Sep. 16, 2020 – NASA Sees Tropical Storm Karina’s Night Moves
Tropical Storm Karina was making night moves like the old Bob Seger song. NASA-NOAA’s Suomi NPP satellite provided an infrared image of Tropical Storm Karina’s nighttime movement as it moved away from the Baja California peninsula of Mexico. Infrared data showed the storm was weakening.
NASA-NOAA’s Suomi NPP satellite passed over the Eastern Pacific Ocean during the early morning of Sept. 16 at 3 a.m. PDT/6 a.m. EDT (1000 UTC) and captured a nighttime image of Tropical Storm Karina moving further away from Baja California, Mexico (seen with city lights). Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
NASA’s Night-Time View of Karina’s Weakening
The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP was used to capture a nighttime image of Karina. NASA-NOAA’s Suomi NPP satellite passed over the Eastern Pacific Ocean during the early morning of Sept. 16 at 3 a.m. PDT/6 a.m. EDT (1000 UTC) and captured a nighttime image of Tropical Storm Karina moving farther away from Baja California, Mexico.
The infrared imagery revealed that there was very little deep convection (and building thunderstorms). Cloud top temperatures were near minus 40 degrees Celsius, which indicates they are warming and cloud heights are dropping. It is an indication that the uplift in the storm is weakening, and thunderstorm development drops off. The coldest cloud tops were found well to the west-northwest of the center of circulation.
The image was created using the NASA Worldview application at NASA’s Goddard Space Flight Center in Greenbelt, Md.
Karina’s Status on Sept. 16
At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Karina was located near latitude 22.6 degrees north and longitude 123.9 degrees west. Karina is moving toward the northwest near 8 mph (13 kph), and a turn back toward the west-northwest is forecast today. A slower westward motion is expected toward the end of the week. Maximum sustained winds are near 40 mph (65 kph) with higher gusts. Continued weakening is forecast, and Karina is expected to become a remnant low by tonight. The estimated minimum central pressure is 1004 millibars.
Karina’s Forecast
“Karina is expected to continue traversing cooler waters while moving farther into an inhibiting thermodynamic environment and unfavorable upper-level winds,” noted U.S. Navy Hurricane Specialist Dave Roberts of NOAA’s National Hurricane Center in Miami, Fla. “Therefore, weakening is forecast and Karina should degenerate to a remnant low [pressure area] tonight.”
About NASA’s EOSDIS Worldview
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 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. 16, 2020 – NASA Finds Coldest Cloud Tops on Hurricane Teddy’s Western Side
NASA analyzed the cloud top temperatures in Hurricane Teddy using infrared light to determine the strength of the storm. Infrared imagery revealed that the strongest storms were on Teddy’s western side.
On Sept. 16 at 12:53 a.m. EDT (0453 UTC) NASA’s Aqua satellite analyzed Hurricane Teddy’s cloud top temperatures using the AIRS instrument. AIRS showed the strongest storms with the coldest cloud top temperatures were as cold as or colder than 210 Kelvin (purple) minus 81 degrees Fahrenheit (minus 63.1 degrees Celsius). Credit: NASA JPL/Heidar Thrastarson
An Infrared View of Teddy
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. 16 at 12:53 a.m. EDT (0453 UTC) NASA’s Aqua satellite analyzed the storm using the Atmospheric Infrared Sounder or AIRS instrument. The AIRS imagery showed the strongest storms west of Teddy’s center of circulation. 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 barely visible in the infrared imagery.
NASA then provides data to tropical cyclone meteorologists so they can incorporate it in their forecasts.
Over 10 hours later at 11 a.m. EDT on Sept. 16, Andrew Latto, Hurricane Specialist at NOAA’s National Hurricane Center in Miami, Fla, noted, “Teddy’s overall appearance has changed little over the past several hours. Microwave and infrared satellite images depict a well-defined inner core with an eye evident in the microwave imagery. However, visible imagery reveals that the eye remains cloud filled. Over the past few hours, the coldest cloud tops and have become confined to the western portion of the circulation, which could be the early signs of the cyclone experiencing some westerly wind shear.”
