05S(DARIAN): Rapid Intensification: +45knots/24h from CAT 1 to Strong CAT 3 US//Invest 94W//Invest 98B//Invest 90S// 2009utc

JTWC IS ISSUING 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 05S(DARIAN).

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A TIGHTLY WRAPPED TROPICAL CYCLONE WITH A WELL DEFINED 23NM EYE AND IMPROVED POLEWARD OUTFLOW. A 200602Z GMI 89GHZ MICROWAVE IMAGE REVEALS THAT 05S HAS A WELL DEFINED, SOLID EYEWALL AND A SERIES OF TIGHTLY WRAPPING DEEP CONVECTIVE BANDS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON MSI AND GMI IMAGERY. THE INITIAL INTENSITY OF 110 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A MAJORITY OF THE AVAILABLE INTENSITY GUIDANCE INDICATING 110-115KTS WITH THE EXCEPTION OF ABOM WHO ESTIMATES CLOSER TO 90KTS.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIR AGREEMENT THAT 05S WILL TRANSIT THE 14TH PARALLEL WESTWARD WITH A 200NM SPREAD IN SOLUTIONS BY TAU 120. FOR THIS REASON THE JTWC TRACK IS PLACED INITIALLY WITH HIGH CONFIDENCE AND EVENTUALLY MEDIUM CONFIDENCE FOR THE EXTENDED TRACK FORECAST. RELIABLE MODEL INTENSITY GUIDANCE INDICATES AN OVERALL AGREEMENT ON THE GENERAL TREND THAT THE SYSTEM WILL TAKE THROUGH THE FORECAST PERIOD. WITH NOTABLE DIFFERENCES IN MAX AND MIN INTENSITIES A WEAKENING TREND APPEARS APPROXIMATELY THROUGH TAU 48, AFTER WHICH INTENSIFICATION AND EVENTUAL DECLINE NEAR TAU 96. THIS 15-20 KNOT VARIABILITY IN MODEL OUTPUT IS WHY THE JTWC FORECAST INTENSITY IS PLACED WITH MEDIUM CONFIDENCE.