WDPN31 PGTW 311500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 22W (GONI) 
WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   SUPER TYPHOON (STY) 22W (GONI), LOCATED APPROXIMATELY 321 NM
EAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD AT 12 
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY (EIR) SHOWS A COMPACT, DENSE, AND SYMMETRICAL 
SYSTEM WITH FEEDER BANDS TIGHTLY WRAPPED AND TUCKED INTO THE 
CENTRAL CONVECTION THAT HAS MAINTAINED A 9-NM SHARPLY-OUTLINED 
EYE. OUTSIDE THE PINHOLE EYE IS A CLOUD-FREE MOAT THAT SEPARATES 
IT FROM AN EVOLVING 35-NM SECONDARY OUTER EYEWALL, PRELUDE TO AN 
EYEWALL REPLACEMENT CYCLE (ERC). THE INITIAL POSITION IS PLACED 
WITH HIGH CONFIDENCE BASED ON THE EYE IN THE EIR LOOP THAT 
PERFECTLY LINED UP WITH A WELL-DEFINED MICROWAVE EYE FEATURE 
IN THE 311000Z SSMIS 37GHZ IMAGE. A CORRESPONDING 31100Z IRBD 
IMAGE STACKS VERTICALLY WITH THE MICROWAVE EYE, INDICATING ZERO 
TILT AND LIGHT VERTICAL WIND SHEAR (VWS). THE INITIAL INTENSITY OF 
155 KTS IS BASED ON HIGH END OF 311140Z ADT ESTIMATE OF 152KTS AND 
CONGRUENT PGTW/RJTD DVORAK CURRENT INTENSITY ESTIMATES OF 
T7.5/155KTS. UPPER LEVEL ANALYSIS INDICATES A VERY FAVORABLE 
ENVIRONMENT WITH LOW (05-10KT) VWS AND ROBUST RADIAL OUTFLOW. 
ADDITIONALLY, SEA SURFACE TEMPERATURES IN THE PHILIPPINE SEA AT 
30-31C ARE VERY CONDUCIVE. THE CYCLONE IS TRACKING ALONG THE 
SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO 
THE NORTHWEST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. THE STR WILL SLIGHTLY WEAKEN AND DRIVE STY 22W ON A FLATTER 
WESTWARD TRAJECTORY, MAKE LANDFALL OVER CENTRAL LUZON JUST AROUND 
TAU 12, TRACK JUST SOUTH OF MANILA, AND EXIT INTO THE SOUTH CHINA 
SEA (SCS) BY TAU 30. THE ENVIRONMENT WILL REMAIN FAVORABLE IN THE 
NEAR TERM. HOWEVER, THE ANTICIPATED ERC WILL CAUSE A SLIGHT AND 
GRADUAL WEAKENING TO 135KTS BY TAU 12, ALBEIT STILL AT SUPER 
TYPHOON INTENSITY. AFTERWARD, INTERACTION WITH THE RUGGED TERRAIN 
WILL CAUSE SIGNIFICANT DECAY AND WEAKEN THE SYSTEM TO 75KTS BY TAU 
36 AFTER IT EXITS INTO THE SCS. AFTER TAU 36, STY 22W WILL STEADILY 
WEAKEN TO 55KTS BY TAU 72 DUE TO INCREASED VWS (20-25KTS). 
NUMERICAL MODELS REMAIN IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE 
IN THIS PORTION OF THE JTWC FORECAST TRACK THAT IS LAID NEAR THE 
MULTI-MODEL CONSENSUS.
   C. BEYOND TAU 72, STY GONI WILL CONTINUE WESTWARD UNDER THE 
SAME STR, MAKING A SECONDARY AND FINAL LANDFALL OVER CENTRAL 
VIETNAM SOUTH OF DA NANG AROUND TAU 108. THE SYSTEM WILL CONTINUE 
TO GRADUALLY WEAKEN DUE TO THE MODERATE (20-25KT) VWS, AND AFTER 
LANDFALL, RAPID WEAKENING WITH THE ADDITION OF FRICTIONAL EFFECTS 
FROM THE TERRAIN. BY TAU 120, THE SYSTEM WILL BE REDUCED TO 35KTS. 
NAVGEM DIVERGES TO THE RIGHT OF THE MAIN CLUSTER OF NUMERICAL 
MODELS AND JGSM TO THE LEFT, THEREBY OFFSETTING EACH OTHER. IN 
VIEW OF THIS, THERE IS HIGH CONFIDENCE IN THE EXTENDED PORTION OF 
THE JTWC TRACK FORECAST THAT IS LAID IN THE MIDDLE OF THE MAIN
CLUSTER.//
NNNN