MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 30W (KONG-REY) WARNING NR 18// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON (STY) 30W (KONG-REY), LOCATED APPROXIMATELY 550 NM SOUTH-SOUTHEAST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS STY 30W HAS MAINTAINED A WELL DEFINED EYE WITH DEEP CONVECTION WRAPPING AROUND IT. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE AND IS BASED ON A 020600Z HIMAWARI VISIBLE SATELLITE IMAGE WHICH SHOWS THE 18 NM WIDE EYE. A 020432Z 89GHZ AMSR2 MICROWAVE IMAGE SHOWS STY 30W HAS CONCENTRIC EYE WALLS AND IS UNDERGOING AN EYEWALL REPLACEMENT CYCLE (ERC). THE INITIAL INTENSITY OF 140 KNOTS IS BASED ON DVORAK CURRENT INTENSITY (CI) ESTIMATES OF T7.0 (140 KNOTS) FROM RJTD AND KNES. THIS IS HEDGED SLIGHTLY BELOW A PGTW DVORAK CI OF T7.5 (155 KNOTS) DUE TO THE ERC. ENVIRONMENTAL ANALYSIS SHOWS THAT STY 30W IS EXPERIENCING FAVORABLE VERTICAL WIND SHEAR (10 TO 15 KNOTS) ALONG WITH EXCELLENT EQUATORWARD OUTFLOW AND GOOD POLEWARD OUTFLOW. SEA SURFACE TEMPERATURES REMAIN FAVORABLE, BETWEEN 29 AND 30 DEGREES CELSIUS. STY 30W IS TRACKING NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) LOCATED TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. THROUGH TAU 72, STY 30W WILL CONTINUE TO TRACK NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE STR. THE AFOREMENTIONED ERC MAY CAUSE MINOR FLUCTUATIONS IN INTENSITY IN THE SHORT TERM. THE COMBINATION OF FAVORABLE VERTICAL WIND SHEAR AND SLIGHTLY COOLER TEMPERATURES WILL ALLOW STY 30W TO SLIGHTLY WEAKEN TO 135 KNOTS BY TAU 12. STY 30W WILL CONTINUE TO ENCOUNTER COOLER SEA SURFACE TEMPERATURES BEYOND TAU 12 WHICH ARE A RESULT OF UPWELLING PRODUCED BY TY TRAMI WHICH PASSED THROUGH THE AREA SEVERAL DAYS AGO. DESPITE COOLER SEA SURFACE TEMPERATURES, VERTICAL WIND SHEAR WILL REMAIN FAVORABLE AND ALLOW KONG-REY TO DECREASE TO AN INTENSITY OF 80 KNOTS BY TAU 72. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 48 WITH A SPREAD OF 110 NM. HOWEVER, MODEL TRACKERS DIVERGE AFTER TAU 48 AND HAVE A SPREAD OF 300 NM BY TAU 72. NAVGEM IS A SIGNIFICANT OUTLIER TO THE WEST COMPARED WITH THE REST OF THE MODEL GUIDANCE. DUE TO THE SPREAD IN MODEL GUIDANCE BY TAU 72 THERE IS OVERALL LOW CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK. C. AFTER TAU 72, STY 30W WILL BEGIN TO ROUND THE WESTERN EDGE OF THE AFOREMENTIONED STR. BY THIS TIME STY 30W WILL BE OVER EVEN COOLER SEA SURFACE TEMPERATURES (27 TO 28 DEGREES CELSIUS). HOWEVER, STY 30W WILL ALSO BEGIN TO EXPERIENCE ENHANCED POLEWARD OUTFLOW AS IT TRACKS NORTHWARD WHICH WILL OFFSET THE COOLER SEA SURFACE TEMPERATURES AND SLOW THE WEAKENING RATE. KONG-REY WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) WITH AN EXPANDING WIND FIELD BY TAU 96 AS IT INTERACTS WITH THE WESTERLIES. DYNAMIC MODEL GUIDANCE IS IN AGREEMENT THAT KONG-REY WILL TRACK TO THE NORTHEAST AFTER TAU 96 BUT THERE ARE SIGNIFICANT DIFFERENCES IN TRACK SPEED. THEREFORE, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK.// NNNN NNNN