MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY MAY, 2006 (For general comments about the nature of these summaries, as well as information on how to download the tabular cyclone track files, see the Author's Note at the end of this summary.) IMPORTANT NOTE FROM THE AUTHOR -- PLEASE READ!!! In order for the tropical cyclone summaries to continue with any degree of timeliness, some changes are going to be necessary in order to significantly reduce the amount of time required to prepare them. I have many commitments and demands made upon my time, and to be honest, I just do not have the enthusiasm I once had for writing them. I find it increasingly difficult to spend hours poring over discussions and warnings just to glean a few tidbits of information here and there to fit into a historical narrative. However, so many persons have told me, and continue to tell me, that they find the summaries and track files useful, so I do not want to completely drop them. Some streamlining of the narratives detailing the synoptic history of the storms will be made for cyclones in all the basins, but there is going to be a significant reduction in the coverage given to Atlantic and Northeast Pacific tropical cyclones. While these basins are personally my primary basins of interest (I live less than 100 km from the Gulf of Mexico), I am reducing coverage of these tropical cyclones for several reasons: (1) A significant majority of the readers of these summaries live in the United States, and Atlantic (and usually Eastern Pacific) storms are given wide coverage on the Atlanta-based Weather Channel as well as various other 24-hour TV cable news providers. (2) Many persons outside the U. S. are also able to watch the cable news channels and follow Atlantic cyclones in particular. (3) Tropical cyclone warnings can be received via e-mail or downloaded from websites from just about every warning agency in the world, and any person interested in performing detailed research on any cyclone can save these warnings for further study if they so desire. In addition, TPC/NHC archives all their tropical cyclone advisories, discussions and graphics on their website, and these are available long-term for any person who desires to research a particular cyclone in greater detail. (4) In addition to the narrative summaries, from the beginning I have prepared a tabular track file to accompany each month's summary. These give a concise and quantitative history of each cyclone, and in conjunction with the graphics which John Diebolt of Tucson is now preparing based upon these track files, present a very adequate numerical and pictorial representation of each cyclone's history. (A picture is worth a thousand words!) Beginning with December, 2004, I have been including the link to each cyclone's track graphic on John's website. (For more information on John's website, see the Feature of the Month article in the February, 2005, summary.) (5) I have discovered an online encyclopedia (Wikipedia) which contains fairly detailed reports of tropical cyclones, especially for Atlantic storms. I have included links to these reports already for several storms and plan to continue doing so. I have recently been in contact with one of the authors and managers of the Wikipedia tropical cyclone project, and plans are for these reports to continue to exist and grow in scope and remain available long-term. (6) And finally, TPC/NHC has their extremely informative storm reports available online beginning usually in late October (sometimes earlier), and for the most part completed by the end of the calendar year. Indeed, ever since the 2000 season the official NHC reports have begun appearing before I could get the preliminary reports completed for many of the latter cyclones each season, so I chose instead to write just a brief article supplementing the official reports for those cyclones. I hope those who are primarily interested in Atlantic cyclones will not be too disappointed, but this is a necessary step to insure that reports on cyclones in other basins for which information is not so readily available will not be running months behind, as has often been the case in the past. Also, Kevin Boyle and Simon Clarke have assured me that they are still interested in writing tropical cyclone reports for the Western North Pacific, Northeast Australia/Coral Sea and South Pacific basins, so summaries for storms in those basins should continue with little change. ************************************************************************* MAY HIGHLIGHTS --> Rare South China Sea super typhoon has adverse effects on several southeastern Asian nations --> First Eastern North Pacific tropical storm forms on schedule ************************************************************************* ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for May: No tropical cyclones ************************************************************************* NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for May: 1 tropical storm Sources of Information ---------------------- Most of the information presented below was obtained from the various tropical cyclone products issued by the Tropical Prediction Center/National Hurricane Center (TPC/NHC) in Miami, Florida (or the Central Pacific Hurricane Center (CPHC) in