18P.Nathan 漫長生命史三度登陸澳洲

krichard2011 · 2015-3-22 00:53

底層眼牆差不多已經重新整合完成了
但由於已經快登陸加上可能地形的干擾
高層風眼要重新開眼的機會應該不高

t02436 · 2015-3-22 10:54

IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 0102 UTC 22/03/2015
Name: Tropical Cyclone Nathan
Identifier: 17U
Data At: 0000 UTC
Latitude: 12.6S
Longitude: 136.8E
Location Accuracy: within 10 nm [20 km]
Movement Towards: northwest [310 deg]
Speed of Movement: 7 knots [13 km/h]
Maximum 10-Minute Wind: 60 knots [110 km/h]
Maximum 3-Second Wind Gust: 85 knots [155 km/h]
Central Pressure: 984 hPa
Radius of 34-knot winds NE quadrant: 45 nm [85 km]
Radius of 34-knot winds SE quadrant: 70 nm [130 km]
Radius of 34-knot winds SW quadrant: 50 nm [95 km]
Radius of 34-knot winds NW quadrant: 30 nm [55 km]
Radius of 48-knot winds NE quadrant: 15 nm [30 km]
Radius of 48-knot winds SE quadrant: 15 nm [30 km]
Radius of 48-knot winds SW quadrant: 15 nm [30 km]
Radius of 48-knot winds NW quadrant: 15 nm [30 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 10 nm [20 km]
Dvorak Intensity Code: T4.0/4.0/D1.0/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 120 nm [220 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC]       : degrees    :    nm  [km]: knots[km/h]: hPa
+06:  22/0600: 12.0S 136.0E:    010 [020]:  050  [095]:  993
+12:  22/1200: 11.5S 135.4E:    025 [045]:  045  [085]:  996
+18:  22/1800: 11.1S 134.9E:    035 [070]:  040  [075]:  998
+24:  23/0000: 10.9S 134.5E:    050 [090]:  040  [075]:  997
+36:  23/1200: 10.7S 133.8E:    070 [130]:  035  [065]: 1000
+48:  24/0000: 11.0S 133.2E:    090 [165]:  030  [055]: 1002
+60:  24/1200: 11.7S 132.6E:    110 [200]:  030  [055]: 1003
+72:  25/0000: 12.4S 132.0E:    125 [235]:  025  [045]: 1005
+96:  26/0000: 13.2S 129.8E:    170 [315]:  025  [045]: 1005
+120: 27/0000: 13.3S 127.2E:    260 [480]:  020  [035]: 1008
REMARKS:
Tropical Cyclone Nathan is approaching landfall on the NE Arnhem coast just
south of Nhulunbuy [Gove peninsula].

Location is very good based on Gove radar and shows a much improved structure
with a tight eye wall developing and good spiral bands. Sustained gales are
being experienced at Gove Airport to the north of the system centre, with
maximum gust of 53kt at 0004UTC.

Dvorak curved band of 1.2 wrap gives a DT=4.0. CDO technique with diameter 75nm
and banding feature also agrees. While there appears to be a warm centre, eye
pattern technique cannot be used due to narrowest width not meeting constraints
due to small size of system. Clear development over last 24hours with MET=4.0
and PAT agrees. So FT=4.0. Intensity is set at 60 knots.

Confidence in the forecast track in the short term remains high with the firm
mid-level ridge expected to remain in place, and NWP model tracks showing tight
clustering as a consequence. Tropical Cyclone Nathan is expected to weaken a
little over the next few hours due to land interaction.

In the longer term, Tropical Cyclone Nathan is expected to weaken due to
increasing shear and the entrainment of dry air.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 22/0730 UTC by Darwin TCWC.

00Z UTC 第二度登陸
實測最大持續風速53Kts
預估後期出海將受到風切及乾空氣影響
所以不再看好增強

第二次登陸雷達動畫

第一次登陸約克角半島雷達動畫

蜜露 · 2015-3-22 11:03

看了一下高層,VIS來看 ,風眼好像隱現了

翻翻一下之前的底層有眼建立

不過祂的移速比2006的Monica快多了. 增強強度相較很難.

