WESTERN PACIFIC:Super Typhoon 09W(BAVI) Extreme Rapid Intensification to CAT 5 US, bearing down on the MARIANAS/TS 10W(MAYSAK)/SOUTH PACIFIC:Invest 97P//03@2200 UTC

JTWC FACEBOOK
Joint Typhoon Warning Center

WDPN31 PGTW 032100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 09W (BAVI) WARNING NR 
012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.7N 152.2E
   INITIAL INTENSITY: 140 KTS
   GEOGRAPHIC REFERENCE: 435 NM EAST OF WFO GUAM 
   MOVEMENT PAST 6 HOURS: WESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 42 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A NEARLY
SYMMETRICAL DEEP-CONVECTIVE CANOPY SURROUNDING THE WELL-DEFINED EYE
FEATURE OF SUPER TYPHOON (STY) 09W (BAVI). ENVIRONMENTAL ANALYSIS
REVEALS A HIGHLY FAVORABLE ENVIRONMENT WITH LOW (5-10 KTS) VERTICAL
WIND SHEAR (VWS), ROBUST UPPER-LEVEL, RADIAL OUTFLOW, WARM (29-30
C) SEA SURFACE TEMPERATURES (SST) AND PLENTY OF ATMOSPHERIC
MOISTURE AVAILABLE THROUGHOUT THE VERTICAL COLUMN. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE ANALYSIS OF A
20 NM DIAMETER EYE FEATURE. THE INITIAL INTENSITY OF 140 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON THE CONSISTENT DVORAK
INTENSITY ASSESSMENT AND OBJECTIVE AIDS LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: ELONGATED EASTERN EXTENSION OF A
DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED EAST OF TAIWAN

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T7.0 - 140 KTS 
   RJTD: T6.0 - 115 KTS
   RCTP: T7.0 - 140 KTS 
   KNES: T7.0 - 140 KTS 
   CIMSS SATCON: 125 KTS AT 031800Z
   CIMSS ADT: 146 KTS AT 031800Z
   CIMSS AIDT: 139 KTS AT 031800Z
   CIMSS D-PRINT: 135 KTS AT 031800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: STY 09W IS FORECAST TO CONTINUE TRACKING
WESTWARD OVER THE NEXT 12-24 HOURS, WHILE SLIGHTLY SLOWING DOWN ITS
TRANSLATION SPEED DUE TO A MINOR SHIFT IN THE STEERING MECHANISM.
WHILE THE STR CENTERED TO THE NORTHEAST CURRENTLY REMAINS THE
PRIMARY MECHANISM, A PASSING LONGWAVE TROUGH TO THE NORTH IS
RESULTING IN A SPLIT OF THE BROAD RIDGING, WITH AXIS JUST TO THE
NORTH OF CURRENT POSITION OF STY BAVI. AS A RESULT, AFTER TAU 24,
THE SYSTEM IS EXPECTED TO TAKE ON A WEST-NORTHWESTWARD TRACK
THROUGHOUT THE CURRENT FORECAST PERIOD. WHILE STY 09W REMAINS IN
THIS WEAKER STEERING ENVIRONMENT, THE EXTREME INTENSIFICATION IS
EXPECTED TO SLIGHTLY COOL OFF, BUT THE SYSTEM IS FORECAST TO REACH
150 KTS WITHIN THE NEXT 24-36 HOURS. AFTERWARDS, AS IT ONCE AGAIN
GAINS SPEED, IT WILL BEGIN TO INTERACT WITH THE MARIANA ISLANDS,
WITH THE PASSAGE OF THE LOW-LEVEL CIRCULATION CENTER BETWEEN TAUS
48 AND 60. DURING THIS PHASE, STY 09W WILL VERY LIKELY MAINTAIN ITS
SUPER TYPHOON STRENGTH. AROUND THE SAME TIME, HAFS-A DEPICTS A
PROBABILITY OF AN EYEWALL REPLACEMENT CYCLE (ERC), WHICH INTRODUCES
ADDITIONAL UNCERTAINTY IN THE TIMING AND MAGNITUDE OF THE PEAK
INTENSITY. AS THE SYSTEM TRANSLATES WEST-NORTHWESTWARD, IT WILL BE
PUSHING AGAINST A DRY AIR MASS TO THE NORTHWEST. VWS IS EXPECTED TO
BEGIN INCREASING SHORTLY AFTER TAU 72, REACHING 25 KTS AT TAU 96.
AS A RESULT OF THOSE CHANGES IN ENVIRONMENTAL CONDITIONS, SOME
WEAKENING IS EXPECTED NEAR THE END OF THE CURRENT FORECAST PERIOD.