Honolulu, Hawaii, for locations west of longitude 140W): discussions, public advisories, forecast/advisories, tropical weather outlooks, special tropical disturbance statements, etc. Some additional information may have been gleaned from the monthly summaries prepared by the hurricane specialists and available on TPC/NHC's website. All references to sustained winds imply a 1-minute averaging period unless otherwise noted. Northeast Pacific Tropical Activity for May ------------------------------------------- In recent years the tropical cyclone season in the Northeast Pacific basin has begun almost like clockwork within the latter 10 days of May, and 2006 was no exception. The first tropical depression (01E) formed on 27 May and later that same day became Tropical Storm Aletta. Over the period 1971-2005, the month of May has averaged about one storm every other year, but 2006 was the seventh consecutive season in which the first named storm has formed in May. By way of contrast, the 8-year period 1992 through 1999 saw only one May tropical storm develop--an unnamed storm in 1996. The only May in which two Eastern Pacific storms developed was in 1984. Aletta produced 2.25 NSD--the average NSD for May is 1.84 for the 35-year period. A short report on Aletta follows. TROPICAL STORM ALETTA (TC-01E) 27 - 30 May ----------------------------------------- Most of the information in this short report was obtained from the monthly summary for May prepared by the staff of TPC/NHC. Tropical Storm Aletta represents the seventh consecutive year in which the Eastern North Pacific tropical cyclone season has begun in the month of May, a month which normally sees a tropical storm or hurricane form only about every other year. Aletta formed as a result of the interaction of a westward-moving tropical wave with a low-level trough near the Gulf of Tehuantepec. The resultant broad low-pressure area was located several hundred miles south of Acapulco on 25 May. Organization gradually increased and the system had developed into Tropical Depression 01E by early on the 27th, centered about 165 nm southwest of Acapulco. The depression embarked on a northerly track toward the Mexican coast and was upgraded to Tropical Storm Aletta later that same day. Aletta's peak intensity of 40 kts was attained at 0600 UTC on 28 May and was maintained for 36 hours. The tropical cyclone moved erratically, executing a counterclockwise loop southwest of Acapulco on the 28th. A strengthening ridge to the north prevented a rendezvous with the Mexican coastline and Aletta began drifting westward on the 29th while slowly weakening to a depression by 30/0000 UTC. Aletta continued to weaken and dissipated about 170 nm south-southeast of Manzanillo later on the 30th. Aletta produced some locally heavy rains over portions of southern Mexico with a 24-hour total of 91 mm in Oaxaca State. No damage nor casualties were reported. A graphic displaying the track of Tropical Storm Aletta may be found at the following link: The track in tabular form may be accessed at the following URL: The link for the online Wikipedia report on Aletta is: (Report written by Gary Padgett) ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for May: 1 super typhoon Sources of Information ---------------------- Most of the information presented below is based upon tropical cyclone warnings and significant tropical weather outlooks issued by the Joint Typhoon Warning Center of the U. S. Air Force and Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion tropical cyclone tracks file, I normally annotate track coordinates from some of the various Asian warning centers when their center positions differ from JTWC's by usually 40-50 nm or more. All references to sustained winds imply a 1-minute averaging period unless otherwise noted. Michael V. Padua of Naga City in the Philippines, owner of the Typhoon 2000 website, normally sends me cyclone tracks based upon warnings issued by the Japanese Meteorological Agency (JMA) and the Philippines' Atmospheric, Geophysical & Astronomical Services Administration (PAGASA). A very special thanks to Michael for the assistance he so reliably provides. In the title line for each storm I have referenced all the cyclone names/numbers I have available: JTWC's depression number, the JMA-assigned name (if any), JMA's tropical storm numeric designator, and PAGASA's name for systems forming in or passing through their area of warning responsibility. SUPER TYPHOON CHANCHU (TC-02W / TY 0601 / CALOY) 8 - 20 May ---------------------------------------------- Chanchu: contributed by the colony of Macau, is the Macanese word for pearl A. Introduction --------------- The second significant tropical cyclone of 2006 in the NW Pacific basin, Chanchu became the earliest system to be designated a super typhoon by JTWC in the South China Sea. Super typhoons are a rarity in that part of the world, and a search through the JTWC archives reveal that the only other tropical cyclones to reach that intensity in the South China Sea were Ryan (1995) and Sally (1996). From its formation late on 8 May Chanchu crossed the Philippine Archipelago on 11-12 May before peaking at 135 kts in the South China Sea early on 15 May. After alarming the community of Hong Kong, China, Chanchu veered sharply away towards