Teddy’s Status on Sept. 16
At 11 a.m. EDT (1500 UTC), the center of Hurricane Teddy was located near latitude 16.5 degrees north and longitude 49.7 degrees west. Teddy was centered about 775 miles (1,245 km) east of the Lesser Antilles. Teddy was moving toward the northwest near 12 mph (19 kph) and this general motion is forecast to continue for the next few days. Maximum sustained winds are near 100 mph (155 kph) with higher gusts. The estimated minimum central pressure is 978 millibars.
Teddy’s Forecast
Additional strengthening is expected over the next couple of days, and Teddy could become a major hurricane by late tonight, Sept. 16.
In addition, large swells generated by Teddy are expected to reach the Lesser Antilles and the northeastern coast of South America today and should spread westward to the Greater Antilles, the Bahamas, and Bermuda by Friday, Sept. 18. These swells are likely to cause life-threatening surf and rip current conditions.
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. 16, 2020 – NASA Imagery Reveals Paulette Became a Strong Extratropical Cyclone
Tropical cyclones can become post-tropical before they dissipate, meaning they can become sub-tropical, extra-tropical or a remnant low-pressure area. As Hurricane Paulette transitioned into an extra-tropical storm, NASA’s Terra satellite provided a visible image of the powerful storm, and the National Hurricane Center issued their final advisory on the system.
On Sept. 16 at 10:16 a.m. EDT (1416), the MODIS instrument aboard NASA’s Terra satellite provided a visible image of Paulette that showed the storm had transitioned into an extra-tropical cyclone in the North Atlantic Ocean. Credit: NASA/NRL
What is a Post-tropical Storm?
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. Former tropical cyclones that have become fully extratropical, subtropical, or remnant lows–all three classes of post-tropical cyclones. In any case, they no longer possesses sufficient tropical characteristics to be considered a tropical cyclone. However, post-tropical cyclones can continue carrying heavy rains and high winds.
What is an Extra-tropical Storm?
Often, a tropical cyclone will transform into an extra-tropical cyclone as it recurves toward the poles (north or south, depending on the hemisphere the storm is located in). An extra-tropical cyclone is a storm system that primarily gets its energy from the horizontal temperature contrasts that exist in the atmosphere.
Tropical cyclones have their strongest winds near the earth’s surface, while extra-tropical cyclones have their strongest winds near the tropopause – about 8 miles (12 km) up. Tropical cyclones, in contrast, typically have little to no temperature differences across the storm at the surface and their winds are derived from the release of energy due to cloud/rain formation from the warm moist air of the tropics.
Visible NASA Imagery Shows the Transition
Visible imagery from NASA’s Terra satellite revealed Paulette’s extra-tropical transition.
On Sept. 16 at 10:16 a.m. EDT (1416), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Terra satellite provided a visible image of the storm. The MODIS image showed Paulette had a closed surface wind circulation about a well-defined center, but the storm has become asymmetric with the bulk of the clouds north of the center.
U.S. Navy Hurricane Specialist Dave Roberts at NOAA’s National Hurricane Center (NHC) in Miami, Fla. noted, “Conventional GOES-16 [satellite] visible and enhanced BD-curve satellite imagery show that Paulette has merged with the large baroclinic zone extending over the north-central Atlantic. Deep convection just to the north of the surface center that was noted on earlier microwave images has dissipated. Therefore, the system is now classified as extratropical cyclone and this is the last NHC advisory.”
According to NOAA, a Baroclinic Zone is a region in which a temperature gradient exists on a constant pressure surface. Baroclinic zones are favored areas for strengthening and weakening systems; barotropic systems, on the other hand, do not exhibit significant changes in intensity. Also, wind shear is characteristic of a baroclinic zone.
Paulette’s Final Advisory
At 11 a.m. EDT (1500 UTC), the center of Post-Tropical Cyclone Paulette was located near latitude 43.3 degrees north and longitude 45.2 degrees west. That is about 450 miles (725 km) east-southeast of Cape Race Newfoundland, Canada. The post-tropical cyclone is moving toward the east-northeast near 35 mph (56 kph), and this general motion is expected through Thursday. Maximum sustained winds have decreased to near 85 mph (140 kph) with higher gusts. The estimated minimum central pressure is 973 millibars.
