WESTERN PACIFIC: TS 09W(BAVI) RI expected next 48h to Super Typhoon Intensity/TD 10W//SOUTH PACIFIC:Invest 97P//EASTERN PACIFIC:TS 04E(DOUGLAS)//02@1800 UTC

JTWC FACEBOOK
Joint Typhoon Warning Center

WDPN31 PGTW 021500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (BAVI) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.3N 158.0E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 770 NM EAST OF ANDERSEN AFB
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 26 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS PERSISTENT 
CONVECTIVE BANDING WRAPPING INTO THE CONSOLIDATING CENTRAL CORE OF TS 
09W. ALTHOUGH THE LOW-LEVEL CIRCULATION CENTER IS FULLY OBSCURED, THE 
SLACKENING VERTICAL WIND SHEAR (VWS) OVER THE PAST 6 HOURS SUGGESTS 
THAT THE VORTEX HAS BECOME BETTER ALIGNED VERTICALLY. ROBUST POLEWARD 
AND EQUATORWARD OUTFLOW IS EVIDENT IN ANIMATED WATER VAPOR IMAGERY, 
ALONG WITH IMPROVING RADIAL OUTFLOW OVER THE PAST FEW HOURS. A 020704Z 
WSFM 37 GHZ MICROWAVE IMAGE REVEALED A NASCENT MICROWAVE EYE WITH 
IMPROVED SYMMETRY OF THE CONVECTIVE BANDING SURROUNDING THE CENTRAL 
CORE. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON 
THE CENTER OF ROTATION IN ANIMATED EIR AND EXTRAPOLATION FROM THE 
EARLIER MICROWAVE IMAGERY. THE INITIAL INTENSITY OF 55 KTS IS ASSESSED 
WITH MEDIUM CONFIDENCE BASED ON A BLEND OF THE AGENCY DVORAK FIXES AND 
CIMSS OBJECTIVE INTENSITY ESTIMATES. THE ENVIRONMENT IS CHARACTERIZED 
AS HIGHLY FAVORABLE WITH VERY WARM (29-30 C) SEA SURFACE TEMPERATURES, 
HIGH OCEAN HEAT CONTENT, AND STRONG OUTFLOW ALOFT. THE ONLY LIMITING 
ENVIRONMENTAL FACTOR IN THE SHORT TERM IS THE 10-15 KTS OF EASTERLY 
VWS.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SOUTHWESTERN FLANK OF AN EXTENSION OF
THE SUBTROPICAL RIDGE (STR) SITUATED TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T3.0 - 45 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 55 KTS AT 021030Z
   CIMSS ADT: 59 KTS AT 021200Z
   CIMSS AIDT: 49 KTS AT 021200Z
   CIMSS D-MINT: 52 KTS AT 020840Z
   CIMSS D-PRINT: 57 KTS AT 021200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL STORM (TS) 09W (BAVI) HAS CONTINUED
ON A NORTHWESTWARD TRACK OVER THE PAST 6 HOURS UNDER THE STEERING
INFLUENCE OF AN EXTENSION OF THE STR POSITIONED TO THE NORTHEAST.
THE SYSTEM IS EXPECTED TO ASSUME A WESTWARD TRAJECTORY THROUGH TAU
48 AS A STR CENTERED NEAR KYUSHU BUILDS IN FROM THE WEST AND TAKES
OVER AS THE PRIMARY STEERING MECHANISM. THE TRACK SPEED IS EXPECTED
TO SLOW BETWEEN TAU 24 AND TAU 72 UNDER THIS STEERING INFLUENCE AS
A LONGWAVE TROUGH PROPAGATES EASTWARD TO THE NORTH, TEMPORARILY
WEAKENING THE STEERING GRADIENT. AFTER TAU 60, TS 09W RETURNS TO A
WEST-NORTHWESTWARD TRACK AS IT APPROACHES THE NORTHERN MARIANA 
ISLANDS, WITH A CPA TO SAIPAN AROUND 052300Z. INTENSIFICATION OVER
THE NEXT 12 HOURS IS EXPECTED TO REMAIN STEADY AS THE SYSTEM 
CONSOLIDATES AND MOVES INTO A LOWER SHEAR ENVIRONMENT. AFTER TAU 12, 
ENVIRONMENTAL CONDITIONS FAVOR AN EXTENDED PERIOD OF RAPID 
INTENSIFICATION (RI) THROUGH TAU 60. HAFS-A CONTINUES TO DEPICT AN
EYEWALL REPLACEMENT CYCLE (EWRC) STARTING BETWEEN TAU 48 AND 60,
CONTINUING THROUGH PASSAGE TROUGH THE NORTHERN MARIANAS. AS A RESULT, 
THE INTENSITY IS FORECAST TO LEVEL OFF AT A PEAK OF 135 KTS FROM TAU 
72 THROUGH THE REMAINDER OF THE FORECAST PERIOD. 

