Sep. 23, 2020 – NASA’s Terra Satellite Confirms Paulette’s Second Post-Tropical Transition
NASA’s Terra satellite passed over post-tropical storm Paulette after it had transitioned for a second time. Using infrared imagery, Terra found no strong storms remained.
On Sept. 23 at 8:45 a.m. EDT (1245 UTC), the MODIS instrument that flies aboard NASA’s Terra satellite gathered infrared data on Paulette and showed it was devoid of strong storms. Imagery revealed a small area of convection (yellow) where cloud top temperatures are as cold as minus 50 degrees Fahrenheit (minus 45.5 Celsius). Credit: NASA/NRL
Paulette has had quite a history. Paulette formed in the Central Atlantic Ocean on Sept. 6 as Tropical Depression Seventeen and became a tropical storm the next day. Paulette became a hurricane on Sept. 12. As a hurricane, Paulette’s eye passed directly over Bermuda, then weakened and became a post-tropical cyclone on Sept. 16 in the North Atlantic Ocean when it was located 450 miles (725 km) east-southeast of Cape Race Newfoundland, Canada. A Post-Tropical Storm is a generic term for a former tropical cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Then on Sept. 22, the remnants of Paulette organized and re-formed into a tropical storm. Only to devolve again to a post-tropical storm later that day.
At 11 p.m. EDT on Sept. 22 (0300 UTC on Sept. 23), Dan Brown, Warning Coordination Meteorologist, Senior Hurricane Specialist at NOAA’s National Hurricane Center in Miami, Fla. noted, “Paulette had been devoid of deep convection since early Tuesday and the shallow convection mentioned in the previous advisory has also waned. Therefore, Paulette has again become a post-tropical cyclone.”
NASA’s Terra Satellite Examines Paulette
NASA’s Terra satellite uses infrared light to analyze the strength of storms by providing temperature information about the system’s clouds. The strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.
On Sept. 23 at 8:45 a.m. EDT (1245 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite gathered infrared data on Paulette. There were no strong storms on the infrared MODIS imagery. The imagery found only one small area of convection where cloud top temperatures are as cold as minus 50 degrees Fahrenheit (minus 45.5 Celsius).
Final Status of Paulette
The last public advisory issued by the National Hurricane Center on Paulette was posted on Sept. 22 at 11 p.m. EDT (0300 UTC). At that time, the center of Post-Tropical Cyclone Paulette was located near latitude 34.8 degrees north and longitude 20.0 degrees west. That is about 445 miles (720 km) east-southeast of the Azores Islands. The Azores Islands are a Portuguese archipelago in the North Atlantic Ocean. They are located about 930 miles (1,500 km) from Lisbon, Portugal.
Maximum sustained winds are near 40 mph (65 kph) with higher gusts. Slow weakening is forecast. The post-tropical cyclone was moving toward the east near 12 mph (19 kph). An eastward to east-northeastward motion is forecast through midday Wednesday. A decrease in the forward motion along with turns to the southeast then south are expected late Wednesday through Thursday. A west-southwestward motion is forecast to begin by late this week.
Paulette’s Final Forecast
Post-tropical cyclone Paulette is expected to become a remnant low later today, Sept. 23.
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.
Sep. 23, 2020 – NASA Finds Dolphin Swimming Against Wind Shear
NASA’s Terra satellite provided a visible image of a slightly elongated Tropical Storm Dolphin as it battled wind shear upon its approach to east central Japan.
On Sept. 23, NASA’s Terra satellite provided a visible image of Tropical Storm Dolphin approaching east central Japan. Image Courtesy: NASA/NRL
A Visible Satellite Image
The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Dolphin on Sept. 23 at 12:30 a.m. EDT (0430 UTC). Dolphin appeared somewhat elongated from west to east likely from the strong vertical wind shear the storm has been battling.
