老農民版夜神月

BoM南調預測路徑,預測將至+36H至+48H後方才能出海
同時亦下調了預測強度,於12Z報中僅上望50KT

IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 1312 UTC 01/02/2021
Name: Tropical Low  
Identifier: 12U
Data At: 1200 UTC
Latitude: 21.1S
Longitude: 118.2E
Location Accuracy: within 15 nm [30 km]
Movement Towards: west southwest [240 deg]
Speed of Movement: 10 knots [19 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 992 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: N/A overland
Pressure of outermost isobar: 996 hPa
Radius of outermost closed isobar: 30 nm [55 km]
FORECAST DATA
Date/Time    : Location    : Loc. Accuracy: Max Wind   : Central Pressure
[UTC]        : degrees     :      nm  [km]: knots[km/h]: hPa
+06:  01/1800: 21.5S 117.0E:     030 [060]:  030  [055]:  992
+12:  02/0000: 21.9S 115.9E:     045 [080]:  030  [055]:  991
+18:  02/0600: 22.3S 115.0E:     050 [095]:  030  [055]:  990
+24:  02/1200: 22.7S 114.5E:     060 [110]:  030  [055]:  990
+36:  03/0000: 22.9S 113.8E:     070 [130]:  035  [065]:  985
+48:  03/1200: 22.9S 113.2E:     090 [165]:  040  [075]:  981
+60:  04/0000: 22.8S 112.5E:     105 [190]:  045  [085]:  978
+72:  04/1200: 22.9S 111.7E:     115 [215]:  050  [095]:  975
+96:  05/1200: 24.9S 111.5E:     150 [280]:  045  [085]:  978
+120: 06/1200: 28.1S 112.3E:     180 [330]:  045  [085]:  978
REMARKS:
Tropical low 12U remains easily identifiable over land with Port Hedland radar.
The low continues to exhibit a reasonably well organised structure.

Other than land, environmental influences [low-moderate easterly wind shear and
moist inflow from the northwest] remain conducive for development.

After slow movement through the day time, the low has increased its westward
movement rapidly over the last 6 hours. The low is expected to continue the west
southwest motion and track parallel to the Pilbara coast, steered by the
mid-level ridge to the south. This keeps the system over land preventing any
further development until it reaches the far northwest coast. The most likely
scenario is that it moves off the NIngaloo coast on the upper west coast late
Tuesday or early Wednesday and then develops. Given the current position of the
low and likely motion over the next 24 hours it now seems unlikely the low could
take a more northerly track and develop earlier.

On Wednesday, the system is expected to slow as the upper steering pattern is
affected by the approach of a mid-latitude trough. From Thursday [+72h] a
secondary upper level trough approaches from the southwest which may assist in
development and influence a more southerly track off the west coast. Anomalously
warm water off the west coast may also assist in maintaining the system at TC
intensity longer than would normally be the case.


Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 01/1930 UTC.

老農民版夜神月

JTWC此次的升格時機還滿詭異的,06Z一度升格為TS時不升,反而是12Z又調降成TD時升格18S
尤其以JTWC的慣例在南半球通常是TS才能獲得升格,此次破例的原因倒令人玩味及想不通了

SH, 18, 2021013112, , BEST, 0, 214S, 1211E, 30, 998, TD, 0, , 0, 0, 0, 0, 1002, 200, 30, 0, 0, S, 0, , 0, 0, EIGHTEEN, M, 0, , 0, 0, 0, 0, TRANSITIONED, shC82021 to sh182021,
SH, 18, 2021013118, , BEST, 0, 213S, 1198E, 30, 997, TD, 34, NEQ, 0, 0, 0, 0, 1001, 170, 30, 0, 0, S, 0, , 0, 0, EIGHTEEN, M,

