Featured Images

Text Size

Hurricane Season 2011: Hurricane Rina (Atlantic Ocean/Caribbean Sea)
10.31.11
 
This 3-D image from the TRMM satellite was captured on Friday, October 28, 2011 at 0753 UTC (3:53 a.m. EDT). › View larger image
This 3-D image from the TRMM satellite was captured on Friday, October 28, 2011 at 0753 UTC (3:53 a.m. EDT). Thunderstorms within Rina were reaching to heights of almost 17km (~10.6 miles).
Credit: SSAI/NASA, Hal Pierce
This radar image of Rina's rainfall was captured by the TRMM satellite on Friday, October 28, 2011 at 1425 UTC. › View larger image
This radar image of Rina's rainfall was captured by the TRMM satellite on Friday, October 28, 2011 at 1425 UTC (10:25 a.m. EDT). Red areas indicate heavy rainfall. Light to moderate rainfall (green and blue) around much of the storm was falling at a rate between .78 to 1.57 inches/20 to 40 mm per hour).
Credit: SSAI/NASA, Hal Pierce
This 3-D image from the TRMM satellite was captured on Friday, October 28, 2011 at 1425 UTC (10:25 a.m. EDT). › View larger image
This 3-D image from the TRMM satellite was captured on Friday, October 28, 2011 at 1425 UTC (10:25 a.m. EDT). Cloud tops reached heights of over 16 km (~9.9 miles).
Credit: SSAI/NASA, Hal Pierce
NASA's TRMM Satellite Gets 2 Views of Dissipating Tropical Storm Rina

The Tropical Rainfall Measuring Mission or TRMM satellite passed over rapidly dissipating tropical storm Rina twice on October 28, 2011 and saw changes in its rainfall. Rina is now just a memory.

Several images of Rina's rainfall were made at NASA's Goddard Space Flight Center in Greenbelt, Md. using TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data.

One set of images was collected by TRMM's first orbit before daylight at 0753 UTC (3:53 AM EDT). At that time, Tropical Storm Rina was still dropping heavy rainfall in a small area off the northeastern tip of the Yucatan Peninsula. However, a larger area of convective rainfall had formed to the north-northwest of Rina. TRMM's Precipitation Radar (PR) data showed powerful convective storms within Rina were reaching to heights of almost 17km (~10.6 miles).

The second TRMM orbit occurred during the daylight on October 28, 2011 at 1425 UTC (10:25 a.m. EDT). Those data collected with this pass showed that Rina had weakened even further. The area of heavy convection north of Rina was still producing heavy rainfall and it was spreading toward southwestern Florida. Another 3-D image from TRMM's Precipitation Radar (PR), on the upper right, shows that this persistent area of extremely heavy convective rainfall had storm tops reaching to heights of over 16 km (~9.9 miles).

The last advisory on Rina was issuad degenerated into a remnant low pressure area over the Yucatan Channel. It was located about 75 miles (125 km) west of the western top of Cuba near 21.9 North and 86.1 West. It was moving to the east-northeast near 5 mph and its minimum central pressure was 1007 millibars.

A small area of maximum sustained winds were near 30 mph at the time, but weakening fast. Rina's remnants became embedded in a trough (elongated area) of low pressure that extended from the east central Gulf of Mexico into the northwestern Caribbean Sea. Satellite data revealed that there was no organized convection (rising air that forms the thunderstorms that make up a tropical cyclone) as much as 15 hours before that time. The remnants were battling strong wind shear and dry air, two things that can cause the demise of a tropical cyclone.

Text credit: Hal Pierce
SSAI/NASA's Goddard Space Flight Center, Greenbelt, Md.
















