GLOBAL TROPICAL CYCLONE TRACKS - APRIL 2011 !!!! IMPORTANT -- PLEASE SEE INFORMATION AT END OF FILE !!!! ************************************************************************* ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Sources of Information ---------------------- The track coordinates, central pressure and 1-minute average maximum sustained wind values were obtained from the operational forecast/advisories issued by the Tropical Prediction Center/National Hurricane Center located in Miami, Florida. A 1-minute averaging period is the standard used by all U. S. civilian and military warning services for tropical cyclone warnings. Systems Tracked --------------- Possible Subtropical LOW (Invest 91L) 20 - 24 Apr ************************************************************************* Storm Name: None Cyclone Number: None Basin: ATL (Identified aS NRL Invest 91L) Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 APR 20 0600 21.0 N 59.3 W 1012 NCEP reanalysis 11 APR 20 1200 21.3 N 50.9 W 1014 11 APR 20 1800 21.4 N 62.0 W 1012 35 SAT=ST1.5 (NRL winds) 11 APR 21 0000 21.1 N 64.0 W 1012 11 APR 21 0600 21.6 N 63.9 W 1011 35 11 APR 21 1200 21.8 N 63.4 W 1011 35 11 APR 21 1800 22.7 N 63.6 W 1012 35 11 APR 22 0000 24.5 N 62.7 W 1012 35 11 APR 22 0600 25.0 N 62.7 W 1010 SAT=ST1.5 11 APR 22 1200 25.3 N 62.9 W 1010 30 SAT=ST1.5 11 APR 22 1800 26.1 N 63.2 W 1010 35 SAT=ST1.5 11 APR 23 0000 25.0 N 63.2 W 1011 11 APR 23 0600 24.9 N 64.7 W 1011 11 APR 23 1200 23.5 N 65.1 W 1012 11 APR 23 1800 22.3 N 66.4 W 1013 11 APR 24 0000 22.1 N 67.6 W 1013 11 APR 24 0600 22.0 N 68.8 W 1014 11 APR 24 1200 21.4 N 70.0 W Open wave 11 APR 24 1800 21.3 N 72.7 W Note: Although the NHC considered this an extratropical cyclone, the NOAA Satellite and Information Service classified this as a subtropical system of ST=1.5. NRL also reorted winds of 35 kts. Thanks to Steve Young for sending me the information on Invest 91L. The above track was based on NCEP reanalysis data. Following is the track from NRL from 20-22 April: Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 APR 20 1800 23.2 N 60.8 W 35 11 APR 21 0600 23.3 N 62.5 W 35 11 APR 21 1200 23.6 N 62.9 W 35 11 APR 21 1800 24.4 N 63.0 W 35 11 APR 22 0000 25.3 N 63.0 W 35 11 APR 22 1200 26.9 N 62.9 W 30 11 APR 22 1800 26.5 N 64.0 W 35 ************************************************************************* ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Sources of Information ---------------------- The track coordinates and 1-minute average maximum sustained wind values in general were taken from operational warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii. The central pressure and 10-minute average maximum sustained wind estimates for most systems were obtained from warnings issued by the Japanese Meteorological Agency (JMA), which is the World Meteorological Organization's Regional Specialised Meteor- ological Centre for the basin. In a few instances, information from warnings issued by other Asian warning centers may have been utilized. The center position coordinates from JMA and other centers were com- pared with those from JTWC and annotations made in the Remarks column when the differences in general amounted to 40-50 nm or more. Michael V. Padua of Naga City in the Philippines, owner of the Typhoon 2000 website, sends me cyclone tracks based upon warnings issued by the Japanese Meteorological Agency and the Philippines' Atmospheric, Geophysical & Astronomical Services Administration (PAGASA). A special thanks to Michael for his efforts. Following is the link to the Wikipedia page for the 2011 Pacific Typhoon Season: Following are links to Michael Padua's storm logs for the April tropical systems: Systems Tracked --------------- Tropical Depression (01W) 31 Mar - 04 Apr Tropical Depression (02W / AMANG) 03 - 07 Apr ************************************************************************* Storm Name: None Cyclone Number: 01W Basin: NWP PAGASA Internal Name: None JMA Tropical Storm Number: None Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 MAR 31 1800 9.0 N 112.0 E 1008 20 Low pressure area 11 APR 01 0000 9.0 N 112.0 E 1004 25 JMA bulletins 11 APR 01 0600 9.0 N 111.0 E 1004 25 11 APR 01 1200 9.0 N 112.0 E 1004 25 11 APR 01 1800 9.0 N 111.0 E 1004 25 11 APR 02 0000 9.3 N 111.3 E 1006 25 30 JMA: 8.7N/111.3E 11 APR 02 0600 9.3 N 111.2 E 1004 25 30 11 APR 02 1200 9.2 N 111.1 E 1004 25 30 JMA: 9.5N/111.7E 11 APR 02 1800 9.5 N 111.6 E 1006 30 30 11 APR 03 0000 9.3 N 111.8 E 1006 30 30 11 APR 03 0600 9.1 N 111.7 E 1004 25 30 JMA: 9.1N/111.7E 11 APR 03 1200 9.0 N 112.4 E 1004 30 JMA bulletins 11 APR 03 1800 9.0 N 113.0 E 1006 25 11 APR 04 0000 8.0 N 113.0 E 1008 25 11 APR 04 0600 8.0 N 114.0 E 1008 25 ************************************************************************* Storm Name: None Cyclone Number: 02W Basin: NWP PAGASA Internal Name: AMANG JMA Tropical Storm Number: None Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 APR 03 0000 11.0 N 130.0 E 1004 20 Low pressure 11 APR 03 0600 9.6 N 131.7 E 1002 30 JMA bulletins 11 APR 03 1200 10.1 N 132.2 E 1002 30 11 APR 03 1800 11.0 N 132.8 E 1000 30 11 APR 04 0000 11.6 N 133.4 E 1002 30 11 APR 04 0600 12.6 N 134.5 E 1002 30 11 APR 04 1200 12.9 N 135.8 E 1002 30 11 APR 04 1800 13.8 N 137.1 E 1002 30 11 APR 05 0000 15.4 N 139.1 E 1002 30 30 JTWC Warnings 11 APR 05 0600 16.1 N 141.1 E 1002 30 30 11 APR 05 1200 16.5 N 143.0 E 1002 30 25 Becoming XT 11 APR 05 1800 17.0 N 145.0 E 1002 30 25 JMA: 16.0N/144.0E 11 APR 06 0000 17.6 N 146.8 E 1004 25 25 JMA: 17.0N/147.0E 11 APR 06 0600 17.0 N 148.0 E 1004 25 JMA bulletins 11 APR 06 1200 17.0 N 149.0 E 1004 25 11 APR 06 1800 18.0 N 151.0 E 1004 Extratropical 11 APR 07 0000 19.0 N 152.0 E 1008 ************************************************************************* ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Sources of Information ---------------------- The track coordinates as well as the central pressure and 10-minute average maximum sustained wind estimates were obtained from warnings issued by Meteo France's Tropical Cyclone Warning Centre on Reunion Island (MFR), which is the World Meteorological Organization's Regional Specialised Meteorological Centre for the basin. The 1-minute average maximum sustained wind estimates were taken from warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii. The center position coordinates from JTWC were compared with those from MFR and annotations made in the Remarks column when the differences in general amounted to 40-50 nm or more. Following is the link to the Wikipedia page for the 2010-2011 Southwest Indian Ocean Cyclone Season: Systems Tracked --------------- Subtropical Depression (MFR-09) 12 - 17 Apr ************************************************************************* Storm Name: None Cyclone Number: None Basin: SWI MFR Tropical Disturbance Number: 09 (NRL Invest 94S) Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 APR 12 0000 24.9 S 50.3 E 1007 NRL pressures 11 APR 12 0600 25.0 S 50.2 E 1007 11 APR 12 1200 24.8 S 50.2 E 1006 11 APR 12 1800 25.2 S 50.1 E 1007 11 APR 13 0000 25.1 S 49.9 E 1007 11 APR 13 0600 25.6 S 50.0 E 1007 11 APR 13 1200 27.9 S 48.6 E 1001 40 Initial MFR warning 11 APR 13 1800 28.6 S 48.7 E 1000 40 11 APR 14 0000 29.1 S 48.3 E 999 40 11 APR 14 0600 29.6 S 47.7 E 999 40 11 APR 14 1200 30.5 S 47.7 E 998 40 11 APR 14 1800 31.5 S 47.4 E 999 40 11 APR 15 0000 32.2 S 47.0 E 995 40 11 APR 15 0600 32.8 S 47.3 E 987 50 11 APR 15 1200 33.8 S 47.5 E 985 50 11 APR 15 1800 34.8 S 48.4 E 986 50 11 APR 16 0000 35.7 S 49.0 E 992 45 Locally 50 kts NW quad 11 APR 16 0600 37.0 S 49.6 E 995 35 Locally 45 kts E semi. 11 APR 16 1200 39.8 S 50.8 E 1002 NCEP re-analysis 