JTWC 香港の東に新たな低圧部99W解析 インド洋にサイクロン｜2023年6月9日06時00分UTC発行

JTWC 香港の東に新たな低圧部99W解析

JTWC（Joint Typhoon Warning Center）は、2023年6月9日（金曜日）06時00分UTC、日本時間同15時00分、香港とベトナム・ハノイの中間付近で、新たな低圧部99Wを解析、情報発行しました。

同時点での低圧部のレベルは「LOW」です。

JTWC 合同台風警報センター発表内容の見方

JTWC 衛星図 2023年6月9日10時00分UTC発行

ABPW10 (Western/South Pacific Ocean)｜Issued at 09/0600Z

気象庁 6月9日21時の実況天気図で99Wの位置に熱帯低気圧を解析

気象庁 発表

2023年06月09日21時の実況

赤い上矢印「⇧」がW99。気象庁天気図では「TD」。▶ 気象庁の発表する予想天気図の見方｜予想天気図の説明

矢印の右下の同心円は、「令和5年台風3号グチョル」。

2023年06月09日21時の実況天気図 気象庁

インド洋にサイクロン Biparjoy と 熱帯低気圧03B

Tropical Cyclone 02A｜Biparjoy

Issued at 09/1500Z Warning Graphic

Issued at 09/1500Z Prognostic Reasoning

WDIO31 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (BIPARJOY)
WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 15.5N 67.3E
INITIAL INTENSITY: 60 KTS
GEOGRAPHIC REFERENCE: 558 NM SOUTH OF KARACHI, PAKISTAN
MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A STEADILY
WEAKENING CONVECTIVE CORE WITH A CLUSTER OF FLARING DEEP CONVECTION
OBSCURING THE LOW-LEVEL CIRCULATION (LLC). EIR ALSO SHOWS A SECOND
CLUSTER OF DEEP CONVECTION SEPARATED FROM THE CORE CONVECTION AND
DISPLACED OVER THE WESTERN PERIPHERY OF THE SYSTEM. A 091146Z SSMIS
91GHZ MICROWAVE IMAGE REVEALS DISORGANIZED CORE CONVECTION SHEARED
WESTWARD OF A PARTIALLY-EXPOSED LLC WITH A CURVED CONVECTIVE BAND
DISCONNECTED TO THE WEST. THE INITIAL POSITION IS PLACED WITH MEDIUM
CONFIDENCE BASED ON THE SSMIS IMAGE. UPPER-LEVEL ANALYSIS CONTINUES TO
INDICATE MODERATE TO HIGH EASTERLY VERTICAL WIND SHEAR (VWS) OFFSET
SOMEWHAT BY BROAD DIFFLUENCE ALOFT. THE INITIAL INTENSITY OF 60 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE PGTW DATA-T ESTIMATE OF
T3.5 (55 KNOTS) AND AN AIDT OBJECTIVE ESTIMATE OF 62 KNOTS. DVORAK
CURRENT INTENSITY ESTIMATES FROM ALL THREE AGENCIES ARE SLIGHTLY
HIGHER AT 65 KNOTS.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) POSITIONED TO
THE EAST OVER WESTERN INDIA

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.0 – 65 KTS
KNES: T4.0 – 65 KTS
DEMS: T4.0 – 65 KTS
CIMSS SATCON: 68 KTS AT 090855Z
CIMSS ADT: 59 KTS AT 091200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 20-25 KTS
SST: 31-32 CELSIUS
OUTFLOW: MODERATE WESTWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 02A IS STRUGGLING TO
CONSOLIDATE DUE TO THE PERSISTENT MODERATE TO HIGH EASTERLY VWS.
MODERATE WESTWARD OUTFLOW AND VERY WARM SEA SURFACE TEMPERATURES
HAVE HELPED MAINTAIN THE INCREASINGLY DISORGANIZED, UNIMPRESSIVE
CORE CONVECTION. GLOBAL MODELS HAVE BEGUN TO BACK OFF ON THE
DECREASING VWS SCENARIO AND NOW INDICATE PERSISTENT MODERATE TO
HIGH VWS, THEREFORE, THE PEAK INTENSITY HAS BEEN DECREASED TO 80
KNOTS AT TAU 36 AND WILL LIKELY BE LOWERED FURTHER. TC 02A IS
MEANDERING POLEWARD SLOWLY AND WILL CONTINUE TRACKING NORTHWARD TO
NORTH-NORTHEASTWARD THROUGH TAU 72. AFTER TAU 36, VWS IS FORECAST
TO INCREASE SLIGHTLY WITH UPPER-LEVEL EASTERLIES STRENGTHENING
SOUTH OF A BUILDING RIDGE TO THE NORTH. THIS IS EXPECTED TO PRODUCE
A STEADY WEAKENING TREND THROUGH TAU 120 AS THE SYSTEM CONTINUES TO
SLOWLY TRACK NORTH-NORTHWESTWARD INTO THE NORTHERN ARABIAN SEA.

