NASA Prepares for Hurricane Zeta

Terra image of Zeta
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.

Shortly after this overpass, the National Hurricane Center reported that Zeta had re-intensified to a Category 1 hurricane, and the NHC currently says Zeta is a Category 2 hurricane as it makes landfall along the southern coast of Louisiana Wednesday evening.

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 LauraSally, 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.

Nangka – Northwestern Pacific Ocean

Oct. 14, 2020 – NASA Finds Wind Shear Affecting Tropical Storm Nangka Post-Landfall  

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.

Aqua image of Nangka
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.

By Rob Gutro
NASA’s Goddard Space Flight Center

Norbert – Eastern Pacific Ocean

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.

IMERG data on Norbert
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/NRL
At 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.

For more information about NASA’s IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

For forecast updates on hurricanes, visit: www.hurricanes.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Delta – Atlantic Ocean

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.

Terra image of Delta
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.

Animated GIF of Delta's movements
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.

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

By Rob Gutro
NASA’s Goddard Space Flight Center

Nangka – Northwestern Pacific Ocean

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).

IMERG data on Nangka
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/NRL
Nangka 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.

For more information about NASA’s IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

For updated forecasts, visit the Hong Kong Observatory: https://www.hko.gov.hk/en/index.html

By Rob Gutro
NASA’s Goddard Space Flight Center

Delta – Atlantic Ocean

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.

GPM data on Delta
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.

By Jacob Reed
NASA Goddard Space Flight Center

Delta – Atlantic Ocean

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.

IMERG data on Delta
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/NRL
Warnings 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.

For more information about NASA’s IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

For updated forecasts, visit: www.hurricanes.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

Chan-hom – Northwestern Pacific Ocean

Oct. 09, 2020 – NASA Shows Heaviest Rainfall Displaced in Typhoon Chan-hom

Typhoon Chan-hom was still moving parallel to Japan’s east coast as NASA’s satellite rainfall product, that incorporates data from satellites and observations, showed its heaviest rainfall was pushed northeast of center.

IMERG data from Chan-hom
On Oct. 9 at 4:30 a.m. EDT (0830 UTC), NASA’s IMERG estimated Chan-hom was generating as much as 30 mm inches of rain (1.18  [dark pink]) just northeast of the center of circulation. Rainfall rates in storms surrounding those areas of heaviest (yellow and green colors) rainfall, were estimated to be falling at a rate between 5 and 15 mm (0.2 to 0.6 inches) per hour. On the southwestern side of the center, rainfall rates were occurring between 0.1 and 1 mm (0.003 and 0.03 inches) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRL
Chan-hom’s Status on Oct. 9

At 5 a.m. EDT (0900 UTC), the center of Chan-hom was located near latitude 30.9 degrees north and longitude 133.9 degrees east. That is approximately 413 nautical miles southwest of Yokosuka, Japan. Chan-hom was moving to the north-northeast. Maximum sustained winds are near 70 knots (81 mph/130 kph).

Estimating Chan-hom’s Rainfall Rates from Space

NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated Chan-hom’s rainfall rates on Oct. 9 at 4:30 a.m. EDT (0830 UTC).

Wind shear, outside winds at different speeds and directions that can adversely affect a tropical cyclone, were pushing Chan-hom’s heaviest rainfall northeast of the center. Chan-hom was generating as much as 30 mm (1.18 inches) of rain per hour just northeast of the center of circulation. Rainfall rates in storms surrounding those areas of heaviest rainfall were estimated as falling at a rate between 5 and 15 mm (0.2 to 0.6 inches) per hour. On the southwestern side of the center, rainfall rates were occurring between 0.1 and 1 mm (0.003 and 0.03 inches) per hour.

Forecasters at the Joint Typhoon Warning Center noted, “Chan-hom is tracking along the western periphery of a subtropical ridge (elongated area of high pressure) positioned to the east and through an overall unfavorable environment with moderate to high (25 knots/29 mph/46 kph) vertical wind shear.”

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.

Chan-hom’s Fate

Chan-hom will gradually weaken as it tracks generally east northeastward over the next day. In three days, the system is expected to become fully embedded in the westerly wind flow aloft. It is expected to complete extra-tropical transitioning becoming a cold core low-pressure area as it moves northeast and away from Japan.

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.

For more information about NASA’s IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

By Rob Gutro
NASA’s Goddard Space Flight Center

Chan-hom – Northwestern Pacific Ocean

Oct. 08, 2020 – NASA Sees Typhoon Chan-hom Blanket Japan

Typhoon Chan-hom’s clouds blanketed much of the big islands of Japan in a visible image from NASA’s Terra satellite. Chan-hom’s center was located southeast of Kyushu, Japan’s southernmost big island, but the western quadrant of the storm had a large reach.

Terra image of Chan-hom
On Oct. 8, 2020, NASA’s Terra satellite provided a visible image of Typhoon Chan-hom’s clouds blanketing much of Japan. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Chan-hom on Oct. 8. Chan-hom’s eye appeared to be obscured by high clouds, but a hint of it could be seen in the imagery. Powerful thunderstorms circled the 30 nautical-mile wide eye.

The satellite imagery was created using NASA’s Worldview product at NASA’s Goddard Space Flight Center in Greenbelt, Md.