However, despite the increasing vertical wind shear of 30 knots (35 mph/56 kph), animated multispectral satellite imagery shows that Dolphin is a consolidated system with strong thunderstorms banding and wrapping into the low-level circulation center.
Wind Shear Affecting Dolphin
The shape of a tropical cyclone provides forecasters with an idea of its organization and strength. When outside winds batter a storm, it can change the storm’s shape. Winds can push most of the associated clouds and rain to one side of a storm.
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.
Dolphin on Sept. 23
On Sept. 23 at 5 a.m. EDT (0900 UTC). Tropical Storm Dolphin was located near latitude 32.0 degrees north and longitude 138.6 degrees east. That is about 205 nautical miles south-southwest of Yokosuka, Japan. Dolphin was moving to the northeast and had maximum sustained winds of 50 knots (58 mph/92 kph).
Dolphin is forecast to move northeast and will gradually weaken before becoming extra-tropical near Tokyo.
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.
NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.
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.
Sep. 23, 2020 – NASA Finds Tropical Storm Lowell’s Center North of Strongest Side
NASA’s Aqua satellite used infrared light to identify strongest storms and coldest cloud top temperatures in Tropical Storm Lowell and found them south of the center of circulation.
Lowell is moving through the Eastern Pacific Ocean and far from land areas. There are no coastal watches or warnings in effect.
On Sept. 23 at 5:55 a.m. EDT (0955 UTC), the MODIS instrument aboard NASA’s Aqua satellite gathered temperature information about Tropical Storm Lowell’s cloud tops. MODIS found the most powerful thunderstorms (red) were east and south of the center, where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Credit: NASA/NRL
Infrared Data Reveals Powerful Storms
On Sept. 23 at 5:55 a.m. EDT (0955 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite gathered temperature information about Lowell’s cloud tops. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.
MODIS found the most powerful thunderstorms were south of the center, where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.
Lowell’s center is located near the northern edge of a band of strong thunderstorms and deep convection which extends over the eastern and southern portion of the circulation due to moderate northwesterly wind shear in the mid-levels below the cirrus layer (high cloud).
Lowell’s Status on Sept. 23
At 5 a.m. EDT (0900 UTC) on Sept. 23, the center of Tropical Storm Lowell was located near latitude 19.8 degrees north and longitude 119.9 degrees west. Lowell is centered about 680 miles (1,090 km) west-southwest of the southern tip of Baja California, Mexico.
Lowell is moving toward the west-northwest near 12 mph (19 kph), and this general motion is expected to continue today. Maximum sustained winds have increased to near 50 mph (85 kph) with higher gusts. The estimated minimum central pressure is 1001 millibars.
Lowell’s Forecast
NOAA’s National Hurricane Center expects Lowell to move in a westward motion beginning early Thursday, Sept. 24 and continue into the weekend. Little change in strength is forecast during the next few days.
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.
Sep. 23, 2020 – NASA Tracking Beta’s Heavy Rainfall into Lower Mississippi Valley
Slow-moving post-tropical storm Beta continues to drop large amounts of rainfall in Texas as it moves into the Lower Mississippi Valley on Sept. 23. A NASA satellite rainfall product that incorporates data from satellites and observations estimated Beta’s rainfall rates.
Flash Flood Watches in Effect on Sept. 23
NOAA’s National Weather Service issued warnings and watches for Beta on Sept. 23. There are Flash Flood Watches currently in effect across southeast Texas and southern Louisiana.
What is a Post-tropical Cyclone?
NHC defines a post-tropical cyclone as a former tropical cyclone. This generic term describes a cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Post-tropical cyclones can continue carrying heavy rains and high winds. Former tropical cyclones that have become fully extratropical as well as remnant lows are both classes of post-tropical cyclones.
Beta’s Status on Sept. 23
At 5 a.m. EDT (0900 UTC), the center of Post-Tropical Cyclone Beta was located near latitude 29.5 degrees north and longitude 95.0 degrees west. That is about 30 miles (45 km) east-southeast of Houston, Texas and about 70 miles (115 km) west-southwest of Port Arthur, Texas.