October 28, 2011

GOES-13 shows Rina between the Yucatan Peninsula and Cuba; System 97L appears as disorganized clouds in the western Caribbean Sea › View larger image
This visible image from NOAA's GOES-13 satellite shows Hurricane Rina between the Yucatan Peninsula (left) and Cuba (right). The much weaker low pressure area called System 97L appears as an area of disorganized clouds in the western Caribbean Sea, east of Honduras and Nicaragua.
Credit: NASA/NOAA GOES Project
GOES-13 Satellite Image Sees Tropical Depression Rina Pop into the Gulf, 97L Behind

Tropical Storm Rina is now a depression in the Gulf of Mexico and is expected to be pushed back south into the Caribbean Sea from a strong cold front this weekend. GOES-13 satellite imagery saw a disorganized Rina with low pressure area 97L to its south.

The NOAA GOES-13 satellite captured a visible image of Tropical Depression Rina, on October 28 at 11 a.m. EDT in the southern Gulf of Mexico. Rina's clouds appear as a rounded area, with outflowing clouds extending northeast over Florida. Far to the south, close to where Rina developed is System 97L. That low pressure area appears disorganized as fragmented clouds in the western Caribbean, east of Honduras and Nicaragua. The visible image was created by NASA's GOES Project at the NASA Goddard Space Flight Center in Greenbelt, Md.

At 11 a.m. EDT on Oct. 28, Tropical Depression Rina's maximum sustained winds were near 35 mph (55 kmh). It was about 55 miles (90 km) north-northeast of Cancun, Mexico. That's about 110 miles (175 km) west of Cuba's western edge, near 21.8 North and 86.6 West. All of the watches and warnings in Mexico's Yucatan Peninsula have now been dropped.

Rina was moving to the north-northeast near 6 mph (9 kmh) but is expected to turn east then back to the south and return to the Caribbean Sea. A strong cold front moving through the Gulf of Mexico is expected to re-route Rina and keep her away from a Florida landfall.

The National Hurricane Center noted that as Rina turns away from the Gulf of Mexico, it could degenerate into a remnant low pressure area over the weekend.

System 97L is currently located east of Honduras and Nicaragua and is still struggling because of upper-level winds. The low pressure area has disorganized showers and thunderstorms and they appear somewhat scattered on the GOES-13 satellite image. The National Hurricane Center gives this system a 10 percent chance of development over the weekend, as it continues to head west.

Much farther east is another new low pressure area. Located in the eastern Atlantic, about 850 miles west-northwest of the Cape Verde Islands, a low is producing showers and thunderstorms. Upper level winds are light, but there's high pressure on the surface, so it only has a 10 percent chance for development over the weekend, just like System 97L.

Text credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.



October 27, 2011

Visible image of Hurricane Rina was taken by MODIS on Oct. 26 at (3:10 p.m. EDT). › View larger image
This visible image of Hurricane Rina was taken by the MODIS instrument on NASA's Aqua satellite on Oct. 26 at (3:10 p.m. EDT). Rina's outer bands were already over eastern areas of Mexico's Yucatan Peninsula.
Credit: NASA Goddard MODIS Rapid Response Team
On Oct. 26 at 12:18 p.m. EDT TRMM noticed areas of heavy rainfall north of Hurricane Rina's eye. › View larger image
On Oct. 26 at 12:18 p.m. EDT NASA's TRMM satellite noticed areas of heavy rainfall (in red) (2 inches/50 mm/hr) north of Hurricane Rina's eye and in the storm's southwestern quadrant. Light to moderate rainfall (green and blue) around much of the storm was falling at a rate between .78 to 1.57 inches/20 to 40 mm per hour).
Credit: SSAI/NASA, Hal Pierce
AIRS infrared image of Hurricane Rina taken on Oct. 27 at 3:47 a.m. EDT › View larger image
This infrared image of Hurricane Rina was taken on Oct. 27 at 3:47 a.m. EDT from the AIRS instrument on NASA's Aqua satellite. The strongest convection (and strongest thunderstorms) were just off the coast of the southeastern Yucatan Peninsula. Cloud top temperatures were colder than -63F (-52C) in that area, indicating strong thunderstorms and heavy rainfall.
Credit: NASA/JPL, Ed Olsen
A Triple Play of Satellite Data as Hurricane Rina Hits Mexico's Yucatan

As Hurricane Rina was approaching Mexico's Yucatan Peninsula NASA satellites were working overtime to provide forecasters with infrared, visible and radar data.

