霧峰追風者

  二級熱帶氣旋  
編號：11 U ( 17 P )
名稱：Lucas

  基本資料  
擾動編號日期：2021 年 01 月 23 日 23 時
JTWC升格日期:2021 年 01 月 31 日 09 時
命名日期　　：2021 年 01 月 31 日 14 時
撤編日期　　：2021 年 02 月 04 日 19 時
登陸地點　　：無

  巔峰時期資料  
近中心最強風速
斐濟氣象局 (FMS)：60 kt
聯合颱風警報中心(JTWC)：65 kt ( TY )
海平面最低氣壓   ：975 百帕

  擾動編號資料  
94P.INVEST.15kts-1007mb-12.8S-138E
以上資料來自：FMS、JTWC、颱風論壇整理製作

老農民版夜神月

JTWC評級Low

(1) AN AREA OF CONVECTION (INVEST 94P) HAS PERSISTED NEAR
14.8S 139.2E, APPROXIMATELY 130 NM NORTH OF MORNINGTON ISLAND,
AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS CYCLING
DEEP CONVECTION OVER A BROAD LOW LEVEL CIRCULATION (LLC) WITH
ADDITIONAL FLARING CONVECTION TO THE NORTH. A 250407Z ASCAT-A IMAGE
INDICATES AN ELONGATED CIRCULATION WITH SOME 20-25KT WIND BARBS TO
THE EAST AND 15-20KT WINDS TO THE NORTHWEST. UPPER LEVEL ANALYSIS
INDICATES A MODERATELY FAVORABLE ENVIRONMENT WITH EQUATORWARD
OUTFLOW AND WARM (29-31C) SEA SURFACE TEMPERATURES OFFSET BY
MODERATE TO HIGH VERTICAL WIND SHEAR (20-25KTS). GLOBAL MODELS
INDICATE 94P TRAVELING GENERALLY EASTWARD AS IT INTENSIFIES.  
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO LOW.

老農民版夜神月

BoM編號11U

At 9:30 am CST [10:00 am EST] on Monday 25 January, a developing tropical low (11U), 1003 hPa, was located in the central Gulf of Carpentaria, near 14.7S 138.8E, about 220 km north of Mornington Island and 260 km east southeast of Groote Eylandt. The tropical low is forecast to move slowly eastwards on Monday and be located over the eastern Gulf of Carpentaria on Tuesday. From Wednesday, the tropical low may become slow moving over the eastern Gulf of Carpentaria with an increasing risk of forming into a tropical cyclone. The system may persist as a tropical cyclone in the Gulf of Carpentaria until the weekend, although there is also a chance that it moves inland of the eastern Gulf coast sooner, or moves towards the southern Gulf coast.


Likelihood of this system being a tropical cyclone in the Northern Region on:
Tuesday:Very Low
Wednesday:Moderate
Thursday:High

老農民版夜神月

BoM開始對於11U(94P)發報，預測+72H後達澳式C2

霧峰追風者

JTWC 評級提升Medium。

(1) THE AREA OF CONVECTION (INVEST 94P) PREVIOUSLY LOCATED
NEAR 14.8S 139.2E IS NOW LOCATED NEAR 15.8S 140.1E, APPROXIMATELY 75
NM NORTHEAST OF MORRINGTON, AUSTRALIA. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS CYCLING DEEP CONVECTION OVER A BROAD LOW
LEVEL CIRCULATION (LLC) WITH ADDITIONAL FLARING CONVECTION TO THE
NORTHEAST. A 251852Z SSMS 91 GHZ IMAGE REVEALS DISORGANIZED BANDING
WRAPPING INTO THE LLC. UPPER LEVEL ANALYSIS INDICATES A MODERATELY
FAVORABLE ENVIRONMENT WITH EQUATORWARD AND EASTWARD OUTFLOW AND WARM
(29-31C) SEA SURFACE TEMPERATURES OFFSET BY MODERATE TO HIGH
VERTICAL WIND SHEAR (20-25KTS). GLOBAL MODELS INDICATE 94P TRAVELING
GENERALLY EASTWARD AS IT INTENSIFIES. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 20 TO 25 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 UPGRADED TO
MEDIUM.