Paulette’s Final Forecast
Further weakening is forecast during the next couple of days. The cyclone is forecast to slow down and turn toward the southeast and south late Thursday and Friday.
Meanwhile, ocean swells generated by Paulette will continue to affect Atlantic Canada, Bermuda, the Bahamas, and portions of the east coast of the United States through tonight. These swells are likely to cause life-threatening surf and rip current conditions.
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. 16, 2020 – NASA Finds Wind Shear Not Letting Up on Tropical Storm Vicky
NASA’s Terra satellite obtained visible imagery of Tropical Storm Vicky as it continued moving through the eastern North Atlantic Ocean fighting strong wind shear. Outside winds are pushing at the storm and weakening it.
On Sept. 16, 2020 at 8:40 a.m. EDT (1240 UTC), NASA’s Terra satellite provided a visible image of Tropical Storm Vicky battling wind shear in the eastern North Atlantic Ocean. Image Courtesy: NASA/NRL
Terra Sees Wind Shear Tearing Vicky Apart
On Sept. 16, 2020 at 8:40 a.m. EDT (1240 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite captured a visible image of Tropical Storm Vicky battling strong southwesterly wind shear. The image showed wispy clouds had surrounded the center of circulation, while the wind shear was blowing the bulk of clouds and showers to the northeast of the center.
NASA’s Terra satellite is one in a fleet of NASA satellites that provide data for hurricane research.
About Wind Shear
The shape of a tropical cyclone provides forecasters with an idea of its organization and strength. When outside winds, or wind shear batters a storm, it can change the shape of it by pushing much of the associated clouds and rain to one side. Vicky has been in an area with strong southwesterly wind shear.
Dr. Michael Brennan, Branch Chief of NOAA’s National Hurricane Center noted in the 11 a.m. EDT (1500 UTC) Discussion, “Hostile vertical shear of 50 to 60 knots has finally taken a toll on Vicky. A 1227 UTC ASCAT-B overpass showed peak winds of 35 knots north of the center, and that is the basis for the advisory intensity. The strong shear is expected to continue while Vicky moves over marginal 26-27 degrees Celsius sea surface temperatures, so additional weakening is forecast. Vicky should become a tropical depression in around 24 hours before weakening to a remnant low in about 2 days, with dissipation expected by day 3.”
Vicky on Sept. 16
NOAA’s National Hurricane Center (NHC) noted at 5 a.m. EDT (0900 UTC), the center of Tropical Storm Vicky was located near latitude 21.6 degrees north and longitude 33.9 degrees west. Vicky is centered about 755 miles (1,215 km) west-northwest of the Cabo Verde Islands. Vicky is moving toward the west-northwest near 9 mph (15 kph). Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. The estimated minimum central pressure is 1004 millibars.
Weakening Forecast for Vicky
A westward motion is expected to begin later today, followed by a west-southwestward motion by late Thursday [Sept. 17]. Gradual weakening is forecast over the next few days, and the system could become a remnant low on Thursday or Friday.
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. 16, 2020 – NASA Observes Hurricane Sally Making Early Morning Landfall in Alabama
NASA’s Aqua satellite and the NASA-NOAA Suomi NPP satellite provided views of the strength, extent and rainfall potential as Hurricane Sally was making landfall during the morning hours of Sept. 16.
Watches and Warnings
NOAA’s National Hurricane Center has many warnings and watches in place today, Sept. 16. A Storm Surge Warning is in effect from Dauphin Island, Alabama to the Walton/Bay County Line, Florida. A Hurricane Warning is in effect for the Mississippi/Alabama border to the Okaloosa/Walton County line, Florida.
A Tropical Storm Warning is in effect for east of the Okaloosa/Walton County line, Florida to Indian Pass, Florida and from the Mississippi/Alabama border to the Mouth of the Pearl River.
On Sept. 16 at 4:10 a.m. EDT (0810 UTC) NASA’s Aqua satellite used infrared light to analyze the strength of storms within Sally. Aqua found the most powerful thunderstorms were north of the eye where cloud top temperatures were as cold as minus 80F/minus 62.2C (yellow) Strong storms with cloud top temperatures as cold as minus 70F/minus 56.6C (red) circled the most powerful storms. Credit: NASA/NRL
NASA’s Infrared Data Reveals Heavy Rainmakers
Tropical cyclones and hurricanes are made up of hundreds of thunderstorms, and infrared data can show where the strongest storms are located. That is because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures.
