WESTERN PACIFIC: Super Typhoon 04W(SINLAKU) CAT 5 US peaked at 160kt,forecast to hit directly TINIAN and SAIPAN islands in 24h at Super Typhoon Intensity//130900 UTC

WDPN31 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 04W (SINLAKU) WARNING NR 
018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.7N 148.0E
   INITIAL INTENSITY: 150 KTS
   GEOGRAPHIC REFERENCE: 203 NM EAST-SOUTHEAST OF NAVSTA GUAM
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 43 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A HIGHLY
ORGANIZED SUPER TYPHOON (STY) 04W (SINLAKU) EXHIBITING A
NEAR-PERFECTLY AXISYMMETRIC STRUCTURE. A WELL-DEFINED, WARM (18 C)
15 NM DIAMETER EYE IS ENCASED WITHIN A COHESIVE CENTRAL DENSE
OVERCAST (CDO). THE SIZE OF THE CDO HAS SLIGHTLY DECREASED OVER THE 
LAST 6 HOURS, WHICH COMBINED WITH A 3-5 DEGREE COOLING OF THE EYE,
INDICATES A VERY SLIGHT OVERALL WEAKENING, RESULTING FROM AN
ONGOING EYEWALL REPLACEMENT CYCLE (ERC) AND DRY AIR ENTRAINMENT. ON
THE OTHER HAND, THE AMBIENT ENVIRONMENT REMAINS LARGELY FAVORABLE AND 
IS CHARACTERIZED BY WARM (28-29 C) SEA SURFACE TEMPERATURES (SST), LOW
(5-10 KTS) VERTICAL WIND SHEAR (VWS) AND A ROBUST RADIAL OUTFLOW.
BASED ON THE CLEARLY DISCERNIBLE EYE IN THE VISIBLE SATELLITE
IMAGERY, THE INITIAL POSITION IS FIXED WITH HIGH CONFIDENCE. THE
INITIAL INTENSITY OF 150 KTS IS SIMILARLY ASSESSED WITH HIGH
CONFIDENCE, A VALUE SUPPORTED BY A CONSENSUS OF ALL AGENCY DVORAK
ESTIMATES AND OBJECTIVE INTENSITY AIDS, WHICH ALL HAVE BEEN VERY
SLOWLY DECREASING OVER THE LAST 6 HOURS.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT, WITH AN
EXTENSION OF A NEAR-EQUATORIAL RIDGE (NER) CENTERED TO THE EAST AND
A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED TO THE NORTHWEST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T7.5 - 155 KTS
   RJTD: T7.5 - 155 KTS
   RCTP: T7.5 - 155 KTS
   KNES: T7.5 - 155 KTS
   CIMSS SATCON: 139 KTS AT 130600Z
   CIMSS ADT: 152 KTS AT 130530Z
   CIMSS AIDT: 151 KTS AT 130530Z
   CIMSS D-MINT: 149 KTS AT 130346Z
   CIMSS D-PRINT: 151 KTS AT 130700Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG RADIAL
   OTHER FACTORS: SLIGHT DRY AIR ENTRAINMENT

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: THE NEAR-TERM INTENSITY FORECAST SUGGESTS THAT
STY 04W HAS ALREADY ATTAINED ITS MAXIMUM INTENSITY AND IS BEGINNING
TO VERY SLOWLY WEAKEN AS IT APPROACHES THE NORTHERN MARIANA
ISLANDS. INCREASING INFLUENCE OF MID-LEVEL DRY AIR ENTRAINMENT,
ONGOING ERC AND REDUCED NORTHEASTWARD OUTFLOW CHANNEL WILL ALL
CONTRIBUTE TOWARD THIS TREND. SOME TEMPORARY INCREASE IN INTENSITY IS 
POSSIBLE, HOWEVER, ONLY IF THE SYSTEM SUCCESSFULLY COMPLETES THE ERC. 
STY 04W IS EXPECTED TO MAINTAIN AN INTENSITY OF AROUND 135 KTS AT ITS 
CLOSEST POINT OF APPROACH TO THE NORTHERN MARIANAS. AFTERWARDS, A 
CONTINUOUS AND GRADUAL WEAKENING IS FORECAST THROUGHOUT THE REMAINDER 
OF THE CURRENT PERIOD. IN REGARD TO THE TRACK PREDICTION, THE SYSTEM 
IS STILL POSITIONED WITHIN A COMPETING STEERING ENVIRONMENT, WITH AN
EXTENSION OF A NER CENTERED TO THE EAST AND A DEEP-LAYER STR CENTERED 
TO THE NORTHWEST, WITH THE FORMER ASSUMING THE PRIMARY STEERING ROLE. 
THE CPA TO THE MARIANA ISLANDS IS EXPECTED TO OCCUR WITHIN THE NEXT 24 
HOURS, WITH THE TRACK POSITIONED BETWEEN THE ISLANDS OF TINIAN AND 
SAIPAN. AFTER THAT, STY 04W WILL BEGIN ITS RECURVATURE ALONG THE AXIS 
OF THE RIDGE BETWEEN TAUS 48 AND 72. BEYOND TAU 72, THE SYSTEM WILL 
CONTINUE TO BE STEERED NORTHEASTWARD BY THE NORTHWARD-BUILDING NEAR-
EQUATORIAL RIDGE, WHICH WILL COINCIDE WITH A MORE PRONOUNCED WEAKENING 
TREND DUE TO INCREASINGLY HOSTILE SHEAR, COOLING SEA SURFACE 
TEMPERATURES, AND DRY AIR ENTRAINMENT.

