GARY PADGETT'S MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY DECEMBER, 2004 (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.) ************************************************************************* DECEMBER HIGHLIGHTS --> Two tropical storms stir Western Pacific waters --> Tropical cyclone moves southward through central Indian Ocean --> South Pacific tropical cyclone forms east of Tahiti ************************************************************************* ***** Feature of the Month for December ***** A REVIEW OF THE 2004 TROPICAL CYCLONE SEASON FOR THE NORTHERN HEMISPHERE Following is a tabular summary of all the tropical depressions, tropical storms, hurricanes, and typhoons which occurred in the Northern Hemisphere between 1 January and 31 December 2004, as reported in the Monthly Global Tropical Cyclone Summaries prepared by the author. (1) Number - this is the sequential cyclone number assigned by either TPC/NHC, CPHC in Honolulu, or JTWC. If neither of these agencies issued any warnings, no number will be given. (2) Name - the name (if any) assigned by either TPC/NHC, CPHC, or JMA (and PAGASA for Western North Pacific systems in their area of warning responsibility). (3) Dates - range of dates for which tracking information for the cyclone is available in the Global Tropical Cyclone Tracks files prepared by the author. (4) Pressure - Lowest central pressure (either estimated or recorded) during the lifetime of the cyclone. For Atlantic and Northeastern Pacific systems these will be the values reported in operational advisories from TPC/NHC or CPHC. For Northwest Pacific systems the central pressure estimates are taken from advisories issued by the Japanese Meteorological Agency. An asterisk (*) following the pressure indicates the reading was an actual measured pressure normally obtained by a drop- sonde released during an aerial reconnaissance flight. Central pressure is given in millibars, which is numerically equivalent to hectopascals. (5) MSW - maximum 1-minute average sustained windspeed in knots. For the Northwestern Pacific and North Indian Ocean basins, these will be the highest value assigned operationally by JTWC. For the Atlantic and Northeastern Pacific basins, the MSW values are taken from the official tropical cyclone reports prepared by the TPC/NHC Hurricane Specialists and which are available on TPC/NHC's website: . (6) Basins - tropical cyclone basins where the cyclone tracked during its life: ATL - North Atlantic, Gulf of Mexico, Caribbean Sea NEP - North Pacific east of Longitude 180 NWP - North Pacific west of Longitude 180 (including South China Sea) NIO - Bay of Bengal and Arabian Sea For tropical systems in the NWP basin, two additional columns of information are given: (1) The tropical storm serial number assigned by the Japanese Meteorological Agency to tropical depressions which are deemed to have reached tropical storm intensity. This does not always agree with JTWC's assessment. (2) An estimate of the maximum 10-minute average sustained wind. The value given represents the highest 10-min avg MSW assigned by any agency. If from any warning center other than JMA, a numbered note below identifies which center's value is given. For tropical systems in the NIO basin, a column is given referencing IMD's identifier for cyclonic storms: ARB for Arabian Sea cyclones and BOB for Bay of Bengal systems. A number in parentheses (e.g. (1) ) following an entry refers to a note following the entries for the given basin. A separate table is given for each of the four Northern Hemisphere basins. *********************************************************************** ATLANTIC BASIN NUM NAME DATES CENT PRS MSW BASIN (mb) (kts) ------------------------------------------------------------------------ 01 Alex 31 Jul-06 Aug 957 * 105 ATL 02 Bonnie 03-14 Aug 1001 * 55 ATL 03 Charley 09-15 Aug 941 * 130 ATL 04 Danielle 13-24 Aug 964 95 ATL 05 Earl 13-15 Aug 1009 * 45 ATL 06 Frances 25 Aug-10 Sep 935 * 125 ATL 07 Gaston 27 Aug-03 Sep 985 * 65 ATL 08 Hermine 27-31 Aug 1002 * 50 ATL 09 Ivan 02-24 Sep 910 * 145 ATL 10 ----- 07-10 Sep 1009 30 ATL 11 Jeanne 13-29 Sep 950 * 105 ATL 12 Karl 16-28 Sep 938 125 ATL 13 Lisa 19 Sep-03 Oct 987 65 ATL 14 Matthew 08-11 Oct 997 * 40 ATL 15 Nicole 10-11 Oct 986 45 ATL (1) 16 Otto 26 Nov-05 Dec 995 45 ATL (2) NOTES: (1) System was a subtropical storm which never developed full tropical cyclone characteristics. (2) System was initially a subtropical storm which evolved into a tropical storm. The peak winds of 45 kts occurred during the subtropical storm stage--the highest MSW after transforming into a tropical storm was 40 kts. ************************************************************************ NORTHEAST PACFICIC BASIN NUM NAME DATES CENT PRS MSW BASIN (mb) (kts) ------------------------------------------------------------------------ 01E Agatha 22-26 May 997 50 NEP 02E ----- 02-05 Jul 1007 30 NEP 01C ----- 05 Jul 1007 25 NEP 03E Blas 12-19 Jul 991 55 NEP 04E Celia 19-26 Jul 981 75 NEP 05E Darby 26 Jul-01 Aug 957 105 NEP 06E ----- 29 Jul-03 Aug 1006 30 NEP 07E Estelle 19-25 Aug 989 60 NEP 08E Frank 23-27 Aug 979 75 NEP 09E ----- 23-28 Aug 1005 30 NEP 10E Georgette 26 Aug-03 Sep 995 55 NEP 11E Howard 30 Aug-10 Sep 943 120 NEP 12E Isis 08-21 Sep 987 65 NEP 13E Javier 10-20 Sep 930 130 NEP 14E Kay 04-07 Oct 1004 40 NEP 15E Lester 11-13 Oct 1000 45 NEP 16E ----- 25-26 Oct 1004 30 NEP ************************************************************************ NORTHWEST PACFICIC BASIN JTWC NAME(S) JMA DATES CENT MSW MSW BASIN NUM TROP STM PRS 1-MIN 10-MIN NUM (mb) (kts) (kts) ------------------------------------------------------------------------ 01W Ambo ---- 11-16 Feb 1000 45 30 NWP (1) 02W Butchoy ---- 16-23 Mar 998 45 45 NWP (2) 03W Sudal/Cosme 0401 03-18 Apr 940 130 95 NWP (3) 04W Nida/Dindo 0402 13-22 May 930 140 110 NWP (4) 05W ----- ---- 14-20 May 1002 35 30 NWP (1) 06W Omais/Enteng 0403 16-23 May 985 65 50 NWP 07W Conson/Frank 0404 04-11 Jun 960 95 80 NWP (5) 08W Chanthu/Gener 0405 07-15 Jun 970 75 65 NWP 09W Dianmu/Helen 0406 12-23 Jun 915 155 130 NWP (5) 10W Mindulle/Igme 0407 23 Jun-05 Jul 940 125 105 NWP (2) 11W Tingting 0408 25 Jun-06 Jul 945 80 85 NWP 12W Kompasu/Julian 0409 13-16 Jul 990 45 45 NWP 13W Namtheun 0410 24 Jul-01 Aug 945 115 100 NWP (5) --- NMCC TS-0411 ---- 26-27 Jul 990 -- 45 NWP (6) 14W Meranti 0412 03-09 Aug 960 90 75 NWP 15W Malou 0411 04-06 Aug 994 30 40 NWP --- ----- ---- 06-07 Aug 1002 -- 30 NWP (7) 16W Rananim/Karen 0413 06-13 Aug 950 90 90 NWP (5) 17W Malakas 0414 10-13 Aug 990 35 45 NWP 18W Megi/Lawin 0415 14-22 Aug 970 65 65 NWP 19W Chaba 0416 18 Aug-03 Sep 910 155 130 NWP (5) 20W Aere/Marce 0417 19-31 Aug 955 85 80 NWP 21W ----- ---- 26-31 Aug 1000 35 30 NWP (1) 22W Songda/Nina 0418 27 Aug-11 Sep 925 * 130 120 NWP (5) 23W Sarika 0419 03-09 Sep 980 60 60 NWP (5) --- NMCC TD04 ---- 08-11 Sep 1002 -- 30 NWP 24W Haima/Ofel 0420 10-14 Sep 996 30 40 NWP --- Pablo ---- 14-18 Sep 1006 -- 30 NWP --- NMCC TD06 ---- 15-16 Sep 1006 -- 30 NWP 25W Meari/Quinta 0421 20 Sep-01 Oct 940 120 100 NWP (5) 26W Ma-on/Rolly 0422 03-10 Oct 920 140 105 NWP (8) 27W Tokage/Siony 0423 12-23 Oct 940 125 100 NWP (5) 28W Nock-ten/Tonyo 0424 14-27 Oct 945 110 90 NWP (5) 29W Muifa/Unding 0425 14-26 Nov 955 115 90 NWP (5) --- Merbok/Violeta 0426 22-23 Nov 998 -- 35 NWP --- Winnie ---- 27-30 Nov 1000 -- 30 NWP 30W Nanmadol/Yoyong 0427 28 Nov-04 Dec 935 130 100 NWP (2) 31W Talas/Zosimo 0428 10-21 Dec 992 45 40 NWP 32W Noru 0429 17-23 Dec 990 55 50 NWP (5) NOTES: (1) Classified as a tropical storm by JTWC only. (2) The highest 10-min avg MSW was assigned by PAGASA. (3) The highest 10-min avg MSW was assigned by HKO. (4) The highest 10-min avg MSW was assigned by HKO and NMCC. (5) The highest 10-min avg MSW was assigned by NMCC. (6) NMCC was the only agency to classify this system as a tropical storm. (7) Classified as a tropical depression by JMA only. (8) The highest 10-min avg MSW was assigned by the CWB of Taiwan. ************************************************************************ NORTH INDIAN OCEAN BASIN NUM NAME IMD ID DATES CENT PRS MSW BASIN (mb) (kts) ------------------------------------------------------------------------ 01A ----- ARB0401 05-10 May --- 45 NIO 02B ----- BOB0401 17-19 May --- 60 NIO 03A Onil ARB0402 01-09 Oct --- 40 NIO (1) --- ----- ------- 02-08 Oct --- 25 NIO (2) 04A ----- ------- 04-07 Nov --- 40 NIO 05A Agni ARB0403 28 Nov-03 Dec --- 65 NIO NOTES: (1) Onil was quite likely more intense than indicated in the warnings from JTWC. SAB ranked the cyclone at T3.5/3.5 (55 kts) on 1 and 2 October. (2) This system was treated as a depression by IMD. No track was available for inclusion in the Global Tropical Cyclone Tracks File for October; however, a short report can be found in the October monthly summary. ************************************************************************ ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for December: No tropical cyclones Atlantic Tropical Activity for December --------------------------------------- As the month of December opened, the final tropical cyclone of the 2004 season, Tropical Storm Otto, was meandering around in the central North Atlantic. Otto weakened on the 2nd, was downgraded to a tropical depression and the final advisory written. However, a remnant LOW persisted for several more days. The report on Tropical Storm Otto can be found in the November summary. ************************************************************************* NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for December: No tropical cyclones ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for December: 2 tropical storms 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 Philippine Atmospheric, Geophysical & Astronomical Services Administration (PAGASA). Also, Huang Chunliang of Fuzhou City, China, sends data taken from synoptic observations around the Northwest Pacific basin. 