The post-tropical cyclone is moving toward the east-northeast near 9 mph (15 kph) and this motion is expected to shift more toward the northeast during the next 48 hours.
Maximum sustained winds are near 30 mph (45 kph) with higher gusts. Slow weakening is forecast during the next 48 hours. The estimated minimum central pressure is 1007 millibars.
NASA’s IMERG rainfall product estimated on Sept. 23 at 3:30 a.m. EDT (0730 UTC) that Beta was generating between 1 and 5 mm (0.04 and 0.2 inches) of rain per hour around the center of circulation in east Texas and in areas extending northeast into Louisiana and out over the Gulf of Mexico. Rainfall throughout most of the storm was estimated as falling at a rate between 0.3 and 1 mm (0.01 to 0.04 inches) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRL
Estimating Beta’s Rainfall Rates from Space
NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated on Sept. 23 at 3:30 a.m. EDT (0730 UTC) that Beta was generating between 1 and 5 mm (0.04 and 0.2 inches) of rain per hour. IMERG also found that rainfall was occurring around the center of circulation in east Texas and in areas extending northeast into Louisiana and out over the Gulf of Mexico. Rainfall throughout most of the storm was estimated as falling at a rate between 0.3 and 1 mm (0.01 to 0.04 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.
NHC Key Messages
NOAA’s National Weather Service Weather Prediction Center in College Park, Md. issued two key messages about Beta on Sept. 23:
RAINFALL: For the upper Texas coast, additional rainfall of 3 to 5 inches with isolated storm totals up to 15 inches is expected through Wednesday afternoon. Significant urban flooding will continue as well as minor to isolated moderate river flooding. Flash flooding will remain possible through Wednesday afternoon. Rainfall totals of 2 to 5 inches are expected east into the Lower Mississippi Valley, portions of the Tennessee Valley, and the southern Appalachians through the end of the week. Flash and urban flooding is possible, as well as isolated minor river flooding on smaller rivers.
SURF: Swells generated by a combination of Beta and a stationary front over the northern Gulf of Mexico will continue from the Upper Coast of Texas to the Western Florida Panhandle during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.
Beta is forecast to continue moving in an easterly direction into the Lower Mississippi Valley, portions of the Tennessee Valley, and the southern Appalachians through the end of the week.
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.
Sep. 23, 2020 – NASA Sees Post-Tropical Storm Teddy Generating Heavy Rain Over Eastern Canada
Hurricane Teddy has transitioned to a large post-tropical cyclone over eastern Canada. Using a NASA satellite rainfall product that incorporates data from satellites and observations, NASA estimated Teddy’s rainfall rates. In addition to the heavy rainfall, Teddy causing destructive waves and strong winds today, Sept. 23, for portions of Atlantic Canada.
Teddy made landfall in the Sheet Harbour area of Nova Scotia on the province’s Eastern Shore around 7:30 a.m. EDT, Sept. 23.
Warnings and Watches in Effect on Sept. 23
NOAA’s National Hurricane Center (NHC) issued warnings and watches for Teddy on Sept. 23. Tropical Storm Warning is in effect for the south coast of Nova Scotia from Digby to Meat Cove, and for Port aux Basques to Francois, Newfoundland, Canada.
A Tropical Storm Watch is in effect for Meat Cove to Tidnish, Nova Scotia, and from north of Digby to Fort Lawrence, Nova Scotia, and for the Magdalen Islands, Quebec and Prince Edward Island.
On Sept. 22 at 1:53 a.m. EDT (0553UTC) NASA’s Aqua satellite analyzed Teddy using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder than (purple) minus 63 degrees Fahrenheit (minus 53 degrees Celsius) north of the center. That’s where the heaviest rainmaking storms were located. Credit: NASA JPL/Heidar Thrastarson
What is a Post-tropical and Extra-tropical Cyclone?
