Typhoon 02W(MAWAR) CAT 3 US slow-mover while on a weakening trend//2821utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TY 02W(MAWAR). JTWC PH

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A SYSTEM SHOWING SIGNS OF BEING ON A WEAKENING TREND WITH THE BULK OF THE DEEP CONVECTION IN THE SOUTHEAST QUADRANT OF THE LOW LEVEL CIRCULATION CENTER (LLCC). EXAMINATION OF THE EYE STRUCTURE REVEALS AN EYE TEMPERATURE OF -3C AND A DIAMETER OF 25 NM. A 281231Z ASCAT-B PASS DEPICTS A FAIRLY SYMMETRICAL WINDFIELD WITH THE EXCEPTION OF THE NORTHEAST QUADRANT AS THE PASS WAS ONLY A PARTIAL IMAGE. THE SYSTEM PROXIMITY TO THE COOLER (26C) SEA SURFACE TEMPERATURES (SST) TO THE NORTH IS CAUSING A LACK OF CONVECTION IN THE NORTHERN PERIPHERY. TY MAWAR IS IN A FAVORABLE ENVIRONMENT FOR FURTHER TROPICAL ACTIVITY. THESE CONDITIONS ARE CHARACTERIZED BY MODERATE RADIAL OUTFLOW ALOFT, A HEALTHY 850 MB VORTICITY SIGNATURE, LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), AND WARM (27-28 C) SST. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON MULTI- AGENCY FIXES, ALONG WITH THE AFOREMENTIONED EIR IMAGERY. THE INITIAL INTENSITY OF 105 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED OFF A BLEND OF MULTI-AGENCY AND AUTOMATED DVORAK ESTIMATES.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY 02W IS TRACKING NORTHWEST AS IT RIDES THE SOUTHWESTERN PERIPHERY OF THE STR TO THE NORTHEAST. THROUGH TAU 36, TY MAWAR WILL STAY ALONG THIS TRAJECTORY AND STEADILY WEAKEN TO 90 KNOTS AS IT ENTERS A HOSTILE ENVIRONMENT FOR CONTINUED TROPICAL ACTIVITY. IN ADDITION, THE SYSTEM WILL SLOW DOWN IN TRACK SPEED AND TURN NORTHWARD AS THE STEERING ENVIRONMENT SHIFTS FROM THE STR TO THE NORTHEAST TO A RIDGE THAT WILL BUILD IN FROM OVER CHINA TO THE NORTHWEST. BY TAU 48 THROUGH TAU 72, THERE IS THE POSSIBILITY THE SYSTEM WILL HAVE A QUASI-STATIONARY POSTURE AS THESE TWO RIDGES ORIENTATE THEMSELVES. BY TAU 72 AND BEYOND, THE STR TO THE NORTHWEST WILL BE THE DOMINANT STEERING MECHANISM AND WILL DRIVE TY MAWAR NORTHEASTWARD. ALL THE WHILE, THE INTENSITY WILL CONTINUE TO DECREASE TO 45 KNOTS BY THE END OF THE FORECAST PERIOD DUE TO THE COOLER (25-26C) SSTS ABOVE THE 20TH PARALLEL, AS WELL AS THE UPWELLING CAUSED BY THE SYSTEM DURING ITS ANTICIPATED SLOW DOWN IN TRACK SPEED.

MODEL DISCUSSION: THE JTWC TRACK CONSENSUS MEMBERS ARE IN A RELATIVELY TIGHT AGREEMENT IN THE NEAR TERM SHOWING A 52 NM SPREAD BY TAU 48. AFTERWARDS, THERE IS SOME DISAGREEMENT AS THEY TRY TO FIGURE OUT HOW TO HANDLE THE ANTICIPATED SLOW DOWN IN TRACK SPEED BETWEEN TAUS 48 AND 72. ALSO, DURING THESE TAUS THE TRACK MEMBERS ARE SPLIT WHERE THE AFUM SOLUTION IS ON THE FAR WEST SIDE OF THE CONSENSUS ENVELOPE, WHEREAS THE NAVGEM AND GFS SOLUTIONS ARE ON THE FAR EAST SIDE. THE ENSEMBLE MODELS ARE IN AGREEMENT OF A RECURVE SCENARIO TO THE NORTHEAST AFTER TAU 60. DUE TO THIS, THE JTWC FORECAST TRACK IS PLACED WITH HIGH CONFIDENCE AND CLOSE TO CONSENSUS THROUGH TAU 72. AFTERWARDS, THE TRACK IS PLACED WITH MEDIUM CONFIDENCE DUE TO THE UNCERTAINTY OF THE MODELS. THE JTWC INTENSITY CONSENSUS MEMBERS ARE IN VERY TIGHT AGREEMENT SHOWING AN OVERALL WEAKENING TREND THROUGHOUT THE FORECAST PERIOD. THE JTWC INTENSITY FORECAST IS SET WITH MEDIUM CONFIDENCE AND SLIGHTLY HIGHER THAN CONSENSUS DUE TO THE UNCERTAINTY OF THE TRACK IN THE LATER TAUS.