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. Northwest Pacific Tropical Activity for December ------------------------------------------------ The active 2004 Northwest Pacific season finally ended in late December just as the year was about to end. As the month of December opened, intense Typhoon Nanmadol/Yoyong was about the strike the island of Luzon--the fourth tropical system to plague that area in only three weeks. After crossing Luzon Nanmadol recurved sharply in the north- eastern South China Sea as it weakened. The system subsequently crossed over the southern portion of Taiwan as it transformed into an extra- tropical cyclone. The full report on Nanmadol can be found in the November summary. Two other tropical cyclones formed during December with neither reaching typhoon status. Tropical Storm Talas (named Zosimo by PAGASA) followed a long trajectory from the Marshall Island area westward, passing well south of the Marianas, and eventually recurving east of the Philippines. Talas was in warning status from the 10th until the 19th--a fairly long life span for a relatively weak system. Shortly after mid-month Tropical Storm Noru sprang up in the Caroline Islands and moved northward, recurving just east of the Mariana Islands. Although much shorter-lived than Talas, Noru was the stronger of the two, reaching severe tropical storm status per JMA's nomenclature. Reports on these two tropical storms, authored by Kevin Boyle, follow. TROPICAL STORM TALAS (TC-31W / TS 0428 / ZOSIMO) 10 - 21 December ----------------------------------------------- Talas: contributed by the Philippines, means 'acuteness' or 'sharpness' A. Storm Origins ---------------- At 0130 UTC 9 December a new area of convection developed and persisted approximately 630 nm east-southeast of Kwajalein, a position located deep within the Western North Pacific close to the border with the Central North Pacific. At this time, multi-spectral satellite imagery showed organized deep convection beginning to consolidate over a possible LLCC. An upper-level analysis revealed that the suspect area was within a moderate wind shear environment coupled with some diffluence. Based on this, the development potential for the formation of a significant tropical cyclone was assessed as 'poor'. This was soon raised to 'fair' at 09/0600 UTC, and as the overall organization of the system continued to improve, was followed by a TCFA at 09/2200 UTC. The first warning was issued at 10/0000 UTC, the west-northwest to northwest heading bringing the newly-formed Tropical Depression 31W to within 220 nm east-southeast of Kwajalein. B. Synoptic History ------------------- Tropical Depression 31W was an immediate threat to Kwajalein, Ailinglaplap and Ujae, and a tropical storm warning was issued for those islands as soon as the first warning was issued by JTWC. Despite exhibiting a partially-exposed LLCC, TD-31W was upgraded to a 35-kt tropical storm at 1200 UTC 10 December while it was passing Kwajalein Atoll with sustained winds reaching tropical storm force. Moving west- ward Tropical Storm 31W's intensity strengthened to 45 kts at 11/0000 UTC and this strength was to be maintained for the next couple of days. In fact, this was to be the peak MSW estimated for this system. The storm was named Talas at 11/0600 UTC when JMA upgraded it to a 35-kt tropical storm. Tracking westward, Talas passed well to the north of Kosrae at 11/0300 UTC, its forward speed increasing to around 23 kts. Although the LLCC was located beneath an almost symmetrical CDO, it became fully-exposed at 12/0000 UTC with a marked decrease in deep convection, which was confined mainly to the western periphery. At 0000 UTC 12 December Tropical Storm Talas was far to the east- southeast of Guam, being located approximately 665 nm from the island. Its westerly heading, governed by the subtropical ridge to the north, took it a little over 200 nm north of Chuuk at 12/0900 UTC. After what seemed to be a reorganizing phase, the system's centre became partially- exposed again. However, the warning at 13/0000 UTC indicated that the deep convection was becoming better-organized. Nonetheless, Talas lacked a significant outflow pattern. In any case, weakening began at 13/1200 UTC, shortly after Talas had tracked nearly 200 nm to the south of Guam and also well south of Saipan, Tinian, and Rota. The MSW dropped to 35 kts at 13/1800 UTC but picked up a little to 40 kts six hours later. This intensity was maintained through the 14th, a day of little to write