MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 20W (HAGIBIS) WARNING NR 013// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON 20W (HAGIBIS), LOCATED APPROXIMATELY 274 NM NORTH- NORTHWEST OF ANDERSEN AFB, HAS TRACKED NORTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS SPIRAL CONVECTIVE BANDS WRAPPING INTO A TIGHT, 5 NM DIAMETER PINHOLE EYE AND A DEFINED MOAT BETWEEN THE PRIMARY EYEWALL AND THE SECONDARY EYEWALL. THE INITIAL INTENSITY ESTIMATE REMAINS 135 KTS BASED ON THE DVORAK CURRENT INTENSITY (CI) ESTIMATES OF T7.0 (140 KTS) FROM PGTW AND RJTD AND T6.5 (127 KTS) FROM KNES. THE AUTOMATED DVORAK TECHNIQUE ESTIMATE AT 080540Z IS LOWER, AT T6.2 (120 KTS). WIND RADII WERE ADJUSTED USING A 080023Z METOP-C ASCAT PASS. THE SYSTEM HAS BEEN UNDERGOING AN EYEWALL REPLACEMENT CYCLE (ERC), WITH AN ERODING PRIMARY EYEWALL AND SURROUNDING SECONDARY EYEWALL APPARENT IN ENHANCED INFRARED SATELLITE IMAGERY AND A 080325Z AMSR-2 89GHZ MICROWAVE IMAGE. UPPER-LEVEL ANALYSIS INDICATES SUSTAINED STRONG RADIAL OUTFLOW, ENHANCED TOWARDS THE EAST AND SOUTH. TO THE NORTH OF THE SYSTEM, THERE IS AN AREA OF DRY AIR WITH HIGH VERTICAL WIND SHEAR (VWS), INHIBITING DEVELOPMENT OF A STRONG POLEWARD OUTFLOW CHANNEL. STY 20W REMAINS IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY LOW (10-15 KTS) VWS AND WARM (29-31 CELSIUS) SEA SURFACE TEMPERATURES (SST). STY 20W HAS TURNED TOWARDS THE NORTHWEST, TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE. B. AFTER TAU 24, A PASSING MIDLATITUDE TROUGH TO THE NORTH WILL CAUSE THE STR TO RE-ORIENT, ALLOWING STY 20W TO SHIFT TO A MORE NORTH-NORTHWESTWARD TRACK AS IT ROUNDS THE RIDGE AXIS. THE ENVIRONMENT IS EXPECTED TO REMAIN FAVORABLE THROUGH TAU 72 WITH LOW VWS, HIGH SST, AND GOOD UPPER-LEVEL OUTFLOW. THE OFFICIAL INTENSITY FORECAST REFLECTS THE POSSIBILITY OF SLIGHT RE-INTENSIFICATION AS THE ERC COMPLETES AND THE NEW, BROADER PRIMARY EYEWALL CONTRACTS, AND IS STILL ABOVE THE MULTI-MODEL INTENSITY CONSENSUS. AFTERWARDS, GRADUAL WEAKENING IS EXPECTED AS THE OUTFLOW BEGINS TO BE DISRUPTED TO THE NORTHWEST DUE TO INTERACTION WITH AN APPROACHING TROUGH. GFS AND THE GFS ENSEMBLE ARE THE EASTERNMOST OUTLIERS, DEPICTING A SOONER RECURVE AND WEAKER STR, THE UKMET SOLUTION IS THE WESTERNMOST OUTLIER, AND THE ECMWF SOLUTION IS IN LINE WITH BUT SLIGHTLY AHEAD OF THE MULTI-MODEL CONSENSUS. THIS PORTION OF THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH GOOD CONFIDENCE. C. IN THE EXTENDED PERIOD, A SHORTWAVE TROUGH OVER JAPAN WILL MOVE THROUGH THE AREA, AGAIN ERODING THE STR AND ALLOWING STY 20W TO RECURVE AFTER TAU 72. THE SYSTEM WILL SLOWLY WEAKEN IN RESPONSE TO INCREASED VWS ASSOCIATED WITH THE APPROACHING TROUGH, OFFSETTING THE OTHERWISE FAVORABLE ENVIRONMENT. AT TAU 120, THE SYSTEM IS FORECAST TO BEGIN INTERACTING WITH THE BAROCLINIC ZONE; OUTFLOW WILL DIMINISH, VWS WILL INCREASE FURTHER, AND THE SYSTEM WILL ACCELERATE TOWARDS THE NORTHEAST AND BEGIN EXTRATROPICAL TRANSITION. CROSS- TRACK AGREEMENT IS GOOD, WITH APPROXIMATELY 175 NM OF SPREAD. HOWEVER, THE TIMING OF THE RECURVE AND EXTRATROPICAL TRANSITION VARY BETWEEN MODELS. ALONG TRACK SPREAD IS 730 NM AT TAU 120, WITH UKMET AND GALWEM BEING THE SLOWEST MODELS, WEST OF CONSENSUS AND BRINGING THE SYSTEM OVER HONSHU, ECMWF JUST SKIRTING THE HONSHU COASTLINE AND IN LINE WITH AND SLIGHTLY AHEAD OF CONSENSUS, AND GFS AND JGSM SIGNIFICANTLY FASTER THAN AND EAST OF THE MULTI-MODEL CONSENSUS. DUE TO THE VARIATION IN THE TIMING OF THE RECURVATURE AND ALONG-TRACK SPEEDS, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK.// NNNN NNNN