Tag: TD08 2020

July 27, 2020 (part 2) – NASA Tracks Hanna’s Soaking Path into Mexico

NASA’s Aqua satellite provided infrared data on Tropical Depression Hanna while imagery from NASA-NOAA’s Suomi NPP satellite was used to create an animation showing its movement from Texas to Mexico. Infrared data can reveal the location of powerful storms that generate heavy rainfall and Hanna drenched Texas upon landfall over the weekend of July 25-26.

Tracking Hanna’s Path to Mexico

Visible imagery of Hurricane Hanna from July 23 to 26, taken from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA’s Suomi NPP satellite was compiled and made into an animation using NASA’s Worldview application. The imagery showed Hanna’s landfall in east central Texas and its track to the southwest into north central Mexico.

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.”

Hanna the Rainmaker Breaks Records

Hanna has been a big rainmaker. On July 25, the National Weather Service (NWS) at Corpus Christi, Texas reported 2.57 inches of rainfall from Hanna. Although not a record, it was a lot of rain.

On July 26, the NWS in Brownsville, Texas reported a new record for rainfall of 3.46 inches, breaking the old record of 2.74 inches that was set in 1890. Record rainfall was also recorded at McAllen Miller International Airport where the NWS reported 4.52 inches of rainfall on July 26, breaking the old record of 1.41 inches set in the year 2000.

An Infrared Look at Hanna’s Rainmaking Capability

One of the ways NASA researches tropical cyclones is using infrared data that provides temperature information. The AIRS instrument aboard NASA’s Aqua satellite captured a look at those temperatures in Hanna and gave insight into the size of the storm and its rainfall potential.

Cloud top temperatures provide information to forecasters about where the strongest storms are located within a tropical cyclone. The stronger the storms, the higher they extend into the troposphere, and the colder the cloud top temperatures.

On July 26 at 3:35 p.m. EDT (1935 UTC) NASA’s Aqua satellite analyzed the storm using the Atmospheric Infrared Sounder or AIRS instrument. The strongest storms with the coldest cloud top temperatures were located over extreme south Texas and northeastern Mexico. AIRS found coldest cloud top temperatures as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). NASA research has shown that cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

NASA provides the AIRS infrared data to forecasters at NOAA’s National Hurricane Center or NHC so they can incorporate it into their forecasting. The AIRS instrument is one of six instruments flying on board NASA’s Aqua satellite, launched on May 4, 2002.

More Heavy Rainfall from Hanna

The strong storms seen in infrared imagery continue to generate heavy rain and that rainfall is expected in parts of south Texas and in northern Mexico on July 27.

NHC forecasters said, “Hanna is expected to produce the following rain accumulations and flood threats through Monday: Far south Texas can expect an additional 1 to 2 inches. The northern Mexican states of Coahuila, Nuevo Leon, and Tamaulipas can expect 4 to 8 inches. Flash flooding and mudslides are possible across these Mexican states. In addition, the northern Mexican states of northern Zacatecas, northern San Luis Potosi, and eastern Durango can expect 1 to 2 inches.

Hanna’s Status on July 27, 2020

NOAA’s National Hurricane Center (NHC) reported at 5 a.m. EDT (0900 UTC) on July 26, the center of Tropical Depression Hanna was located near latitude 24.1 north, longitude 102.9 west. Hanna was centered about 65 miles (105 km) north of Fresnillo, Mexico. The estimated minimum central pressure was 1004 millibars. The depression was moving toward the west near 5 mph (7 kph) and this motion is expected to continue today. Maximum sustained winds were near 25 mph (35 kph) with higher gusts.

Hanna’s Forecast

NHC noted, “Ocean swells generated by Hanna will continue to affect much of the Texas and northeastern Mexico coasts early today. These swells may cause rip current conditions. Hanna will weaken into a remnant low today.”

For more than five decades, NASA has used the vantage point of space to understand and explore our home planet, improve lives and safeguard our future. NASA brings together technology, science, and unique global Earth observations to provide societal benefits and strengthen our nation. Advancing knowledge of our home planet contributes directly to America’s leadership in space and scientific exploration.

