25P.Raquel 南半球史上首個跨風季熱帶氣旋

BlankCat 發表於 2015-7-5 10:58

氣旋在 160E 左右擺動
澳洲跟斐濟輪流發佈

記得很久以前的北半球
試過有颱風在換日線左右擺動?

t02436 發表於 2015-7-5 10:40

之前受限於風切影響發展都不是很順利
降格熱低後JTWC昨天晚上再度評級Low

B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (REMNANTS OF TC 25P) HAS PERSISTED
NEAR 8.9S 158.1E, APPROXIMATELY 120 NM NORTH-NORTHWEST OF HONIARA,
SOLOMON ISLANDS. ANIMATED EIR LOOP SHOWS THE SYSTEM CONTINUES TO
HAVE SOME LIMITED CONVECTION IN THE WESTERN SIDE OF THE LLCC. THE
LOCATIONAL INFORMATION IS DIFFICULT AS A 041033Z ASCAT IMAGE SHOWS
A BROAD, BUT WELL ORGANIZED SYSTEM. UPPER-LEVEL ANALYSIS IS FAVORABLE
FOR DEVELOPMENT HOWEVER THE GLOBAL MODELS HAVE LIMITED DEVELOPMENT
OF THIS SYSTEM OVER THE NEXT 48 HOURS. MAXIMUM SUSTAINED SURFACE WIND
S ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF
A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.

周邊海溫仍有攝氏28度且風切有減弱趨勢
BoM認為06Z會重回一級熱帶氣旋

IDQ20018
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by BRISBANE TROPICAL CYCLONE WARNING CENTRE
at: 0052 UTC 05/07/2015
Name: Ex-Tropical Cyclone Raquel
Identifier: 01U
Data At: 0000 UTC
Latitude: 9.8S
Longitude: 157.4E
Location Accuracy: within 45 nm [85 km]
Movement Towards: southwest [225 deg]
Speed of Movement: 5 knots [9 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 997 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant:
Radius of 34-knot winds NW quadrant:
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds:
Dvorak Intensity Code: T2.5/2.5/D1.0/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 180 nm [335 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC]       : degrees    :    nm  [km]: knots[km/h]: hPa
+06:  05/0600: 10.3S 157.2E:    055 [105]:  035  [065]:  995
+12:  05/1200: 10.7S 157.0E:    070 [130]:  035  [065]:  995
+18:  05/1800: 11.1S 156.9E:    080 [150]:  035  [065]:  995
+24:  06/0000: 11.5S 156.6E:    095 [175]:  030  [055]:  997
+36:  06/1200: 12.1S 156.1E:    115 [210]:  030  [055]:  998
+48:  07/0000: 13.1S 155.8E:    135 [245]:  025  [045]: 1001
+60:  07/1200: 14.3S 156.3E:    155 [285]:  025  [045]: 1001
+72:  08/0000: 15.3S 156.2E:    170 [320]:  025  [045]: 1001
+96:  09/0000:          :             :          :
+120: 10/0000:          :             :          :
REMARKS:
Ex-tropical cyclone Raquel is located to the southwest of the Solomon Islands
and moving towards the south-southwest under the influence of a mid-level ridge
situated to the east of the Solomon Islands. The system appears to have
developed in the last 24 hours with convection now occurring closer to the
estimated centre.

The strong northeasterly wind shear that has been impacting the system over the
last few days appears to have decreased during the last 24 hours. The satellite
imagery now shows improved outflow to the north and south of the system.
Ex-tropical cyclone Raquel is also still situated over warm sea surface
temperatures of around 28 degrees.

With all these factors combined and computer model guidance indicating some
intensification in the system, it is anticipated that Raquel could still reform
into a tropical cyclone during today. However, the window for redevelop is
primarily confined to today with an upper trough expected to increase vertical
wind shear across the system during Monday.

The latest Dvorak analysis was based on a curved band pattern with a 0.5 degree
wrap, giving a DT of 2.5. MET and PAT were 3.0 and 2.5 respectively. FT based on
PAT as DT was not clear. Confidence in the location of the low level centre is
still rated as poor. The ASCAT-B scatterometer image at 2317UTC supports this
analysis with around 30 knots near the centre of the system.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 05/0700 UTC by Brisbane
TCWC.