WNP: 06W(CHAMPI) has reached Typhoon intensity, near-rapid intensification likely next 24hours, 25/09utc update

WARNING 18 ISSUED AT 25/09UTC.FORECAST DISCUSSION: TYPHOON CHAMPI IS FORECAST TO CONTINUE TRACKING NORTHWARD OVER THE NEXT 12 HOURS, SLOWING SLIGHTLY AS IT APPROACHES THE AXIS OF THE STEERING SUBTROPICAL RIDGE. IT IS EXPECTED TO ROUND THE AXIS OF THE RIDGE BY TAU 24 AND THEN ACCELERATE NORTHEASTWARD THROUGH THE REMAINDER OF THE FORECAST PERIOD. OVERALL ENVIRONMENTAL CONDITIONS ARE EXPECTED TO CONTINUE TO IMPROVE THROUGH 24H, WITH VERTICAL WIND SHEAR(VWS) REMAINING LOW, AND POLEWARD OUTFLOW INCREASING, ALLOWING FOR A PERIOD OF NEAR-RAPID INTENSIFICATION, REACHING A PEAK OF 90 KNOTS/ US CATEGORY 2 BY 24H. BEYOND 24H, FIRST SLOW, THEN RAPID WEAKENING IS EXPECTED AS THE SYSTEM MOVES OVER COOLER WATERS (LESS THAN 26C) AND ENCOUNTERS RAPIDLY INCREASING VWS AS IT MOVES STEADILY CLOSER TO THE BAIU BOUNDARY TO THE SOUTHEAST OF HONSHU. BY 48H, THE INTERACTION WITH THE BAIU WILL BEGIN, AND THE SYSTEM WILL MOVE UNDER THE NOSE OF A 200MB JET MAX, INDUCING EXTRATROPICAL TRANSITION (ETT), WHICH IS EXPECTED TO BE COMPLETE NO LATER THAN 72H, BUT LIKELY BY 60H.

25/0602UTC.SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL(MSI) AND ENHANCED INFRARED IMAGERY SHOWS THAT OVERALL CONVECTIVE ACTIVITY HAS WANED AND CLOUD TOPS HAVE WARMED OVER THE PAST SIX HOURS. HOWEVER, BY THE 0600Z HOUR, NUMEROUS VORTICAL HOT TOWERS (VHT) WERE OBSERVED TO BE RAPIDLY DEVELOPING IN AND AROUND THE CORE OF THE SYSTEM, PARTICULARLY ON THE SOUTHEAST AND WESTERN PERIPHERY, POTENTIALLY INDICATIVE OF A NEW ROUND OF INTENSIFICATION. UPPER-LEVEL WATER VAPOR IMAGERY, AND CIMMS ANALYSIS SHOWS SOME FAIRLY STRONG EASTERLY ENVIRONMENTAL FLOW TO THE EAST OF THE SYSTEM, WHICH IS INHIBITING DEVELOPMENT ON THAT SIDE OF THE SYSTEM. A 250510Z GMI 89 GHZ MICROWAVE IMAGE CONFIRMED THE INITIAL POSITION, AND ALSO SHOWED THAT WHILE THE MSI DEPICTION IS FAIRLY IMPRESSIVE, THE INNER CORE HAS YET TO COMPLETELY FORM, WITH A DISTINCT LACK OF CONVECTIVE ACTIVITY ON THE EASTERN SIDE OF THE CORE, AS INDICATED BY THE WATER VAPOR IMAGERY. THE CURRENT INTENSITY IS INCREASED TO TYPHOON STRENGTH (65 KNOTS) IN LINE WITH THE MAJORITY OF DVORAK SUBJECTIVE INTENSITY ESTIMATES. THE OVERALL ENVIRONMENT CONTINUES TO IMPROVE, WITH THE STRONG EQUATORWARD OUTFLOW BEING COMPLIMENTED BY A WEAK BUT QUICKLY IMPROVING POLEWARD OUTFLOW CHANNEL INTO STRONG MID-LATITUDE WESTERLIES. VERTICAL WIND SHEAR (VWS) REMAINS LOW AND SEA SURFACE TEMPERATURES (SSTS) REMAIN ABOVE 28C, LENDING ADDITIONAL FUEL FOR FURTHER INTENSIFICATION.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH 48H, WITH ONLY A 110 KM SPREAD, WITH INCREASING ALONG-TRACK UNCERTAINTY BY 72H, LENDING MEDIUM CONFIDENCE TO THE FORECAST TRACK. THE JTWC FORECAST LIES CLOSE TO THE MULTI-MODEL CONSENSUS THROUGH 24H, THEN ON THE RIGHT SIDE OF THE ENVELOPE AND SLIGHTLY FASTER THAN THE CONSENSUS MEAN THROUGH THE REMAINDER OF THE FORECAST. IN TERMS OF INTENSITY, THE RAPID INTENSIFICATION PREDICTION AID (RIPA) IS PREDICTING A 60 PERCENT PROBABILITY OF RAPID INTENSIFICATION THROUGH 24H, WHILE THE HWRF SOLUTION HAS BACKED OFF SLIGHTLY WITH THE LATEST RUN. THE JTWC FORECAST LIES ABOVE THE CONSENSUS MEMBERS IN LINE WITH THE HIGH RIPA PROBABILITIES. BUT DUE TO THE COMPACT NATURE OF THE SYSTEM, AND THE SHORT-CYCLING IN INTENSITY WITNESSED OVER THE PREVIOUS FEW DAYS, THERE IS ONLY MEDIUM CONFIDENCE IN THE JTWC INTENSITY FORECAST.

25/00UTC. HWRF INTENSITY GUIDANCE: 93KT AT +42H.

25/00UTC. AVN INTENSITY GUIDANCE: 76KNOTS AT +30H.

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

25/00UTC.

25/00UTC.

25/0840UTC. HIMAWARI-8. PH.