On Sept. 16 at 4:10 a.m. EDT (0810 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite used infrared light to analyze the strength of storms within Sally. MODIS found the most powerful thunderstorms were north of the eye where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius).
Strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) circled the most powerful storms. NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.
NASA’s Night-Time View of Sally’s Landfall Approach
On Sept. 16 at 4:15 a.m. EDT (0815 UTC), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NOAA-NASA’s Suomi NPP satellite captured an early morning image of Hurricane Sally approaching landfall near Gulf Shores, Alabama as a Category 2 Hurricane. This nighttime image shows the extent of Sally’s clouds blotting out the city lights from southern Mississippi to the northwestern coast and panhandle of Florida.
On Sept. 16 at 4:15 a.m. EDT (0815 UTC)NASA-NOAA’s Suomi NPP satellite captured an early morning image of Hurricane Sally approaching landfall near Gulf Shores, Alabama as a Category 2 Hurricane. This nighttime image shows the extent of Sally’s clouds blotting out the city lights from southern Mississippi to the northwestern coast and panhandle of Florida. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
Sally’s Official Landfall
NOAA’s National Hurricane Center reported that Hurricane Sally made landfall at 5:45 a.m. EDT (4:45 a.m. EDT/0945) near Gulf Shores, Alabama as a as a Category 2 hurricane, with maximum sustained winds of 105 mph (165 kph) and a minimum central pressure of 965 millibars.
Sally’s Status at 8 a.m. EDT on Sept. 16
The NHC noted at 8 a.m. EDT (1200 UTC), the center of the eye of Hurricane Sally was located by NOAA Doppler weather radars near latitude 30.4 degrees north and longitude 87.6 degrees west. Sally’s eye was just 15 miles (25 km) north-northeast of Gulf Shores, Alabama and 25 miles (40 km) west-southwest of Pensacola, Florida.
Sally is moving toward the north-northeast near 3 mph (6 kph). A north-northeastward to northeastward motion at a slightly faster forward speed is expected later today and tonight, followed by a faster northeastward motion on Thursday. Doppler weather radar data indicate that the maximum sustained winds are near 100 mph (155 kph) with higher gusts.
Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). A sustained wind of 74 mph (119 kph) and a gust to 92 mph (148 kph) were recently reported at the Pensacola Naval Air Station in Pensacola, Florida. The estimated minimum central pressure based on surface observations is 967 millibars.
NHC Key Messages, Historic and catastrophic flooding is unfolding
The National Hurricane Center issued Key Messages about Rainfall, Wind, Tornadoes and Surf:
RAINFALL: Through this afternoon, Sally will produce additional rainfall totals of 8 to 12 inches with localized higher amounts possible along and just inland of the central Gulf Coast from west of Tallahassee, Florida to Mobile Bay, Alabama. Storm totals of 10 to 20 inches to isolated amounts of 35 inches is expected. In addition, this rainfall will lead to widespread moderate to major river flooding.
Sally is forecast to turn northeastward after making landfall today and move across the Southeast through Friday, producing the following rainfall totals:
Southern and central Alabama to central Georgia: 4 to 8 inches, with isolated maximum amounts of 12 inches. Significant flash and urban flooding is likely, as well as widespread minor to moderate flooding on some rivers.
Western South Carolina into western and central North Carolina: 4 to 6 inches, with isolated maximum amounts of 9 inches. Widespread flash and urban flooding is possible, as well as minor to moderate river flooding.
Southeast Virginia: 2 to 5 inches, with isolated maximum amounts of 7 inches. Scattered flash and urban flooding is possible, as well as scattered minor river flooding.
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.
AL/FL Border to Okaloosa/Walton County Line, FL including Pensacola Bay and Choctawhatchee Bay, 4-7 ft
Okaloosa/Walton County Line, FL to Walton Bay County Line, FL, 2-4 ft
Dauphin Island, AL to AL/FL Border including Bon Secour Bay, 2-4 ft
Walton Bay County Line, FL to Chassahowitzka, FL including Saint Andrew Bay, 1-3 ft
The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and damaging waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances.
