MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (FITOW) WARNING NR 04// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 22W (FITOW), LOCATED APPROXIMATELY 627 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) CONFIRMS THE CONVECTION IS CONSOLIDATING AND DEEPENING AROUND THE LOW-LEVEL CIRCULATION CENTER (LLCC), ESPECIALLY ALONG THE WESTERN SEMICIRCLE. VIGOROUS CONVECTION NOW EXISTS IN ALL QUADRANTS, WITH THE EXCEPTION OF A DWINDLING BREAK OVER THE NORTHEASTERN QUADRANT. HOWEVER, THE LLCC IS ALMOST FULLY EXPOSED AS THE INNER BANDING HAS YET TO CONSOLIDATE OVER THE CORE. THE LATEST AMSU RADIAL CROSS SECTION DOES CONFIRM THE PRESENCE OF A POSITIVE TWO-CELSIUS WARM ANOMALY. RECENT ANIMATED WATER VAPOR IMAGERY INDICATES THAT THE STORM IS STILL STRUGGLING AGAINST A SUBSIDENT ENVIRONMENT ON THE POLEWARD FLANK. EQUATORWARD OUTFLOW REMAINS WELL ESTABLISHED AND THE EAST-NORTHEASTWARD VENTING HAS IMPROVED DURING THE PAST SIX HOURS. THE CURRENT INTENSITY IS BASED ON AN AVERAGE OF DVORAK ASSESSMENTS BETWEEN PGTW AND RJTD. EXPECTED NORTHWARD MOVEMENT HAS YET TO MANIFEST, PRESUMABLY DUE TO STRONGER-THAN-EXPECTED STRENGTH OF THE NEAR-EQUATORIAL RIDGE (NER). BUT THE LAST TWO FIXES HAVE SHOWN THE NORTHWESTWARD TRAJECTORY SLOWING. THE SOUTHWESTERN EXTENSION OF THE NER IS THE STEERING FORCE ON THE STORM. THE SUBTROPICAL RIDGE, WHICH IS ANCHORED IN AN ANTICYCLONE JUST TO THE SOUTHWEST OF TAIWAN, IS PRODUCING SOME SHEAR TO THE NORTHWEST OF THE STORM BUT IS NOT ACTING AS A STEERING INFLUENCE YET. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 22W WILL GRADUALLY TURN MORE POLEWARD DURING THE NEXT 72 HOURS DUE TO A PUSH FROM THE NER. BIFURCATED TRACK GUIDANCE IS STRADDLING OKINAWA. NAVGEM, GFDN, AND THE JAPANESE ENSEMBLE SHOW A TRACK SOUTH OF OKINAWA. CONSENSUS INDICATES A TRACK BETWEEN OKINAWA AND ANAMI SHIMA, WHILE ECMWF AND COAMPS-TC SHOW A TRACK TOWARDS THE KYUSHU AND SHIKOKU AREA. THERE EXISTS A WIDE WEAKNESS IN THE STR BETWEEN THE 130TH AND 135TH MERIDIANS THAT WILL COUPLE WITH A GENTLE PUSH FROM THE NER AND THE BETA FORCE TO NUDGE THE STORM POLEWARD OVER THE NEAR TERM. THE POLEWARD TRACK WILL TAKE THE STORM THROUGH AN AREA OF LOW VERTICAL WIND SHEAR (VWS) AND IMPROVING POLEWARD OUTFLOW, THUS THE INTENSITY FORECAST LOOKS FOR DEVELOPMENT ON THE HIGH-SIDE OF THE CLIMATOLOGICAL RATE. OCEAN HEAT CONTENT PROFILES DO SHOW SOME LIMITATIONS, AND ALTHOUGH THE UPPER-LEVEL SUBSIDENCE POLEWARD OF THE STORM IS EASING, IT IS STILL SIGNIFICANT ENOUGH THAT A RAPID INTENSIFICATION SCENARIO IS LOOKING INCREASINGLY UNLIKELY. C. AFTER TAU 72 AND NEAR THE 23RD LATITUDE, THE STEERING FORCE WILL SHIFT FROM THE NER TO THE STR. MODEL GUIDANCE, INCLUDING ENSEMBLES AND MULTI-MODEL CONSENSUS ARE IN POOR AGREEMENT AS TO EXACTLY WHEN AND WHERE THE STEERING INFLUENCE SWITCHES, AS WELL AS TO HOW FIRM THE WESTWARD PUSH WILL BE ONCE THE HAND-OFF DOES OCCUR. THE INTENSITY FORECAST STAYS ON THE HIGH SIDE OF GUIDANCE BASED ON THE LOW VWS ENVIRONMENT ALONG THE TRACK, BUT AS THE STORM MOVES NORTH OF THE 30TH LATITUDE, RISING VWS AND FALLING SEA SURFACE TEMPERATURES WILL COMBINE TO INITIATE A WEAKENING TREND. CONSENSUS HAS STABILIZED OVER THE PAST TWO MODEL RUNS BUT TRACK GUIDANCE REMAINS BIFURCATED. THE JTWC TRACK FORECAST STAYS EAST OF CONSENSUS DUE TO THE UNDUE WESTWARD INFLUENCE PROVIDED BY EGRR, NAVGEM, GFDN, AND THE JAPANESE ENSEMBLE, AND FAVORS THE ECMWF, GFS, AND COAMPS SOLUTIONS. THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST THROUGH TAU 72 AND LOW CONFIDENCE THEREAFTER. TRACK CONFIDENCE WILL NOT LIKELY IMPROVE GREATLY UNTIL THE HAND-OFF BETWEEN THE STEERING MECHANISM PLAYS OUT.// NNNN NNNN