about. Talas passed safely north of Yap between 14/1200 UTC and 14/1800 UTC. At 0000 UTC 15 December Talas slowed somewhat as it continued westward along the southwestern portion of the steering ridge--the storm was located approximately 190 nm northwest of Yap at this time. The intensity had fallen to 35 kts and this was maintained for another six hours before Talas was downgraded to a 30-kt tropical depression at 15/1200 UTC. At this time, the weak tropical system had drifted into PAGASA's AOR and was named Zosimo by that agency. The MSW remained at 30 kts through the 16th as the rather disorganized storm's westward motion persisted, but this changed at 16/1200 UTC as a northwesterly motion commenced. The forward speed slowed further as the steering currents slackened and by 17/0000 UTC Talas was crawling along at 3 kts. At 0000 UTC 17 December Tropical Depression Talas was located approximately 615 nm east of Manila, Philippines. Initially moving slowly northwestward, the system turned north as it began to nudge into a weakness in the subtropical ridge. At this time, deep convection began to rapidly flare up, resulting in an expanding CDO. The MSW rose to 35 kts at this time and Talas was reinstated as a tropical storm. It soon re-intensified back to its earlier peak intensity of 45 kts at 17/0600 UTC. Continuing slowly northward, Talas' strength started to wane again and fell to 40 kts at 17/1800 UTC. At 18/0000 UTC Tropical Storm Talas was nearly stationary 820 nm southwest of Iwo Jima and weakened a little more to 35 kts at 18/0600 UTC, but held on to minimal tropical storm strength for the rest of the 18th as it began to speed up a little towards the north. The cyclone began to fall apart early on the 19th as the LLCC split from the deep convection. Talas was down- graded to a tropical depression at 19/0600 UTC, and JTWC logged the system for the final time at 19/1200 UTC after 39 warnings--the final position 700 nm west-southwest of Iwo Jima. JMA continued to follow the remnant weak depression eastward along the 20th parallel for a couple more days. Tropical Storm Talas was an average-sized system with gales extending no further than 110 nm from the centre in any one quadrant. The peak MSW estimated by JMA, NMCC and CWB was 40-kts (10-min avg) with the lowest estimated CP per JMA warning being 992 mb. During the period that Talas/Zosimo was within PAGASA's AOR the maximum intensity reckoned by that agency was 35 kts. HKO issued no warnings on this system. A graphic displaying the track of Tropical Storm Talas/Zosimo may be found at the following link: C. Damage and Casualties ------------------------ There were no damages or casualties reported in association with Tropical Storm Talas. (Report written by Kevin Boyle) TROPICAL STORM NORU (TC-32W / TS 0429) 17 - 23 December --------------------------------------- Noru: contributed by the Republic of Korea, is the roe deer--a type of small deer which lives in the forest A. Storm Origins ---------------- Tropical Storm Noru stemmed from an area of convection that had persisted approximately 235 nm northeast of Chuuk. JTWC issued a TCFA on this suspect area at 0300 UTC 17 December, a QuikScat pass at 16/1950 UTC revealing a broad, well-defined LLCC. Water vapor imagery showed deep convection starting to consolidate around this centre with strong radial outflow associated with the system. Since an upper-level analysis indicated an environment of low vertical shear and favourable divergence, further development was expected. The first warning on Tropical Depression 32W was released at 17/1800 UTC with the system moving west- northwest at 7 kts, located at that time 370 nm east-southeast of Saipan. It was upgraded to a tropical storm at 18/0600 UTC when satellite CI estimates had reached 35 kts, and because of the threat posed by this tropical cyclone to the Marianas, the National Weather Service on Guam urged the island communities to monitor the progress of this storm. The intensity remained at 35 kts throughout the 18th as the storm continued westward, and the system was named Noru when JMA upped their MSW to 35 kts at 1800 UTC on 18 December. B. Synoptic History ------------------- At 0000 UTC 19 December Tropical Storm Noru was maintaining 35-kt winds approximately 165 nm southeast of Saipan. At this time, it decelerated and veered sharply north-northwestwards, passing 50 nm east of Saipan at 19/1200 UTC. Three hours later, Noru made its closest approach to Tinian, roughly 85 nm to the east-northeast. During this period it had undergone a strengthening phase which brought the MSW up to 50 kts at 19/1800 UTC. Tropical Storm Noru reached its peak intensity of 55 kts at 20/0000 UTC when it began pushing northwards, and at 20/0300 UTC Noru was passing roughly 45 nm east of Pagan and around 45 nm east of Agrihan