MODEL DISCUSSION: WITH THE EXCEPTION OF THE UKMET ENSEMBLE MEAN AS
A SOUTHERN OUTLIER AND EC-AIFS AS THE NORTHERN OUTLIER, MODEL GUIDANCE 
HAS COME INTO CLOSER AGREEMENT WITH THE LATEST MODEL RUN, SHOWING A 
CROSS-TRACK SPREAD OF 50 NM AT TAU 72. OVERALL, THE GUIDANCE AGREES ON 
THE WEST-NORTHWESTWARD TRACK WITHOUT MUCH FURTHER SPREAD THROUGH THE 
END OF THE FORECAST PERIOD. THE JTWC TRACK FORECAST IS PLACED NEAR A 
MODIFIED MULTI-MODEL CONSENSUS THAT ACCOUNTS FOR THE OUTLIERS WITH 
HIGH CONFIDENCE THROUGHOUT THE FORECAST PERIOD. MODEL INTENSITY 
GUIDANCE STRONGLY FAVORS THE RAPID INTENSIFICATION SCENARIO WITH ALL 
MODEL SOLUTIONS DEPICTING VARYING DEGREES OF RI WITH THE EXCEPTION OF 
DECAY SHIPS. THE JTWC INTENSITY FORECAST IS PLACED ALONG THE MEAN OF 
THE REMAINING MODEL GUIDANCE THROUGH TAU 48, THEN ON THE HIGHER END OF 
GUIDANCE IN THE LATER TAUS, WITH MEDIUM CONFIDENCE THROUGHOUT.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   TRACK 72-120 HR: HIGH
   INTENSITY 00-72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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WDPN32 PGTW 021500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 10W (TEN) WARNING 
NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.6N 111.0E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 182 NM EAST-NORTHEAST OF DA NANG, VIETNAM
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THE
PREVIOUSLY EXPOSED LOW-LEVEL CIRCULATION CENTER INCORPORATING WITH
FLARING CONVECTION IN THE SOUTHWEST QUADRANT AS THE SYSTEM APPEARS
TO BE REORGANIZING AROUND THE BROADER SURROUNDING CYCLONIC
CIRCULATION. LACKING ANY RECENT SCATTEROMETER DATA TO FURTHER
ILLUMINATE THE NATURE OF THE BROADER CIRCULATION, THE INITIAL
POSITION IS PLACED WITH LOW CONFIDENCE NEAR THE CENTER OF THE
LOW-LEVEL WIND FIELD EXPOSED IN THE ANIMATED EIR. WITH THE
REORGANIZATION UNDERWAY, THE INITIAL INTENSITY IS HELD AT 30 KTS
WITH MEDIUM CONFIDENCE, SUPPORTED BY THE AGENCY DVORAK FIXES AND
CIMSS OBJECTIVE INTENSITY ESTIMATES. THE ENVIRONMENT IS
CHARACTERIZED AS MARGINAL WITH WARM (29-30 C) SEA SURFACE
TEMPERATURES AND MODERATE EQUATORWARD OUTFLOW BEING OFFSET BY 15-20
KTS OF NORTHEASTERLY VERTICAL WIND SHEAR (VWS).