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

By Rob Gutro
NASA’s Goddard Space Flight Center

July 27, 2020 (part 1) – Hurricane Hanna Brings Heavy Rains to Parts of South Texas

Hanna formed from a westward propagating tropical easterly wave that entered the southeast corner of the Gulf of Mexico on Tuesday July 21st.  The wave provided a focus for shower and thunderstorm activity, which then led to the formation of an area of low pressure over the central Gulf of Mexico.  The National Hurricane Center (NHC) found that this low had developed a closed circulation by the evening of Wednesday July 22nd, making it Tropical Depression #8.  Over the next 24 hours, the depression slowly organized and intensified over the central Gulf before reaching tropical storm intensity on the evening of the 23rd, becoming Tropical Storm Hanna, the earliest 8th named storm of the Atlantic season on record.  A subtropical ridge to the north kept Hanna moving in a mainly westward direction towards the south Texas coastline.  On Friday the 24th, Hanna continued to show signs of intensifying but remained at tropical storm intensity.  On the morning of Saturday, the 25th, NHC found that Hanna had reached hurricane intensity, the first of the season.  At this point, the storm was centered about 100 miles ESE of Corpus Christi, TX and still moving west.  Hanna was still in the process of strengthening when it made landfall later that day around 5 pm (CDT) over Padre Island as a strong category 1 storm with sustained winds reported at 90 mph by NHC.

IMERG surface rainfall accumulations are shown here for the period 22 to 26 July 2020 for the central and northern Gulf of Mexico and the adjacent coastal regions.  The heaviest rainfall totals, in excess of 225 mm (~9 inches, shown in dark red) are located offshore over the northwestern Gulf of Mexico.   Over land, the highest rainfall amounts occur along the southern coast and southern tip of Texas where between 100 mm (~4 inches, shown in yellow) to as much as 200 mm (~8 inches, shown red) of rain are estimated to have fallen.  In addition to the heavy rain over south Texas, Hanna’s onshore flow brought coastal flooding to many parts of the south Texas coast, while Hanna’s outer rainbands also brought localized areas of heavy rain to portions of the northern Gulf Coast.

This animation shows IMERG rain rates (blue/yellow shading) and accumulations (green shading) observed from July 22-26, 2020 along Hurricane Hanna’s track as it crossed the Gulf of Mexico and reached southern Texas and northeastern Mexico. The National Hurricane Center began tracking the tropical depression that would become Hanna on July 23, shown here as a red line, smoothed in time. Hanna continued to strengthen into a Category 1 hurricane with a clearly visible eye on July 25 when it made landfall in southern Texas at 22:00 UTC. During Hanna’s approach, IMERG observed rain rates in excess of 25 millimeters/hour (~1 inch/hour; yellow shading). Accumulations during Hanna’s passage exceeded 20 centimeters (~8 inches; dark green shading) in parts of southern Texas and northeastern Mexico. Credit: Animation and caption by Jason West (NASA GSFC)

 

July 26, 2020 – NASA Infrared Data Shows Hanna a Heavy Rainmaker

Infrared imagery of Tropical Storm Hanna obtained from NASA’s Aqua satellite found powerful storms with heavy rainmaking capabilities along the Texas coast.

On July 26, NOAA’s National Hurricane Center (NHC) posted a Tropical Storm Warning from Barra el Mezquital, Mexico to Baffin Bay, Texas.

NASA’s Infrared Data Reveals Heavy Rainmakers

Tropical cyclones are made of up 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 July 27 at 4:35 a.m. EDT (0835 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 Hanna. MODIS found the most powerful thunderstorms were east of Hanna’s center and over the Gulf of Mexico, where cloud top temperatures were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius). NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Strong storms with cloud top temperatures as cold as minus 70 degrees Fahrenheit (minus 56.6. degrees Celsius) were over land, and were dropping large amounts of rain.

NHC Forecast for Heavy Rain and a Key Message

On July 26, NOAA’s National Hurricane Center (NHC) posted a Tropical Storm Warning from Barra el Mezquital, Mexico to Baffin Bay, Texas.