At 11 p.m. EDT on Sept. 22, U.S. Navy Hurricane Specialist Dave Roberts at the NHC said, “Extratropical transition has been ongoing since last night, with the cyclone’s associated rain shield expanding over a great distance in the northern semicircle. In addition, multiple dropsonde observations from the Air Force Reserve hurricane hunters and buoy data show a sharp temperature gradient of nearly 20 degrees F from northwest quadrant to the southeast, indicative of the cyclone’s involvement with the strong baroclinic frontal zone. Accordingly, Teddy has become a strong post-tropical extratropical cyclone.”
NHC defines a post-tropical cyclone as a former tropical cyclone. This generic term describes a cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. Post-tropical cyclones can continue carrying heavy rains and high winds. Former tropical cyclones that have become fully extratropical or remnant lows are both classes of post-tropical cyclones.
What does Extra-tropical Mean?
When a storm becomes extra-tropical it means that a tropical cyclone has lost its “tropical” characteristics. The National Hurricane Center defines “extra-tropical” as a transition that implies both poleward displacement (meaning it moves toward the north or south pole) of the cyclone and the conversion of the cyclone’s primary energy source from the release of latent heat of condensation to baroclinic (the temperature contrast between warm and cold air masses) processes. It is important to note that cyclones can become extratropical and still retain winds of hurricane or tropical storm force.
Teddy’s Status on Sept. 23
At 8 a.m. EDT (1200 UTC), the center of Post-Tropical Cyclone Teddy was located near latitude 44.8 degrees north and longitude 62.3 degrees west. That is 65 miles (105 km) east-northeast of Halifax, Nova Scotia, Canada. The post-tropical cyclone is moving toward the north-northeast near 23 mph (37 kph), and this motion, with an increase in forward speed, is expected for the next day or so. On the forecast track, the center will move over eastern Nova Scotia soon, and then near or over Newfoundland by tonight, and be east of Labrador on Thursday.
Maximum sustained winds are near 65 mph (100 km/h) with higher, gusts. Some weakening is forecast during the next day or so, but Teddy should remain a strong post-tropical cyclone while passing over Nova Scotia and near Newfoundland. Teddy is a huge storm. Tropical-storm-force winds extend outward up to 520 miles (835 km) from the center. The estimated minimum central pressure is 963 millibars.
Estimating Teddy’s Rainfall Rates from Space
NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated on Sept. 23 at 3:30 a.m. EDT (0730 UTC) that Teddy was generating between 5 and 15 mm (0.20 and 0.60 inches) of rain per hour around the center of circulation. Rainfall throughout most of the storm was estimated as falling at a rate between 0.3 and 2 mm (0.01 to 0.08 inches) per hour.
NASA’s IMERG rainfall product estimated on Sept. 23 at 3:30 a.m. EDT (0730 UTC) that Teddy was generating between 5 and 15 mm (0.20 and 0.60 inches) of rain per hour around the center of circulation. Rainfall throughout most of the storm was estimated as falling at a rate between 0.3 and 2 mm (0.01 to 0.08 inches) per hour. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRL
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.
NHC Key Messages
The National Hurricane Center (NHC) issued three key messages about Teddy on Sept. 23:
Teddy is expected remain a powerful post-tropical cyclone while it moves near or over portions of Atlantic Canada through tonight. The most significant hazard expected from Teddy is large destructive waves forecast along the southern coast of Nova Scotia today.
Very large swells produced by Teddy are expected to affect portions of Bermuda, the Leeward Islands, the Greater Antilles, the Bahamas, the east coast of the United States, and Atlantic Canada during the next few days. These swells are expected to cause life-threatening surf and rip current conditions.
Tropical Storm Watches and Warnings are in effect for portions of Nova Scotia, Newfoundland, Prince Edward Island and the Magdalen Islands, and heavy rainfall across Atlantic Canada is expected through Thursday.