Chan-hom’s Status on Oct. 8  

At 11 a.m. EDT (1500 UTC) on Oct. 8, the center of Typhoon Chan-hom was located near latitude 29.8 degrees north and longitude 133.4 degrees east. Chan-hom was about 475 nautical miles southwest of Yokosuka, Japan. The storm is moving toward the north-northeast. Maximum sustained winds have increased to near 80 knots (92 mph/148 kph) with higher gusts.
Chan-hom is forecast to continue weakening and track parallel to the eastern coast of Japan while remaining offshore. Its center is forecast to pass just offshore from Tokyo on Oct. 12 as it moves in a northeasterly direction. The storm is forecast to undergo transition into an extra-tropical storm over the next several days.

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.

By Rob Gutro
NASA’s Goddard Space Flight Center

Delta – Atlantic Ocean

Oct. 08, 2020 – NASA Examines Hurricane Delta’s Early Morning Structure

The NASA-NOAA Suomi NPP satellite provided two nighttime views of Hurricane Delta as it moved toward the U.S. Gulf Coast. A moonlit image and an infrared image revealed the extent and organization of the intensifying hurricane.

Hurricane Delta from Suomi NPP at night
The Waning Gibbous moon (65% illumination) was enough to see both the tropospheric waves as well as the central dense overcast and long ranging feeder bands in Hurricane Delta on Oct. 8 at 4:05 a.m. EDT. Credit: UWM/SSEC/CIMSS/William Straka III

Satellite Imagery Shows Delta’s Extent

On Oct. 8 at 4:05 a.m. EDT (0805 UTC), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured an infrared and nighttime imagery of Hurricane Delta as it moved through the Gulf of Mexico.

One hour before Suomi NPP passed overhead, Delta had winds of 100 mph, making it a Category 2 storm on the Saffir-Simpson Hurricane Wind Scale. “The imagery showed enhanced convection near the center of circulation, though the actual circulation was covered by a central dense overcast (CDO) feature, but the curved bands beyond that, extending all the way to the U.S., can also be seen,” noted William Straka III, researcher at University of Wisconsin – Madison’s Space Science and Engineering Center, Cooperative Institute for Meteorological Satellite Studies, Wisconsin.

Suomi NPP infrared image of Delta
On Oct. 8 at 4:05 a.m. EDT (0805 UTC), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite captured an infrared image of Hurricane Delta. It revealed enhanced convection near the center of circulation, and bands of thunderstorms extended all the way to the U.S.  Credit: UWM/SSEC/CIMSS/William Straka III

“The Waning Gibbous moon (65% illumination) was enough to see both the tropospheric waves as well as the CDO and long ranging feeder bands (of thunderstorms.”

On Oct. 8 at 3:35 a.m. EDT (0735 UTC) NASA’s Aqua satellite analyzed Delta using the Atmospheric Infrared Sounder or AIRS instrument.  AIRS found coldest cloud top temperatures as cold as or colder 210 Kelvin minus 81 degrees Fahrenheit (minus 63.1 degrees Celsius). NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain. The eye was obscured by high clouds and central dense overcast.

AIRS image of infrared
On Oct. 8 at 3:35 a.m. EDT (0735 UTC) NASA’s Aqua satellite analyzed Hurricane Delta using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder 210 Kelvin minus 81 degrees Fahrenheit (minus 63.1 degrees Celsius). The eye was obscured by high clouds. Credit: NASA/JPL/Heidar Thrastarson

NASA provides all of this data to tropical cyclone meteorologists so they can incorporate it in their forecasts.

NHC forecaster Jack Beven noted, “Satellite imagery shows that Delta is better organized this morning, with the center well embedded in a cold central dense overcast and a hint of an eye developing in the overcast.”

Watches and Warnings on Oct. 8

NOAA’s National Hurricane Center (NHC) has issued various warnings and watches for Delta’s approach to the U.S. mainland.

A Storm Surge Warning is in effect for High Island, Texas to Ocean Springs, Mississippi including Calcasieu Lake, Vermilion Bay, Lake Pontchartrain, Lake Maurepas, 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 San Luis Pass, Texas and from east of Morgan City Louisiana to the mouth of the Pearl River, including New Orleans. A Hurricane Warning is also in effect for Lake Pontchartrain and Lake Maurepas.

A Tropical Storm Watch is in effect from east of the mouth of the Pearl River to Bay St. Louis Mississippi.

Delta’s Status on Oct. 8

At 11 a.m. EDT (1500 UTC), the center of Hurricane Delta was located near latitude 24.0 degrees north and longitude 92.7 degrees west. That is about 400 miles (645 km) south of Cameron, Louisiana. Delta was moving toward the northwest near 14 mph (22 kph), and this motion with a reduction in forward speed is expected today.  Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 105 mph (165 kph) with higher gusts.  The latest minimum central pressure reported by the Hurricane Hunter aircraft is 968 millibars.

Delta’s Forecast

NHC expects a turn toward the north by late tonight, followed by a north-northeastward motion by Friday afternoon or Friday night.  Additional strengthening is forecast, and Delta is expected to become a major hurricane again by tonight.  On the forecast track, the center of Delta will move over the central Gulf of Mexico today, over the northwestern Gulf of Mexico on Friday. Some weakening is possible as Delta approaches the northern Gulf coast on Friday, with rapid weakening expected after the center moves inland within the hurricane warning area Friday afternoon or Friday night.

NASA Researches Earth from Space

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.

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

By Rob Gutro 
NASA’s Goddard Space Flight Center