TC 22S(HALIMA) failed to reach STY intensity, forecast to weaken significantly next 48h//21S(CHARLOTTE):subtropical//Invest 92W, 26/03utc

JTWC IS ISSUING 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 22S(HALIMA).

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THE OVERALL FORECAST PHILOSOPHY HAS NOT CHANGED IN TERMS OF THE TRACK, BUT THE PEAK INTENSITY HAS DECREASED BY 15 KNOTS TO REFLECT THE LATEST GUIDANCE DUE TO EXCESSIVE UPWELLING. FORECAST DISCUSSION: TC 22S WILL CONTINUE ON A SOUTHERLY TRACK ALONG THE WESTERN PERIPHERY OF THE NORTH-SOUTH ORIENTED STEERING RIDGE THROUGH 24H. DUE TO HIGHLY FAVORABLE CONDITIONS, THE SYSTEM WILL SLIGHTLY INTENSIFY ONCE IT BEGINS MOVING FURTHER SOUTH AND REGAINS THE WARMER SSTS TO A PEAK INTENSITY OF 115 KNOTS/CAT 4 US AT 12H. THERE IS SLIGHT POTENTIAL FOR THE SYSTEM TO PEAK HIGHER WITHIN THE NEXT 24 HOURS AS ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE. TC HALIMA WILL WEAKEN QUICKLY IN THE NEAR TAUS AS IT BEGINS ENCOUNTERING A HIGHER VERTICAL WIND SHEAR (VWS) ENVIRONMENT TO THE SOUTH. VWS APPEARS TO INCREASE TO 20-25 KNOTS WITH THE APPROACHING UPPER-LEVEL TROUGH MIGRATING IN FROM THE WEST. TC 22S WILL TURN SOUTHEASTWARD THEN EASTWARD THROUGH 96H AS IT CONTINUES TO BE IMPACTED BY THE COMPLEX STEERING OF THE UPPER-LEVEL TROUGH TO THE WEST AND THE NORTH-SOUTH ORIENTED RIDGE TO THE EAST. THE RIDGE TO THE EAST WILL SLIGHTLY BUILD WEST, FORCING TC HALIMA TO TURN EQUATORWARD BEGINNING AT 96H. AT THIS TIME, TC HALIMA WILL HAVE A SMALL WINDOW WHEREBY THE POLEWARD OUTFLOW WILL INCREASE AND DEEPEN THE SYSTEM BACK TO TYPHOON STRENGTH FOR THE EXTENDED TIMEFRAME.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A COMPACT SYSTEM WITH MODERATE CONVECTION WRAPPING AROUND A LOW-LEVEL CIRCULATION (LLC). THE MINIMAL MOTION TO THE SOUTH AND CONSTANT UPWELLING NEAR THE CIRCULATION CENTER OVER THE LAST TWELVE HOURS HAS CAUSED THE EYE TO FILL. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE USING THE EMBEDDED CENTER METHOD, A NOTCH APPEARING ON THE EIR LOOP, AND A 252336Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY OF 110 KTS/CAT 3 US IS ASSESSED WITH MEDIUM CONFIDENCE USING MULTIPLE AGENCY DVORAK ESTIMATES AND IS HELD SLIGHTLY LOWER THAN PGTW FIX, BOUND BY CONSTRAINTS. THE INTENSITY IS A BLEND OF THE MULTIPLE AGENCY FIX ESTIMATES, WHICH IS SLIGHTLY HIGHER THAN THE 260015Z ADT ESTIMATE OF 107KTS, AI-ENHANCED ADT (AIDT) 103KTS, AND THE 252345Z SATELLITE CONSENSUS (SATCON) OF 99KTS, WHICH ARE NOT BOUND BY THE SAME CONSTRAINTS. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT, WITH MODERATE POLEWARD AND EQUATORWARD OUTFLOW, MODERATE VERTICAL WIND SHEAR, AND WARM SST THAT IS NOW TEMPORARILY IMPACTED BY UPWELLING.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH 72H, EXCEPT FOR NAVGEM. HOWEVER, THE TRACK GUIDANCE WEAKENS IN THE EXTENDED FORECAST. BOTH THE DETERMINISTIC AND PROBABILISTIC GUIDANCE ARE IN POOR AGREEMENT AS THE STEERING HIGH TO THE EAST BEGINS BUILDING BACK TOWARDS THE WEST AND TURNS TC 22S EQUATORWARD. INTENSITY GUIDANCE NO LONGER INDICATES RAPID INTENSIFICATION, AND HWRF CONTINUES TO WEAKEN THE SYSTEM THROUGH THE NEXT 12 HOURS DUE TO COOL WATER UPWELLING, INDICATED IN THE HWRF SST FIELDS. THE GUIDANCE CONTINUES TO INDICATE A STEADY WEAKENING TREND IN THE LATER FORECAST PERIOD, EXCEPT FOR HWRF, WHICH INDICATES A RAPID INTENSIFICATION AT 96H. THIS SCENARIO IS UNLIKELY, HOWEVER, PLAUSIBLE AS THE SYSTEM HAS A SMALL WINDOW TO GAIN THE ROBUST POLEWARD OUTFLOW CHANNEL BEFORE THE UPWELLING DECREASES THE SYSTEM. THEREFORE, THE OVERALL JTWC TRACK AND INTENSITY GUIDANCE IS MEDIUM UP TO 72H AND LOW THEREAFTER.

26/0415UTC.