WIND: Hurricane conditions are spreading onshore within the hurricane warning area in Florida and Alabama. Tropical storm conditions will continue in portions of the warning areas through tonight.
TORNADOES: A few tornadoes may occur today and tonight across portions of the Florida Panhandle, southern Alabama, and southwestern Georgia.
SURF: Swells from Sally will continue to affect the coast from the Florida Big Bend westward to southeastern Louisiana during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.
Sally’s Forecast from NHC
Weakening is expected as the center moves inland today and tonight. On the forecast track, the center of Sally will move across the extreme western Florida panhandle and southeastern Alabama through early Thursday, and move over central Georgia Thursday afternoon through Thursday night.
About NASA’s EOSDIS Worldview
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 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. 15, 2020 – A NASA-NOAA Nighttime View Finds a Slightly Better Organized Tropical Storm Karina
NASA-NOAA’s Suomi NPP satellite provided an infrared look at Tropical Storm Karina in the Eastern Pacific Ocean that gave forecasters a nighttime view of the storm. It revealed a slightly more organized tropical storm.
NASA-NOAA’s Suomi NPP satellite passed over the Eastern Pacific Ocean on Sept. 15 at 6:50 a.m. EDT (3:50 a.m. PDT/1050 UTC) and captured an early morning image of Tropical Storm Karina. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
NASA’s Night-Time View
On Sept. 15 at 6:50 a.m. EDT (3:50 a.m. PDT/1050 UTC), the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP passed over the Eastern Pacific Ocean and captured an early morning image of Tropical Storm Karina. The image showed that Karina continued to become a little better organized with a concentrated area of deep convection near and over the estimated low-level center. The image was created using the NASA Worldview application at NASA’s Goddard Space Flight Center in Greenbelt, Md.
By 11 a.m. EDT (8 a.m. PDT) on Sept. 15, Andrew Latto, Hurricane Specialist at NOAA’s National Hurricane Center in Miami, Fla. noted in the storm’s Discussion, “Karina has changed little in organization over the past several hours. [It has] a concentrated area of deep convection mostly over the southwestern portion of the circulation and over the estimated position of the low-level center.”
Karina’s Status on Sept. 15
At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Karina was located near latitude 20.4 degrees north and longitude 121.1 degrees west. That is about 740 miles (1,190 km) west of the southern tip of Baja California, Mexico.
Karina was moving toward the northwest near 10 mph (17 kph), and this motion is expected to continue for the next couple of days. A turn to the west and then toward the west-southwest is expected late this week. Maximum sustained winds were near 60 mph (95 kph) with higher gusts. Some weakening is forecast during the next 48 hours. The estimated minimum central pressure was 996 millibars.
Karina’s Forecast
“The cyclone is forecast to move over progressively cooler waters and into a drier, more stable atmosphere over the next couple of days. These conditions should induce a weakening trend soon, and the deep convection is expected to gradually wane during that time,” Latto said in the Discussion.
Gradual weakening should begin by tonight, and Karina is forecast to become a remnant low in two or three days.
About NASA’s EOSDIS Worldview
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 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. 15, 2020 – Water Vapor Imagery Reveals Hurricane Paulette’s Strongest Side, Dry Air
NASA’s Aqua satellite analyzed Hurricane Paulette’s water vapor content as it continued to move away from Bermuda and found structural changes, the strongest side, and dry air moving in.
On Sept. 15 at 3:25 a.m. EDT (0725 UTC), the MODIS instrument aboard NASA’s Aqua satellite gathered water vapor information about Hurricane Paulette. Highest concentrations of water vapor (dark brown) and coldest cloud top temperatures were around the center and northeast of the center. Credits: NASA/NRL
Water Vapor Imagery’s Indications
Water vapor analysis of tropical cyclones tells forecasters how much potential a storm has to develop. Water vapor releases latent heat as it condenses into liquid. That liquid becomes clouds and thunderstorms that make up a tropical cyclone. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and stronger they are.
The Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite gathered water vapor content and temperature information on Paulette on Sept. 15 at 3:25 a.m. EDT (0725 UTC). The MODIS data showed highest concentrations of water vapor and coldest cloud top temperatures were north of the center of circulation. That area had coldest cloud top temperatures that were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in those storms. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.
