WNP: TS 06W(CHAMPI) is getting better organized, forecast to peak at Typhoon intensity by 72hours, center relocated at 23/06utc

WARNING 10 ISSUED AT 23/09UTC.FORECAST DISCUSSION: TS 06W WILL TRACK MORE NORTH-NORTHWESTWARD AS IT GETS STEERED AT A HIGHER LAYER ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE(STR), THEN AFTER 48H, MORE NORTHWARD AS IT CRESTS THE STR AXIS. AFTER 72H, THE CYCLONE WILL ACCELERATE NORTH-NORTHEASTWARD ON THE POLEWARD SIDE OF THE STR AXIS. THE MARGINALLY FAVORABLE ENVIRONMENT, WILL FUEL A GRADUAL INTENSIFICATION TO A PEAK OF 65KNOTS/US CATEGORY 1 BY 72H AS POLEWARD OUTFLOW INCREASES DUE TO THE INITIAL EXPOSURE TO THE PREVAILING WESTERLIES. AFTERWARD, INCREASING VERTICAL WID SHEAR AND COOLING SSTS WILL SLOWLY ERODE THE CYCLONE.CONCURRENTLY BY 96H, IT WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT ENTERS THE COLD BAROCLINIC ZONE AND MERGES WITH THE BAIYU FRONTAL BOUNDARY SOUTHEAST OF JAPAN. BY 120H, TS CHAMPI WILL COMPLETE ETT AND EMBED INTO THE GRADIENT FLOW AS A STRONG GALE-FORCE COLD CORE LOW WITH AN EXPANDING WIND FIELD.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A COMPACT SYSTEM THAT HAS BEGUN TO CONSOLIDATE AS CONVECTIVE TOPS DEEPENED AND RAIN BANDS HAVE BECOME MORE DEFINED. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A LOW LEVEL CIRCULATION (LLC) FEATURE IN THE 230416Z ATMS MICROWAVE IMAGE AND LINED UP WITH AN LLC IN THE 230207Z SCATTEROMETRY BULLSEYE PASS. THE INITIAL INTENSITY OF 40 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON AN OVERALL ASSESSMENT OF BELOW AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE IMPROVED STATE OF THE SYSTEM.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT WITH GRADUAL SPREADING TO 555KM AT 72H AND 640KM AT 120H. JGSM IS THE SOLE OUTLIER ON THE LEFT MARGIN OF THE MODEL ENVELOPE. THIS LENDS MEDIUM CONFIDENCE TO THE NEAR- TO MID-TERM PORTION OF THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF AND SLIGHTLY FASTER THAN THE MODEL CONSENSUS (CONW). ON THE OTHER HAND, THERE IS LOW CONFIDENCE IN THE EXTENDED PORTION OF THE FORECAST TO ACCOUNT FOR THE NOTABLE MODEL DIFFERENCES IN ALONG-TRACK ACCELERATION.

23/00UTC. HWRF INTENSITY GUIDANCE: 76KNOTS AT +66H.

23/06UTC.24H SHEAR TENDENCY.UW-CIMSS Experimental Vertical Shear and TC Intensity Trend Estimates: CIMSS Vertical Shear Magnitude : 3.2 m/s (6.3 kts)Direction : 90.8deg Outlook for TC Intensification Based on Current Env. Shear Values and MPI Differential: VERY FAVOURABLE OVER 24H.

THE JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON 06W.