BOM不在支持祂增強了

t02436 · 2015-3-22 15:53

BoM 06Z 一改二次登陸後即持續減弱之預報
最新預測將持續增強並重回三級強烈熱帶氣旋

IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 0652 UTC 22/03/2015
Name: Tropical Cyclone Nathan
Identifier: 17U
Data At: 0600 UTC
Latitude: 12.2S
Longitude: 136.1E
Location Accuracy: within 10 nm [20 km]
Movement Towards: west northwest [299 deg]
Speed of Movement: 8 knots [15 km/h]
Maximum 10-Minute Wind: 55 knots [100 km/h]
Maximum 3-Second Wind Gust: 75 knots [140 km/h]
Central Pressure: 988 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 55 nm [100 km]
Radius of 34-knot winds SW quadrant: 40 nm [75 km]
Radius of 34-knot winds NW quadrant: 40 nm [75 km]
Radius of 48-knot winds NE quadrant: 15 nm [30 km]
Radius of 48-knot winds SE quadrant: 15 nm [30 km]
Radius of 48-knot winds SW quadrant: 15 nm [30 km]
Radius of 48-knot winds NW quadrant: 15 nm [30 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 10 nm [20 km]
Dvorak Intensity Code: T4.5/4.0/D1.5/24HRS
Pressure of outermost isobar: 1008 hPa
Radius of outermost closed isobar: 120 nm [220 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC]       : degrees    :    nm  [km]: knots[km/h]: hPa
+06:  22/1200: 11.7S 135.5E:    020 [040]:  060  [110]:  985
+12:  22/1800: 11.3S 134.9E:    035 [065]:  065  [120]:  980
+18:  23/0000: 11.0S 134.4E:    045 [085]:  070  [130]:  976
+24:  23/0600: 10.9S 134.0E:    060 [110]:  065  [120]:  980
+36:  23/1800: 11.1S 133.5E:    080 [145]:  055  [100]:  987
+48:  24/0600: 11.7S 132.9E:    100 [180]:  045  [085]:  994
+60:  24/1800: 12.3S 132.4E:    120 [220]:  030  [055]: 1002
+72:  25/0600: 12.9S 131.7E:    135 [255]:  025  [045]: 1005
+96:  26/0600: 13.1S 129.7E:    180 [335]:  025  [045]: 1005
+120: 27/0600: 13.3S 127.1E:    270 [500]:  025  [045]: 1005
REMARKS:
Tropical Cyclone Nathan has crossed over Gove Peninsula in northeast Arnhem
Land.

Location is very good based on Gove radar, as the system maintains a healthy
structure with a tight eye wall and clear spiral bands. Gales were experienced
at Gove for several hours early this afternoon, but are now easing. Winds at
Elcho Island are currently near gale force and are expected to increase further.

Dvorak curved band of 1.6 wrap on visible satellite imagery gives a DT=4.5.
Clear development over last 24hours with MET=4.5 and PAT agrees. FT=4.5. However
current intensity is restricted to 4.0 due to land interaction.

Confidence in the forecast track in the short term remains high with the firm
mid-level ridge expected to remain in place, and NWP model tracks showing tight
clustering as a consequence.
Tropical Cyclone Nathan is now expected to strengthen overnight as it moves
northwest over open waters away from the coast.

