Invest 91P up-graded to Medium, 17/06utc

JTWC IS ISSUING 3HOURLY SATELLITE BULLETINS ON INVEST 91P.

THE AREA OF CONVECTION (INVEST 91P) PREVIOUSLY LOCATED NEAR 13.5S 171.7E IS NOW LOCATED NEAR 13.7S 171.6E, APPROXIMATELY 575 KM NORTHEAST OF PORT VILA, VANUATU. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS CONSOLIDATING CONVECTION OBSCURING A BROAD LOW LEVEL CIRCULATION (LLC). INVEST 91P IS PRIMARILY SUPPORTED BY NEARLY RADIAL OUTFLOW AND WARM (29-30C) SEA SURFACE TEMPERATURES (SST), AND DEVELOPMENT IS MARGINALLY OFFSET BY MODERATE (10-20KT) VERTICAL WIND SHEAR (VWS). GLOBAL MODELS GENERALLY AGREE THAT INVEST 91P WILL MEANDER SOUTH-SOUTHWESTWARD AS IT CONTINUES TO CONSOLIDATE AND STRENGTHEN. GFS ENSEMBLE MEMBERS CONTINUE TO TAKE A MORE AGGRESSIVE SOLUTION FOR INTENSIFICATION WITH 91P WHILE THE ECMWF ENSEMBLE MEMBERS REMAIN CONSISTENT ON ONLY A SLIGHT INTENSIFICATION OF THE SYSTEM IN THE NEXT 48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

GLOBAL MODELS GENERALLY AGREE THAT INVEST 91P WILL MEANDER SOUTH-SOUTHWESTWARD AS IT CONTINUES TO CONSOLIDATE AND STRENGTHEN. GFS ENSEMBLE MEMBERS CONTINUE TO TAKE A MORE AGGRESSIVE SOLUTION FOR INTENSIFICATION WITH 91P WHILE THE ECMWF ENSEMBLE MEMBERS REMAIN CONSISTENT ON ONLY A SLIGHT INTENSIFICATION OF THE SYSTEM IN THE NEXT 48 HOURS.