老農民版夜神月

BoM上望60節

IDQ20018
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 0700 UTC 26/01/2021
Name: Tropical Low  
Identifier: 11U
Data At: 0600 UTC
Latitude: 15.1S
Longitude: 140.5E
Location Accuracy: within 30 nm [55 km]
Movement Towards: east southeast [105 deg]
Speed of Movement: 4 knots [7 km/h]
Maximum 10-Minute Wind: 25 knots [45 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 999 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: T2.0/2.0/D1.5/18HRS STT:S0.0/06HRS
Pressure of outermost isobar: 1001 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:  26/1200: 15.2S 140.7E:     045 [085]:  030  [055]:  995
+12:  26/1800: 15.4S 140.7E:     060 [105]:  030  [055]:  994
+18:  27/0000: 15.5S 140.8E:     065 [120]:  030  [055]:  994
+24:  27/0600: 15.5S 140.7E:     075 [135]:  030  [055]:  994
+36:  27/1800: 15.5S 140.5E:     085 [160]:  045  [085]:  986
+48:  28/0600: 15.5S 140.5E:     105 [195]:  050  [095]:  982
+60:  28/1800: 15.3S 140.5E:     120 [220]:  055  [100]:  979
+72:  29/0600: 14.8S 141.0E:     130 [245]:  060  [110]:  976
+96:  30/0600: 14.1S 142.2E:     165 [310]:  040  [075]:  990
+120: 31/0600: 14.4S 143.9E:     195 [355]:  030  [055]:  995
REMARKS:
The satellite signature of tropical low 11U has remained overall steady during
the last 6 hours. Loose banding has developed through the western and northern
flanks, while a separate area of convection has persisted to the southeast of
the estimated low level centre. The 00Z ASCAT pass suggested the centre remained
slightly elongated, and current satellite and radar imagery suggests the system
still has yet to consolidate around a single well defined centre. 11U was
located using a combination of radar, satellite, and surface observations.
Proximal surface pressures from the latter indicate the surface centre may be
further from the coast than recent radar imagery would suggest.

Dvorak analysis was based on a curved band pattern with an 0.35 wrap, giving DT
2.0. FT is also 2.0. Intensity is estimated at 25 knots based on the morning
ASCAT pass.

CIMSS satellite winds depict the system lying under highly diffluent upper level
flow with well defined outflow channels to the north and south. Deep layer wind
shear over the system is estimated at about 15 knots easterly, which has reduced
considerably from the 00Z estimate. Sea surface temperatures are around 30 to 31
degrees. The evolution of this environment is somewhat complex, but most NWP
guidance suggests the upper level shortwave to the south will rotate northwards
over the system in the next 12 to 18 hours. This would result in a period of
increased westerly shear overnight, followed by another decrease. The system's
proximity to land is another complicating factor. Deterministic NWP guidance
suggests continued development of the system through the next 48 hours, as does
the latest SHIPS guidance.

Overnight, the steering influences on the system are expected to become weak
with mid-level ridges to the southwest and northeast. The system is therefore
likely to stall over the eastern Gulf for a period. In the longer term the
northern steering ridge is expected to become dominant as the southern ridge is
eroded by a mid-level trough. From late in the week the system should recommence
easterly motion, crossing Cape York Peninsula and potentially emerging into the
Coral Sea.

Given the current and forecast favourable environment for development, it is
likely that the system will intensify to at least category 2 over the Gulf,
possibly category 3 depending on how much time it spends over water. However
some uncertainty exists with some guidance suggesting it may cross the coast
before tropical cyclone development can occur.