The Advanced Microwave Scanning Radiometer 2 (AMSR2) onboard the GCOM-W1 satellite is a remote sensing instrument for measuring weak microwave emission from the surface and the atmosphere of the Earth. U.S. Navy Hurricane Specialist Dave Roberts at NOAA’s National Hurricane Center in Miami, Fla. noted, “At 1:53 a.m. EDT (0533 UTC) the AMSR2 overpass on Paulette already reveals structural changes associated with the approaching mid-latitude baroclinic zone. The microwave image and GOES-16 satellite’s mid- to upper-level water vapor imagery show drier more stable air beginning to intrude into the western portion of the cyclone. Additionally, Paulette’s rain shield is more confined to the northern half of the system, while drying out in the southern semi-circle. Only fragments of the eyewall remain in that particular area.”
Paulette’s Status on Sept. 15
At 11 a.m. EDT (1500 UTC), the center of Hurricane Paulette was located near latitude 38.3 degrees north and longitude 57.9 degrees west. That is about 570 miles (915 km) northeast of Bermuda. Paulette is moving toward the northeast near 29 mph (46 kph). Maximum sustained winds are near 105 mph (165 kph) with higher gusts. The estimated minimum central pressure is 965 millibars.
Paulette’s Forecast
The NHC said, “Some strengthening is possible through tonight, but rapid weakening is forecast to begin on Wednesday as the cyclone undergoes extratropical transition. Paulette should complete its transition to an extratropical cyclone on Thursday. A faster motion toward the east-northeast is expected through Thursday. Afterward, Paulette is forecast to slow down and turn toward the east-southeast and south-southeast late Thursday and Friday.”
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 Aqua 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. 15, 2020 – NASA Satellite Imagery Shows Teddy Consolidating
When a tropical cyclone consolidates, it means that it is getting more organized and its circulation is improving. An improved circulation helps make for a stronger storm. Infrared imagery from NASA’s Aqua satellite showed that Teddy was consolidating in the Central North Atlantic Ocean.
On Sept. 15 at 12:15 a.m. EDT (0415 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite gathered temperature information about Teddy’s cloud tops. Some cloud top temperatures were as cold as or colder than minus 70 degrees (red) Fahrenheit (minus 56.6 Celsius) and building thunderstorms around the storm’s core. Credit: NASA/NRL
Infrared Data Reveals Teddy is organizing
On Sept. 15 at 12:15 a.m. EDT (0415 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA’s Aqua satellite gathered temperature information about Teddy’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 some cloud top 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. The infrared data showed that Teddy’s structure is slowly improving. The infrared imagery and visible imagery revealed that the building of thunderstorms around the storm’s core has increased, despite the continued presence of dry slots.
Teddy’s Status on Sept. 15
At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Teddy was located near latitude 14.0 degrees north and longitude 47.0 degrees west. Teddy is located about 960 miles (1,545 km) east of the Lesser Antilles. Teddy is moving toward the west-northwest near 13 mph (20 kph). A steady northwest motion at 10 to 15 mph is expected through the end of the week.
Maximum sustained winds have increased to near 65 mph (100 kph) with higher gusts. Additional strengthening is forecast for the next several days. Teddy will likely become a hurricane later today or tonight and could reach major hurricane strength in a few days. The estimated minimum central pressure is 999 millibars.
Teddy’s Forecast
“Teddy’s low [wind] shear and warm sea surface temperature environment should be conducive for further strengthening, and the NHC intensity forecast is largely unchanged,” noted David Zelinsky, Hurricane Model Diagnostician and Meteorologist at the NHC. “Some dry air in the environment could restrict Teddy’s intensification rate, but is not expected to prevent Teddy from becoming a hurricane later today or tonight. Continued strengthening is expected thereafter and Teddy is forecast to become a major hurricane within 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.
NASA’s Aqua 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. 15, 2020 – NASA Aqua Satellite Casts Three Eyes on Sally and Finds Heavy Rain Potential
NASA’s Aqua satellite analyzed the cloud top temperatures and water vapor content in Hurricane Sally as it crawls toward landfall, and found the potential for large amounts of rainfall, which, coupled with slow movement, can lead to catastrophic flooding. Two instruments provided three views of Sally’s temperatures and water vapor that revealed the soaking capability of the slow-moving hurricane.
