12W(HINNAMNOR) forecast to reach Super Typhoon intensity before 48h//Invest 98W// Invest 91L//Invest 92L, 29/09utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TY 12W.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TY 12W HAS RAPIDLY INTENSIFIED (35 KNOTS) FROM 40 KNOTS AT 280600Z TO 75 KNOTS AT 290600Z. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A COMPACT, 90NM DIAMETER CENTRAL DENSE OVERCAST OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC). RECENT MSI SHOWS A DEVELOPING EYE OVER THE WESTERN EDGE OF THE CDO. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED THE MSI AS WELL AS ON A 290327Z AMSR2 89GHZ MICROWAVE IMAGE, WHICH REVEALS A SMALL, WELL- DEFINED MICROWAVE EYE FEATURE. THE INITIAL INTENSITY OF 75 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE CIMSS ADT ESTIMATE AND AN AMSR2 WINDSPEED IMAGE SHOWING MAXIMUM WINDS OF 69 KNOTS OVER THE WESTERN QUADRANT. DVORAK ESTIMATES HAVE INCREASED BUT REMAIN TOO LOW BASED ON CONSTRAINTS AND THE COMPACT SIZE OF THE SYSTEM, WHICH IS NOT TYPICALLY HANDLED WELL BY THE DVORAK METHOD. ENVIRONMENTAL CONDITIONS ARE HIGHLY FAVORABLE WITH RADIAL OUTFLOW, LOW VERTICAL WIND SHEAR AND VERY WARM SST VALUES.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: INCREASED THE PEAK INTENSITY TO 140 KNOTS. SHIFTED THE 3-DAY TO 5-DAY FORECAST TRACK SOUTH OF OKINAWA. FORECAST DISCUSSION: TY 12W IS FORECAST TO TRACK QUICKLY WESTWARD TO WEST-SOUTHWESTWARD OVER THE NEXT TWO DAYS AS IT TRACKS ALONG THE SOUTHERN PERIPHERY OF THE STR, TRANSITIONING FROM THE EASTERN STR TO THE WESTERN STR POSITIONED OVER THE EAST CHINA SEA. A MIDLATITUDE SHORTWAVE TROUGH IS STILL EXPECTED TO DIG OVER THE KOREAN PENINSULA NEAR 311200Z, HOWEVER, THE TROUGH IS TOO FAR NORTH AND PROPAGATES NORTHEASTWARD QUICKLY WITH LITTLE IMPACT ON TY 12W'S TRACK. TY 12W IS EXPECTED TO RAPIDLY INTENSIFY OVER THE NEXT 24 TO 36 HOURS REACHING A PEAK INTENSITY OF 140 KNOTS BY TAU 48. NEAR TAU 72, TY 12W WILL ENCOUNTER A COMPETING STEERING SYNOPTIC PATTERN WITH A STR TO THE NORTHEAST AND WEST AND THE NEAR-EQUATORIAL RIDGE TO THE SOUTH, WHICH WILL ESSENTIALLY BOX THE SYSTEM IN, LEADING TO AN EXTENDED PERIOD OF SLOW, QUASI-STATIONARY MOTION. AS THE SYSTEM SLOWS, UPWELLING COOLER WATER WILL SERVE TO GRADUALLY WEAKEN THE SYSTEM THROUGH TAU 120. DUE TO THE COMPETING STEERING, THERE IS HIGH UNCERTAINTY IN THE EXACT TRACK OF THE CENTER. REGARDLESS, THE SYSTEM IS EXPECTED TO TRANSITION INTO A LARGE SYSTEM WITH A 400-500NM DIAMETER.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT THROUGH TAU 48 WITH A 120NM SPREAD IN SOLUTIONS AT TAU 48. AFTER TAU 48, HOWEVER, DETERMINISTIC GUIDANCE DIVERGES AND IS IN POOR AGREEMENT. ALL THE MODELS INDICATE THE SYSTEM WILL SLOW AND BECOME QUASI-STATIONARY BUT DISAGREE ON WHERE THE SYSTEM WILL STALL. THE BULK OF THE DETERMINISTIC AND PROBABILISTIC GUIDANCE (ECMWF ENSEMBLE AND GEFS) INDICATES THE SYSTEM WILL STALL SOUTH TO SOUTH-SOUTHWEST OF OKINAWA FOR AT LEAST TWO DAYS. THERE IS A HIGH PROBABILITY OF RAPID INTENSIFICATION CONTINUING OVER THE NEXT TWO DAYS WITH JTWC'S RAPID INTENSIFICATION (RI) GUIDANCE TRIGGERED AT 60 TO 75 PERCENT. ADDITIONALLY, THE 281800Z COAMPS-TC ENSEMBLE INDICATES THE PROBABILITY OF RI AT 80 TO 100 PERCENT IN THE NEXT 06-42 HOURS.

ZCZC MIATWOAT ALL TTAA00 KNHC DDHHMM Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 AM EDT Mon Aug 29 2022 For the North Atlantic...Caribbean Sea and the Gulf of Mexico: 1. Central Tropical Atlantic: A broad area of low pressure over the central tropical Atlantic is producing a large area of disorganized cloudiness and showers. Although environmental conditions ahead of the system are currently only marginal favorable, some gradual development of this system is expected over the next several days and a tropical depression is likely to form later this week. The disturbance is forecast to move slowly toward the west and then west-northwest at 5 to 10 mph, toward the waters east and northeast of the Leeward Islands. Additional information on this system can be found in high seas forecasts issued by the National Weather Service. * Formation chance through 48 hours...medium...50 percent. * Formation chance through 5 days...high...80 percent.