the north and made landfall in Guangdong Province in eastern China on 17 May. B. Synoptic History ------------------- Super Typhoon Chanchu began its life as a persistent area of convection approximately 310 nm southeast of Yap. It was first noted in JTWC's STWO issued at 2030 UTC 5 May. The tropical disturbance remained a weak, poorly-organized feature until 7 May when the system's organization began to improve and the LLCC began to consolidate. A TCFA was issued at 08/1100 UTC, relocating the disturbance to a position approximately 100 nm west-southwest of Yap. The first warning on Tropical Depression 02W was issued at 08/1800 UTC with the system at this time passing north of Palau. TD-02W was upgraded to a 35-kt tropical storm at 09/0000 UTC, and acquired the name Chanchu at 09/1200 UTC when JMA raised their 10-min avg MSW to 35 kts. Tropical Storm Chanchu continued to intensify as it tracked predominantly west-northwestward along the southern periphery of a subtropical ridge. It was upgraded to a 75-kt typhoon at 1800 UTC 10 May while centred approximately 440 nm east-northeast of Zamboanga, Philippines. Typhoon Chanchu weakened slightly as it crossed the northern tip of Samar, Philippines, on 11 May. However, despite the hindering effects of land, Chanchu re-strengthened while over the Sibuyan Sea on 12 May. The storm's intensity fluctuated as it tracked erratically westward across the Philippine island of Mindoro, emerging into the South China Sea early on 13 May where it slowly began to reorganize. The tropical cyclone was forecast in the long-term to become very intense and to make landfall in the vicinity of Hong Kong, China. Drifting westwards, Typhoon Chanchu underwent rapid intensification over the South China Sea on 14 May. It was upgraded to a super typhoon at 1800 UTC 14 May while located approximately 515 nm south of Hong Kong, China, before peaking at 135 kts six hours later. Chanchu abruptly veered north on 15 May as the subtropical ridge split apart, and this northward path into the resulting weakness took the storm into a less favourable environment. At 15/0600 UTC Chanchu was downgraded back to typhoon intensity. The tropical cyclone gradually weakened further but remained a powerful system for the next two days while moving on a north to north-northeasterly trajectory through the South China Sea towards the Chinese coast, away from Hong Kong. The typhoon made landfall near Shantou, Guangdong Province, late on 17 May with the MSW estimated at 75 kts. Chanchu continued up the eastern coastal region of China and was downgraded to a 45-kt tropical storm on JTWC's final warning at 18/0000 UTC. JMA also downgraded Chanchu to a tropical storm at this time but continued to issue bulletins until it was declared extratropical over the East China Sea at 19/0000 UTC. The weak residual LOW continued northeastward, passing over the Japanese islands of Kyushu, Shikoku and Honshu, eventually exiting into the North Pacific near Tokyo. The highest MSW estimated by JMA was 90 kts with a minimum CP of 930 mb. PAGASA estimated a peak intensity of 80 kts while Typhoon Chanchu/Caloy was within their AOR. PAGASA first assigned the name Caloy at 09/0000 UTC after the system had crossed 135E. A graphic displaying the track of Super Typhoon Chanchu/Caloy may be found at the following link: The track in a tabular format may be accessed at the following URL: C. Damage and Casualties ------------------------ Typhoon Chanchu was responsible for 41 deaths in the Philippines, including 21 persons who perished when a motor boat capsized off Masbate Island. In China, at least twenty-five people were reported dead with four missing. Eleven fishing vessels from Vietnam were sunk, killing 44 fishermen, and at least 190 Vietnamese were reported missing. The above casualty information, along with a much more detailed description on the impact of Super Typhoon Chanchu, may be obtained at the following link: (Report written by Kevin Boyle) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for May: No tropical cyclones ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for May: No tropical cyclones ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for May: No tropical cyclones ************************************************************************* NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for May: No tropical cyclones ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Activity for May: No tropical cyclones ************************************************************************* SPECIAL FEATURE - SOURCES OF TROPICAL CYCLONE INFORMATION The purpose of this section is to list some websites where many and varied types of tropical cyclone information are archived. Many readers will know about these already, but for the benefit of those who don't, I wanted to include them. (1) Aircraft Reconnaissance Information --------------------------------------- Various types of messages from reconnaissance aircraft may be retrieved from the following FTP site: Information regarding how to interpret the coded reconnaissance messages may be found at the following URL: Links are also included to websites with further information about the U. S. Air Force 53rd Weather Reconnaissance Squadron and the NOAA Air- craft Operations Center. (2) Archived