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Kulab says “Please Classify Me!”

Not much has been happening in recent weeks in the tropics (with the notable exception of the extreme western Pacific), so allow me to try generate some fake excitement by highlighting one of our four featured storms – KULAB.  Why Kulab?   Read More…

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A Tropical Cyclone Nursery

The next four storms on CycloneCenter are new ones from the Western Pacific basin. They represent four storms that each start in a small region of the Pacific Ocean, but follow very different paths.

Ever wondered what happened to the baby that was shared time with you in the hospital nursery when you were born? Born in the same hospital on the same day, you have likely taken very different paths (unless you’re a twin).

CycCen-WP-StartingPoint

Chalk it up to chaos (remember this wacky definition of it?) or something else, but it is interesting that — like babies in a hospital — tropical cyclones with similar origins take different paths as well. These storms — Kulap, Roke, Sonca and Nesat — formed in roughly the same location of the western Pacific Ocean in 2005 however they took very different paths.

Help us better understand their lifetime by classifying the Four Storms.

http://www.cyclonecenter.org/

Also thanks for your help on the fours storms from 2004. They were a great success and the initial results look very good.

Featured Storm – Super Typhoon Fengshen (2002)

Origin and Track of Typhoon Fengshen

Origin and Track of Typhoon Fengshen

Typhoon Fengshen was the strongest storm of the 2002 Pacific typhoon season. It developed on July 13 near the Marshall Islands and rapidly intensified due to its small size. Fengshen went from being a tropical depression to a cyclone in only 6 hours. By July 15, Fengshen was given typhoon status, and after initially moving to the north, it turned toward the northwest. On July 18, the typhoon reached its peak intensity of 185 km/h (115 mph), according to the Japan Meteorological Agency; the Joint Typhoon Warning Center (JTWC) estimated peak winds of 270 km/h (165 mph). Disparities like this between agencies are the driving force behind the creation/purpose of  Cyclone Center, and with your help these dissimilarities can be smoothed out. Your classifications are important to us, so we ask that you please take a moment and provide your input on Typhoon Fengshen to help us determine its peak winds.

Typhoons Fengshen (north) and Fung-Wong

Typhoons Fengshen (north) and Fung-Wong (south) undergo the Fujiwhara effect

The JTWC estimated that Fengshen was a super typhoon for five days, which broke the record for longest duration at that intensity. This record would later be tied by Typhoon Ioke in 2006. While approaching peak intensity, Typhoon Fengshen underwent the Fujiwhara effect with Typhoon Fung-wong, causing the latter storm to loop to its south. The Fujiwhara effect is when two nearby cyclonic vortices orbit each other and close the distance between the circulations of their corresponding low-pressure areas. Interaction of smaller circulations can cause the development of a larger cyclone, or cause two cyclones to merge into one.

Fengshen gradually weakened while approaching Japan, and it crossed over the country’s Ōsumi Islands on July 25 as a severe tropical storm. The typhoon swept a freighter ashore, killing four of the 19 crew members aboard. In Japan, Fengshen dropped heavy rainfall that caused mudslides and left $4 million (¥475 million Japanese Yen) in crop damage. After affecting Japan, Fengshen weakened in the Yellow Sea to a tropical depression, before moving across China’s Shandong Peninsula and dissipating on July 28. The typhoon produced strong winds and heavy rain in Japan. A station in Miyazaki Prefecture reported the highest rainfall in Japan with a total of 717 mm (28.2 in). Most of the precipitation fell in a 24 hour period, and the heaviest 1 hour total was 52 mm (2.0 in) in Taira, Toyama. The remnants of Fengshen produced heavy rainfall in northeastern China. The storm affected the capital city of Beijing, becoming the first storm to produce significant impact there since Typhoon Rita in 1972.

– Kyle Gayan is an undergraduate student in Atmospheric Sciences at the University of North Carolina at Asheville and is also a retired USAF Master Sergeant; his 20 years of service was spent exclusively in the weather career field. He recently joined the Cyclone Center team as a classifier and contributor to our social media.

Featured Storm – Hurricane Rita (2005)

Hurricane Rita is now the featured storm from the 2005 record-breaking Atlantic season.  She was the third Category 5 hurricane of the season, producing an estimated $10 billion in damage across the southern United States.

Hurricane Rita at peak intensity in the Gulf of Mexico

Hurricane Rita at peak intensity in the Gulf of Mexico

Less than a month after Katrina had hit the central Gulf region, Rita was in the works.  On September 16th, 2005 a tropical wave interacted with the remains of a trough from a dissipating stationary front. This was her beginning.  The next day, near the Turks and Caicos Islands, this interaction turned into a tropical depression.

