TC 23S(HIDAYA) peaked at 80 knots/CAT 1 US A NEW RECORD AS THE MOST INTENSE TC IN THIS REGION//0315utc

JTWC IS ISSUING 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 23S(HIDAYA)

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE (TC) 23S (HIDAYA) HAS SET A NEW RECORD, AS THE MOST INTENSE TC IN THIS REGION IN THE HISTORICAL DATABASE, PEAKING AT AN ESTIMATED 80 KNOTS EARLIER IN THE DAY. RAPIDLY INCREASING SHEAR AND AN INFLUX OF DRY AIR IN THE MID-LEVELS MEANS THAT THE SYSTEM WILL WEAKEN FROM HERE FORWARD. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAPIDLY DETERIORATING STRUCTURE, WITH THE AREAL EXTENT OF THE INNER CORE QUICKLY DECREASING, ESPECIALLY ON THE EASTERN SIDE, AS DRY AIR FLOWS IN FROM THE NORTH. THE INNER CORE REMAINS WELL-DEFINED WITH INTENSE CONVECTION OBSCURING THE LOW LEVEL CIRCULATION CENTER (LLCC), THOUGH THE PREVIOUSLY VISIBLE EYE HAS NOW FILLED IN COMPLETELY. THE LAST MICROWAVE IMAGE, A GMI PASS FROM 030748Z SHOWED A WELL-DEFINED LOW-LEVEL MICROWAVE EYE FEATURE IN THE 36GHZ BAND, THOUGH THE EYEWALL IS CLEARLY ERODING FROM THE NORTH. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON AN EXTRAPOLATION OF A WEAK MICROWAVE EYE FEATURE IN A 031040 NOAA-20 ATMS IMAGE AND THE TIGHT GROUPING OF AGENCY FIX POSITIONS. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE AT 75 KNOTS, DOWN A NOTCH FROM THE PEAK, HEDGED SLIGHTLY LOWER THAN THE ADT AND AIDT ESTIMATES AND IN LINE WITH THE AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T4.5 (77 KNOTS). THE LATEST CIMSS SHEAR ANALYSIS INDICATES NORTHERLY DEEP-LAYER SHEAR IS RAMPING UP, NOW ESTIMATED AT 15 KNOTS OR HIGHER. GFS MODEL SOUNDINGS SUGGEST EVEN HIGHER MID-LEVEL SHEAR. AS MENTIONED, DRY AIR IS ALSO FLOWING IN FROM THE NORTH ALONG THE EASTERN SIDE OF THE SYSTEM, FURTHER ERODING THE INNER CORE AND INHIBITING CONVECTION. OTHERWISE, ENVIRONMENTAL CONDITIONS ARE GENERALLY GOOD, WITH MODERATE POLEWARD OUTFLOW AND WARM SSTS, BUT THESE ARE JUST NOT ENOUGH TO OFFSET NEGATIVE INFLUENCE OF THE SHEAR AND DRY AIR.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THE PREVIOUS FORECAST CALLED FOR CONTINUED INTENSIFICATION, BUT THIS FORECAST CALLS FOR THE OPPOSITE, RESULTING IN A LARGE CHANGE IN THE FORECAST INTENSITY, PARTICULARLY IN THE FIRST 12 TO 24 HOURS. FORECAST DISCUSSION: TC 23S HAS CONTINUED TO TRACK WEST-NORTHWEST OVER THE PAST DAY, ALONG THE NORTHEASTERN PERIPHERY OF THE DEEP-LAYER STR CENTERED OVER SOUTH AFRICA. THE SYSTEM IS EXPECTED TO MAINTAIN THIS GENERAL TRACK MOTION THROUGH THE NEXT 24 HOURS, APPROACHING A LANDFALL ALONG THE COAST OF TANZANIA SOUTH OF DAR ES SALAAM BY TAU 24. AS THE SYSTEM WEAKENS RAPIDLY, THE STEERING FLOW BECOMES PROGRESSIVELY SHALLOWER, WHERE THE RIDGE IS ORIENTED MORE NORTH-SOUTH. THE NET EFFECT WILL BE FOR THE SYSTEM TO TURN MORE EQUATORWARD AS IT WEAKENS. THE CURRENT FORECAST CALLS FOR THE SYSTEM TO TRACK VERY CLOSE TO DAR ES SALAAM AND THEN REMAIN INLAND AS IT DISSIPATES. A FASTER RATE OF WEAKENING COULD RESULT IN THE SYSTEM TURNING MORE SHARPLY NORTHWARD AND TRACKING BACK OUT OVER WATER AS IT DISSIPATES, AS IT SUGGESTED BY SOME OF THE MODEL GUIDANCE. IN TERMS OF INTENSITY, THE SYSTEM PEAKED AROUND 030000Z AT 80 KNOTS BUT IS NOW STARTING TO COME DOWN, ALBEIT SLOWLY AS IT IS JUST BEGINNING TO FEEL THE EFFECTS OF INCREASING SHEAR AND DRY AIR ENTRAINMENT. SHEAR IS EXPECTED TO RAPIDLY INCREASE OVER THE NEXT 12 TO 24 HOURS, WHICH QUICKLY ERODE THE VORTEX, AS WELL AS USHER IN ADDITIONAL DRY AIR. ADD IN THE DISRUPTION OF THE LOW-LEVEL INFLOW DUE TO FRICTIONAL EFFECTS AS THE SYSTEM APPROACHES LAND, AND THE SYSTEM WILL RAPIDLY WEAKEN FROM HERE FORWARD. DISSIPATION OVER OR JUST ALONG THE EAST COAST TANZANIA IS FORECAST BY TAU 48, IF NOT A BIT EARLIER.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE CONTINUES TO SHOW A VERY LARGE SPREAD BETWEEN SOLUTIONS. THE GFS, NAVGEM AND THE BULK OF THE MESOSCALE MODELS SHOW A TRACK ALMOST DUE WEST THROUGH THE FORECAST PERIOD, WHILE THE UKMET, GALWEM AND GFS ENSEMBLE TRACKERS SHOW THE SYSTEM TURNING MORE EQUATORWARD AFTER TAU 12, AND KEEPING THE VORTEX OVER WATER THROUGH ALL OR MOST OF THE FORECAST PERIOD. THE ECMWF LIES CLOSE TO THE CONSENSUS MEAN, AS DOES THE JTWC FORECAST, ON THE SOUTHWESTERN EDGE OF THE NORTHERN GROUP OF TRACKERS. INTENSITY GUIDANCE IS IN GOOD AGREEMENT THAT THE SYSTEM WILL RAPIDLY WEAKEN THROUGH THE FORECAST PERIOD. THE JTWC FORECAST LIES ON THE HIGH SIDE OF THE GUIDANCE ENVELOPE WITH MEDIUM CONFIDENCE.