three hours later. Noru completed recurvature at 20/1800 UTC and began to track towards the northeast, its associated cloud pattern becoming elongated with cold, dry air entraining from the west, a sign that extratropical transition was underway. The MSW had remained 55 kts up to this point but began to slowly fall off at 21/0000 UTC. The tropical cyclone continued north- eastward and had merged with a baroclinic zone by 21/0600 UTC. JTWC issued the final warning at this time, placing the 45-kt extratropical system some 815 nm west-northwest of Wake Island. JMA maintained Noru as a 45-kt tropical storm through the 22nd and gradually weakened the storm down to 35 kts by 23/1200 UTC. The intensity was brought back up to 40 kts when JMA mentioned ex-Noru for the last time in their bulletins at 23/1800 UTC. The extratropical gale by this time had crossed the Dateline into the Central North Pacific and was still racing rapidly eastward. Tropical Storm Noru was somewhat smaller than average with the radius of storm-force winds never exceeding 20 nm while gales extended no further than 80 nm in any one quadrant. NMCC considered Noru as a 50-kt severe tropical storm while JMA estimated a peak intensity of 45-kts and a minimum CP of 990 mb. CWB estimated a maximum intensity of 40-kts. A graphic displaying the track of Tropical Storm Noru may be found at the following link: C. Damage and Casualties ------------------------ There were no reports of damages or casualties from any of the islands in association with Tropical Storm Noru. (Report written by Kevin Boyle) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for December: No tropical cyclones North Indian Ocean Tropical Activity for December ------------------------------------------------- No tropical cyclones or depressions formed in the North Indian Ocean basin during December. As the month opened Severe Cyclonic Storm Agni was weakening as it moved westward through the southern Arabian Sea. Agni had been of hurricane intensity on 29 and 30 November but had weakened into a tropical storm late on the 30th. Agni had the unusual distinction of having reached tropical storm intensity only 40 nm north of the equator! The report on Agni can be found in the November summary. ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for December: 1 subtropical depression 1 tropical cyclone Sources of Information ---------------------- The primary sources of tracking and intensity information for Southwest Indian Ocean tropical cyclones are the warnings issued by the Tropical Cyclone Warning Centre on La Reunion Island, part of Meteo France (MFR), and the Regional Specialised Meteorological Centre for the basin. However, tropical cyclones in this region are named by the sub-regional warning centres on Mauritius and Madagascar with longitude 55E being the demarcation line between their respective areas of warning responsibility. The La Reunion centre only advises these agencies regarding the intensity of tropical systems. 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 MFR's 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. Southwest Indian Ocean Tropical Activity for December ----------------------------------------------------- One named tropical system formed in the South Indian Ocean west of longitude 90E during December, and it reached tropical cyclone intensity. (In that basin, the term 'tropical cyclone' is equivalent to 'hurricane' in the Atlantic and Northeast Pacific basins and to 'typhoon' in the Northwest Pacific basin.) Tropical Cyclone Chambo formed in the eastern portion of the region and pursued a southwesterly trajectory across the central South Indian Ocean, passing far to the southeast of Diego Garcia and well east of Rogrigues Island. A report on this cyclone follows. MFR issued bulletins for one other system, designated as Subtropical Depression 05. This very short-lived system (only two bulletins were issued) formed and dissipated on 11 December in the southern Mozambique Channel 200-300 nm west of the southern tip of Madagascar. Maximum winds in this short-lived disturbance were estimated at only 25 kts. As brief as it was, a track was included for Subtropical Depression 05 in the companion cyclone tracks file. TROPICAL CYCLONE CHAMBO (MFR-06 / TC-06S) 23 December - 2 January ------------------------------------------- Chambo: contributed by Malawi A. Storm Origins ---------------- Around 1800 UTC on 18 December an area of convection had formed about 550 nm west-northwest of Jakarta, Indonesia, and persisted for 24 hours. The disturbance was located within a region of low vertical shear and favorable divergence aloft, and microwave imagery revealed a weak LLCC. Over the next few days the system drifted westward with little change. By 0900 UTC on 22 December the disturbance had reached a