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Hurricane Season 2012: Tropical Cyclone Hilwa (Southern Pacific Ocean)
02.23.12
 
AIRS captured this visible of a battered Cyclone Hilwa on February 22, 2012 at 0905 UTC (4:05 a.m. EST). › View larger image
On February 22, 2012 at 0905 UTC (4:05 a.m. EST) the AIRS instrument on NASA's Aqua satellite captured this visible of a battered Cyclone Hilwa. By February 23, Hilwa had dissipated.
Credit: NASA/JPL, Ed Olsen
NASA's Aqua Satellite Sees Cyclone Hilwa Hit the Highway

Cyclone Hilwa "hit the highway" and basically faded out of sight after being battered by strong northwesterly wind shear. NASA's Aqua satellite passed over the quickly weakening storm on February 22 and captured a visible image before it dissipated on February 23 over open waters in the Southern Pacific Ocean.

The last advisory on Cyclone Hilwa issued by the Joint Typhoon Warning Center placed Hilwa's center about 360 nautical miles southeast of Port Louis, Mauritus near 23.1 South and 63.6 East. On Wednesday, February 22, 2012 at 0900 UTC (4 a.m. EST), Hilwa was a tropical storm with maximum sustained winds near 35 knots (~40 mph/~65 kph). Hilwa was moving to the south at 11 knots (12.6 mph/20.3 kph) and into an area of increasing wind shear.

On February 22, 2012 at 0905 UTC (4:05 a.m. EST) the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured a visible of a battered Cyclone Hilwa. By February 23, Hilwa had dissipated.

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



Feb. 22, 2012

On February 21, 2012 at 2059 UTC (3:59 p.m. EST) the AIRS instrument on NASA's Aqua satellite captured an infrared image of thunderstorms in Cyclone Hilwa. The strongest thunderstorms with highest, coldest cloud tops were depicted in purple. › View larger image
On February 21, 2012 at 2059 UTC (3:59 p.m. EST) the AIRS instrument on NASA's Aqua satellite captured an infrared image of thunderstorms in Cyclone Hilwa. The strongest thunderstorms with highest, coldest cloud tops were depicted in purple.
Credit: NASA/JPL, Ed Olsen
NASA Infrared Imagery Shows a Battered Cyclone Hilwa

Cyclone Hilwa continues to move further south in the Southern Indian Ocean into cooler waters and a more hostile environment, and NASA infrared imagery revealed that the storm is falling apart because of wind shear. Winds from the northwest are taking their toll on Hilwa's thunderstorms and have pushed the bulk of them away from the center of circulation.

On Wednesday, February 22, 2012 at 0900 UTC (4 a.m. EST), Hilwa was a tropical storm with maximum sustained winds near 35 knots (~40 mph/~65 kph). It was located about 360 nautical miles southeast of Port Louis, Mauritus near 23.1 South and 63.6 East. Hilwa is moving to the south at 11 knots (12.6 mph/20.3 kph).

On February 21, 2012 at 2059 UTC (3:59 p.m. EST) the Atmospheric Infrared Sounder ( AIRS) instrument on NASA's Aqua satellite captured an infrared image of thunderstorms in Cyclone Hilwa. Satellite imagery showed the low level circulation center had become partially exposed to outside winds, and the bulk of the convection (rising air that form thunderstorms) and thunderstorms were pushed to the southeast of the center, from northwesterly wind shear.

The Joint Typhoon Warning Center forecast calls for Cyclone Hilwa to dissipate late today, February 22 because of increasing wind shear and cooling sea surface temperatures.

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



Feb. 21, 2012

MODIS captured Hilwa on February 21 at 1007 UTC (5:07 a.m. EST) and showed its rounded formation. › View larger image
NASA's Aqua satellite passed over Hilwa on February 21 at 1007 UTC (5:07 a.m. EST) and captured a visible image of the storm that showed its rounded formation. The strongest, highest, thunderstorms (that cast shadows on lower clouds) appeared to be on the eastern side of the storm.
Credit: NASA/NRL
NASA Satellite Sees Tropical Cyclone Hilwa at Sea

Tropical Storm 13S was renamed Hilwa as it continues to track through the open waters of the South Pacific Ocean.