Teddy’s Fate in the Atlantic
NHC Senior Hurricane Specialist Richard Pasch said, “Teddy’s deep convection has been diminishing, but based on buoy observations the cyclone still has a strong circulation with a central pressure in the 950’s (millibars). Assuming a gradual spin down of the system since the earlier aircraft observations, the estimated maximum winds have dropped to just below hurricane strength. The system is expected to traverse Nova Scotia today as a strong extratropical cyclone, and move near Newfoundland by tonight. After passing east of Labrador on Thursday, the global models show Teddy merging with another large extratropical low over the north Atlantic.”
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.
Sep. 22, 2020 – NASA Catches Tropical Storm Dolphin Swimming North
NASA’s Terra satellite obtained visible imagery of Tropical Storm Dolphin as it continued moving north though the Northwestern Pacific Ocean on a track toward east central Japan.
On Sept. 22, 2020, NASA’s Terra satellite provided a visible image of Tropical Storm Dolphin as it continued moving north through the Northwestern Pacific Ocean. Credit: NASA/NRL
NASA Satellite View: Dolphin’s Organization
The Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Dolphin on Sept. 22 at 0345 UTC (Sept. 21 at 11:45 p.m. EDT). The visible image revealed strong storms around the low-level center of circulation with bands of thunderstorms in the northeastern quadrant. Microwave satellite imagery revealed an eye feature.
The Joint Typhoon Warning Center noted that another satellite image indicates that the upper-level circulation center is tilted about 30 nautical miles east of the low-level center due to increasing westerly vertical wind shear.
NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.
Dolphin on Sept. 22
At 5 a.m. EDT (0900 UTC) on Sept. 22 Tropical storm Dolphin was located near latitude 27.9 degrees north and longitude 135.5 degrees east, about 493 nautical miles south-southwest of Yokosuka, Japan. Dolphin was moving to the north and had maximum sustained winds 60 knots (69 mph/111 kph).
Dolphin will move north, later turning to the northeast. It is expected to weaken gradually before becoming extra-tropical near Tokyo.
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.
Sep. 22, 2020 – NASA Analyzes Tropical Storm Lowell’s Very Cold Cloud Tops
NASA analyzed the cloud top temperatures in Tropical Storm Lowell using infrared light to determine the strength of the storm. Infrared imagery revealed that the strongest storms were around Lowell’s center and in its southern quadrant because of northerly wind shear.
On Sept. 22 at 4:15 a.m. EDT (0915 UTC) NASA’s Aqua satellite analyzed Tropical Storm Lowell’s cloud top temperatures and found strongest storms (yellow) were around Lowell’s center of circulation and pushed into its southern quadrant. Temperatures in those areas were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). An area of strong storms with cloud top temperatures as cold as minus 70 degrees (red) Fahrenheit (minus 56.6. degrees Celsius) surrounded the center. Credit: NASA/NRL
Tropical Storm Lowell developed about 500 miles away from Baja California, Mexico. On Sept. 21, it formed as Tropical Depression 17E. By 5 p.m. EDT, the depression organized and strengthened into a tropical storm and was renamed Lowell.
Lowell is Battling Wind Shear
“Lowell continues to be affected by north-northeasterly shear, and the center is estimated to be located near the north-northeastern edge of the main convective mass,” said Senior Hurricane Specialist Richard Pasch at NOAA’s National Hurricane Center in Miami, Fla.
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.
An Infrared View of Lowell
One of the ways NASA researches tropical cyclones is using infrared data that provides temperature information. Cloud top temperatures identify where the strongest storms are located. The stronger the storms, the higher they extend into the troposphere, and the colder the cloud top temperatures.
On Sept. 22 at 4:15 a.m. EDT (0915 UTC) NASA’s Aqua satellite analyzed the storm using the Moderate Resolution Imaging Spectroradiometer or MODIS instrument. The MODIS imagery showed the strongest storms were around Lowell’s center of circulation and pushed into its southern quadrant. Temperatures in those areas were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). An area of strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded the center. NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.