point slightly more than 400 nm northwest of the Cocos Islands. Deep convection was increasing around an elongated LLCC, and the upper-level environment was still conducive to strengthening. MFR initiated bulletins on Tropical Disturbance 06 at 23/0000 UTC, placing a weak 25-kt center approximately 650 nm northwest of the Cocos. JTWC issued a TCFA at 23/0100 UTC as the LLCC had become well-organized with increasing consolidation of deep convection. MFR upgraded the disturbance to a 30-kt tropical depression at 23/0600 UTC, and JTWC issued their first warning on TC-06S at 1800 UTC. B. Synoptic History ------------------- JTWC's initial warning intensity of 35 kts (1-min avg) was based on CI estimates of 30 and 35 kts. The system was then moving southward at 8 kts, but soon turned to a southwesterly track which it would follow for most of its life. Intensification proceeded slowly, and it was not until 24/0600 UTC that MFR upgraded the depression to tropical storm status with Mauritius supplying the name Chambo. Tropical Storm Chambo at that time was located approximately 750 nm west of the Cocos Islands and moving southwestward with 40-kt winds. After reaching tropical storm intensity, Chambo intensified rather steadily, reaching cyclone (i.e., hurricane) intensity 24 hours later. At 0600 UTC on Christmas Day Tropical Cyclone Chambo was located about 650 nm east-southeast of Diego Garcia sporting a MSW of 70 kts. For most of its existence Tropical Cyclone Chambo followed a general southwesterly course across the central South Indian Ocean, guided by a persistent anticyclone anchored to its southeast. The intensity levelled off at 80 kts after 25/1200 UTC where it remained pegged for almost two days. The cyclone reached its peak intensity of 85 kts at 27/0000 UTC when centered approximately 725 nm southeast of Diego Garcia. The minimum CP estimated by MFR was 945 hPa, and gales reached outward 90 nm from the center in most quadrants. JTWC's peak 1-min avg MSW of 95 kts is in good accord with MFR's peak 10-min avg MSW of 85 kts. Thus, Chambo fell just shy of the 90 kts (10-min avg) required for classification as an intense tropical cyclone. The cyclone's motion had slowed somewhat as it reached its peak intensity and became mostly westerly for a day or so. On the 27th a west-southwesterly motion ensued, becoming southwesterly on the 28th. Chambo's decline following its peak was rather rapid. Twenty-four hours after peaking at 85 kts, MFR's MSW had dropped to 50 kts, and JTWC's estimated 1-min avg MSW fell from 95 kts to 35 kts in a like time span. As Chambo moved poleward of the 18th parallel, it began to run into some rather strong vertical shear. MFR lowered the cyclone to tropical storm status at 28/0000 UTC, placing the center about 725 nm south-southeast of Diego Garcia. JTWC issued their final warning at 28/0600 UTC, basing the MSW of 35 kts (1-min avg) on final T-shear estimates ranging from 30 to 45 kts and QuikScat data showing 35-40 kt winds associated with the LLCC. The CI estimates were not followed since they remained at 45 and 55 kts per Dvorak constraint rules. Chambo's center was fully-exposed over 85 nm northeast of the remaining deep convection. MFR continued to classify Chambo as a slowly weakening tropical storm for another couple of days. The system gradually transformed into an extratropical system, and was formally classified thusly by MFR at 0600 UTC on 30 December when located about 500 nm southeast of Rodrigues Island. The ex-Chambo system continued to move slowly southwestward, turning to the south early on 1 January. Gales to 45 kts occurred during this period, and MFR continued issuing gale warning through 0000 UTC on 2 January. The final bulletin placed the 40-kt extratropical LOW approximately 675 nm south-southeast of Rodrigues Island. A graphic displaying the track of Tropical Cyclone Chambo may be found at the following link: C. Damage and Casualties ------------------------ No damage or casualties are known to have resulted from Tropical Cyclone Chambo. (Report written by Gary Padgett) ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for December: 1 tropical LOW ** ** - classfied as a minimal tropical storm by JTWC 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 December ------------------------------------------ No tropical cyclones formed in Southern Hemisphere waters between 90E and 135E during December. A tropical LOW formed very early in the month near Java and moved off to the west-southwest, passing south of Christmas Island as it was weakening on the 6th. The Perth TCWC issued gale warnings on this LOW for a couple of days in anticipation of the system's developing into a tropical cyclone, but this never happened. Since JTWC estimated the peak winds to have reached 35 kts (1-min avg), I have included a brief report