NASA's Aqua satellite passed over Hilwa on February 21 at 1007 UTC (5:07 a.m. EST) and captured a visible image of the storm that showed its rounded formation. The strongest, highest, thunderstorms (that cast shadows on lower clouds) appeared to be on the eastern side of the storm.

On February 21, 2012, Tropical cyclone Hilwa was located approximately 480 nautical miles east of La Reunion, near position near 20.0 South and 63.8 East, moving southwest at 6 knots (7 mph/11 kph). Maximum sustained winds are near 40 knots (46 mph/74 kph).

The Joint Typhoon Warning Center forecasters expect that Hilwa will briefly strengthen and then weaken as it heads south.

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



Feb. 16, 2012

NASA's Aqua satellite captured this visible image of Tropical Storm 13S on Feb. 17, 2012 at 0854 UTC. The storm appears to be struggling to consolidate with the strongest convection (most clouds) over the southeastern quadrant. › View larger image
NASA's Aqua satellite captured this visible image of Tropical Storm 13S on Feb. 17, 2012 at 0854 UTC. The storm appears to be struggling to consolidate with the strongest convection (most clouds) over the southeastern quadrant.
Credit: NASA/NRL
NASA Satellite Sees Tropical Storm 13S Struggling

Tropical Storm 13S continues to move through the South Pacific Ocean and appeared to be struggling to consolidate on visible imagery from NASA's Aqua satellite.

NASA's Aqua satellite passed over Tropical Storm 13S (TS13S) Feb. 17, 2012 at 0854 UTC (3:54 a.m. EST) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument captured a visible image of the storm. The storm appears to be struggling to consolidate with the strongest convection (most clouds) over the southeastern quadrant. Those clouds are also associated with an elongated area of low pressure (a trough) to the southeast of the center of TS13S.

As Aqua passed over TS13S, the storm had maximum sustained winds near 35 knots (40 mph/~65 kph). It was located about 660 nautical miles (759.5 miles/1,222 km) southeast of Diego Garcia near 15.2 South and 80.6 East. It was far from land areas as it moved to the west-southwest at 4 knots (~5 mph/~7 kph).

TS13S is currently battling wind shear from the east-northeast. The forecasters at the Joint Typhoon Warning Center expect that conditions will improve for TS13S, and it will begin to strengthen for a couple of days before running into cooler waters and another area of strong wind shear.

TS13S is forecast to continue moving west and strengthen while staying in open ocean and away from land areas.

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



On infrared imagery from the NASA AIRS instrument, some thunderstorms from northeast to the south of the center of Tropical Storm 13S were strong (purple) on imagery captured on February 16, 2012 at 0805 UTC (3:05 a.m. EST). › View larger image
On infrared imagery from the NASA AIRS instrument, some thunderstorms from northeast to the south of the center of Tropical Storm 13S were strong (purple) on imagery captured on February 16, 2012 at 0805 UTC (3:05 a.m. EST).
Credit: NASA JPL, Ed Olsen
NASA Sees Tropical Cyclone 13S Moving Through Open Southern Pacific Ocean

NASA's Aqua satellite passed over Tropical Storm 13S in the Southern Pacific Ocean as it continued to strengthen. Infrared data showed cloud top temperatures were growing colder, a sign that there is stronger uplift in the storm.

Tropical cyclones are made up of hundreds of thunderstorms. Higher thunderstorm cloud tops in tropical cyclones mean stronger uplift and more energy. The higher the cloud top, the colder it is, as temperatures in the troposphere fall as you go higher.

When cloud top temperatures reach -63F/-52.7C on infrared imagery from NASA's Atmospheric Infrared Sounder (AIRS) that flies on NASA's Aqua satellite, that's an indication that thunderstorms are very strong, and likely have heavy rainfall. Some of the thunderstorms from northeast to the south of the center of Tropical Storm 13S were strong on imagery captured on February 16, 2012 at 0805 UTC (3:05 a.m. EST).

