Tropical Storm IN-FA Advisory Qua, 18-11

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 27W (IN-FA) WARNING NR 06//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 27W (IN-FA), LOCATED APPROXIMATELY 158 NM
WEST-SOUTHWEST OF POHNPEI, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MSI SHOWED A BRIEF EYE FEATURE THAT HAS
SINCE BECOME CLOUD-FILLED. TY 27W CONTINUES TO HAVE VISIBLE RADIAL
OUTFLOW. A 180600Z SSMIS 91 GHZ IMAGE REVEALS A SOLID MICROWAVE EYE
WITH THE DEEP CONVECTION CONCENTRATED ON THE SOUTHERN SIDE OF THE
LLCC. THE CURRENT POSITION IS BASED ON THE ABOVE WITH HIGH
CONFIDENCE AND THE INITIAL INTENSITY HAS BEEN RAISED TO 65 KNOTS TO
REFLECT THE BETTER STRUCTURE OF THE SYSTEM AS WELL AS A DT OF 4.0
FROM PGTW. UPPER LEVEL ANALYSIS INDICATES RADIAL OUTFLOW AND LOW VWS
OVER THE LLCC THAT SUPPORTS THE STEADY DEVELOPMENT AS THE SYSTEM
CONTINUES TO TRACK UNDER THE INFLUENCE OF THE STR EXTENSION TO THE
NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE PREVIOUS FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY 27W WILL CONTINUE TO TRACK TO THE NORTHWEST OVER THE NEXT
36 HOURS AND CONTINUE TO INTENSIFY. ENVIRONMENTAL CONDITIONS WILL
REMAIN OVERALL FAVORABLE THROUGHOUT THIS PERIOD. BEYOND TAU 36, THE
STR WILL DEEPEN AND FLATTEN TO THE NORTH OF TY 27W, FORCING THE
SYSTEM TO TAKE A MORE WEST-NORTHWEST TRACK. AT THIS TIME, TY IN-FA
WILL SLOW ITS RATE OF INTENSIFICATION AS THE OUTFLOW MECHANISMS WILL
BE SLIGHTLY HAMPERED DUE TO THE PRESENCE OF THE DEEP STR TO THE
NORTH. IT SHOULD BE NOTED THAT DUE TO THE CURRENT HIGHLY FAVORABLE
ENVIRONMENTAL CONDITIONS, TY IN-FA MAY INCREASE ITS INTENSITY AT A
MORE RAPID RATE; HOWEVER, MODELS DO NOT CURRENTLY REFLECT THAT
SCENARIO.
   C. BEYOND TAU 72, TY IN-FA WILL TRACK MORE POLEWARD AS A MID-
LATITUDE TROUGH WILL CREATE A WEAKNESS IN THE STR. THE SYSTEM WILL
ROUND THIS RIDGE AXIS AND BEGIN ITS TURN. INTENSITY IS EXPECTED TO
MAINTAIN ITS PEAK OF 11O KNOTS THROUGH THIS PERIOD UNTIL TY 27W WILL
REGAIN ITS POLEWARD OUTFLOW BEYOND THE FORECAST PERIOD. WHILE THE
DYNAMIC MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT, THERE IS AN
INCREASING SPREAD WITH REGARD TO NORTH-SOUTH EXTENT BEGINNING PAST
TAU 48. AS SUCH, THERE IS MODERATE CONFIDENCE IN THE JTWC FORECAST
TRACK, WHICH IS PLACED NEAR, BUT SLIGHTLY FASTER THAN MULTI-MODEL
CONSENSUS.//
NNNN
NNNN