NHC Key Messages
In addition the heavy and flooding rainfall expected, NHC’s other key messages are about storm surge, hurricane-force winds, isolated tornadoes and dangerous surf:
STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide:
Rockefeller Wildlife Refuge to Morgan City, LA including Vermilion Bay…7-11 ft
Holly Beach, LA to Rockefeller Wildlife Refuge, LA…5-8 ft
Sabine Pass to Holly Beach, LA…3-5 ft
Morgan City, LA to Port Fourchon, LA…4-7 ft
Port Fourchon, LA to the Mouth of the Mississippi River…2-4 ft
Calcasieu Lake…2-4 ft
High Island, TX to Sabine Pass…2-4 ft
Mouth of the Mississippi River to Mouth of the Pearl River…2-4 ft
Lake Borgne…2-4 ft
Lake Pontchartrain and Lake Maurepas…1-3 ft
Mouth of the Pearl River, LA to the AL/FL border including Mobile Bay…1-3 ft
Sabine Lake…1-3 ft
Port O’Connor, TX to High Island, TX including Galveston Bay…1-3 ft
It is important to note that small changes in the track, structure, or intensity of Delta could have large impacts on where the highest storm surge occurs.
WIND: Hurricane conditions are expected within the hurricane warning area by this afternoon, with tropical storm conditions expected within this area later this morning. Tropical storm conditions are expected within the tropical storm warning areas later today.
TORNADOES: A few tornadoes are possible today and tonight over southern portions of Louisiana and Mississippi.
SURF: Swells from Delta are affecting portions of the northern and western Gulf coast. These swells are likely to cause life-threatening surf and rip current conditions.
Delta’s Expected Track
NHC forecasters said slow weakening is expected before landfall, with rapid weakening expected after the center moves inland. On the forecast track, the center of Delta should make landfall along the coast of southwestern Louisiana later this afternoon or this evening, and then move across central and northeastern Louisiana tonight and Saturday morning.
NASA Researches Tropical Cyclones
Hurricanes/tropical cyclones are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.
For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.