Instruments on NASA's Aqua and TRMM satellites provided a look at cloud extent, cloud height and temperature, and rainfall rates as Hurricane Rina neared the Yucatan.

On Oct. 26 at 12:18 p.m. EDT NASA's Tropical Rainfall Measuring Mission satellite called TRMM noticed areas of heavy rainfall (2 inches/50 mm/hr) north of Hurricane Rina's eye and in the storm's southwestern quadrant. Light to moderate rainfall around much of the storm was falling at a rate between .78 to 1.57 inches/20 to 40 mm per hour). Earlier TRMM passes had just seen heavy rainfall north of Rina's eyewall.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Aqua satellite took a visible image of Hurricane Rina on Oct. 26 at (3:10 p.m. EDT). At that time, Rina's outer bands were already over eastern areas of Mexico's Yucatan Peninsula. The image was created at NASA's Goddard Space Flight Center, Greenbelt, Md.

Early today, October 27, NASA's Aqua satellite made another pass over Hurricane Rina and this time the Atmospheric Infrared Sounder (AIRS) instrument took the temperatures of Rina's clouds and surrounding sea surface. AIRS took the image at 3:47 a.m. EDT and it showed the strongest convection (and strongest thunderstorms) were just off the coast of the southeastern Yucatan Peninsula. Cloud top temperatures were colder than -63F (-52C) in that area, indicating strong thunderstorms and heavy rainfall. AIRS data showed that cloud tops were warming, indicating weakening, which usually occurs when a tropical cyclone interacts with land.

At 8 a.m. EDT on October 27, Rina's maximum sustained winds were near 75 mph (120 kmh) making it a minimal category one hurricane. Rina's eye was located near 18.9 North and 87.0 West only 90 miles (145 km) east-northeast of Chetumal and 115 miles (190 km) south of Cozumel, Mexico. Rina is moving to the northwest at 6 mph (9 kmh) and is expected to turn to the north and track over the northeastern Yucatan. Minimum central pressure is 988 millibars.

A Hurricane warning is in effect on Mexico's Yucatan peninsula from north of Punta Gruesa to San Felipe. A tropical storm warning is in effect for the east coast of the Yucatan Peninsula from Chetumal to Punta Gruesa and the north coast of the Yucatan Peninsula west of San Felipe to Progreso. The warning area is expected to receive between 3 and 6 inches of rainfall, with isolated areas up to 10 inches along the eastern Yucatan. Storm surge is expected between 2 and 4 feet.

Rina is expected to move north, then east toward Cuba and then to the south while being pushed by a cold front moving through the Gulf of Mexico.

Text credit: Rob Gutro
NASA's Goddard Space Flight Center, Greenbelt, Md.












TRMM noticed an area of intense rainfall falling at 2 inches/50 mm/hr, mostly north of Hurricane Rina's eye. › View larger image
At 8:06 UTC (3:06 a.m. CDT) on October 26, 2011 NASA's TRMM satellite noticed an area of intense rainfall (darker red) falling at 2 inches/50 mm/hr, mostly north of Hurricane Rina's eye. To the south of the center the eyewall is mostly absent with very little rain. In fact outside of the northern eyewall, most of the rain is contained in a couple of rainbands far away from the center (scattered blue and green areas indicating, light and moderate rain, respectively). Light to moderate rainfall (green and blue) was falling at a rate between .78 to 1.57 inches/20 to 40 mm per hour).
Credit: SSAI/NASA, Hal Pierce
In this TRMM 3-D image the areas shown in red are the tops of deep convective towers. › View larger image
In this TRMM 3-D image the areas shown in red are the tops of deep convective towers where precipitation-sized particles have been carried aloft by stronger updrafts within thunderstorms. TRMM shows several towers both near the center and in the outer rainbands with tops over 15 km (brighter red areas). The heat released within these updrafts, mainly from condensation, is what drives tropical cyclones, including their intensity. At this stage, Rina seems poised to intensify.
Credit: SSAI/NASA, Hal Pierce
NASA's TRMM Satellite Sees Hurricane Rina Threaten the Yucatan

After a two-week period without any storms, the 2011 Atlantic hurricane season has picked up with the arrival of Hurricane Rina. NASA's TRMM satellite captured some intense rainfall and powerful, high towering thunderstorms within Rina as it moves toward Mexico.