MODEL DISCUSSION: NUMERICAL TRACK MODEL GUIDANCE IN THE SHORT TERM
IS ASSESSED WITH MEDIUM CONFIDENCE, AS THE CROSS-TRACK SPREAD
DURING THE CPA TO THE MARIANAS IS CURRENTLY 46 NM, INCLUDING THE
PRIMARY OUTLIER NAVGEM, WHICH POSITIONS THE TRACK BETWEEN ROTA AND
TINIAN. EXCLUDING NAVGEM WOULD RESULT IN A 26 NM SPREAD. OFFICIAL JTWC
TRACK FORECAST IS THEREFORE LAID CLOSE TO THE MULTI-MODEL CONSENSUS
WITH MEDIUM CONFIDENCE, OFFSET SLIGHTLY TO THE NORTHEAST. LONG-TERM
TRACK FORECAST IS ASSESSED WITH LOW CONFIDENCE. WHILE ALL MODELS
CONTINUE TO FAVOR THE RECURVATURE SCENARIO, THE CROSS-TRACK AND
ALONG-TRACK SPREAD ARE VERY HIGH, DUE TO DIFFERENT DEPICTION OF THE
TIMELINE OF THE SYSTEM ROUNDING THE AXIS OF THE RIDGE. IN REGARD TO
INTENSITY, JTWC OFFICIAL FORECAST IS LAID WITH MEDIUM CONFIDENCE
AND CLOSE TO THE HAFS INTENSITY PREDICTION. ALL AVAILABLE CONSENSUS
MEMBERS INDICATE GRADUAL WEAKENING, BUT SOME MODELS (COAMPS-TC AND
GFS PRIMARILY) PREDICT A RAPID WEAKENING OVER THE NEXT 24-36 HOURS,
WHICH DOES NOT HAVE STRONG SUPPORT IN THE ANALYSIS OF THE
ENVIRONMENT. 

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   TRACK 72-120 HR: LOW
   INTENSITY 00-72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
NNNN

0426040512  30N1609E  15
0426040518  38N1605E  15
0426040600  43N1603E  15
0426040606  40N1600E  15
0426040612  40N1585E  15
0426040618  40N1570E  15
0426040700  41N1562E  15
0426040706  43N1552E  15
0426040712  50N1541E  15
0426040718  57N1534E  15
0426040800  64N1530E  15
0426040806  75N1533E  20
0426040812  80N1530E  20
0426040818  81N1527E  20
0426040900  81N1524E  25
0426040906  81N1522E  30
0426040912  82N1518E  30
0426040918  83N1515E  35
0426041000  82N1512E  40
0426041006  82N1510E  45
0426041012  80N1509E  55
0426041018  81N1513E  65
0426041100  85N1516E  75
0426041106  88N1516E  80
0426041112  89N1514E  85
0426041118  92N1514E  95
0426041200  98N1512E 115
0426041206 103N1506E 130
0426041212 111N1502E 150
0426041218 116N1495E 160
0426041300 122N1488E 155
0426041306 127N1480E 150

NNNN

TPPN10 PGTW 130848 

A. SUPER TYPHOON 04W (SINLAKU)

B. 13/0830Z

C. 12.80N

D. 147.80E

E. ONE/GK2A

F. T7.0/7.0/W0.5/24HRS  STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 01A/PBO 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 6.5. PT YIELDS 7.0. DBO DT.

I. ADDITIONAL POSITIONS:
   13/0304Z  12.42N  148.32E  AMS2


   THOMPSON