In the longer term, Tropical Cyclone Nathan is expected to slowly weaken due to
increasing shear as it reapproaches the coast near the Cobourg Peninsula.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 22/1330 UTC by Darwin TCWC.

ben811018 · 2015-3-22 22:03

形成至今快12天了！

t02436 · 2015-3-24 13:28

今天凌晨第三度登陸澳洲
以二級熱帶氣旋強度二次登陸北領地

BoM 04Z 降格熱帶低壓並發出最後一報

IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 0455 UTC 24/03/2015
Name: Ex-Tropical Cyclone Nathan
Identifier: 17U
Data At: 0300 UTC
Latitude: 12.5S
Longitude: 132.6E
Location Accuracy: within 20 nm [35 km]
Movement Towards: west southwest [243 deg]
Speed of Movement: 13 knots [24 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1002 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: over land
Pressure of outermost isobar:  1010 hPa
Radius of outermost closed isobar: 120 nm [200 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC]       : degrees    :    nm  [km]: knots[km/h]: hPa
+06:  24/0900: 12.6S 131.9E:    050 [095]:  030  [055]: 1002
+12:  24/1500: 12.7S 131.5E:    080 [150]:  030  [055]: 1003
+18:  24/2100: 12.8S 131.0E:    100 [185]:  030  [055]: 1004
+24:  25/0300: 12.9S 130.5E:    120 [220]:  030  [055]: 1003
+36:  25/1500: 13.0S 129.2E:    160 [295]:  030  [055]: 1002
+48:  26/0300: 12.8S 127.5E:    190 [350]:  025  [045]: 1004
+60:  26/1500: 12.7S 125.9E:    240 [445]:  025  [045]: 1004
+72:  27/0300: 13.0S 124.0E:    280 [520]:  025  [045]: 1004
+96:  28/0300: 13.6S 120.6E:    300 [555]:  025  [045]: 1003
+120: 29/0300: 14.4S 117.3E:    310 [570]:  025  [045]: 1004
REMARKS:
Position based on surface observations and Warruwi radar, which indicate that
Nathan has accelerated inland to be located close to Jabiru at 0300 UTC. The
low-level circulation centre passed close to Gunbalunya and jabiru, and both
stations reported below gale force winds.

Deep convection has persisted close to the circulation centre however, low-level
dry air surrounds the system on its southern, western and inner northern
sectors. This has suppressed deep convection except where deep moisture and
low-level convergence remain in the eastern semicircle. Low-level cloud lines
associated with a partially exposed LLCC are evident in the northern semicircle.
Dvorak anaysis was not possible as the circulation is over land, but intensity
is now below 35 knots.

The mid level ridge to the south has weakened and the recent motion has been
towards the west southwest.  The latest guidance maintains a west southwest
track, keeping the remnant tropical low over land today and tomorrow, in the
northern Daly District. The low level centre is expected to move over the Timor
Sea early on Thursday, however, environmental conditions are not conducive for
redevelopment of a tropical cyclone, due to moderate northwest shear and deep
dry air.

Copyright Commonwealth of Australia
==
There will be no further bulletins for this system unless it reintensifies.

登陸雷達動畫

krichard2011 · 2015-3-27 11:10

JTWC 重新評級為LOW

B. TROPICAL DISTURBANCE SUMMARY: AN AREA OF CONVECTION (REMNANTS
OF TC 18P) HAS PERSISTED NEAR 13.3S 127.9E, APPROXIMATELY 215 NM
WEST-SOUTHWEST OF DARWIN, AUSTRALIA. RECENT ANIMATED INFRARED
SATELLITE IMAGERY SHOWS DEEP CONVECTION DEVELOPING ALONG THE
SOUTHERN PERIPHERY OF A WEAK LOW-LEVEL CIRCULATION CENTER EVIDENT IN
A 261411Z GPM MICROWAVE SATELLITE IMAGE AND IN RECENT RADAR DATA.
THE CIRCULATION LIES IN AN AREA OF MODERATE NORTHERLY VERTICAL WIND
SHEAR AND STRONG POLEWARD OUTFLOW ALOFT. VERTICAL WIND SHEAR IS
EXPECTED TO PERSIST AS THE CIRCULATION MOVES WEST-SOUTHWESTWARD OVER
THE NEXT SEVERAL DAYS, LIMITING THE POTENTIAL FOR FURTHER
DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO
20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1009
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.