Rina began as a tropical depression on October 23rd in the western Caribbean. Like many storms that form later in the season, Rina's formation was influenced by a midlatitude front that had penetrated deeper into the Tropics over warm water. These fronts can provide a focus for showers and thunderstorms that can eventually evolve into a tropical cyclone. During the peak of hurricane season in late August and September, a lot of storms form out over the central tropical Atlantic from waves moving off of the coast of Africa; Hurricane Philippe, the last storm prior to Rina, originated in this area at the end of September.

By mid October, the focus tends to shift to the western Caribbean as is the case with Rina. After forming about 100 miles (~160 km) northeast of the border between Honduras and Nicaragua, Rina intensified over the warm waters of the western Caribbean as it tracked slowly westward toward Belize, becoming a minimal Category 1 hurricane on the 24th and a Category 2 storm on the 25th.

Early the next morning on the 26th, Rina was a little stronger but still a Category 2 storm on the Saffir-Simpson hurricane intensity scale and was located about 200 miles (~330 km) east of Belize, when the TRMM satellite flew over the storm.

The Tropical Rainfall Measuring Mission (or TRMM) satellite was launched back in November of 1997 with the primary mission of measuring rainfall from space using a combination of both passive microwave and active radar sensors. TRMM has also proven to be a valuable platform for observing tropical cyclones. TRMM shows an area of intense rain (2 inches/50 mm per hour) just north of the center of the storm that makes up the northern eye wall. To the south of the center the eyewall is mostly absent with very little rain. In fact outside of the northern eyewall, most of the rain is contained in a couple of rainbands far away from the center areas indicating, light and moderate rain.

TRMM collected a first image of Rina at 8:06 UTC (3:06 am CDT) on 26 October 2011. The first image showed a top-down view of the rain intensities within Rina. Rain rates in the center of the swath were from the higher resolution TRMM Precipitation Radar (PR), while those in the outer swath are from the TRMM Microwave Imager (TMI). The rainrates are overlaid on visible and infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS).

TRMM data was also used to create a 3-D image of the storm. The 3-D image showed deep convective towers where precipitation-sized particles have been carried aloft by stronger updrafts within thunderstorms. TRMM showed several towers both near the center and in the outer rainbands with tops over 15 km (over 9 miles high). The heat released within these updrafts, mainly from condensation, is what drives tropical cyclones, including their intensity. At this stage, Rina seems poised to intensify.

Immediately after the TRMM images were taken, Rina's central pressure fell slightly, but after that the storm weakened. Rina's small size means it can quickly become vulnerable to changing environmental conditions. At the time of the TRMM images, Rina was a Category 2 storm with sustained winds reported at 95 knots (~110 mph). Later in the day, Rina was downgraded to a Category 1 storm with maximum sustained winds of 85 mph.

Rina is expected to pass over the northeast tip of the Yucatan Peninsula before turning east.

TRMM is a joint mission between NASA and the Japanese space agency JAXA.

Text credit: Steve Lang,
SSAI/NASA's Goddard Space Flight Center, Greenbelt, Md.