MODEL DISCUSSION: NUMERICAL MODEL PREDICTION IN REGARD TO THE TRACK
REMAINS IN VERY GOOD AGREEMENT, AS WITNESSED BY A CROSS-TRACK
SPREAD OF 48 NM AT THE TIME OF CPA TO TINIAN AND ROTA. THE OFFICIAL
JTWC TRACK IS PLACED WITH HIGH CONFIDENCE IN CLOSE PROXIMITY TO THE
MULTI-MODEL CONSENSUS, LEANING SLIGHTLY ON THE SOUTHERN SIDE AND
TOWARDS THE EXPERIMENTAL AI GUIDANCE. INTENSITY IS ASSESSED WITH
MEDIUM CONFIDENCE THROUGHOUT THE CURRENT FORECAST PERIOD. CURRENTLY
AVAILABLE GUIDANCE INDICATES CONTINUOUS MINOR INTENSIFICATION OVER
THE NEXT 24 HOURS, HOWEVER, THE INTENSITY PREDICTION SPREAD
INCREASES TO 55 KTS AROUND TAU 72. HAFS IS CURRENTLY THE MOST
AGGRESSIVE, PREDICTING A PEAK NORTH OF 160 KTS, WHILE DETERMINISTIC
GFS OSCILLATES AROUND 105-120 KTS THROUGHOUT THE REMAINDER OF THE
FORECAST. OFFICIAL JTWC PREDICTION IS LAID ON THE HIGHER SIDE OF
THE CONSENSUS, AS A RESULT OF FAVORABLE ENVIRONMENTAL CONDITIONS
PREDICTION.

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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TPPN10 PGTW 032057 

A. SUPER TYPHOON 09W (BAVI)

B. 03/2030Z

C. 12.58N

D. 151.90E

E. ONE/GK2A

F. T7.0/7.0/D3.0/24HRS  STT: S0.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 07A/PBO IRREG EYE/ANMTN. WMG EYE SURROUNDED BY W 
YIELDS AN E# OF 6.0. ADDED 1.0 EYE ADJUSTMENT FOR CMG, TO YIELD A 
DT OF 7.0. MET YIELDS 5.5. PT YIELDS 6.0. DBO DT.

I. ADDITIONAL POSITIONS: NONE


   RUCKER
 

WDPN32 PGTW 032100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (MAYSAK) WARNING NR 
009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.8N 108.7E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 173 NM EAST-SOUTHEAST OF HANOI, VIETNAM
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 15 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) OF TROPICAL
STORM (TS) 10W (MAYSAK) AS IT REEMERGES OVER THE WARM WATERS OF THE
GULF OF TONKIN, JUST NORTHWEST OF HAINAN ISLAND. THE LOCAL
THERMODYNAMIC REGIME AND CYCLONE ENVIRONMENT ARE ASSESSED AS
MARGINALLY FAVORABLE FOR SOME SLIGHT INTENSIFICATION, DRIVEN BY LOW
TO MODERATE (15-20 KTS) DEEP-LAYER VERTICAL WIND SHEAR (VWS),
RESTRAINED LAND INTERACTION WHILE TRANSLATING OVER HAINAN ISLAND,
ALTHOUGH MITIGATED TO AN EXTENT BY SUSTAINED MODERATE EQUATORWARD
UPPER-LEVEL OUTFLOW VENTILATION AND VERY WARM (29-30 C) SEA SURFACE
TEMPERATURES. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE
BASED ON AN ANIMATED RADAR LOOP IN CONJUNCTION WITH LOCAL SURFACE
WIND DIRECTION OBSERVATIONS. THE INITIAL INTENSITY ANALYSIS OF 40
KTS IS ALSO ESTABLISHED WITH MEDIUM CONFIDENCE, AND IS DERIVED BY
INTERPOLATING RJTD AGENCY DVORAK ASSESSMENT AND CIMSS OBJECTIVE
INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: A 031636Z OCEANSAT-3 OSCAT PASS

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR)
CENTERED TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE
   RJTD: T2.5 - 35 KTS
   CIMSS D-MINT: 38 KTS AT 031830Z
   CIMSS D-PRINT: 43 KTS AT 031900Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD

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: TS 10W IS FORECAST TO CONTINUE TRACKING
NORTHWESTWARD OVER THE NEXT 12-24 HOURS UNTIL IT MAKES LANDFALL
NEAR THE CHINA-VIETNAM BORDER. DURING THIS SHORT TRANSIT, TS MAYSAK
IS EXPECTED TO REMAIN AT ITS WIND SPEED MAXIMUM, OR SLIGHTLY
INTENSIFY; HOWEVER, SHORTLY AFTER LANDFALL, TERMINAL WEAKENING WILL
COMMENCE. FRICTIONAL EFFECTS OF THE LAND INTERACTION WILL RESULT IN
FULL DISSIPATION BY OR BEFORE TAU 48.

MODEL DISCUSSION: DETERMINISTIC NUMERICAL MODEL TRACK PREDICTIONS
MAINTAIN HIGHLY COHERENT SPATIAL CONVERGENCE REGARDING THE CORE
TRAJECTORY OF TS 10W, DISPLAYING VERY TIGHT CROSS-TRACK AND
ALONG-TRACK ENVELOPE SPREADS. JTWC OFFICIAL TRACK FORECAST IS
THEREFORE PLACED WITH HIGH CONFIDENCE. MODEL INTENSITY GUIDANCE IS
LIKEWISE IN EXCELLENT AGREEMENT, WITH ENVELOPE SPREADS DEVIATING BY A
MAX OF ONLY 5 KTS CONCERNING THE INTENSIFICATION TRANSIT PHASE OVER
THE GULF OF TONKIN BEFORE POST-LANDFALL DECAY AND DISSIPATION TAKES
OVER. CONSEQUENTLY, THE JTWC OFFICIAL INTENSITY PREDICTION IS
LAID NEAR THE CONVERGENCE OF DYNAMICAL MODEL OUTPUTS WITH HIGH
CONFIDENCE.

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