TC 14S(VERNON): very small but powerful CAT 4: weakening while absorbing Invest 93S//TC 15S(ANIKA) up-date, 26/09utc

JTWC IS ISSUING 12HOURLY WARNINGS ON TC 14S(VERNON) AND 6HOURLY WARNINGS ON TC 15S. 3HOURLY SATELLITE BULLETINS ARE ISSUED ON 14S,15S, INVEST 93S AND INVEST 98P.

26/1015UTC.

FORECAST DISCUSSION: TC 14S WILL TRACK WEST-NORTHWEST OVER THE NEXT 12 HOURS AND WILL CONTINUE BINARY INTERACTION WITH INVEST 93S, CURRENTLY LOCATED APPROXIMATELY 370KM TO THE NORTHWEST. INVEST 93S WILL SLOWLY SPIRAL CLOSER AS TC 14S PASSES TO THE SOUTH. THE TWO SYSTEMS WILL BEGIN TO FUJIWARA ABOUT ONE ANOTHER WITH TC 14S ABSORBING THE SMALLER SYSTEM COMPLETELY SHORTLY AFTER 48H. AFTERWARDS, A MID-LATITUDE TROUGH TO THE SOUTH WILL ERODE THE SUBTROPICAL RIDGE, ALLOWING FOR TC 14S TO TURN POLEWARD AND ACCELERATE SOUTH-SOUTHWEST THROUGH THE REMAINDER OF THE FORECAST.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GENERAL AGREEMENT IN REGARDS TO TRACK FORECAST WITH ALL MODELS SHOWING THE FUJIWARA INTERACTION WITH 93S FOLLOWED BY A GENERALLY SOUTH-SOUTHWEST TRACK.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 15S HAS MOVED SLIGHTLY TO THE SOUTHWEST OVER THE LAST 6 HOURS DUE TO THE WEAK STEERING ENVIRONMENT FROM THE MID-LEVEL RIDGE TO THE SOUTH. OVER THE NEXT 24 HOURS, THE SYSTEM WILL PEAK OUT AT 60KTS AS IT BRUSHES ACROSS THE NORTHWEST KIMBERLEY COAST AND TRACKS SLOWLY SOUTH-SOUTHWESTWARD. AROUND 36H, A SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST WILL BUILD, STEERING TC 15S TO THE SOUTHWEST ALONG THE KIMBERLEY COAST. THE RIDGE WILL REORIENT AND PUSH THE SYSTEM SOUTHWEST DOWN THE NORTHWESTERN AUSTRALIA COAST THROUGH THE REMAINDER OF THE FORECAST WITH THE POTENTIAL TO NUDGE IT OFF THE COAST BEFORE 72H. THE SYSTEM IS FORECAST TO REMAIN AT 60KTS THROUGH 36H, BUT IS EXPECTED TO DECREASE INTENSITY SLIGHTLY DUE TO THE LAND INTERACTION. HOWEVER, THE DECREASING TREND WILL REMAIN UNTIL 72H WHEN IT IS FORECAST TO MOVE BACK OUT OVER OPEN WATER. AFTERWARDS, TC 15S WILL BEGIN TO DEPART FROM THE COASTLINE AND ONCE AGAIN INCREASE IN INTENSITY, REACHING 55 KTS BY 120H.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD SYSTEM WITH TWO REGIONS OF CONVECTION WITH THE LOW LEVEL CIRCULATION CENTER (LLCC) REMAINING TO THE EASTERN CONVECTION REGION. THE INITIAL POSITION IS BASED LOOSELY ON A 260501Z ATMS IMAGE. THE INTENSITY IS BASED UPON MULTIPLE AGENCY DVORAK ESTIMATES RANGING FROM T3.0 TO T3.5, WITH ADT REMAINING THE HIGHEST AT T3.6 (57KTS). TC 15S IS CURRENTLY IN A MARGINALLY FAVORABLE ENVIRONMENT WITH MODERATE VERTICAL WIND SHEAR, OFFSET BY WARM SEA SURFACE TEMPERATURES, AND MODERATE RADIAL OUTFLOW.