October 26, 2011

On Oct. 26 at 4:06 a.m. NASA's TRMM satellite noticed areas of heavy rainfall mostly north of Hurricane Rina's eye. › View larger image
On Oct. 26 at 4:06 a.m. NASA's TRMM satellite noticed areas of heavy rainfall (2 inches/50 mm/hr) mostly north of Hurricane Rina's eye. Light to moderate rainfall (green and blue) around much of the storm was falling at a rate between .78 to 1.57 inches/20 to 40 mm per hour).
Credit: SSAI/NASA, Hal Pierce
NASA Sees Rainfall in Category One Hurricane Rina Bearing Down on Mexico

Hurricane and tropical storm warnings are in effect from Mexico's Yucatan Peninsula to Belize and Honduras as satellites track the progress of Category One Hurricane Rina. NASA's TRMM satellite captured a look at the rainfall within Rina and noticed heavy rainfall around the eye.

A Hurricane Warning is in effect for the northeastern coast of the Yucatan Peninsula from north of Punta Gruesa to San Felipe. A Tropical Storm Warning is in effect for the east coast of the Yucatan Peninsula from Chetumal to Punta Gruesa and the north coast of the Yucatan west of San Felipe to Progreso. In addition, Tropical Storm Watches are in effect for the coast of Belize from Belize City northward and the Honduran Bay islands of Roatan and Guanaja.

NASA's Tropical Rainfall Measuring Mission satellite called "TRMM" captured radar data that showed Hurricane Rina had an area of heavy rain falling mostly to the north of her eye. Rainfall rates were in excess of 2 inches (50 mm) per hour.

Data from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) was used to create a rainfall image from the TRMM team at NASA's Goddard Space Flight Center in Greenbelt, Md. The rainfall filled the western Caribbean Sea on TRMM satellite imagery, extending from the Cayman Islands northeast of the storm to Belize and Honduras to the storm's west and south.

At 1:30 p.m. EDT on October 26, Rina's maximum sustained winds were near 85 mph (140 kmh). Rina's hurricane force winds extend outward only up to 25 miles (35 km) from the center while the tropical storm force winds extend as far as 115 miles (185 km) from the center.

Rina's center was about 180 miles (290 km) south-southeast of Cozumel, Mexico and about 165 miles (270 km) east of Chetumal, Mexico near 18.1 North and 85.8 West. Rina is moving west-northwest near 6 mph (9 kmh) and is expected to gradually turn to the northwest, then north on Thursday.

Tropical storm-force winds are expected along the coast today and hurricane conditions are expected on Thursday as Rina nears. Heavy rainfall, storm surge, and dangerous tides will accompany Rina's approach. The heavy rainfall that was seen by TRMM is expected to drop between 8 to 16 inches over the eastern Yucatan Peninsula and Cozumel through Friday.

USA Today reported on Oct. 26 that Carnival Cruise Lines and Celebrity Millennium cruises altered itineraries because of Rina today.

Although Rina is expected to continue weakening, she's expected to still be at hurricane force when making landfall in Mexico's Yucatan Peninsula. Rina's center will be moving near or over the east coast of the Yucatan Peninsula on Thursday, according to the National Hurricane Center.

Text credit: Rob Gutro,
NASA's Goddard Space Flight Center, Greenbelt, Md.



October 25, 2011

MODIS image of Rina› View larger image
This visible image of Hurricane Rina was taken by the MODIS instrument on NASA's Terra satellite on Oct. 24, 2011 at 12:15 p.m. EDT (16:15 UTC) when it was off the coast of Mexico. The strongest thunderstorms around the center are casting shadows on the surrounding lower clouds. Rina's southwestern edge was over Honduras at this time.
Credit: NASA Goddard MODIS Rapid Response Team
AIRS image of Rina › View larger image
On October 25, when NASA's Aqua satellite passed overhead it collected valuable data about Rina's cloud top temperatures. It showed a large area of strong thunderstorms (purple) completely surrounding the center of circulation. The strongest, coldest, highest cloud tops that surrounded the center of Rina (the eye) were colder than -63 Fahrenheit. The eye (blue surrounded by purple) showed warmer temperatures, indicating that it may be seen on visible satellite data.
Credit: NASA JPL, Ed Olsen
NASA Satellite Sees a More Powerful Hurricane Rina, Warnings Up in Mexico

Hurricane warnings are in effect in Mexico's Yucatan Peninsula and visible and infrared satellite imagery from NASA continues to show Hurricane Rina getting stronger. Rina is now a category 2 hurricane on the Saffir-Simpson hurricane scale.