Advisories ----------------------- All the advisory products (public advisories, forecast/advisories, strike probabilities, discussions, various graphics) issued by TPC/NHC are archived on TPC's website. For the current year (using 2004 as an example), the archived products can be found at: Links to tropical products archives for earlier years are available at the following URL: JTWC warnings for past storms are archived on the NRL Monterry website: On the NRL site, the link to past years can be found in the upper left corner of the screen. I am not aware at the moment of any other TCWC which archives all its tropical cyclone warning/advisory products for public access, but if I learn of any, I will add them to this list. (3) Satellite Imagery --------------------- Satellite images of tropical cyclones in various sensor bands are available on the NRL Monterrey and University of Wisconsin websites, courtesy of Jeff Hawkins and Chris Velden and their associates. The links are: On the NRL site, the link to past years can be found in the upper left corner of the screen. For the CIMSS site, a link to data archives is located in the lower left portion of the screen. Additional tropical satellite imagery, along with looping ability for composite microwave imagery for the Western Hemisphere north of the equator, can be found at: (1) For the Eastern North Pacific: (2) For the Atlantic, Gulf of Mexico and Caribbean Sea: I'm sure there are other sites with available imagery available, and as I learn of them, I will add the links to this list. ************************************************************************* EXTRA FEATURE In order to shorten the amount of typing in preparing the narrative material, I have been in the habit of freely using abbreviations and acronyms. I have tried to define most of these with the first usage in a given summary, but I may have missed one now and then. Most of these are probably understood by a majority of readers but perhaps a few aren't clear to some. To remedy this I developed a Glossary of Abbreviations and Acronyms which I first included in the August, 1998 summary. I don't normally include the Glossary in most months in order to help keep them from being too long. If anyone would like to receive a copy of the Glossary, please e-mail me and I'll be happy to send them a copy. ************************************************************************* AUTHOR'S NOTE: This summary should be considered a very preliminary overview of the tropical cyclones that occur in each month. The cyclone tracks (provided separately) will generally be based upon operational warnings issued by the various tropical cyclone warning centers. The information contained therein may differ somewhat from the tracking and intensity information obtained from a "best-track" file which is based on a detailed post-seasonal analysis of all available data. Information on where to find official "best-track" files from the various warning centers will be passed along from time to time. The track files are not being sent via e-mail. They can be retrieved from the archive sites listed below. (Note: I do have a limited e-mail distribution list for the track files. If anyone wishes to receive these via e-mail, please send me a message.) Both the summaries and the track files are standard text files created in DOS editor. Download to disk and use a viewer such as Notepad or DOS editor to view the files. The first summary in this series covered the month of October, 1997. Back issues can be obtained from the following websites (courtesy of Michael Bath, Michael V. Padua, Michael Pitt, Chris Landsea, and John Diebolt): Another website where much information about tropical cyclones may be found is the website for the UK Meteorological Office. Their site contains a lot of statistical information about tropical cyclones globally on a monthly basis. The URL is: TROPICAL CYCLONE REPORTS AVAILABLE JTWC now has available on its website the Annual Tropical Cyclone Report (ATCR) for 2004 (2003-2004 season for the Southern Hemisphere). ATCRs for earlier years are available also. The URL is: Also, TPC/NHC has available on its webpage nice "technicolor" tracking charts for the 2004 Atlantic and Eastern North Pacific tropical cyclones; also, storm reports for all the 2004 Atlantic and Eastern North Pacific cyclones are now available, as well as track charts and reports on storms from earlier years. The URL is: A special thanks to Michael Bath of McLeans Ridges, New South Wales, Australia, for assisting me with proofreading the summaries. PREPARED BY Gary Padgett E-mail: garyp@alaweb.com Phone: 334-222-5327 Kevin Boyle (Eastern Atlantic, Western Northwest Pacific, South China Sea) E-mail: newchapelobservatory@btinternet.com Simon Clarke (Northeast Australia/Coral Sea, South Pacific) E-mail: saclarke@iprimus.com.au ************************************************************************* ************************************************************************* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ To unsubscribe, e-mail LISTSERV@UIUC.EDU with "unsub wx-atlan" in the body of the message or e-mail chris@lib.siu.edu for help. Products are also available directly from NHC via e-mail. See: http://www.nhc.noaa.gov/signup.shtml for available products and sign-up.