Tropical Storm ATSANI Advisory 16 Αυγ.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 17W (ATSANI) WARNING NR
07//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 17W (ATSANI), LOCATED APPROXIMATELY 216 NM
NORTH-NORTHWEST OF ENEWETAK, HAS TRACKED NORTHWESTWARD AT 04 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH TIGHTLY-CURVED BANDING (TCB) WRAPPING INTO A DEFINED CENTER. A
151729Z SSMIS 91GHZ IMAGE ALSO REVEALS RAPIDLY IMPROVING DEEP
CONVECTIVE BANDING OVER ALL QUADRANTS WITH A SLIGHTLY BROAD CENTER.
DUE TO THE BROAD CENTER, THERE IS FAIR CONFIDENCE IN THE CURRENT
POSITION. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT
WITH NEAR-RADIAL OUTFLOW. THE CURRENT INTENSITY IS ASSESSED AT 55
KNOTS BASED ON DVORAK INTENSITY ESTIMATES OF T3.5 (55 KNOTS) FROM
PGTW AND KNES, WHICH ARE CONSISTENT WITH THE OVERALL CONVECTIVE
STRUCTURE. TS 17W REMAINS EMBEDDED WITHIN A COMPETING STEERING
ENVIRONMENT BETWEEN THE STR TO THE NORTH AND THE NER TO THE SOUTH.
CONSEQUENTLY, TRACK MOTION REMAINS SLOW.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TS 17W IS EXPECTED TO CONTINUE TRACKING SLOWLY WESTWARD
THROUGH TAU 24 DUE TO THE COMPETING STEERING ENVIRONMENT. HOWEVER,
AFTER TAU 24, THE NER WILL SHIFT TO THE NORTHEAST ALLOWING THE STR
TO BECOME THE DOMINANT STEERING INFLUENCE. THEREFORE, TS ATSANI
SHOULD ACCELERATE NORTHWESTWARD. DYNAMIC MODEL GUIDANCE IS IN FAIR
AGREEMENT AND SUPPORTS THE JTWC FORECAST TRACK, WHICH IS POSITIONED
JUST SOUTH OF THE MULTI-MODEL CONSENSUS FAVORING THE MORE CONSISTENT
ECMWF AND GFS SOLUTIONS. TS 17W IS FORECAST TO RAPIDLY INTENSIFY
AFTER TAU 24 TO AN INTENSITY OF 125 KNOTS BY TAU 72.
   C. IN THE EXTENDED PERIOD, TS ATSANI WILL MAINTAIN A
NORTHWESTWARD TRAJECTORY AS THE SYSTEM TRACKS ALONG THE WESTERN
PERIPHERY OF THE STR. AVAILABLE MODEL GUIDANCE REMAINS IN FAIR
AGREEMENT, BUT DUE TO ITS SLOW MOVEMENT IN THE SHORT-TERM,
THERE IS LOW OVERALL CONFIDENCE IN THE FORECAST TRACK.//
NNNN
NNNN