dom

JTWC升格18S

老農民版夜神月

JTWC於澳洲陸地上將其升格為TS

SH, 98, 2021013106, , BEST, 0, 209S, 1223E, 35, 998, TS

老農民版夜神月

JTWC1500Z發布TCFA

WTXS21 PGTW 301500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 98S)//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/300321ZJAN2021//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT (WTPS21 PGTW
300330)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 18.5S 124.4E TO 20.0S 119.1E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT
IMAGERY AT 301200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 18.5S 124.2E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 06
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 98S) PREVIOUSLY LOCATED
NEAR 17.5S 125.2E IS NOW LOCATED NEAR 18.5S 124.2E, APPROXIMATELY
114 NM EAST-SOUTHEAST OF BROOME, AUSTRALIA. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY AND A 300838Z SSMIS 91 GHZ MICROWAVE
IMAGE DEPICT FORMATIVE BANDING WRAPPING INTO A DEFINED LOW LEVEL
CIRCULATION. ENVIRONMENTAL ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT FOR DEVELOPMENT WITH LOW (<15KTS) VERTICAL WIND SHEAR
AND GOOD OUTFLOW ALOFT. GLOBAL MODELS ARE IN STRONG AGREEMENT THAT
INVEST 98S WILL TRACK GENERALLY WEST-SOUTHWESTWARD OVER THE NEXT 24-
30 HOURS AND DEVELOP QUICKLY ONCE OVER WATER. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 995 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
311500Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 13.2S 148.2E.//
NNNN

老農民版夜神月

JTWC評級提升至Medium

(1) THE AREA OF CONVECTION (INVEST 98S) PREVIOUSLY LOCATED
NEAR 16.1S 125.7E IS NOW LOCATED NEAR 17.5S 125.2E, APPROXIMATELY
170 NM EAST OF BROOME, AUSTRALIA. ANIMATED ENHANCED INFRARED IMAGERY
(EIR) AND A 291315Z GMI 89GHZ SATELLITE IMAGE DEPICTS DISORGANIZED
LOW LEVEL BANDING WRAPPING INTO A LOW LEVEL CIRCULATION CENTER
(LLCC) THAT IS OVER LAND. UPPER LEVEL ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT FOR DEVELOPMENT WITH LOW (10-15 KTS) VERTICAL WIND SHEAR
(VWS) AND POLEWARD OUTFLOW. SURROUNDING SEA SURFACE TEMPERATURES
(SST) ARE VERY WARM (30-31C), PROVIDING A CONDUCIVE ENVIRONMENT FOR
DEVELOPMENT IN THE EVENT THAT INVEST 98S TRACKS OVER WATER. GLOBAL
MODELS ARE IN GOOD AGREEMENT THAT INVEST 98S WILL TRACK WEST-
SOUTHWESTWARD ALONG THE COAST AS IT STRENGTHENS, CONSOLIDATES, AND
LATER ON MOVE INTO THE SOUTH INDIAN OCEAN. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 15 TO 20 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

JTWC0300Z評級Low

1. AN AREA OF CONVECTION (INVEST 98P) HAS PERSISTED NEAR 16.1S
125.7E, APPROXIMATELY 373 NM SOUTHWEST FROM DARWIN, AUSTRALIA.
ANIMATED MULTISPECTRAL IMAGERY (MSI) DEPICTS LOW LEVEL BANDING
WRAPPING INTO A LOW LEVEL CIRCULATION CENTER (LLCC) THAT IS OVER
LAND. A 290056Z METOP-B 89GHZ SATELLITE IMAGE REVEALS AN OVERALL
LACK OF DEEP CONVECTION ASSOCIATED WITH THE SYSTEM. UPPER LEVEL
ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH LOW TO MODERATE (10-20 KTS) VERTICAL WIND SHEAR
(VWS) AND POLEWARD OUTFLOW. SURROUNDING SEA SURFACE TEMPERATURES
(SST) ARE VERY WARM (30-31C), PROVIDING A CONDUCIVE ENVIRONMENT FOR
DEVELOPMENT IN THE EVENT THAT INVEST 98P TRACKS OVER WATER. GLOBAL
MODELS ARE IN GOOD AGREEMENT THAT INVEST 98P WILL TRACK WEST-
SOUTHWESTWARD ALONG THE COAST AS IT STRENGTHENS, CONSOLIDATES, AND
LATER ON MOVE INTO THE SOUTH INDIAN OCEAN. 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 LOW.

老農民版夜神月

BoM於00Z起開始對12U發報