MODEL DISCUSSION: IN GENERAL, DETERMINISTIC GUIDANCE HAS COME INTO
BETTER AGREEMENT WITH GFS AND NAVGEM, IN PARTICULAR, ALIGNED CLOSER
TO THE ECMWF AND ECMWF ENSEMBLE MEAN SOLUTIONS. HOWEVER, THERE IS
STILL A 170NM CROSS-TRACK SPREAD IN SOLUTIONS AT TAU 72 AND A LARGE
385NM CROSS-TRACK SPREAD IN SOLUTIONS AT TAU 120 REFLECTING
INCREASING UNCERTAINTY (LOW CONFIDENCE) IN THE EXTENDED JTWC
FORECAST TRACK. THE 090600Z ECMWF AND GFS ENSEMBLES ARE ALSO BETTER
ALIGNED BUT ALSO REFLECT INCREASING UNCERTAINTY IN THE TRACK
FORECAST AFTER TAU 72. THERE IS ALSO MEDIUM CONFIDENCE IN THE JTWC
INTENSITY FORECAST THROUGH TAU 72 WITH A LARGE SPREAD IN RELIABLE
INTENSITY GUIDANCE. SEVERAL MODELS HAVE INDICATED AND CONTINUE TO
INDICATE SOME POTENTIAL FOR A SHORT PERIOD OF RAPID INTENSIFICATION
WITHIN THE NEXT 36 HOURS. THE 090600Z COAMPS-TC ENSEMBLE INDICATES
INCREASING PROBABILITIES OF RAPID INTENSIFICATION FROM 80 TO 90
PERCENT DURING THE NEXT 36 HOURS.

FORECAST CONFIDENCE:
TRACK 0 – 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 – 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN

Tropical Cyclone 03B (Three)

Issued at 09/1500Z Warning Graphic

Issued at 09/1500Z Prognostic Reasoning

WDIO32 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03B (THREE)      
WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.9N 91.7E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 144 NM SOUTH OF CHITTAGONG
   MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 02 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 
PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION (LLC) WITH DEEP CONVECTION
FLARING OVER THE WESTERN SEMICIRCLE. A 091004Z SSMIS 91GHZ COLOR
COMPOSITE MICROWAVE IMAGE REVEALS A LINEAR BAND OF DEEP CONVECTION
SHEARING WESTWARD WITH A WEAKLY DEFINED LLC NEAR THE EASTERN EDGE OF 
THE BAND. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED 
ON THE EIR IMAGERY AND THE SSMIS IMAGE. ENVIRONMENTAL ANALYSIS 
INDICATES A MARGINALLY UNFAVORABLE ENVIRONMENT WITH HIGH (25-30 KNOTS) 
EASTERLY VERTICAL WIND SHEAR AND BROAD DIFFLUENCE ALOFT. THE INITIAL 
INTENSITY OF 40 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A 
RECENT 090355Z ASCAT-B BULLSEYE IMAGE SHOWING A SWATH OF 35 TO 40 KNOT 
WINDS OVER THE SOUTHERN SEMICIRCLE. DVORAK INTENSITY ESTIMATES REMAIN 
TOO LOW HOWEVER THE CIMSS ADT ESTIMATE OF 41 KNOTS IS SUPPORTIVE.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: LOW-LEVEL STEERING RIDGE POSITIONED TO
THE SOUTHEAST WITH FLOW ENHANCED BY THE SOUTHWEST MONSOON

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   DEMS: T1.0 - 25 KTS
   CIMSS ADT: 41 KTS AT 091130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 20-25 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE WESTWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TC 03B IS FORECAST TO TRACK NORTHEASTWARD TO
NORTH-NORTHEASTWARD ALONG THE NORTHWESTERN FLANK OF THE STEERING
FLOW THROUGH THE FORECAST PERIOD. DUE TO THE MARGINALLY UNFAVORABLE
ENVIRONMENTAL CONDITIONS, THE SYSTEM IS NOT EXPECTED TO INTENSIFY
BUT SHOULD STEADILY WEAKEN AS IT APPROACHES THE MYANMAR COAST WITH
DISSIPATION OCCURRING WITHIN THE NEXT 24 HOURS.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS VERY LIMITED WITH
HWRF, ECMWF AND GFS SUPPORTING THE JTWC FORECAST TRACK INTO
MYANMAR. THE 090000Z GFS ENSEMBLE (GEFS) SHOWS THE BULK OF
SOLUTIONS TRACKING THE SYSTEM INTO MYANMAR WITH NO SIGNIFICANT
DEVELOPMENT. THE 081800Z ECMWF ENSEMBLE (EPS) IS MORE LIMITED WITH
A SPARSE SET OF SOLUTIONS TRACKING THE WEAK SYSTEM NORTHEASTWARD TO
NORTH-NORTHEASTWARD. DUE TO THE LACK OF GUIDANCE, THE CONFIDENCE IN
BOTH THE JTWC TRACK AND INTENSITY FORECAST IS MEDIUM.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM//
NNNN