老農民版夜神月

IMD編號BOB05

Sub: Depression over southwest Bay of Bengal.
The Well Marked Low Pressure Area over central parts of south Bay of Bengal moved
west-northwestwards, concentrated into a Depression and lay centred at 1730 hrs IST
of 10th November 2021, over Southwest Bay of Bengal, near Lat. 10.6°N and Long.
83.4°E, about 430 km east-southeast of Chennai & 420 km east-southeast of
Puducherry. It is very likely to move west–northwestwards and reach near north
Tamilnadu coast by the early morning of 11th November, 2021. Thereafter, it is likely to
continue to move west-northwestwards and cross north Tamil Nadu & adjoining south
Andhra Pradesh coasts between Karaikal & Sriharikota close to the north of Puducherry
by the evening of 11th November 2021.

Forecast track and intensity are given in the following table:
Date/Time(IST) Position(Lat. 0N/ long. 0E) Maximum sustained surface wind speed (Kmph) Category of cyclonic disturbance
10.11.21/1730 10.6/83.4 45-55 gusting to 65 Depression
11.11.21/0530 11.7/81.6 45-55 gusting to 65 Depression
11.11.21/1730 12.2/80.0 45-55 gusting to 65 Depression

老農民版夜神月

即將登陸印度東南沿岸

老農民版夜神月

JTWC升格04B

04B FOUR 211111 0600 13.0N 80.9E IO 35 997

老農民版夜神月

JTWC開始發報

WDIO31 PGTW 110900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 04B (FOUR) WARNING NR
001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.0N 80.9E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 717 NM SOUTHWEST OF KOLKATA, INDIA
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A LARGE AREA OF DEEP
CONVECTION EAST AND NORTHEAST OF A FULLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE MSI LOOP AND A 110550Z GMI 89GHZ IMAGE. THE
INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED AND AN EARLIER 110355Z BULLSEYE METOP-B ASCAT PASS AND
MULTIPLE AGENCY DVORAK ESTIMATES BETWEEN A T1.5 (25KTS) AND T2.0
(30KTS). THE ENVIRONMENT IS OVERALL MARGINALLY FAVORABLE WITH
MODERATE POLEWARD OUTFLOW, WARM (28-29 CELCIUS) SEA SURFACE
TEMPERATURES, ALL BEING OFFSET BY MODERATE TO STRONG VERTICAL WIND
SHEAR.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: T2.0 - 30 KTS
   DEMS: T1.5 - 25 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 15-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION:  TC 04B IS EXPECTED TO CONTINUE ON A
WEST-NORTHWEST TRACK TOWARDS THE COAST OF INDIA AND MAKE LANDFALL
NEAR CHENNAI, INDIA WITHIN THE NEXT 6 HOURS. TC 04B IS EXPECTED TO

老農民版夜神月

JTWC判定已於1115Z登陸印度

TPIO10 PGTW 111200

A. TROPICAL CYCLONE 04B (SE INDIA)

B. 11/1115Z

C. 12.91N

D. 80.14E

E. THREE/GOES-IO

F. N/A

G. IR/EIR/VIS/MSI

H. REMARKS: 15A/PBO TIGHTLY CURVED BNDG/ANMTN. DVORAK VALUES
UNAVAILABLE DUE TO LLCC OVER LAND.

I. ADDITIONAL POSITIONS: NONE


   RHOADES

老農民版夜神月

15Z發布Final Warning

WTIO31 PGTW 111500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04B (FOUR) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 04B (FOUR) WARNING NR 002   
   01 ACTIVE TROPICAL CYCLONE IN NORTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   111200Z --- NEAR 13.1N 80.0E
     MOVEMENT PAST SIX HOURS - 275 DEGREES AT 09 KTS
     POSITION ACCURATE TO WITHIN 015 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   REPEAT POSIT: 13.1N 80.0E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   120000Z --- 13.3N 79.2E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 24 HR POSIT: 290 DEG/ 03 KTS
    ---
   24 HRS, VALID AT:
   121200Z --- 13.5N 78.6E
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
111500Z POSITION NEAR 13.1N 79.8E.
11NOV21. TROPICAL CYCLONE 04B (FOUR), LOCATED APPROXIMATELY 13
NM WEST OF CHENNAI, INDIA, HAS TRACKED WESTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS A LARGE AREA OF DEEP CONVECTION SHEARED TO THE WEST OF
A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) AS IT MADE
LANDFALL NEAR CHENNAI, INDIA. WEATHER OBSERVATIONS FROM CHENNAI HAVE
SHOWN A DECREASE AND RISE IN SURFACE PRESSURE OVER THE PAST THREE
HOURS INDICATING TC 04B HAS MADE ITS WAY OVER LAND. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED
MSI LOOP AND AN 111045Z SSMIS 91 GHZ IMAGE. THE INITIAL INTENSITY OF
30 KTS IS ASSESSED WITH MEDIUM CONFIDENCE HEDGED SLIGHTLY HIGHER
THAN PGTW AND DEMS DVORAK ESTIMATES OF 1.5 (25 KTS) AT THE 0900Z
ANALYSIS WHILE TC 04B WAS STILL OVER WATER. SURFACE WIND
OBSERVATIONS FROM CHENNAI AT THE TIME OF LANDFALL WERE 25 KTS WITH
GUSTS TO 40 KTS. TC 04B WILL CONTINUE TO WEAKEN AS IT PASSES OVER
THE TERRAIN OF SOUTHERN INDIA OVER THE NEXT 24 HOURS. THE REMNANTS
OF TC 04B WILL CONTINUE TRACKING WEST-NORTHWESTWARD OVER SOUTHERN
INDIA AND MAY MOVE OVER THE ARABIAN SEA, HOWEVER, THERE IS LOW
PROBABILITY OF REGENERATION. MODEL GUIDANCE IS IN GOOD AGREEMENT
THAT TC 04B WILL CONTINUE TRACKING WEST-NORTHWESTWARD OVER LAND,
WITH AFUM BEING THE OUTLIER SHOWING A SOUTHWESTWARD TRACK. THE JTWC
FORECAST TRACK IS PLACED WITH HIGH CONFIDENCE SLIGHTLY RIGHT OF
MODEL CONSENSUS DUE TO AFUM'S ERRATIC MOTION TO THE SOUTHWEST. THE
INTENSITY GUIDANCE IS IN GOOD AGREEMENT SHOWING STEADY WEAKENING DUE
TO TERRAIN INTERACTION, LENDING HIGH CONFIDENCE IN THE JTWC
INTENSITY FORECAST. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE
JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY
MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 111200Z IS 11 FEET.//
NNNN

老農民版夜神月

IMD做出無視風場的行為,不僅沒有升格命名,09Z更是僅定強25KT,等會看看登陸報會判定以什麼強度登陸

老農民版夜神月

IMD判定於12Z左右登陸,登陸強度為低壓25KT(.....)

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