The depression started moving westward and Tropical Storm Rita was named that afternoon.  Rita began a rapid intensification phase when she moved through the Florida Straits on September 20th, with a wind speed of over 60 knots. That day she reached hurricane status and peaked at Category 2 intensity on the Saffir-Simpson scale. When Rita entered the Gulf she went from a Category 2 to Category 5 intensity in just 24 hours. This was only the third time in history that two Category 5 storms had been recorded forming in the Atlantic during the same year, and it was the first time that two hurricanes reached Category 5 intensity in the Gulf of Mexico in the same year.  Rita reached her peak intensity on September 24th when her sustained winds exceeded 155 knots.

Track of Hurricane Rita (2005)

Track of Hurricane Rita (2005)

Rita began weakening as she made landfall just east of the Texas/Louisiana border on September 24th.  She was still at tropical storm intensity when she reached northwestern Louisiana later that day,  turning northeastern and merging with a frontal system.  She produced torrential rainfall of as much as 5 to 9 inches in many areas of Louisiana, Mississippi, and eastern Texas. Storm surge flooding and wind damage were some of the major causes of the devastating damage Rita left behind, along with  an estimated 90 tornadoes across the southern US.

Rita was definitely a memorable one.  Luckily, with forecasters being on alert, they evacuated an estimated 3 million people from their homes in preparation for the storm.  Of course, with Katrina only being in the recent past, no one was prepared for the damage Rita would cause.  She was directly responsible for seven deaths, and indirectly responsible for 113.

Go to Cyclone Center today to start classifying Rita.  She was a historic, one-of-a-kind storm. To learn more about her, you can go to US National Hurricane Center tropical cyclone report for Rita.

– Kelly Dobeck is an undergraduate student in Atmospheric Sciences at the University of North Carolina at Asheville.  She recently joined the Cyclone Center team as a classifier and contributor to our social media.  

Hurricane Katrina and the Intensifying Coastal Threat

This week Cyclone Center introduces Hurricane Katrina (2005) as one of our featured storms.  This is the 8th anniversary of Katrina’s assault on the northern Gulf of Mexico coast.  The city of New Orleans, despite a massive system of protective levees and pumps, lost over 1500 souls, almost all from drowning when water flooded about 80% of the city.  Since then,  millions of dollars have been spent on the repair and upgrade of the levee system in and around metro New Orleans.  Are they ready for the next one?

“We’ll be absolutely ready for it,” said U.S. Army Corps communications officer Wade Habshey in a recent Discovery News article. “What we have in place now can withstand a Katrina-level storm.”

New Orleans flooding caused by 60 kt. winds, 10-14 ft. storm surge.  Category-5 values: 150 kt winds, 30-35 ft. storm surge.

New Orleans flooding caused by 60 kt. winds, 10-14 ft. storm surge. Category-5 values: 140 kt winds, 25-35 ft. storm surge.

But what exactly is a “Katrina-level” storm?  Winds in downtown New Orleans rarely exceeded minimal hurricane force at the peak of the event.  Storm surge and the strongest winds from the weakening Katrina were focused well to the east in coastal Mississippi.  And yet levees failed, water flooded significant portions of the city, and over 1,500 perished.

An even bigger concern in the long-term are geological changes occurring in the area; coastal portions of Louisiana are sinking into the ocean as climate-forced sea levels continue to rise and land areas sink.  This exacerbates the threat of  hurricanes for a region that experiences one on average every couple of years.  Many climate scientists now believe that hurricanes will be stronger on average in the future as the ocean, which provides the fuel for the storms, continues to warm.

What more should be done?  Government officials exude confidence that the improvements to the levy system will hold up, but we’ve heard that story before.  Claims were made soon after Katrina that the levee system was designed to withstand a Category-3 storm , not something like “Katrina’s strength”.  We’ve already seen that Katrina wasn’t even a hurricane in New Orleans – what happens when a real Category-4 or 5 storm hits the area?  We can only hope that residents will have left, because it’s a very good bet that there will be little dry land to stand on.

– Chris Hennon is part of the Cyclone Center Science Team and Associate Professor of Atmospheric Sciences at the University of North Carolina at Asheville

Featured Storm – Hurricane Emily (2005)

By the time Emily made her appearance in the second week of July, the 2005 Atlantic season had already produced four named storms (tropical storm strength or better) and was on its way to a record breaking performance.  So it was hard to stand out from the crowd that year, but Emily sure did.

