Typhoon 11W(SHANSHAN) intensifying//CAT 1 01C(HONE) brushing HAWAII//HU 07E(GILMA) peaked at CAT 4 US//INVEST 92E//2515utc

JTWC IS ISSUING 6HOURLY WARNINGS ON 11W, ON 01C AND ON 07E. 3HOURLY SATELLITE BULLETINS ARE ISSUED ON 11W AND 01C.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A MEDIUM-SIZED SYSTEM THAT CONTINUED TO SLOWLY CONSOLIDATE AS EVIDENCED BY COOLING CONVECTIVE TOPS OVER THE COLD DENSE OVERCAST (CDO) THAT HAS RECENTLY DEVELOPED A PINHOLE EYE. A ROBUST POLEWARD OUTFLOW, A TUTT CELL AND DRY AIR INTRUSION ALONG THE WESTERN FLANK ARE ALSO EVIDENT ON THE EIR LOOP. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PINHOLE EYE, ADJUSTED FOR A SLIGHT FORWARD TILT AND LINED UP WITH A MICROWAVE EYE ON THE 250857Z SSMIS IMAGE. THE INITIAL INTENSITY OF 75KTS IS ALSO ASSESSED WITH HIGH CONFIDENCE BASED ON THE HIGH END OF AGENCY AND OBJECTIVE DVORAK ESTIMATES AND REFLECTS THE IMPROVED 6-HR EIR SIGNATURE. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH WARM ALONG-TRACK SST AND A STRONG, EFFICIENT VENTILATION ALOFT OFFSET BY MODERATE RELATIVE VWS, SUBSIDENCE FROM THE TUTT CELL TO THE WEST, AND COLD DRY AIR INTRUSION AT THE LOWER LEVELS.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TYPHOON SHANSHAN WILL CONTINUE ON A FISHBONE NORTHWESTWARD TRACK AS THE STEERING STR BUILDS. AFTER TAU 36, IT WILL TURN MORE NORTHWARD AS IT CRESTS THE STR AXIS AND AFTER TAU 48, ACCELERATE NORTHEASTWARD ON THE POLEWARD SIDE OF THE STR AND BY TAU 72, MAKE LANDFALL OVER SHIKOKU THEN TRACK ACROSS HONSHU AND EXIT INTO THE SEA OF JAPAN (SOJ) AROUND TAU 90. BY TAU 120, IT WILL MAKE LANDFALL OVER THE SOUTHERN TIP OF HOKKAIDO. THE FAVORABLE ENVIRONMENT WILL FUEL A GRADUAL INTENSIFICATION TO A PEAK OF 110KTS BY TAU 48 AS THE POLEWARD OUTFLOW, ENHANCED BY THE STRONG WESTERLIES, IS AMPLIFIED. AFTERWARD, LAND INTERACTION, INCREASING VWS, AND COOLER SST IN THE SOJ WILL RAPIDLY ERODE THE SYSTEM DOWN TO 45KTS BY TAU 120. CONCURRENTLY BY TAU 72, TY 11W WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT ENTERS THE COLD BAROCLINIC ZONE AND BECOME A STRONG GALE-FORCE COLD CORE LOW WITH AN EXPANDING WIND FIELD BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH A GRADUAL AND EVEN SPREAD TO A MERE 100NM BY TAU 72, LENDING HIGH CONFIDENCE TO THE NEAR- TO MID-PORTION OF THE JTWC TRACK FORECAST AND MEDIUM CONFIDENCE TO THE INTENSITY FORECAST. AFTERWARD, THE MODEL ENVELOPE SPREADS OUT UNEVENLY TO 234NM BY TAU 120. THIS WIDE RANGE PLUS THE VARIABILITY ASSOCIATED WITH LAND INTERACTION AND ETT LEND LOW CONFIDENCE TO THE EXTENDED PORTION OF THE TRACK AND INTENSITY FORECASTS.