NASA then provides data to tropical cyclone meteorologists so they can incorporate it in their forecasts.
Lowell’s Status on Sept. 22
At 5 a.m. EDT (0900 UTC) on Sept. 22, the center of Tropical Storm Lowell was located near latitude 18.0 degrees north and longitude 115.6 degrees west. That is about 500 miles (805 km) southwest of the southern tip of Baja California, Mexico. Lowell is moving toward the west-northwest near 13 mph (20 kph). Maximum sustained winds are near 45 mph (75 kph) with higher gusts. The estimated minimum central pressure is 1001 millibars.
Lowell’s Forecast
Some strengthening is forecast during the next couple of day as Lowell continues to move away from land areas and in a west-northwest direction followed by a turn toward the west. Lowell is no threat to land areas.
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.
Sep. 22, 2020 – NASA Sees Hurricane Teddy Threaten Eastern Canada
NASA’s Aqua satellite used infrared light to identify strongest storms and coldest cloud top temperatures in Hurricane Teddy as it nears eastern Canada. Teddy has triggered multiple warnings and watches.
On Sept. 22 at 1:55 a.m. EDT (0555 UTC), the MODIS instrument aboard NASA’s Aqua satellite gathered temperature information about Teddy’s cloud tops. MODIS found the most powerful thunderstorms (red) were in a very small area near the center where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Most of the rest of the storm had cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Credit: NASA/NRL
Warnings and Watches on Sept. 22
NOAA’s National Hurricane Center noted that a Tropical Storm Warning is in effect for the south coast of Nova Scotia from Digby to Meat Cove, Canada.
A Tropical Storm Watch is in effect from Meat Cove to Tidnish, Nova Scotia, from north of Digby to Fort Lawrence, Nova Scotia. A Watch is also in effect for the Magdalen Islands, Quebec, for Port aux Basques to Francois, Newfoundland and for Prince Edward Island.
Infrared Data Reveals Powerful Storms
On Sept. 22 at 1:55 a.m. EDT (0555 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS aboard NASA’s Aqua satellite gathered temperature information about Teddy’s cloud tops. MODIS found the most powerful thunderstorms were in a very small area near the center where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Most of the rest of the storm had cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.
Recent satellite imagery shows that the central convection is diminishing, with a comma-like cloud pattern developing.
Teddy’ Status on Sept. 22
At 8 a.m. EDT (1200 UTC) on Sept. 22, the center of Hurricane Teddy was located near latitude 39.3 degrees north and longitude 63.5 degrees west. That is about 365 miles (590 km) south of Halifax, Nova Scotia, Canada.
Teddy is moving toward the north-northwest near 28 mph (44 kph), and a turn toward the north-northeast is expected by early Wednesday. Maximum sustained winds are near 105 mph (165 kph) with higher gusts. Teddy is a large hurricane. Hurricane-force winds extend outward up to 105 miles (165 km) from the center and tropical-storm-force winds extend outward up to 400 miles (645 km). The estimated minimum central pressure is 950 millibars.
Teddy’s Forecast
On the forecast track, the center will move over eastern Nova Scotia on Wednesday, Sept. 23 and then near or over Newfoundland by Wednesday night. Although some weakening is likely later today and Wednesday, Teddy should be a strong post-tropical cyclone when it moves near and over Nova Scotia.
NHC Key Messages
The National Hurricane Center’s key messages are:
WIND: Tropical storm conditions are expected to begin in the warning area by this afternoon. Tropical storm conditions could begin in the watch areas late today or early Wednesday.
SURF: Large swells generated by Teddy are affecting Bermuda, the Lesser Antilles, the Greater Antilles, the Bahamas, the east coast of the United States, and Atlantic Canada. These swells are likely to cause life-threatening surf and rip current conditions.