Emily formed the way many of the strongest tropical cyclones do in the Atlantic – as a tropical “wave” or disturbance that left the coastline of Africa on July 6.  She struggled at first to get her act together, as dry air penetrated her core and the upper level winds in the area kept trying to rip her apart.  But Emily kept it together long enough to obtain tropical storm status on July 11.  But the fun was just beginning.

Hurricane Emily (2005)

Hurricane Emily readies herself for the final plunge into Mexico

The next day, the “steering winds”, or the upper level winds in the atmosphere that push the system along, increased in intensity.  Emily’s forward speed increased from a sluggish 10 kt. to a quite respectable 17 kt.  Although this initially made Emily’s environment less favorable,  recon planes noticed her winds at the surface unexpectedly began to increase.  Everything seemed to fall into place and just 2 days later Emily was a major Category-4 hurricane with maximum winds near 115 kt.

As Emily passed south of Jamaica, the records began to fall.  She became the earliest (since records began in the 19th century)  tropical cyclone to reach Category-5 status.  Furthermore, Emily to this day is the only known storm to ever achieve Cat-5 intensity in the month of July in the Atlantic.

Fortunately, Emily spent most of her time over the ocean when she was strongest.   But she did pass directly over Grenada, Cozumel Mexico, and northeastern Mexico near San Fernando.  Damage was unexpectedly light in the Yucatan, with mostly minor wind damage and flooding reported.  Northern Mexico appeared to receive the worst of the storm, with 90,000 people driven from their homes and thousands of buildings destroyed.  Miraculously only 6 deaths were reported from the storm, 4 in Jamaica when a car was pushed over a cliff from flood waters.

Go to Cyclone Center today and start classifying Hurricane Emily.  She was truly a memorable one.  Much of the information given here and more can be found in the U.S. National Hurricane Center tropical cyclone report for Emily.

– Chris Hennon is part of the Cyclone Center Science Team and Associate Professor of Atmospheric Sciences at the University of North Carolina at Asheville

Featured Storm – Cyclone Alibera (1989)

Very Intense Cyclone Alibera

Citizen scientists working at Cyclone Center now have four storms to choose from when they sign in to classify.  Our first set of storms includes Cyclone Alibera, a long-lasting Southern Indian Ocean storm that thrashed coastal Madagascar on New Years Day 1990.

The path the Cyclone Alibera followed

The path the Cyclone Alibera followed during the first 3 weeks of its life.  The storm formed in the upper right portion of the map and moved toward the lower left.

Alibera formed in the Indian Ocean on December 14, 1989 and did not dissipate until January 7, 1990 – a whopping 25 days!  During that time, the storm traveled several thousand kilometers, which included a big loop.  Cyclones like Alibera are steered by the large-scale winds in the atmosphere.  Sometimes when these winds are weak and/or changing, storms can move in strange ways.  The first image shows the long and interesting track of Alibera.

During the second week of Alibera’s life, the atmospheric and ocean conditions became very favorable for intensification.  The storm rapidly strengthened from a subdued tropical storm into a minor or very intense tropical cyclone, depending on who you believe.

Two forecast centers tracked Alibera during this time.  The Joint Typhoon Warning Center, or JTWC, is a U.S. Navy and Air Force office in Hawaii that monitors the western Pacific and Indian Oceans.  Based on imagery like those that citizen scientists are analyzing in Cyclone Center, analysts determined that Alibera was a “Very Intense Cyclone”, with wind speeds on the threshold of Category 5 intensity in the Saffir-Simpson scale.   However, analysts at a French forecast centre on La Reunion, an island off the east coast of Madagascar, determined that Alibera was only a minimal Category 1 tropical cyclone at the same time.  The figure below shows that these differences in opinion were not limited to the time of Alibera’s strongest intensity.

Alibera best track intensities

Alibera intensities as determined by JTWC and Reunion forecast centers.

This is why Alibera is one of the first storms that we would like citizen scientists to analyze.  We want to know what YOU think Alibera’s intensity was – we will use this information to reconcile these big differences.

Alibera eventually would make landfall in coastal Madagascar on New Year’s day, killing 46 people.  Though not widely known outside of the southern Indian Ocean region, Alibera is certainly a storm worthy of our attention – and a good example of how tropical cyclone forecasters can wildly disagree on a storm’s intensity when observations are not available.

Log on to Cyclone Center today and classify Alibera.

– Chris Hennon is part of the Cyclone Center Science Team and Associate Professor of Atmospheric Sciences at the University of North Carolina at Asheville