At 8 a.m. EDT on Sept. 15, NOAA’s National Hurricane Center (NHC) cautioned, “Historic flooding is possible from Sally with extreme life-threatening flash flooding likely through Wednesday [Sept. 16] along portions of the northern Gulf Coast.” Forecasters are using NASA’s infrared and water vapor data to analyze the rainfall potential from Sally.
Warnings and Watches in Effect on Sept. 15
NHC issued a Storm Surge Warning for the mouth of the Mississippi River to the Okaloosa/Walton County Line, Florida and for Mobile Bay. A Hurricane Warning is in effect for east of the Mouth of the Pearl River to Navarre, Florida. A Tropical Storm Warning is in effect for east of Navarre, Florida to Indian Pass, Florida and from the mouth of the Pearl River westward to Grand Isle, Louisiana, including Lake Pontchartrain and Lake Maurepas and metropolitan New Orleans.
On Sept. 15 at 3:25 a.m. EDT (0725 UTC), the MODIS instrument that flies aboard NASA’s Aqua satellite revealed the most powerful thunderstorms (yellow) were around Hurricane Sally’s center and in the northeastern quadrant. There, cloud top temperatures were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius.) They were located over the Gulf of Mexico and just offshore from coastal Alabama, Mississippi and the Florida Panhandle. Strong storms (red) with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded both areas and were generating large amounts of rain. Credit: NASA/NRL
NASA’s Infrared Data Reveals Heavy Rainmakers
Tropical cyclones consist of hundreds of thunderstorms, and infrared data can show where the strongest storms are located. That is because infrared data provides temperature information, and the strongest thunderstorms that reach highest into the atmosphere have the coldest cloud top temperatures. Two instruments aboard NASA’s Aqua satellite provided infrared data on Sally’s cloud tops.
On Sept. 15 at 3:25 a.m. EDT (0725 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite revealed the most powerful thunderstorms were around Hurricane Sally’s center and in the northeastern quadrant. In those areas, cloud top temperatures were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius). They were located over the Gulf of Mexico and just offshore from coastal Alabama, Mississippi and the Florida Panhandle. Strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) surrounded both areas and were generating large amounts of rain.
On Sept. 15 at 3:29 a.m. EDT (0729 UTC) NASA’s Aqua satellite analyzed Sally’s cloud top temperatures using the AIRS instrument. AIRS showed the strongest storms were offshore in the northern Gulf of Mexico where they were as cold as or colder than 210 Kelvin (purple) minus 81 degrees Fahrenheit (minus 63.1 degrees Celsius). Credit: NASA JPL/Heidar Thrastarson
Four minutes later, another instrument aboard NASA’s Aqua satellite analyzed Sally’s cloud top temperatures to verify the data from MODIS. The Atmospheric Infrared Sounder or AIRS instrument or AIRS instrument showed the strongest storms were offshore in the northern Gulf of Mexico where they were as cold as or colder than 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.
On Sept. 15 at 3:25 a.m. EDT (0725 UTC) Aqua’s MODIS instrument also gathered water vapor content and temperature information on Sally. The MODIS image showed highest concentrations of water vapor (dark brown) and coldest cloud top temperatures were around the center of circulation and in the northeastern quadrant of the storm. The water vapor data showed coldest cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in those storms. Credits: NASA/NRL
Water Vapor Content
Water vapor analysis of tropical cyclones tells forecasters how much potential a storm has to develop. Water vapor releases latent heat as it condenses into liquid. That liquid becomes clouds and thunderstorms that make up a tropical cyclone. Temperature is important when trying to understand how strong storms can be. The higher the cloud tops, the colder and stronger the storms.
On Sept. 15 at 3:25 a.m. EDT (0725 UTC) Aqua’s MODIS instrument also gathered water vapor content and temperature information on Sally. The MODIS image showed the highest concentrations of water vapor and coldest cloud top temperatures were around the center of circulation and in the northeastern quadrant of the storm. The water vapor data showed the coldest cloud top temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) in those storms. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.
