WDPS31 PGTW 160300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19P (NINETEEN) WARNING NR 003// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 13.9S 137.9E INITIAL INTENSITY: 50 KTS GEOGRAPHIC REFERENCE: 417 NM EAST-SOUTHEAST OF DARWIN, AUSTRALIA MOVEMENT PAST 6 HOURS: SOUTH-SOUTHEASTWARD AT 04 KTS SIGNIFICANT WAVE HEIGHT: 18 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE (TC) 19S (NINETEEN) CONTINUES TO STEADILY ORGANIZE AND INTENSIFY IN THE GULF OF CARPENTARIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP, PERSISTENT CONVECTION STEADILY ORGANIZING INTO A BETTER DEFINED STRUCTURE, AND OBSCURING THE LOW LEVEL CIRCULATION CENTER (LLCC). A 152202Z SSMIS 91GHZ IMAGE SHOWED A WEAK, NASCENT MICROWAVE EYE-LIKE FEATURE WHICH ALIGNED WITH THE RADAR-DERIVED CENTER OF ROTATION. HOWEVER, ANALYSIS OF THE 36GHZ IMAGE REVEALS A PRONOUNCED VORTEX TILT, INDUCED BY PERSISTENT MID-LEVEL EASTERLY SHEAR. THE INITIAL POSITION WAS ASSESSED WITH MEDIUM CONFIDENCE BASED ON EXTRAPOLATION OF THE LOW EMISSIVITY REGION (LER) IN THE 36GHZ MICROWAVE IMAGE AND THE AGENCY FIX POSITIONS. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON AN AVERAGE OF AGENCY DVORAK INTENSITY ESTIMATES AS WELL AS THE OBJECTIVE ESTIMATES NOTED BELOW. ADDITIONALLY, A HOT OFF THE PRESSES 160027Z ASCAT-B BULLSEYE PASS REVEALED WINDS UP TO 45-50 KNOTS IN THE NORTHERN HEMISPHERE OF THE CIRCULATION, THOUGH WINDS IN THE REMAINDER OF THE CIRCULATION AT 35 KNOTS OR LESS. THE SYSTEM CONTINUES TO STRUGGLE SOMEWHAT AGAINST MODERATE MID-LEVEL EASTERLY SHEAR. ANIMATED WATER VAPOR IMAGERY AND STORM-SCALE ATMOSPHERIC MOTION VECTORS FROM CIMSS CONTINUE TO DEPICT THAT THE PERSISTENT CONVECTION IS GENERATING EASTWARD OUTFLOW WHICH IS PUSHING BACK AGAINST THE SHEAR, BUT THE SYSTEM HAS YET TO TAKE ADVANTAGE OF THE DECREASED MESOSCALE SHEAR VALUES. OTHER THAN THE SHEAR, THE ENVIRONMENT IS FAVORABLE, WTIH VERY WARM SSTS, HIGH OHC AND DECENT POLEWARD OUTFLOW ALOFT. INITIAL WIND RADII BASIS: PERSISTENCE AND ASCAT DATA. CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A MID-LEVEL NEAR EQUATORIAL RIDGE (NER) TO THE EAST-NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS KNES: T3.5 - 55 KTS ADRM: T2.5 - 35 KTS CIMSS SATCON: 51 KTS AT 152203Z CIMSS ADT: 49 KTS AT 152330Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 19S IS FORECAST TO CONTINUE TRACKING EAST-SOUTHEASTWARD THROUGH TAU 12 BEFORE TURNING SOUTH AND EVENTUALLY SOUTHWEST AS THE NER TO THE NORTHEAST STEADILY BUILDS AND EXTENDS TOWARDS THE SOUTHWEST. THE SYSTEM WILL