Forecasters at NOAA’s National Hurricane Center (NHC) use NASA’s infrared data in their forecast. One of the Key messages on Hanna is about its rainfall potential. NHC noted that, “Hanna is expected to produce total rain accumulations of 6 to 12 inches, with isolated maximum amounts of 18 inches through Monday in south Texas and into the Mexican states of Coahuila, Nuevo Leon, and northern Tamaulipas.  This rain will produce life-threatening flash flooding, rapid rises on small streams, and isolated minor to moderate river flooding. Hanna is also expected to produce 2 to 4 inches of rain along the upper Texas and Louisiana coasts.”

Other NHC Key Messages

NHC’s other key messages on Hanna include storm surge, winds, and isolated tornadoes. Water levels along the Texas coast will gradually subside through this morning. Tropical storm conditions will continue near the center of Hanna for the next several hours and along the Texas and northeastern Mexican coast in the warning area for a few more hours. Swells generated by Hanna will continue to affect much of the Texas and Louisiana coasts for another day or so. These swells are likely to cause life-threatening surf and rip current conditions.  A few tornadoes are possible today into this evening across parts of south Texas.

Hanna’s Status on July 26, 2020

At 8 a.m. EDT (1200 UTC), the center of Tropical Storm Hanna was located near latitude 26.2 north, longitude 99.1 west. Hanna is moving toward the west-southwest near 9 mph (15 kph) and this motion is expected to continue through Monday. Maximum sustained winds are near 50 mph (85 kph) with higher gusts. The estimated minimum central pressure is 992 millibars.

Tropical-storm-force winds extend outward up to 115 miles (185 km) mainly over water to the east of the center. A wind gust of 49 mph (80 kph) was reported within the past couple of hours at Port Isabel-Cameron County Airport.

Hanna’s Forecast from NHC

Rapid weakening is expected as the center of Hanna moves farther inland, and the cyclone is expected to weaken to a tropical depression later today and dissipate Monday or Monday night. On the forecast track, the center of Hanna should continue to move farther inland over northeastern Mexico through tonight.

Typhoons/hurricanes are the most powerful weather events on Earth. NASA researches these storms to determine how they rapidly intensify, develop and behave. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

By Rob Gutro
NASA’s Goddard Space Flight Center

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July 26, 2020 – International Space Station View of Hanna

July 25, 2020 – NASA Sees Hanna Strengthen into First Atlantic Hurricane of 2020

NASA satellite imagery revealed powerful thunderstorms fueled the intensification of Hanna into a hurricane along the Texas coast. Hanna has become the first hurricane of the Atlantic Ocean hurricane season, and has triggered warnings along the Texas coast today, July 25, 2020.

Warnings in Effect

The National Hurricane Center posted warnings on July 25 for areas of the Texas coast as Hanna approaches for landfall. A Storm Surge Warning is in effect from Port Mansfield to Sargent, Texas. A Hurricane Warning is in effect from Port Mansfield to Mesquite Bay, Texas.

A Tropical Storm Warning is in effect from Barra el Mezquita, Mexico to Port Mansfield, Texas and for Mesquite Bay to High Island, Texas.

NASA Infrared Data Shows Hanna Strengthened

On July 25 at 3:50 a.m. EDT (0750 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 Hanna. MODIS revealed that cloud tops in very powerful thunderstorms around Hanna’s center had become colder since the previous day. That means the uplift in the storm was stronger and pushed the cloud tops higher into the troposphere. Cloud top temperatures in those areas were as cold as minus 80 degrees Fahrenheit (minus 62.2 Celsius), indicating the storm had strengthened. NASA research has found that cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Tropical cyclones are made of up 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.  NASA researches these storms to determine how they rapidly intensify, develop and behave.

Heavy Rainfall, Storm Surge, Hurricane-force Winds, Isolated Tornadoes

The National Hurricane Center forecast warns about storm surge up to 5 feet in various areas, hurricane conditions, isolated tornadoes, heavy rainfall, flooding, and dangerous ocean swells from Texas to Louisiana.

Infrared imagery from NASA shows the capability of Hurricane Hanna to generate heavy rainfall, and the National Hurricane Center has included that rainfall potential in their forecast. NHC said, “Hanna is expected to produce 6 to 12 inches of rain with isolated maximum totals of 18 inches through Sunday night in south Texas and into the Mexican states of Coahuila, Nuevo Leon, and northern Tamaulipas.  This rain may result in life-threatening flash flooding, rapid rises on small streams, and isolated minor to moderate river flooding in south Texas.”

Hanna’s Status on Saturday, July 25

At 8 a.m. EDT (1200 UTC), the center of Hurricane Hanna was located by reconnaissance aircraft and NOAA Doppler weather radars near latitude 27.1 degrees north and longitude 96.0 degrees west. Hanna is just 90 miles (150 km) east-northeast of Port Mansfield, Texas. Hanna is moving toward the west near 9 mph (15 km), and this motion should continue through this morning.  A gradual turn toward the west-southwest is expected by tonight and that motion should continue through Sunday.

Data from the reconnaissance aircraft and Doppler weather radars indicate that maximum sustained winds have increased to near 75 mph (120 kph) with higher gusts.  Data from the NOAA Hurricane Hunter aircraft indicate that the minimum central pressure is 982 millibars.

Additional strengthening is forecast before Hanna makes landfall later today. Rapid weakening is expected after Hanna moves inland. On the forecast track, the center of Hanna should make landfall along the Texas coast within the hurricane warning area this afternoon or early this evening.

Typhoons/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

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

For previous Hanna updates visit: https://blogs.nasa.gov/hurricanes/tag/td08-2020/

July 24, 2020 – NASA Animation Tracks Tropical Storm Hanna’s Progression

NASA’s Aqua satellite obtained visible imagery as Tropical Storm Hanna formed in the Gulf of Mexico and continued to organize. A new animation from NASA shows how Hanna developed and intensified as it heads toward landfall in Texas this weekend.

NASA Satellite View: Hanna’s Organization

The Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Aqua satellite captured a visible image of Tropical Storm Hanna on July 23 at 1:30 p.m. EDT. The image showed the storm appeared more organized and had a more rounded shape than it did the previous couple of days. That is an indication that the storm was consolidating, organizing and strengthening.

Satellite imagery from the two days before were coupled with the July 23 image and made into an animation using NASA’s Worldview product at NASA’s Goddard Space Flight Center in Greenbelt, Md. That animation showed the clouds associated with the low-pressure area near south Florida and moving west over the Gulf of Mexico where it formed into a depression and further into a tropical storm.

Warnings Posted

On July 24, 2020, the National Hurricane Center posted a Tropical Storm Warning from the mouth of the Rio Grande to San Luis Pass, Texas.

Tropical Storm Hanna on July 24

At 11 a.m. EDT (1500 UTC) on July 24, the National Hurricane Center (NHC)  noted the center of Tropical Storm Hanna was located by NOAA reconnaissance aircraft near latitude 27.2 degrees north and longitude 93.2 degrees west. That is 260 miles (420 km) east of Corpus Christi, Texas.

Hanna is moving toward the west-northwest near 9 mph (15 kph), and this motion should continue today. Maximum sustained winds have increased to near 45 mph (75 kph) with higher gusts. Reports from the NOAA reconnaissance aircraft indicate that the minimum central pressure is 1000 millibars.

Hanna’s Forecast Track  

The NHC forecast calls for a turn toward the west is expected tonight, followed by a westward to west-southwestward motion through the weekend. Gradual strengthening is expected until the tropical cyclone makes landfall. On the forecast track, the center of Hanna should make landfall along the Texas coast within the warning area Saturday afternoon or evening. Steady weakening is expected after Hanna moves inland.

About NASA’s Worldview and Aqua Satellite

NASA’s Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks “right now.”

NASA’s Aqua satellite is one in a fleet of NASA satellites that provide data for hurricane research.

Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

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

By Rob Gutro
NASA’s Goddard Space Flight Center