The Mexican government issued a hurricane warning for the east coast of the Yucatan Peninsula from north of Punta Gruesa to Cancun. From Chetumal to Punta Gruesa a tropical storm warning is in effect.

As NASA's Terra satellite passed over Hurricane Rina on October 24 at 12:15 p.m. EDT (16:15 UTC) the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument took a visible image of the storm as it nears the Yucatan. The strongest thunderstorms around the center are casting shadows on the surrounding lower clouds. Rina's southwestern edge was over Honduras at this time.

On October 25, when NASA's Aqua satellite passed overhead it collected valuable data about Rina's cloud top temperatures. High, cold cloud top temperatures indicate a lot of power in the storm, as strong uplift pushes cloud tops higher in the troposphere, where temperatures drop. The higher and colder the thunderstorms within a hurricane, the stronger they are, and the heavier the rainfall within.

When Aqua passed overhead, the infrared data was collected from the Atmospheric Infrared Sounder (AIRS) instrument on the satellite. It showed a large area of strong thunderstorms completely surrounding the center of circulation.

Infrared imagery is color coded at NASA. It is created at the NASA Jet Propulsion Laboratory in Pasadena, Calif. In the image from earlier today, the strongest, coldest, highest cloud tops that surrounded the center of Rina (the eye) were colder than -63 Fahrenheit (-52 Celsius). The eye showed warmer temperatures, indicating that it may be seen on visible satellite data.

On October 25 at 11 a.m. EDT, Rina continues to strengthen, as is evident from the AIRS infrared imagery showing powerful convection surrounding the eye of the storm. Rina's maximum sustained winds are now up to 105 mph (165 kmh).

Hurricane Rina is closing in on Mexico's Yucatan Peninsula. It is now centered near 17.4 North and 83.9 West, about 300 miles (480 km) east-southeast of Chetumal, Mexico and 305 miles (490 km) southeast of Tulum, Mexico. That's not too far away when you consider that the tropical storm-force winds extend out 115 miles (185 km) from the center. The hurricane-force winds, however are confined to a much smaller area at this time- outward 15 miles (30 km) from the center.

The National Hurricane Center (NHC) noted that Rina is crawling to the west-northwest near 3 mph (6 kmh) and is expected to turn to the northwest and speed up a little over the next two days. Rina's center is expected to approach the Mexican coastline in the hurricane warning area by Wednesday night or early Thursday. Tropical storm-force winds are expected in the warning area tomorrow (Oct. 26) afternoon, followed by hurricane-strength winds.

Heavy rainfall as seen in NASA AIRS infrared imagery is going to accompany those winds. The NHC is expecting Rina to produce between 8 and 16 inches of rainfall over the eastern Yucatan late Wednesday and early Thursday, as dangerous storm surge hits coastal areas. Storm surge is expected to be as much as 5 to 7 feet above normal tide levels near the track of the storm's center and right of center.

NASA AIRS infrared data also shows that Rina is in an area of very warm ocean temperatures, over the 80 degree Fahrenheit (26.6 C) minimum to maintain a tropical cyclone, which will help Rina strengthen over the next day or two.

Text credit: Rob Gutro,
NASA's Goddard Space Flight Center, Greenbelt, Md.



October 24, 2011

Rina has strengthened into a hurricane during the early afternoon (EDT) on Oct. 24 › View larger image
Rina has strengthened into a hurricane during the early afternoon (EDT) on Oct. 24 as is evident in its organized structure in this visible image from the GOES-13 satellite at 1:31 p.m. EDT.
Credit: NASA/NOAA GOES Project
GOES-13 Satellite Sees Hurricane Rina Grow Larger and Stronger

Tropical Storm Rina achieved hurricane status around 2 p.m. EDT today, Oct. 24 and NOAA's GOES-13 visible imagery showed her getting bigger as she gets stronger.