On February 16 at 0900 UTC (4 a.m. EST), Tropical Storm 13S (13S) had maximum sustained winds near 50 knots. It was moving to the west at 8 knots in the open waters of the Southern Pacific Ocean. 13S was quite far from land areas. In fact, it was 695 nautical miles southeast of Diego Garcia, near 15.0 South and 81.8 East.

Forecasters at the Joint Typhoon Warning Center expect 13S to continue intensifying over open waters for the next couple of days.

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



Feb. 15, 2012

Cloud top temperatures in 13S were high enough to reach the -63F/-52.7C threshold, indicating powerful storms. › View larger image
NASA's Aqua satellite passed over the eastern edge of Tropical Storm 13S on February 15 at 07:23 UTC (2:23 a.m. EST). Thunderstorms in the eastern side of the center of circulation were strong, and had high cloud tops. Cloud top temperatures were high enough to reach the -63F/-52.7C threshold, indicating powerful storms.
Credit: NASA/JPL, Ed Olsen
Infrared NASA Data Shows Strength in Tropical Storm 13S

Infrared data from a NASA satellite shows that the Southern Pacific's thirteenth tropical cyclone has developed some strong convection around its center, indicating strengthening.

Forecasters using satellite data have seen the power in the thunderstorms that make up Tropical Storm 13S, but it has been slow to consolidate.

On February 15, 2012 at 0900 UTC (4 a.m. EST), Tropical Storm 13S had maximum sustained winds near 40 knots (46 mph/74 kph), the same speed they were on the previous day. It was in a favorable environment with low wind shear and warm sea surface temperatures (warmer than 80F/26.6C) which will help it strengthen over the next couple of days.

Tropical Storm 13S was located about 860 nautical miles (~990 miles/~1,593 km) east-southeast of Diego Garcia, near 14.4 South and 84.6 East. It was moving to the west at 12 knots (13.8 mph/22.2 kph).

NASA's Aqua satellite passed over the eastern edge of Tropical Storm 13S on February 15 at 07:23 UTC (2:23 a.m. EST). Thunderstorms in the eastern side of the center of circulation were strong, and had high cloud tops. Cloud top temperatures were high enough to reach the -63F/-52.7C threshold, indicating powerful storms. Some thunderstorm banding was also evident in satellite data, and is another indication that the storm is consolidating and organizing.

Tropical Storm 13S is expected to continue on a west-southwesterly track over open ocean.

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



Feb. 14, 2012

TRMM captured rainfall data on Tropical Storm 13S (TS13S) on Feb. 14 at 0900 UTC (4 a.m. EST) › View larger image
When TRMM passed over Tropical Storm 13S (TS13S) on Feb. 14 at 0900 UTC (4 a.m. EST), it captured rainfall data. East of the center of circulation, rain was falling at around 1 inch (25 mm) per hour. TRMM noticed bands of thunderstorms wrapping into the low-level center, indicating that the storm was getting organized. TRMM data overlaid on METEO-7 Satellite data.
Credit: NASA/JAXA/NRL
NASA's TRMM Satellite Sees Tropical Storm 13S Form in Southern Pacific

The Tropical Rainfall Measuring Mission satellite flew over newborn Tropical Storm 13S on February 14, 2012 and noticed that there was moderate rain falling in its eastern quadrant.

When TRMM passed over Tropical Storm 13S (TS13S) on Feb. 14 at 0900 UTC (4 a.m. EST), it captured rainfall data. East of the center of circulation, rain was falling at around 1 inch (25 mm) per hour. TRMM noticed bands of thunderstorms wrapping into the low-level center, indicating that the storm was getting organized.

TS13S formed quickly during the morning hours west of the Cocos Islands. It has maximum sustained winds near 40 knots (46 mph/74 kph) and is expected to strengthen into a cyclone. It was located about 1,130 miles east-southeast of Diego Garcia, near 13.6 South and 90.7 East. Is moving to the west at 19 knots (~22 mph/~35 kph). It is forecast not to affect any land areas over the next several days.

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