Sally’s Rainfall Forecast from NHC
The NHC warns, “Sally is expected to be a slow moving system as it approaches land producing 10 to 20 inches of rainfall with isolated amounts of 30 inches along and just inland of the central Gulf Coast from the western Florida Panhandle to far southeastern Mississippi. Historic flooding is possible with extreme life-threatening flash flooding likely through Wednesday. In addition, this rainfall will lead to widespread moderate to major flooding on area rivers.
Sally is forecast to move inland early Wednesday and move across the Southeast producing rainfall of 4 to 8 inches, with isolated maximum amounts of 12 inches, across portions of southeastern Mississippi, southern and central Alabama, northern Georgia, and the western Carolinas. Significant flash and urban flooding is likely, as well as widespread minor to moderate flooding on some rivers.”
Sally’s Status on Sept. 15
At 8 a.m. EDT (1200 UTC) on Sept. 15, the National Hurricane Center noted the center of Hurricane Sally was located near latitude 29.1 degrees north and longitude 88.0 degrees west. That is about 65 miles (110 km) east of the mouth of the Mississippi River.
Sally is moving toward the northwest near 2 mph (4 kph), and this general motion is expected to continue this morning. A northward turn is expected this afternoon, followed by a slow north-northeastward to northeastward motion tonight and continuing through Wednesday night. Maximum sustained winds are near 85 mph (140 kph) with higher gusts. The estimated minimum central pressure based on data from the Air Force Hurricane Hunter aircraft is 982 millibars.
Sally’s Forecast Track
NHC said, “Although little change in strength is forecast until landfall occurs, Sally is still expected to be a dangerous hurricane when it moves onshore along the north-central Gulf coast. On the forecast track, the center of Sally will pass near the coast of southeastern Louisiana today, and make landfall in the hurricane warning area tonight or Wednesday morning.”
NASA Researches Tropical Cyclones
Hurricanes are the most powerful weather event 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 Aqua 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.
Infrared imagery is like having night vision, and NASA-NOAA’s Suomi NPP satellite provided a nighttime view of Tropical Storm Vicky that revealed outside winds are weakening the storm.
NASA-NOAA’s Suomi NPP satellite passed the eastern north Atlantic Ocean overnight on Sept. 15 at 0335 UTC (Sept. 14 at 11:35 p.m. EDT) and captured a night-time image of Tropical Storm Vicky that revealed wind shear was pushing the bulk of its clouds to the northeastern quadrant of the storm. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS)
About Wind Shear
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. Outside winds from the southwest are pushing against Tropical Storm Vicky.
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.
NASA’s Night-Time View of Vicky’s Wind Shear
The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a nighttime image of Vicky on Sept. 15 at 0335 UTC (Sept. 14 at 11:35 p.m. EDT) using infrared imagery. That imagery revealed strong southwesterly wind shear was pushing the bulk of its clouds to the northeastern quadrant of the storm.
In the NHC Discussion at 5 a.m. EDT on Sept. 15, Eric Blake, senior hurricane specialist at NOAA’s National Hurricane Center in Miami, Fla. noted, “Vicky remains sheared this morning with strong upper-level winds causing any deep convection to be located northeast of the center. The low-level circulation has also become distorted as well, with new bursts of convection causing the mean circulation to re-form to the north.”
The image was created using the NASA Worldview application at NASA’s Goddard Space Flight Center in Greenbelt, Md.
Vicky’s Status on Sept. 15
NOAA’s National Hurricane Center (NHC) noted at 5 a.m. EDT (0900 UTC), the center of Tropical Storm Vicky was located near latitude 20.3 degrees north and longitude 30.1 degrees west. Vicky is 500 miles (800 km) northwest of the Cabo Verde Islands. Vicky is moving toward the northwest near 9 mph (15 kph), and a turn toward the west-northwest is expected within the next day or so, followed by a turn toward the west. Maximum sustained winds are near 50 mph (85 kph) with higher gusts. The estimated minimum central pressure is 1004 millibars.
Vicky’s Fading Forecast
Weakening is forecast due to strong upper-level winds during the next 48 hours, and Vicky is likely to degenerate into remnant low by Wednesday, Sept. 16.
About NASA’s EOSDIS Worldview
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 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.
