MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (NARI) WARNING NR 005// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 07W (NARI), LOCATED APPROXIMATELY 311 NM WEST-NORTHWEST OF CHICHI JIMA, HAS TRACKED NORTHWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS BANDING WRAPPING INTO THE EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS BASED WITH HIGH CONFIDENCE FROM MSI, MULTIPLE AGENCY DVORAK FIXES AND A 252126Z SSMIS 91 GHZ PASS. THE INTENSITY IS SET AT 35 KNOTS BASED ON MULTIPLE AGENCY DVORAK ESTIMATES OF T2.0-T2.5 AND A 260110Z ADT ESTIMATE OF 32 KNOTS. TS 07W HAS CONTINUED POLEWARD OVER THE PAST SIX HOURS ALONG THE PERIPHERY OF A SUBTROPICAL RIDGE TO THE EAST. PERSISTENT, MODERATE SOUTHWESTERLY VERTICAL WIND SHEAR (VWS) ASSOCIATED WITH THE FLOW AROUND AN UPPER-LEVEL LOW TO THE WEST HAS STIFLED DEEP CONVECTION. WARM SEA SURFACE TEMPERATURES (28-29C) AND GOOD POLEWARD OUTFLOW ALOFT HAVE COUNTERED THE IMPACT OF THE PERSISTENT VWS, ENABLING THE SYSTEM TO MAINTAIN OVER THE PAST SEVERAL HOURS. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS WARNING. B. TS 07W WILL CONTINUE TRACKING POLEWARD THROUGH TAU 24, AND SUBSEQUENTLY TURN EASTWARD AS IT ROUNDS THE SUBTROPICAL STEERING RIDGE AXIS. PASSAGE OVER WARM WATER AND FAIR OUTFLOW SHOULD ALLOW THE SYSTEM TO MAINTAIN WEAK TROPICAL STORM INTENSITY FOR THE NEXT 24 HOURS, DESPITE THE MODERATE TO STRONG SHEAR ALONG THE FORECAST TRACK. AFTER TAU 24, PASSAGE OVER LAND WILL INDUCE PRONOUNCED WEAKENING. C. TS 07W WILL DISSIPATE BY TAU 72 DUE TO PASSAGE OVER LAND AND COOL WATER (24-26 DEGREES CELSIUS) AS IT EXITS OFF THE EAST COAST OF JAPAN. THE CIRCULATION IS EXPECTED TO REMAIN SEPARATE FROM THE MID-LATITUDE FLOW PATTERN AS IT DISSIPATES, SO EXTRATROPICAL TRANSITION IS NOT ANTICIPATED. NUMERICAL MODEL GUIDANCE REMAINS IN GOOD AGREEMENT REGARDING THE STEERING SCENARIO, LENDING HIGH CONFIDENCE TO THE CURRENT JTWC TRACK FORECAST.// NNNN NNNN