MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W (PRAPIROON) /WARNING NR 32// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 22W (PRAPIROON), LOCATED APPROXIMATELY 305 NM SOUTHEAST OF KADENA AIR BASE, OKINAWA, JAPAN, HAS BECOME QUASI-STATIONARY (QS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A DEEP CONVECTIVE BAND THAT HAS PERSISTED ALONG THE NORTHERN HALF OF THE SYSTEM HAS WRAPPED AROUND THE LOW LEVEL CIRCULATION CENTER (LLCC) FORMING A BIG 60-NM EYE. THE INITIAL POSITION IS BASED ON THE MSI LOOP AND EXTRAPOLATED FROM A 150409Z AMSU-B MICROWAVE IMAGE WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS AVERAGED FROM DVORAK ESTIMATES FROM PGTW, KNES AND RJTD. UPPER LEVEL ANALYSIS INDICATES A POINT SOURCE ANTICYCLONE IS LOCATED DIRECTLY OVER THE LLCC WITH LOW VERTICAL WIND SHEAR (VWS). ANIMATED WATER VAPOR IMAGERY SHOWS THE SYSTEM HAS MAINTAINED GOOD RADIAL OUTFLOW WITH AN IMPROVING POLEWARD OUTFLOW CHANNEL. THE CYCLONE IS NOW OUT OF THE INFLUENCE OF THE WEAKENED NEAR EQUATORIAL RIDGE TO THE SOUTHEAST AND IS IN A COL AREA WITH NO DOMINANT STEERING MECHANISM. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TY 22W IS EXPECTED TO REMAIN QS OVER THE NEXT 24-36 HOURS AS TS 23W AWAITS FOR THE SUBTROPICAL RIDGE (STR) TO THE EAST TO BUILD AND EVENTUALLY EJECTS IT POLEWARD FROM THE COL AREA. THIS IS EXPECTED TO OCCUR AFTER TAU 24. BUT SHORTLY AFTER TAU 48 JUST WHEN THE STR ASSUMES SOLID STEERING, A MID-LATITUDE TROUGH APPROACHING FROM THE NORTHWEST WILL WEAKEN THE STR AND CAUSE TY 22W TO RECURVE AND ACCELERATE NORTHEASTWARD. WHILE THE SYSTEM IS IN A QS STATE AND WITH CONTINUED FAVORABLE OUTFLOW, IT WILL SLIGHTLY INTENSIFY. THE NUMERIC MODEL CONSENSUS CONTINUES TO BRING THE CYCLONE EXTREMELY WESTWARD BEFORE RECURVING IT NORTHEASTWARD. THIS MAY BE A RESULT OF EXCESSIVE DIRECT CYCLONE INTERACTION (E-DCI) WITH ANOTHER CYCLONE TO THE SOUTHEAST. DUE TO THE UNCERTAINTY IN THE STEERING AND POSSIBLE E-DCI FROM THE NUMERIC MODEL GUIDANCE, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE TRACK FORECAST. C. AFTER TAU 72, TY PRAPIROON IS EXPECTED TO CONTINUE ACCELERATING NORTHEASTWARD AND WEAKEN AS SSTS DECREASE AND VWS INCREASES. BY TAU 120 TY 22W WILL BEGIN EXTRATROPICAL TRANSITION. MODEL GUIDANCE IS UNIFIED IN A RECURVATURE SCENARIO AFTER TAU 72 BUT WIDELY DIFFER IN LATERAL SPEED, LENDING POOR CONFIDENCE IN THE EXTENDED PORTION OF THE TRACK FORECAST. // NNNN NNNN