RAINFALL: Through Thursday, Teddy is expected to produce rainfall accumulations of 2 to 4 inches (50 to 100 mm) with isolated totals of 6 inches (150 mm) across sections of Atlantic Canada.
STORM SURGE: A dangerous storm surge is expected to produce significant coastal flooding near and to the east of where the center makes landfall in Nova Scotia. Near the coast, the surge will be accompanied by very large and destructive waves.
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.
Sep. 22, 2020 – NASA Imagery Reveals Strongest Areas of Tropical Storm Beta
NASA’s Aqua satellite analyzed Tropical Storm Beta in infrared imagery to determine where the strongest parts of the storm were located. Beta is expected to stall inland over Texas today, Sept. 21, and heavy rains will continue over portions of the middle and upper Texas coast.
On Sept. 21 at 3:29 p.m. EDT (1929 UTC) NASA’s Aqua satellite analyzed Tropical Storm Beta using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder than (purple) minus 63 degrees Fahrenheit (minus 53 degrees Celsius) northeast of the center and in a band of thunderstorms southeast of center. Credit: NASA JPL/Heidar Thrastarson
Beta’s center has continued to move farther inland since making landfall on the southern end of the Matagorda Peninsula around 11 p.m. EDT on Sept. 21.
One of the ways NASA researches tropical cyclones is by using infrared data that provides temperature information. The AIRS instrument aboard NASA’s Aqua satellite captured a look at those temperatures in Beta and gave insight into the size of the storm and its rainfall potential.
Infrared Data Shows Storms with Greatest Rainfall Potential
Cloud top temperatures provide information to forecasters about where the strongest storms are located within a tropical cyclone. Tropical cyclones do not always have uniform strength, and some sides are stronger than others. The stronger the storms, the higher they extend into the troposphere, and the colder the cloud top temperatures. NASA provides that data to forecasters at NOAA’s National Hurricane Center or NHC so they can incorporate into their forecasting.
The heavy rains that have been occurring over the Texas coast were found in infrared imagery from NASA. On Sept. 21 at 3:29 p.m. EDT (1929 UTC) NASA’s Aqua satellite analyzed Tropical Storm Beta using the Atmospheric Infrared Sounder or AIRS instrument. AIRS found coldest cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius) around the center and in a thick band of storms southeast of Beta’s center. Those storms were just offshore from southeastern Louisiana and over the northern Gulf of Mexico. NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.
This snapshot of the storms that have the greatest rainfall potential help forecasters determine what areas are more subject to flooding. NOAA’s GOES-East satellite stays in a fixed position over the eastern U.S. and provides continuous infrared imagery that enables forecasters to see the movement of the areas of strongest storms.
Warnings and Watches on Sept. 21
NOAA’s National Hurricane Center issued a Storm Surge Warning on Sept. 21 from Sargent, Texas to Sabine Pass including Galveston Bay. A Tropical Storm Warning is in effect from Port Aransas, Texas to Sabine Pass.
Beta’s Status of Sept. 10
By 8 a.m. EDT CDT (1200 UTC), the center of Tropical Storm Beta was located by surface observations and NOAA Doppler radars near latitude 28.8 degrees north and longitude 96.8 degrees west. That is about 10 miles (15 km) east-southeast of Victoria and about 35 miles (55 km) west of Palacios, Texas.
Beta is moving toward the northwest near 3 mph (6 kph). Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Beta is likely to begin weakening later today. The estimated minimum central pressure is 999 millibars.
Beta’s Forecast
NHC expects Beta to stall inland over Texas today but will then begin to move slowly toward the east-northeast tonight. An east-northeast to northeast motion with increasing forward speed is expected Wednesday through Friday. On the forecast track, the center of Beta will move inland over southeastern Texas through Wednesday and then over Louisiana and Mississippi Wednesday night through Friday (Sept. 25).