Copyright Commonwealth of Australia
==

霧峰追風者

IDQ20018
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 1930 UTC 26/01/2021
Name: Tropical Low  
Identifier: 11U
Data At: 1800 UTC
Latitude: 14.9S
Longitude: 141.4E
Location Accuracy: within 30 nm [55 km]
Movement Towards: east northeast [063 deg]
Speed of Movement: 4 knots [8 km/h]
Maximum 10-Minute Wind: 25 knots [45 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 999 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: T2.0/2.0/D0.5/24HRS STT:S0.0/06HRS
Pressure of outermost isobar: 1001 hPa
Radius of outermost closed isobar: 40 nm [75 km]
FORECAST DATA
Date/Time    : Location    : Loc. Accuracy: Max Wind   : Central Pressure
[UTC]        : degrees     :      nm  [km]: knots[km/h]: hPa
+06:  27/0000: 15.0S 141.6E:     045 [085]:  030  [055]:  995
+12:  27/0600: 15.1S 141.6E:     060 [105]:  030  [055]:  994
+18:  27/1200: 15.2S 141.5E:     065 [120]:  030  [055]:  992
+24:  27/1800: 15.2S 141.3E:     075 [135]:  035  [065]:  990
+36:  28/0600: 15.1S 141.2E:     085 [160]:  045  [085]:  985
+48:  28/1800: 14.9S 141.3E:     105 [195]:  050  [095]:  981
+60:  29/0600: 14.4S 141.5E:     120 [220]:  060  [110]:  978
+72:  29/1800: 13.8S 142.1E:     130 [245]:  045  [085]:  984
+96:  30/1800: 13.2S 144.3E:     165 [310]:  030  [055]:  996
+120: 31/1800: 13.9S 146.6E:     195 [355]:  030  [055]:  996
REMARKS:
The satellite signature of tropical low 11U has shown significant weakening with
loss of deep convection over the last 3 to 6 hours, possibly due to land
interaction as the low moves closer to the coast. 11U was located using a
combination of microwave [AMSR at 1610Z], satellite, and surface observations,
with moderate confidence. An ASCAT pass at 1131Z showed an elongated trough with
25kt winds on the northeast side of the centre, indicative of a disorganised
structure. Radar suggests the mid-level circulation is offset to the east of the
low-level centre. The monsoon flow to the north has also weakened slightly over
the last 12 hours.

Dvorak analysis was based on a curved band pattern with a 0.25 wrap, giving DT
1.5. However FT is held at 2.0 due to constraints for lowering at night.
Similarly, intensity is held at 25 knots based on the earlier ASCAT pass.

CIMSS satellite winds depict the system lying under highly diffluent upper level
flow with well defined outflow channels to the north and south due to an upper
level trough rotating onto the system overnight. Deep layer wind shear over the
system is estimated at about 10 knots easterly. Sea surface temperatures are
around 30 to 31 degrees. While the environment is generally favourable for
development, the system's proximity to land is a complicating factor, so its
cyclogenesis potential is largely dependant on its time over water.  

Steering influences on the system are currently fairly well balanced, with
mid-level ridges to the southwest and northeast. The system is therefore likely
to remain fairly slow-moving over the eastern Gulf for a period. In the longer
term the northern steering ridge is expected to become dominant as the southern
ridge is eroded by a mid-level trough. From late in the week the system should
recommence easterly motion, crossing Cape York Peninsula and potentially
emerging into the Coral Sea. However, there remains significant variation in
model guidance, with both a faster easterly movement, or further stalling in the
Gulf both possible scenarios.

Given the current and forecast favourable environment for development, if the
system remains over Gulf waters, it is likely to intensify to at least category
2. However some uncertainty exists with some guidance suggesting it may cross
the coast before tropical cyclone development can occur.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 27/0130 UTC.

dom

BoM新報不再看好成旋

94P INVEST 210127 0000 14.7S 142.6E SHEM 20 1002