A visible image from NOAA's Geostationary Operational Environmental Satellite called GOES-13 at 1:31 p.m. EDT showed that Rina had taken a more organized and circular form. The image was created at the NASA GOES Project at NASA's Goddard Space Flight Center, Greenbelt, Md.

Rina exploded into hurricane status with maximum sustained winds of 75 mph, after having maximum sustained winds only near 45 mph this morning. The imagery from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite showed areas of heavy rainfall around Rina's center, where hot towering clouds were likely. Research done at NASA's Goddard Space Flight Center in Greenbelt, Md. has shown that tropical cyclones are likely to intensify within six hours of a "hot tower" being spotted in a tropical cyclone.

At 2 p.m. EDT Rina was located near 17.1 North and 83.0 West. That's about 195 miles (310 km) southwest of Grand Cayman and about 360 miles (580 km) east-southeast of Chetumal, Mexico. It was moving to the northwest near 5 mph (7 kmh) and is expected to turn west-northwest later today.

Currently, Rina is a Category one hurricane on the Saffir-Simpson scale, but the National Hurricane Center expects Rina to continue intensifying.

Text credit: Rob Gutro,
NASA's Goddard Space Flight Center, Greenbelt, Md.



TRMM noticed limited areas of heavy rainfall (2 inches/50 mm/hr) in developing Tropical Storm Rina. › View larger image
On Oct. 23 at 1:28 p.m. NASA's TRMM satellite noticed limited areas of heavy rainfall (2 inches/50 mm/hr) in developing Tropical Storm Rina. Light to moderate rainfall (green and blue) around much of the storm was falling at a rate between .78 to 1.57 inches/20 to 40 mm per hour).
Credit: SSAI/NASA, Hal Pierce
This AIRS infrared image of the eastern half of Tropical Storm Rina was taken on Oct. 24 at 2:47 a.m. EDT. › View larger image
This infrared image of the eastern half of Tropical Storm Rina was taken on Oct. 24 at 2:47 a.m. EDT from the AIRS instrument on NASA's Aqua satellite. It shows a very large area of strong convection and thunderstorms around the center (purple) of circulation. Cloud top temperatures were colder than -63F (-52C) in that area, indicating strong thunderstorms and heavy rainfall.
Credit: NASA/JPL, Ed Olsen
GOES animation shows the low pressure area called System 96L (bottom, center) from October 22through Oct. 24 › View GOES animation
An animation of NOAA satellite observations from October 22 at 8:45 a.m. EDT through Oct. 24 at 7:45 a.m. EDT shows the low pressure area called System 96L (bottom, center) in the western Caribbean Sea. System 96L strengthened into the eighteenth tropical depression and further into Tropical Storm Rina at 10 p.m. EDT on Oct. 23. The GOES-13 cloud images are overlaid on a true-color NASA/MODIS map.
Credit: NASA/NOAA GOES Project
NASA Caught Tropical Storm Rina Forming, Strengthening

NASA's Tropical Rainfall Measuring Mission satellite called "TRMM" and NASA's Aqua satellite captured radar and temperature data that showed Tropical Storm Rina forming in the western Caribbean Sea yesterday. Today, Rina continues strengthening.

The National Hurricane Center (NHC) upgraded an area of disturbed weather in the Caribbean to tropical depression eighteen and then to tropical storm Rina on October 23, 2011. The TRMM satellite flew over the forming tropical cyclone on October 23, 2011 at 1728 UTC (1:28 p.m. EDT).

Data from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) was used to create a rainfall image from the TRMM team at NASA's Goddard Space Flight Center in Greenbelt, Md. The rainfall image showed that the future storm already was well organized and had a large area of heavy rainfall extending toward the northeast from eastern Honduras. Up until the morning hours (local time) on Monday, October 24, Honduras had a tropical storm watch in effect for its northeastern coast. That watch was dropped by 10 a.m. EDT as Rina moved away.