11 APR 16 1800 40.3 S 52.6 E 1005 11 APR 17 0000 43.1 S 56.7 E 1007 11 APR 17 0600 45.1 S 62.6 E 1007 Note: The pre and post-warning portions of the above track were sent to the author by Steve Young. Following is a short write-up of this system by Steve: "On April 9 a diffuse area of low pressure moved from Mozambique into the Indian Ocean. By the 12th a circulation formed north of the initial system and was quasi-stationary near 25S/50E. Designated Investigative Area 94S, the system drifted southeastward. Although the NRL considered this a weak system (15 kts, 1010 mb), reanalysis data indicated a stronger system with central pressure of 997 mb or less. Following extratropical transisition, the system continued to track southeastward, being absorbed into a frontal system on April 17. At one time, there were indications that this was a subtropical depression (ST=2.0) with winds of 25-30 kts." It should be noted that SAB rendered Hebert/Poteat ratings as high as ST 3.0 on 15 April. ************************************************************************* ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - Longitude 90E to 135E Sources of Information ---------------------- The track coordinates as well as the central pressure and 10-minute average maximum sustained wind estimates were obtained from warnings issued by the Tropical Cyclone Warning Centres at Perth, Western Australia, and Darwin, Northern Territory. The 1-minute average maximum sustained wind estimates were taken from warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii. The center position coordinates from JTWC were compared with those from the Australian centres and annotations made in the Remarks column when the differences in general amounted to 40-50 nm or more. Following is the link to the Wikipedia page for the 2010-2011 Australian Region Cyclone Season: Systems Tracked --------------- Tropical Cyclone ERROL (29U / 21S) 14 - 18 Apr ************************************************************************* Storm Name: ERROL Cyclone Number: 21S Basin: AUW (Name assigned by Darwin TCWC - Australian LOW 29U) Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 APR 14 0600 12.0 S 126.0 E 1000 30 11 APR 14 1200 12.5 S 126.3 E 1000 25 11 APR 14 1800 12.4 S 126.4 E 1000 30 11 APR 15 0000 12.7 S 126.1 E 996 40 35 Named TC Errol 11 APR 15 0600 12.5 S 125.8 E 996 40 11 APR 15 1200 12.6 S 126.0 E 996 45 40 11 APR 15 1800 12.2 S 125.4 E 997 40 11 APR 16 0000 11.7 S 125.1 E 989 50 50 11 APR 16 0600 11.3 S 124.7 E 986 50 55 11 APR 16 1200 11.0 S 124.7 E 986 55 55 JTWC: 11.5S/124.5E 11 APR 16 1800 11.1 S 124.4 E 991 50 50 11 APR 17 0000 10.9 S 124.1 E 993 45 45 Jakarta warnings 11 APR 17 0600 11.0 S 124.0 E 999 40 11 APR 17 1200 11.0 S 123.2 E 1001 40 35 JTWC: 10.1S/125.1E 11 APR 17 1800 10.6 S 123.6 E 1001 35 11 APR 18 0000 10.2 S 123.5 E 1003 35 30 Ex-TC 11 APR 18 1200 9.9 S 123.1 E 30 ************************************************************************* ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Sources of Information ---------------------- The track coordinates as well as the central pressure and 10-minute average maximum sustained wind estimates were obtained from warnings issued by the Tropical Cyclone Warning Centres at Nadi, Fiji, and Wellington, New Zealand. The 1-minute average maximum sustained wind estimates were taken from warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii. The center position coordinates from JTWC were compared with those from the Southern Hemisphere centres and annotations made in the Remarks column when the differences in general amounted to 40-50 nm or more. Following is the link to the Wikipedia page for the 2010-2011 South Pacific Cyclone Season: Systems Tracked --------------- Tropical Depression (14F) 09 - 11 Apr Tropical Depression (15F) 15 - 16 Apr ************************************************************************* Storm Name: None Cyclone Number: None Basin: SPA Fiji Tropical Disturbance Number: 14F Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 APR 09 2100 19.0 S 171.0 E 1007 11 APR 10 0600 17.3 S 170.0 E 1005 11 APR 10 1800 19.5 S 171.0 E 1005 11 APR 10 2100 20.6 S 172.7 E 1005 11 APR 11 0000 21.2 S 172.8 E 1005 11 APR 11 0600 21.6 S 173.6 E 1005 11 APR 11 1800 23.4 S 175.6 E 1008 11 APR 11 2100 23.9 S 175.6 E 1008 ************************************************************************* Storm Name: None Cyclone Number: None Basin: SPA Fiji Tropical Disturbance Number: 15F Date Time Lat Lon Cent MSW MSW Remarks (GMT) Press 1-min 10-min (mb) (kts) (kts) ------------------------------------------------------------------------- 11 APR 15 1800 20.7 S 159.6 E 1003 11 APR 15 2100 22.4 S 160.9 E 11 APR 16 0000 23.0 S 160.6 E 1000 30 11 APR 16 0600 23.4 S 161.9 E 1000 35 Gales NE quad 11 APR 16 1200 23.8 S 163.0 E 1000 30 11 APR 16 1800 24.7 S 164.6 E 999 30 11 APR 16 2100 25.0 S 165.9 E 1000 30 ************************************************************************* ************************************************************************* ********** SPECIAL NOTE ********** I now have some assistants who are helping to prepare the monthly tropical cyclone files, and I'd like to thank them for their willing- ness to assist me. Kevin Boyle, of Stoke-on-Trent, UK, will be preparing the tracks for Northwest Pacific basin tropical cyclones during the most active part of the NWP season from June through December. Michael Bath, of McLeans Ridges, New South Wales, Australia, is now preparing the track files for Australian Region and South Pacific tropical cyclones. Also, Steve Young sends me tracks with data for the pre-warning and post-warning stages of tropical cyclones in all basins, prepared primarily from NCEP re-analysis data or else taken from NRL files. A very special thanks is due to Kevin, Michael and Steve for their assistance. ************************************************************************* 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: ************************************************************************* !!!!!! IMPORTANT NOTE - PLEASE READ !!!!!! To repeat the caveat which is included in the Author's Note at the end of the cyclone summaries--the tropical cyclone tracks I prepare are based upon the operational warnings/advisories/ advices/bulletins which are issued by the various tropical cyclone warning agencies around the world. Users of these tracks should be aware that they are preliminary and subject to revision during post-seasonal analyses of the cyclones by the forecasters and analysts at the several warning centers. For the Atlantic and Northeast Pacific basins, official tropical cyclone reports and "best tracks" can be found at the website of the Tropical Prediction Center/National Hurricane Center: The Joint Typhoon Warning Center's website contains links to their Annual Tropical Cyclone Reports which include that agency's "best tracks" for tropical cyclones in the Northwest Pacific basin, the North Indian Ocean, and the Southern Hemisphere: SPECIAL NOTE: Back issues of the global tropical cyclone summaries and monthly cyclone track files can be obtained at the following websites: PREPARED BY: Gary Padgett garyp@alaweb.com Kevin Boyle michaelpace@btinternet.com Michael Bath mbath@ozemail.com.au SIGNIFICANT CONTRIBUTIONS BY: Michael V. Padua michaelpadua@hotmail.com webmaster@typhoon2000.ph Steve Young shy9@earthlink.net ************************************************************************* ************************************************************************* ************************************************************************* Posted: 08.09.11 for Typhoon2000.com, Typhoon2000.ph, Maybagyo.com