MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY APRIL, 2008 (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.) ************************************************************************* APRIL HIGHLIGHTS --> Strong South China Sea typhoon for month of April --> Intense cyclone strikes Myanmar with catastrophic loss of life ************************************************************************* WIKIPEDIA TROPICAL CYCLONE REPORTS Short reports with satellite pictures and small-scale maps for all tropical cyclones may be found at the following links: For some storms more detailed reports have been prepared. In those cases I will include the specific links in the reports for the applicable tropical cyclones. ************************************************************************* !!!!!!!!!! EXTRA FEATURE !!!!!!!!!! INTERESTING SUBTROPICAL CYCLONE NEAR ADELAIDE, SOUTH AUSTRALIA The following report was written by Michael Bath of McLeans Ridges, New South Wales, who has assisted me with proofreading the summaries for several years. A special thanks to Michael for taking the time to write up this interesting system. Subtropical Low 8 - 15 July, 2008 ------------------------------------- A low-pressure system developed around 25S/96E (or about 925 nm west of Carnarvon, WA) in response to a lagging surface trough extending from a cold front crossing the southwest of Western Australia on 08/1200 UTC. By 10/0000 UTC the LOW had barely intensified but was now located approximately 250 nm WNW of Perth, WA. Over the next 24 hours the LOW intensified significantly, the pressure dropping 17 hPa to 996 hPa, while skirting around the southwest coast of WA. A number of severe weather warnings were issued by the Bureau of Meteorology during the 10th and 11th of July for damaging wind gusts possibly reaching 65-70 kts. This was certainly the case with damage to property reported at a number of coastal locations. These types of subtropical LOWs which intensify near southwest Western Australia are not uncommon and are normally unworthy of much discussion. However, this system gathered interest as it continued a slow eastward movement across the Great Australian Bight. The satellite signature between 11/0000 UTC and 12/1200 UTC was fairly typical of a mid-winter cold cored LOW with a large well-dispersed spiral cloud pattern. By 13/0000 UTC most of the outer cloud had dissipated, leaving a small circular core of convection with an eye feature resembling a compact tropical cyclone. The system edged north of east and crossed Kangaroo Island, South Australia, between 13/1000 and 13/1500 UTC. At Cape Willoughby northerly wind gusts reached 53 kts by 8:37pm, peaking at 64 kts at 12:17am. The centre of the LOW passed south of this location, which reported a shift in winds to west then southwest by 7:00am. The Adelaide radar revealed a well-defined 20-25 nm diameter eye as the LOW was centred over the western parts of Kangaroo Island. The eye contracted somewhat but remained a feature as the LOW headed slowly southeast and impacted the Cape Jaffa area by 14/0000 UTC. The weakened but still easily discernable LLCC made a small clockwise loop in this region during the following 24 hours before again crossing the coast north of Cape Jaffa at 15/0000 UTC. Analysis of the LOW during 13/14 July shows the system had a cold core at the synoptic scale and a warm core at the mesoscale. More information on the LOW may be found at the following link: (Report written by Michael Bath) ************************************************************************* ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for April: No tropical cyclones ************************************************************************* NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for April: No tropical cyclones ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for April: 1 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). Also, Huang Chunliang of Fuzhou City, China, sends me each month tracks obtained from warnings issued by the National Meteorological Center of China (NMCC), the Central Weather Bureau of Taiwan (CWBT) and the Hong Kong Observatory (HKO). A very special thanks to Michael and Chunliang for the assistance they so reliably provide. 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. TYPHOON NEOGURI (TC-02W / TY 0801 / AMBO) 13 - 19 April --------------------------------------------- Neoguri: contributed by the Republic of Korea (South), is the Korean word for raccoon dog--a small grayish-brown animal with black markings on its face and on its thick, furry tail (NOTE: When this name was first used in June, 2002, it was spelled 'Noguri'. The English spelling was modified to better reflect the correct pronunciation.) Typhoon Neoguri, unusually strong for an April typhoon in the South China Sea, became the earliest tropical cyclone on record to make landfall in China, although it had weakened to a minimal tropical storm by the time the center came ashore. The cyclone's beginnings lay with an area of disturbed weather which had formed east of Mindanao in the Philippines. The system moved westward, crossing the southern portion of the Philippine Archipelago as a weak tropical depression. Once into the South China