NHC Key Messages
The National Hurricane Center issued three Key Messages about Beta:
Significant flash and urban flooding is occurring and will continue for the middle and upper Texas coast today. The slow motion of Beta will continue to produce a long duration rainfall event from the middle Texas coast to southern Louisiana. Flash, urban, and minor river flooding is likely. Periods of rainfall will continue into the ArkLaTex region and spread east into the Lower Mississippi Valley and portions of the Southeast through the end of the week. Flash, urban, and isolated minor river flooding is possible.
Storm surge flooding will continue throughout the morning, around the times of high tide along portions of the Texas coast within the storm surge warning areas. Residents in these areas should continue to follow advice of local officials.
Tropical-storm-force winds will continue near portions of the Texas coast within the warning area today.
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.
The AIRS instrument is one of six instruments flying on board NASA’s Aqua satellite, launched on May 4, 2002.
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.
Sep. 22, 2020 – NASA Sees Rebirth of Tropical Storm Paulette
Tropical Storm Paulette just reformed in the central North Atlantic Ocean today, Sept. 22. Using a NASA satellite rainfall product that incorporates data from satellites and observations, NASA estimated Paulette’s rainfall rates.
On Sept. 22 at 3:30 a.m. EDT (0730 UTC), NASA’s IMERG estimated Tropical Storm Paulette was generating as much as (5 mm/0.20 inches of rain (yellow) around the center of circulation. The rainfall data was overlaid on infrared imagery from NOAA’s GOES-16 satellite. Credit: NASA/NOAA/NRL
Paulette was a hurricane whose eye passed directly over Bermuda, then weakened and became a post-tropical cyclone on Sept. 16 in the North Atlantic Ocean when it was located 450 miles (725 km) east-southeast of Cape Race Newfoundland, Canada. A Post-Tropical Storm is a generic term for a former tropical cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical cyclone.
At 11 a.m. EDT (1500 UTC) on Sept.16 NOAA’s National Hurricane Center (NHC) issued the final advisory on Paulette but tracked its remnants over the last 6 days. NHC forecasters had assigned a medium chance that Paulette could redevelop over that time. At 11 p.m. EDT on Sept. 21 (0300 UTC on Sept. 22), Paulette regained tropical characteristics.
Paulette’s Status on Sept. 22
At 5 a.m. EDT (0900 UTC) on Sept. 22, the center of Tropical Storm Paulette was located near latitude 34.7 degrees north and longitude 23.7 degrees west. That is about 295 miles (470 km) southeast of the Azores Islands. The Azores islands are an autonomous region of Portugal in the mid-Atlantic.
Paulette was moving toward the east-northeast near 17 mph (28 kph). An east or east-northeast motion at a slower forward speed is expected through Wednesday. Paulette is then expected to turn southward and southwestward Wednesday night and Thursday.
Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Weakening is forecast during the next couple of days, and Paulette is expected to become post-tropical by Wednesday night or Thursday. The estimated minimum central pressure is 1002 millibars.
Estimating Paulette’s Rainfall Rates from Space
At 11 p.m. EDT on Sept. 21, deep convection and thunderstorm development associated with the post-tropical remnants of Paulette had become better organized over the past 6 to 12 hours. “An ASCAT over pass from a few hours ago indicate that increase in convective organization has resulted in strengthening and the system is being classified as a tropical cyclone once again,” noted Daniel Brown, senior hurricane specialist and warning coordination meteorologist at NOAA’s National Hurricane Center in Miami, Fla.
Four and a half hours later, NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG, which is a NASA satellite rainfall product, estimated rainfall occurring in the newly reformed tropical storm. On Sept. 22 at 3:30 a.m. EDT (0730 UTC) IMERG formed Paulette was generating as much as 5 mm (0.20 inches) of rain per hour around the center of circulation.
By 5 a.m. EDT (0900 UTC), the NHC noted that the tops of Paulette’s convective clouds have been warming since the previous advisory, and first-light visible images showed that a swirl of low- to mid-level clouds is about all that is left.
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.