Today, Oct. 24, that rainfall is affecting the northeastern coast of Honduras and Cayman Islands. The NHC said "Rina is expected to produce total rain accumulations of 1 to 3 inches along the northeast coast of Honduras. Rainfall amounts of 2 to 4 inches are possible over the Cayman Islands."

At 11 a.m. EDT on Oct. 24, Rina's maximum sustained winds were near 45 mph (75 kmh). Those tropical storm-force winds extend out 85 miles (140 km) from the center, making Rina a small tropical storm over 170 miles in diameter.

Rina is in an environment with warm water (over the 80F/26.6C threshold needed to maintain a tropical cyclone) and low wind shear. It is centered near 17.1 North latitude and 82.9 West longitude, which is about 190 miles (305 km) southwest of Grand Cayman and 370 miles (595 km) east-southeast of Chetumal, Mexico. Rina was moving to the northwest at 6 mph (9 kmh). Minimum central pressure is 1001 millibars.

When NASA's Aqua satellite passed over Rina earlier today at 2:47 a.m. EDT the Atmospheric Infrared Sounder (AIRS) instrument took an infrared reading of Rina's cloud top temperatures. The colder the cloud top temperatures, the higher and stronger they are. AIRS temperature data showed a very large area of strong convection and thunderstorms around the center of circulation where cloud top temperatures were colder than -63F (-52C). Those temperatures indicate strong thunderstorms and heavy rainfall. AIRS infrared data showed that Rina continues to become better organized. The AIRS data was created into a color-coded image at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

There are a couple of factors steering Rina through the Caribbean Sea. In the mid-level of the atmosphere there's a ridge (elongated area) of high pressure building over the northern Gulf of Mexico, which is expected to turn Rina to the west-northwest. The NHC noted that as the ridge moves eastward in a couple of days, it will take Rina northwest, then northward. The NHC expects Rina to become a hurricane tomorrow.

Text credit: Rob Gutro,
NASA's Goddard Space Flight Center, Greenbelt, Md.











October 21, 2011

A 3-D slice through System 96L with TRMM Precipitation Radar data revealed it contained heavy rainfall (red). › View larger image
A 3-D slice through System 96L with TRMM Precipitation Radar data revealed it contained heavy rainfall (red). Some thunderstorms in the area of the cross-section were also shown to reach to heights of over 15 km (~9.3 miles).
Credit: NASA/SSAI, Hal Pierce
The TRMM satellite noticed areas of heavy rainfall (2 inches/50 mm/hr - seen in red) in System 96L. › View larger image
The TRMM satellite noticed areas of heavy rainfall (2 inches/50 mm/hr - seen in red) in System 96L. Light to moderate rainfall (green and blue) around much of the storm was falling at a rate between .78 to 1.57 inches/20 to 40 mm per hour).
Credit: SSAI/NASA, Hal Pierce
TRMM Satellite Sees Potential Tropical Cyclone Development In The Caribbean

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite captured data of rainfall and cloud heights of System 96L in the southern Caribbean Sea today, and noticed some signs of organization.

The TRMM satellite passed over the area of disturbed weather located between Nicaragua and Jamaica on October 21, 2011 at 09:29 UTC (5:29 a.m. EDT).

The National Hurricane Center (NHC) has given this area a medium chance (30%) of becoming a tropical cyclone over the weekend. Data from TRMM's Precipitation Radar (PR) instrument were used to make the 3-D image above that shows that a cluster of strong convective storms in the southern part of this area were higher than 15 km (~9.3 miles). The heavy rainfall in this area of deep convection releases heat, known as latent heating, into these storms. This energy release provided fuel for the possible development of a tropical cyclone.

The NHC reported that atmospheric pressure on the surface is falling, indicating the low pressure area is strengthening. The upper-level winds are also expected to become more favorable for development, so forecasters will be watching this low over the weekend. If it does become a depression it would be the eighteenth depression of the Atlantic Hurricane Season, which ends November 30.

Text credit: Hal Pierce/Rob Gutro,
SSAI/NASA's Goddard Space Flight Center, Greenbelt, Md.