Sea the system found favorable conditions for strengthening and eventually intensified into a strong Category 2 typhoon on the Saffir/Simpson scale (95 kts per JTWC). Neoguri reached its peak intensity as it neared Hainan Dao and steadily weakened until landfall in Guangdong Province a short distance west of Macau. A very detailed Wikipedia report is available on Typhoon Neoguri at the following link: According to this report, there were three deaths directly attributable to the storm with 40 persons reported missing. According to Derrick Herndon, Neoguri passed directly over Sanhu Dao (WMO 59985), an island in the South China Sea. The station reported a SLP of 973.2 hPa at 1200 UTC on the 17th when the center passed 10 nm to the east. The strongest winds at the station were 040@42 kts at 0900 UTC. The station only reports every 3 hours, so it is likely that stronger winds occurred between reporting times. For the landfall in mainland China, Yangjiang (WMO 59663) reported winds of 070@28 kts with a pressure of 1001.7 hPa at 19/0300 UTC while the center was about 40 nm to the southwest. This suggests 1-min avg over water winds of at least 40 kts at landfall. The lowest pressure at the station was 998.6 hPa at 19/0600 UTC with northwest winds of 15 kts. (Thanks to Derrick for sending the information.) (Report written by Gary Padgett with information supplied by Derrick Herndon) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for April: 1 very intense cyclonic storm 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. Occasionally some information may be gleaned from the daily tropical weather outlooks and other bulletins issued by the Indian Meteorological Department (IMD), which is the World Meteorological Organization's Regional Specialised Meteorological Centre (RSMC) for the basin. The reported maximum sustained winds (MSW) are based on a 1-minute averaging period, which is used by all U. S. civilian and military weather services for tropical cyclone warnings. For synoptic observations in the North Indian Ocean region, both 10-minute and 3-minute average winds are employed, but IMD makes no attempt to modify the Dvorak scale for estimating tropical cyclone intensity; hence, a 1-minute average MSW is implied. In the North Indian Ocean basin JTWC usually does not initiate warnings until a system has become well-organized and likely to attain tropical storm status within 48 hours. VERY SEVERE CYCLONIC STORM NARGIS (TC-01B) 27 April - 3 May ----------------------------------------------------- Nargis: contributed by Pakistan, is an Urdu word meaning daffodil Cyclonic Storm Nargis was responsible for the worst natural disaster in the history of Myanmar (formerly Burma). The storm struck the nation on 2 May as a lower-end Saffir/Simpson Category 4 cyclone (per JTWC's warnings), causing catastrophic destruction. At least 146,000 persons were reported killed, and many thousands more still missing. Relief efforts were hampered by policies of the Burmese government, and it is considered possible that the combined death toll from the storm itself plus those dying from lack of aid could possibly reach the one million mark. Damage has been estimated at over US$10 billion. The storm was the first cyclone to strike Myanmar since Cyclone Mala in 2006, which was slightly stronger, but had a significantly lower impact. Nargis developed in the eastern Bay of Bengal near the Andaman Islands and moved west-northwestward to a point in the west-central Bay where it abruptly recurved to the east-northeast. As the cyclone approached Myanmar, its track became due eastward and it intensified rapidly, striking the country near peak intensity. JTWC estimated Nargis' peak MSW at 115 kts, while IMD's peak intensity was reported at 95 kts. IMD's standard for reporting tropical cyclone winds seems to be a 3-min averaging period; however, they do not modify the Dvorak scale, so for a given T-number, a 1-min avg is implied. An excellent and very detailed report on this disastrous cyclone is available online at: (Report written by Gary Padgett) ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for April: No tropical cyclones ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for April: 2 tropical cyclones Sources of Information ---------------------- The primary sources of tracking and intensity information for Northwest Australia/Southeast Indian Ocean tropical cyclones are the warnings and advices issued by the Tropical Cyclone Warning Centres at Perth, Western Australia, and Darwin, Northern Territory. References to sustained winds imply a 10-minute averaging period unless otherwise stated. In the companion tropical cyclone tracks file, I occasionally annotate positions from warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii, when they differ from the Australian centres' coor- dinates by usually 40-50 nm or more. The JTWC warnings are also the source of the 1-minute average maximum sustained wind values included in the tracks file. Additionally, information describing details of satellite imagery and atmospheric circulation features included in the narratives is often gleaned from the JTWC warnings. Northwest Australia/Southeast Indian Ocean Tropical Activity for April ------------------------------------------ For several years a new Tropical Cyclone Warning Centre (TCWC) at Jakarta, Indonesia, has been in the planning stages. Personnel from Australia's Bureau of Meteorology were instrumental in assisting the Indonesian government with implementing the centre and in helping to train personnel. During the period that the new TCWC was being phased in, the BoM warning centres at Perth and Darwin issued TC warnings for the region that would one day be Jakarta's responsibility, namely for the area north of 10S and from 125E westward to 90E. Perth continued to issue warnings for waters north of 10S south of Java and Sumatra while Darwin covered the region west of 125E within the Indonesian Archipelago in the Java, Banda and Flores Seas. The Jakarta TCWC was ready by early 2008 and became operational in January. This region has a very low expectancy of TC genesis, but within three months the Jakarta centre was given the opportunity to issue warnings for two late-season, minor tropical cyclones. Jakarta issued tropical depression advices on the system which would become Tropical Cyclone Rosie after it had entered Perth's AOR, and only a couple days later, the new TCWC got to actually name its first tropical cyclone. According to the Wikipedia report, Tropical Cyclone Durga was christened early on 23 April. Rosie and Durga followed similar tracks from their points of origin southeast of Sumatra, moving eastward at a low latitude and turning to the south as they weakened. Short reports on both these cyclones follow. TROPICAL CYCLONE ROSIE (TC-28S) 20 - 25 April ------------------------------------------ According to the Wikipedia report, a tropical LOW formed southwest of Sumatra on 18 April with the Jakarta TCWC designating it a tropical depression early on the 20th. Based on a SAB satellite fix bulletin, a tropical depression with winds likely of 30 kts was located about 250 nm north-northeast of the Cocos Islands around 2100 UTC on 20 April. The system moved east-southeastward and gradually became better organized with JTWC issuing the first warning on TC-28S at 21/1200 UTC. The center at this time was located about 200 nm west-northwest of Christmas Island. By 0000 UTC on 22 April TC-28S had moved south of 10S into Perth's AOR and was upgraded to Tropical Cyclone Rosie. Rosie's center at the time was only about 50 nm west of Christmas Island, and the cyclone reached its peak intensity of 50 kts six hours later while centered about 50 nm south-southwest of the island. (JTWC's peak 1-min avg MSW was 45 kts.) Rosie moved rather slowly and erratically around this time, and on the 23rd began to weaken quickly as vertical shear increased significantly. The cyclone was downgraded to a tropical LOW at 23/1200 UTC while centered about 75 nm south-southeast of Christmas Island. Ex-Rosie turned toward the south and accelerated to the south-southwest on the 24th and JTWC issued their final warning at 24/0600 UTC. BoM Perth continued to issue gale warnings for peripheral gales in certain quadrants on the 23rd and 24th, but by 25/0000 UTC no more gales were forecast so the final warning on the LOW was issued, locating the center about 450 nm to the south of Christmas Island. No reports of damage or casualties resulting from Tropical Cyclone Rosie have been received. (Report written by Gary Padgett) TROPICAL CYCLONE DURGA (TC-29S) 22 - 25 April ------------------------------------------ A STWO issued by JTWC on 21 April mentioned a tropical disturbance deep in the tropics just west of 90E. The system drifted eastward and a satellite fix bulletin from SAB located a 30-kt tropical depression about 500 nm northwest of the Cocos Islands at 0600 UTC on 22 April. According to the Wikipedia report, Jakarta designated the system as a tropical depression on the 22nd. In the meantime, JTWC issued the first warning on TC-29S at 22/1800 UTC, placing the center about 300 nm northwest of the Cocos Islands. Early on the 23rd the Jakarta TCWC upgraded the depression to tropical storm intensity and assigned the name Durga--the first cyclone to be named by the new warning center. Tropical Cyclone Durga was moving basically eastward with a very slight southerly component of motion. By 24/0000 UTC Durga had reached a position near 10.1S/98.1E, and official warning responsibility was passed to BoM Perth. The peak intensity for Durga was estimated at 40 kts by Jakarta, Perth and JTWC. Shortly after entering Perth's AOR Durga began to weaken. JTWC issued their final warning at 24/0600 UTC, but Perth maintained Durga at 35 kts through 24/1800 UTC, downgrading the system and issuing their final warning at 25/0000 UTC. The final Perth bulletin placed ex-Durga's center approximately 150 nm east of the Cocos Islands, or a few hundred miles west of Christmas Island. No reports of damage or casualties resulting from Tropical Cyclone Durga have been received. (Report written by Gary Padgett) ************************************************************************* NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for April: No tropical cyclones ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Activity for April: 2 tropical depressions ** ** - one of these classified as a minimal tropical storm by JTWC Sources of Information ---------------------- The primary sources of tracking and intensity information for South Pacific tropical cyclones are the warnings and advisories issued by the Tropical Cyclone Warning Centres at Nadi, Fiji (for waters north of latitude 25S), and Wellington, New Zealand (for waters south of latitude 25S). References to sustained winds imply a 10-minute averaging period unless otherwise stated. In the companion tropical cyclone tracks file, I occasionally annotate positions from warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii, when they differ from the Southern Hemisphere centres' coordinates by usually 40-50 nm or more. The JTWC warnings are also the source of the 1-minute average maximum sustained wind values included in the tracks file. Additionally, information describing details of satellite imagery and atmospheric circulation features included in the narratives is often gleaned from the JTWC warnings. South Pacific Tropical Activity for April ----------------------------------------- The final two numbered (by Fiji) tropical depressions of the 2007-2008 season formed during April. (The final named cyclone, Gene, operated from late January into early February.) The two depressions followed quite similar tracks, forming near the border between Nadi's and Brisbane's respective AORs south of the Solomons and moving southeastward between New Caledonia and Vanuatu to dissipation over waters between Norfolk Island and Fiji. A short report describing both of these systems follows. TROPICAL DEPRESSION (TD-15F) 4 - 7 April --------------------------------------- AND TROPICAL DEPRESSION (TD-16F / TC-27P) 17 - 19 April --------------------------------------- As noted above, Tropical Depressions 15F and 16F followed remarkably similar tracks, although separated in time by almost two weeks. A tropical disturbance was located on 4 April approximately 225 nm north- northeast of the Chesterfield Islands. Since the system was essentially on the border between the Brisbane and Fiji AORs, RSMC Nadi designated it as Tropical Disturbance 15F at 1600 UTC, and at 2300 UTC elevated it to tropical depression status. TD-15F moved generally southeastward, passing between New Caledonia and Vanuatu. Gale warnings were issued late on the 5th and early on the 6th for peripheral gales extending from the northeastern sector to the southern semicircle. The final reference to TD-15F was at 07/0600 UTC when it was located approximately 400 nm northeast of Norfolk Island. A Tropical Weather Outlook issued by BoM Brisbane on 6 April referred to this system as a subtropical depression. Satellite fix bulletins were apparently not issued by SAB, Brisbane and CPHC for this system, suggesting that it was very poorly-organized and likely not of clear tropical character. Almost two weeks after TD-15F had formed, another area of disturbed weather appeared about 300 nm north-northeast of the Chesterfield Islands and showed signs of increased organization. RSMC designated the system as Tropical Depression 16F at 1800 UTC on 17 April and issued a warning for peripheral gales from the southwestern quadrant extending around the eastern side of the depression to the north. TD-16F, much like its predecessor, moved generally southeastward between New Caledonia and the Republic of Vanuatu. TD-16F was better organized and of more clear tropical character than TD-15F, and JTWC issued three warnings on the system as TC-27P. It was initially forecast to intensify further, but entered a high shear environment and quickly weakened. The final reference to the system by Nadi was at 2300 UTC on 19 April when the center was located about 375 nm northeast of Norfolk Island. The peak 1-min avg MSW estimated by JTWC was 35 kts. Dvorak ratings from both CPHC and BoM Brisbane reached T3.0/3.0 early on 18 April. JTWC's ratings peaked at T2.5/2.5 at 17/2330 UTC while the highest noted from SAB was T2.0/2.0. TC-27P was almost certainly a tropical storm based on a 1-min avg MSW criterion, and the satellite intensity estimates from CPHC and Brisbane suggest that it was possibly a minimal "10-min avg" tropical cyclone. (Report written by Gary Padgett) ************************************************************************* 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 Monterrey 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: (4) Cyclone Tracking Information -------------------------------- There is a U. S. Navy site that tracks tropical cyclones at 6-hourly intervals which often includes pre and post-advisory positions. The link to the site is: Steve Young has compiled many of these tracks onto a single webpage which is very user-friendly: 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, and Chris Landsea): 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 2006 (2005-2006 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 2007 Atlantic and Eastern North Pacific tropical cyclones; also, storm reports for all the 2007 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 (Northwest Pacific) E-mail: newchapelobservatory@btinternet.com ************************************************************************* ************************************************************************* Posted: 08.31.08 / Typhoon2000.ph, Typhoon2000.com