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) CENTERED SOUTHEAST OF KYUSHU

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T2.0 - 30 KTS
   CIMSS ADT: 35 KTS AT 021140Z
   CIMSS AIDT: 33 KTS AT 021140Z
   CIMSS D-MINT: 28 KTS AT 021118Z
   CIMSS D-PRINT: 25 KTS AT 021140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 20-25 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL DEPRESSION (TD) 10W HAS SLOWED ITS
TRACK SPEED OVER THE PAST 6 HOURS AS THE LOW-LEVEL CIRCULATION
REORGANIZES. THE TRACK IS EXPECTED TO RESUME A NORTHWESTWARD
TRAJECTORY TOWARD HAINAN ISLAND WITHIN THE NEXT 12 HOURS UNDER THE
STEERING INFLUENCE OF THE STR TO THE NORTHEAST. INITIAL LANDFALL
ALONG THE SOUTHEASTERN COAST OF HAINAN IS FORECAST SHORTLY BEFORE
TAU 18, THEN 10W IS EXPECTED TO REEMERGE OVER WATER IN THE GULF OF
TONKIN JUST BEFORE TAU 30, WITH A SECOND LANDFALL NEAR THE
SINO-VIETNAMESE BORDER REGION SHORTLY BEFORE TAU 48. THE DECAYING
REMNANTS WILL THEN TRACK INLAND OVER MAINLAND CHINA ON A
NORTH-NORTHEASTERLY TRACK FOR THE REMAINDER OF THE FORECAST PERIOD.
THERE IS EXPECTED TO BE A BRIEF WINDOW OF OPPORTUNITY FOR THE
SYSTEM TO INTENSIFY BEFORE TRACKING OVER HAINAN, THEN ANOTHER BRIEF
PERIOD OF INTENSIFICATION OVER THE GULF OF TONKIN, REACHING A PEAK
OF 40 KTS JUST BEFORE THE SECOND LANDFALL. 

MODEL DISCUSSION: MODEL TRACK GUIDANCE IS IN OVERALL AGREEMENT
ABOUT THE EVENTUAL NORTHWESTWARD TRAJECTORY OVER HAINAN ISLAND AND
A SECOND LANDFALL NEAR THE SINO-VIETNAMESE BORDER REGION, WITH A
CROSS-TRACK SPREAD OF 95 NM AT TAU 48. THE GFS DETERMINISTIC AND
THE GFS ENSEMBLE MEAN COMPRISE THE EASTERNMOST SOLUTIONS WHILE THE
EXPERIMENTAL GOOGLE DEEPMIND IS THE WESTERNMOST SOLUTION. THE JTWC
TRACK FORECAST IS PLACED SLIGHTLY TO THE WEST OF THE MULTI-MODEL
CONSENSUS, HEDGED CLOSER TO THE GOOGLE DEEPMIND WITH MEDIUM
CONFIDENCE THROUGHOUT THE FORECAST PERIOD. MODEL INTENSITY GUIDANCE
DEPICTS A CONTINUOUS INTENSIFICATION UNTIL THE SECOND LANDFALL,
THEN RAPID WEAKENING OVER LAND. THE JTWC INTENSITY FORECAST IS
PLACED BELOW THE MULTI-MODEL CONSENSUS FOR THE PERIOD OF TIME THAT
THE SYSTEM IS TRANSITING OVER HAINAN ISLAND, THEN FOLLOWS CLOSELY
TO THE ULTIMATE WEAKENING TREND DEPICTED BY THE CONSENSUS MODELS.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   INTENSITY 00-72 HR: MEDIUM//
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