on TC-05S below. At the end of December another tropical LOW formed off the coast of Western Australia north of Broome which necessitated the issuance of gale warnings. This LOW pursued an unusual eastward track and on the 2nd of January intensified into Tropical Cyclone Raymond, eventually making landfall in the Kimberley region. The report on Tropical Cyclone Raymond will be contained in the January summary. TROPICAL LOW (TC-05S) 2 - 7 December ---------------------------------- The daily STWO issued by Perth on 2 December indicated that a weak tropical LOW had developed in the Java Sea near the north-central coast of Java and had a moderate chance of strengthening into a tropical cyclone in about three days. The first gale warning was issued at 03/0400 UTC, relocating the center along the southeastern coast of Java, or about 450 nm east-northeast of Christmas Island. A few hours later JTWC issued an interim STWO which mentioned the disturbance. Low-level cloud lines were converging into a developing LLCC, and an upper-level analysis indicated good outflow and low vertical shear in the region. By 0200 UTC on the 4th deep convection had continued to increase near the LLCC and JTWC issued a TCFA for the LOW, which was then centered approximately 320 nm southeast of Jakarta, Indonesia. The first JTWC warning on TC-05S was issued at 04/0600 UTC. The system was tracking west-southwestward at 7 kts, and this motion was forecast to continue under the steering influence of a low to mid-level anticyclone anchored to the southeast of the tropical LOW. The system moved on a general west-southwesterly track throughout its short life. Perth maintained the MSW at 30 kts from 03/2200 UTC through 1600 UTC on the 5th, while JTWC assigned a peak 1-min avg MSW of 35 kts on the 4th and 5th. By 1800 UTC on 5 December the LOW had moved into a region of increased vertical wind shear and marginal SSTs. JTWC dropped the MSW to 25 kts (1-min avg) and ceased to issue warnings. Shortly afterward, at 05/2100 UTC, BoM Perth issued their final gale warning on the system which was then centered approximately 200 nm south-southeast of Christmas Island. The remnant LOW continued to move west-southwestward and was last mentioned at 0200 UTC on 7 December when it was located about 425 nm southwest of Christmas Island. A graphic displaying the track of the tropical LOW (TC-05S) may be found at the following link: No reports of damage or casualties resulting from this system have been received. (Report written by Gary Padgett) ************************************************************************* NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for December: No tropical cyclones ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Activity for December: 2 tropical depressions 1 tropical cyclone of gale intensity ** ** - No warnings were issued on this system 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 December -------------------------------------------- Three tropical depressions formed in the South Pacific east of 160E during December. The first, designated Tropical Depression 02F by the Nadi, Fiji, TCWC formed on 3 December with the broad center located approximately 150 nm north of Port Vila, Vanuatu. This depression was very slow-moving and erratic--over the next week it meandered aimlessly around over waters northeast of Vanuatu and northwest of Fiji. On the 10th it was relocated far to the east of the previous position--about 325 nm north-northeast of Fiji. But later the same day the center was shifted well back to the west to a position about 325 nm north- northwest of Fiji. Obviously the disturbance was broad and poorly organized and likely had multiple low-level centers. Ultimately, a LLCC consolidated on the 12th a few hundred miles east of northern Vanuatu, and Nadi commenced gale warnings due to some peripheral gales. TD-02F subsequently began to move southward and passed between Vanuatu and Fiji on the 13th and 14th. The system then weakened and the final gale warning was issued at 14/1800 UTC, placing the center about 250 nm southeast of Port Vila. The second system, Tropical Depression 03F, formed and dissipated during the rather long life of Tropical Depression 02F. TD-03F formed on 5 December south of Tuvalu, or about 425 nm north-northeast of Fiji. It subsequently moved southward to a position just east of Fiji, then turned east-southeastward and accelerated on the 9th. The final bulletin on the system at 0900 UTC on 10 December placed the center approximately 450 nm east of Nuku'alofa in the Kingdom of Tonga. Tracks for both of these depressions can be found in the companion cyclone tracks file. Graphics displaying the tracks of these two tropical depressions may be found at the following links: The third depression, TD-04F, formed on 22 December well