SLOW DOWN AS IT APPROACHES THE COAST AS THE PRIMARY STEERING MECHANISM SHIFTS. AFTER MAKING LANDFALL SHORTLY AFTER TAU 48, THE SYSTEM WILL ACCELERATE ON A WESTWARD TRACK AS IT COMES UNDER THE STEERING INFLUENCE OF A LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR) LAYING ACROSS CENTRAL AUSTRALIA. IN TERMS OF INTENSITY, THE SYSTEM STILL HAS SOME WORK TO DO TO ORGANIZE A VERTICALLY ALIGNED VORTEX. AS NOTED ABOVE, SIGNS ARE STARTING TO APPEAR THAT THIS IS ALREADY OCCURRING. ASSUMING THE CONVECTION WILL PERSIST FOR ANOTHER 12 HOURS AND CONTINUE TO EXPAND EASTWARD INTO THE FACE OF THE SHEAR, THE SYSTEM SHOULD ACHIEVE AXISYMMETRIZATION AND EMBARK ON A PERIOD OF RAPID INTENSIFICATION. THE FORECAST CALLS FOR RI TO BEGIN IN EARNEST BY TAU 12, WITH THE SYSTEM REACHING A PEAK OF AT LEAST 80 KNOTS BY TAU 36. AN INCREASE OF DRY MID-LEVEL AIR ENTRAINING INTO THE CORE OF THE SYSTEM, ACCOMPANIED BY A REDUCTION IN UPPER-LEVEL OUTFLOW, WILL INHIBIT ADDITIONAL INTENSIFICATION AFTER TAU 36, BUT THE SYSTEM WILL REMAIN A STRONG TC AS IT CROSSES THE SHORE. ONCE THE SYSTEM IS ASHORE, IT WILL RAPIDLY WEAKEN DUE TO TERRAIN EFFECTS AND WILL FULLY DISSIPATE BY TAU 96. MODEL DISCUSSION: NO MAJOR CHANGES ARE OBSERVED THE DETERMINISTIC OR ENSEMBLE TRACK GUIDANCE AS COMPARED TO THE PREVIOUS RUN. ALL CONSENSUS MEMBERS AGREE ON THE OVERALL TRACK SCENARIO, WITH SOME MINOR DIFFERENCES IN THE TIMING AND STRENGTH OF THE TURN TOWARDS THE SOUTHWEST AND IN THE TRACK SPEED AFTER TAU 36. THE TRACK ENVELOPE IS 100NM AT LANDFALL, EXPANDING TO 115NM AT TAU 96, DEFINED BY THE NAVGEM ON THE EAST AND SOUTH, AND THE ECMWF AND GFS ENSEMBLE MEANS ON THE NORTH AND WEST. THE JTWC TRACK FORECAST IS CONSISTENT WITH THE PREVIOUS FORECAST, AND LIES JUST NORTH OF THE CONSENSUS MEAN AND IN LINE WITH THE CONSENSUS IN TERMS OF TRACK SPEED. CONFIDENCE IS MEDIUM DUE TO THE MODEST SPREAD IN THE GUIDANCE MEMBERS AND UNCERTAINTY IN TRACK SPEED. INTENSITY GUIDANCE IS MIXED, WITH THE MESOSCALE MODELS INCLUDING HWRF, HAFS-A, AND COAMPS-TC BASICALLY GIVING UP ON THE SYSTEM AND KEEPING A LID ON INTENSITY, PEAKING OUT BETWEEN 50-65 KNOTS. MEANWHILE THE SHIPS (NAVGEM) RAMPS UP THE PEAK TO 95 KNOTS AT TAU 48, WHILE SEVERAL RAPID INTENSIFICATION (RI) AIDS INCLUDING RIPA, RICN AND FRIA CONTINUE TO TRIGGER. THE JTWC FORECAST LIES WELL ABOVE THE MESOSCALE MODELS AND THE CONSENSUS MEAN, BUT BELOW THE MOST AGGRESSIVE RI AIDS. HOWEVER, IN LIGHT OF THE VERY LARGE SPREAD IN THE GUIDANCE, THE FORECAST IS SET WITH LOW CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN