4. Typhoon NESAT (Dante/04w)
>> May 30-June 14, 2005
Nesat: contributed by Cambodia, means 'fishing' (i.e., the verb 'to fish')
Introduction
Nesat was the third Western North Pacific tropical cyclone of 2005
to reach typhoon intensity. It became a very intense storm, peaking at
125 kts, the strongest of the year so far. The only active tropical
cyclone in June, Nesat followed a very similar recurving track to that
followed by Typhoon Sonca in late April and proved to be noteworthy for
its resilience.
Storm Origins
The disturbance that became Typhoon Nesat was first mentioned in
JTWC's STWO at 2130 UTC 27 May when it was located approximately 860 nm
southeast of Guam. Despite a light wind shear environment and a
favourably-placed TUTT, the system remained dormant until late on the
29th when it began to organize. After further development, a TCFA was
released, followed by the first warning at 30/0600 UTC. At this time,
Tropical Depression 04W was centred 280 nm southeast of Guam, drifting
slowly west-northwestward along the southern periphery of the mid-level
steering ridge. Intensifying, it reached tropical storm intensity at
30/1800 UTC. The tropical cyclone maintained 35-kt winds through much
of the 31st while exhibiting a partially-exposed LLCC.
Synoptic History
More rapid strengthening occurred on 1 June and, after JMA upgraded
their MSW to 45 kts at 0000 UTC 1 June, the newly christened Nesat was
upgraded to a typhoon at 01/1200 UTC (per JTWC warnings) while located
approximately 310 nm west-southwest of Guam. Nesat then underwent an
explosive deepening phase which brought the intensity up to 115 kts by
02/0000 UTC. Intensification then abruptly ceased and the system began
to slowly weaken on 3 June, apparently due to moderate easterly shear
and restricted poleward outflow. However, the typhoon began to rapidly
strengthen once more later that day, and aided by favourable interaction
with a TUTT cell centred 600 nm to the east, rapidly intensified to
125 kts at 04/0000 UTC, just shy of becoming the first super typhoon of
the year. This was to be the peak intensity of the tropical cyclone.
At this time, Typhoon Nesat was centred about 720 nm south-southeast of
Okinawa and was still plodding along towards the west-northwest at
around 6 kts. (PAGASA had already assigned the name Dante, the fourth
name from their list, after the cyclone had crossed longitude 135 degrees
east shortly after 02/1800 UTC.)
Typhoon Nesat/Dante began to steadily weaken on 4 June as it turned
rather sharply northwards around the western extremity of the mid-level
steering ridge. Animated satellite imagery indicated that the northern
semicircle had eroded significantly in association with a large area of
convergence aloft. Also, weak northeasterly shear was displacing the
deep convection slightly to the southwest of the LLCC. However, after
the MSW had levelled off at 90 kts at 1200 UTC 5 June, poleward outflow
began to improve and Typhoon Nesat began its third and final
strengthening phase which brought the intensity back up to 120 kts at
06/1800 UTC. In response to a brief enhancement of the steering ridge
in association with the passage of a mid-latitude shortwave ridge, Nesat
moved onto a more northerly heading at 07/0000 UTC, and the storm,
centred approximately 410 nm southeast of Okinawa, began to feel the
effects of dry air and increasing shear.
The slow northward drift persisted on 7 June. On the 8th steering
currents became increasingly influenced by a mid-latitude trough over
China, and this feature guided Nesat back onto a northeasterly heading.
Typhoon Nesat weakened rather quickly and was downgraded to a tropical
storm at 0000 UTC 9 June while located approximately 520 nm south-
southwest of Tokyo, Japan. JTWC issued the final warning at 10/0000 UTC,
locating the centre of the extratropical system 310 nm south of Tokyo.
JMA maintained Nesat as a tropical cyclone until 11/0600 UTC, when that
agency also ended warning coverage. Typhoon Nesat's remnants accelerated
northeastward and were last noted as a 35-kt LOW in the vicinity of the
Aleutian Islands in the High Seas Bulletin issued at 14/0600 UTC.
JMA, PAGASA, and the CWB of Taiwan all estimated peak winds of 95 kts
(10-min avg) while the lowest CP estimated by JMA was 930 mb. NMCC's
peak wind estimate was higher at 110 kts (10-min avg).
A graphic displaying the track of Typhoon Nesat may be found at
the following link: this link.
Damage and Casualties
There were no reports of damages or casualties associated with
Typhoon Nesat/Dante.
(Report written by Kevin Boyle)
© 2005 Typhoon2000.com All Rights Reserved.
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