east of Tahiti and on Christmas Eve Day was named Tropical Cyclone Judy--the first cyclone of the 2004-2005 season in the South Pacific basin. A report on Judy, written by Simon Clarke, follows. TROPICAL CYCLONE JUDY (TC 04F) 22 - 27 December ----------------------------------------- A. Storm Origins ---------------- An almost stationary tropical depression was analyzed by RSMC Nadi over French Polynesia (near 18.0S/145.0W), approximately 270 nm east of Tahiti, as early as 21 December 2004 (TD-04F). The system was subject to significant shear as the LLCC was clearly exposed with major convection located to its east and south. Aloft, TD-04F was situated to the south- west of the 250-hPa anticyclone and underneath an intensifying 250-hPa trough. At the surface the sub-tropical ridge along 30S caused strong easterly winds, inducing more cyclonic vorticity into the area. However, the area of gale force winds was detached to the south and east of the centre. The SST was approximately 28 C. A little over 36 hours later, the depression remained subject to shear, displaying baroclinic characteristics. However, deeper convection began to wrap around the LLCC from the southern convective band. By 24/2100 UTC, gales had worked their way to the centre of TD-04F and it was named Tropical Cyclone Judy, located approximately 275 nm east- southeast of Tahiti. B. Synoptic History ------------------- At this time Judy was moving south-southwestward at about 5 kts with a CP of 993 hPa. The system strengthened marginally in the ensuing hours (peaking at 989 hPa) and produced a broad area of gales, especially in the southern semi-circle. The maximum 10-min avg winds near the centre were estimated to be about 40 kts. A slight weakening in shear allowed a small flare up of convective activity close to the LLCC during Judy's life which was clearly evident in satellite imagery. At 26/1200 UTC Judy moved into Wellington's AOR. However, twelve hours later (27/0000 UTC), increasing shear and cooler SSTs put a halt to further development and Judy underwent extra-tropical transition (near 28.5S/146.5W) and eventually merged with a low-pressure system to the south about 750 nm south-southeast of Tahiti soon after. A graphic displaying the track of Tropical Cyclone Judy may be found at the following link: C. Meteorological Observations ------------------------------ Thunderstorms from the initial depression produced some heavy rainfall totals in parts of French Polynesia. The island of Takaroa at 14.3S/145.0W received 160 mm between midnight and 24/1200 UTC, making a total of 356 mm there since 21/0000 UTC--well above the average December rainfall of 195 mm. D. Damage and Casualties ------------------------ No reports of damage or casualties resulting from Tropical Cyclone Judy have been received. E. Additional Discussion ------------------------ On a final note, while RSMC Nadi issued warnings on Judy, JTWC did not officially recognize the cyclone. It is possible that Judy was no more than a subtropical hybrid rather than a tropical cyclone. However, as noted by meteorologists at Nadi, the storm packed winds of gale force intensity and possibly higher around the LLCC. Naming Judy drew public attention to the system during the Christmas festive season to ensure that other technical/scientific issues were not down-played or ignored. This approach has been adopted elsewhere in the Southeast Pacific where data can be difficult to obtain and the need to relay potentially life- saving advice is necessary: the most recent example being Tropical Cyclone Epi (TCWC Port Moresby) in the Solomon Island group in June, 2003. (Editor's Note: Tropical Cyclone Judy was attached to a large cloud mass which does suggest that it was located near a baroclinic zone. However, the central area of the cyclone looked very much like a tropical cyclone. It is interesting to note that SAB, which occasionally does assign subtropical ST classifications using the Hebert-Poteat scale, assigned Judy tropical T classifications, peaking at T2.5/2.5 on the 24th and 25th, lending support to the idea that Judy was nominally a tropical cyclone.) (Report written by Simon Clarke) ************************************************************************* 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. 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 John Wallace (Assistance with Eastern North Pacific) E-mail: dosidicus@aol.com Huang Chunliang (Assistance with Western Northwest Pacific, South China Sea) E-mail: huangchunliang@hotmail.com Simon Clarke (Northeast Australia/Coral Sea, South Pacific) E-mail: saclarke@iprimus.com.au ************************************************************************* ************************************************************************* Uploaded: 03.27.05 / Typhoon2000.ph, Typhoon2000.com