JTWC: MEDIUM
(1) AN AREA OF CONVECTION (INVEST 91W) HAS PERSISTED NEAR 21.3N 153.2E, APPROXIMATELY 677 NM NORTHEAST OF GUAM. MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A 272107Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT PERSISTENT CONVECTION OFFSET TO THE SOUTHEASTERN PERIPHERY OF AN EXPOSED LOW LEVEL CIRCULATION (LLC). A 272143Z METOP-A ASCAT PASS SHOWS HIGHER WINDS IN THE EASTERN HEMISPHERE OF THE ELONGATED LLC. ENVIRONMENTAL ANALYSIS INDICATES GENERALLY FAVORABLE CONDITIONS FOR DEVELOPMENT, WITH ROBUST EQUATORWARD OUTFLOW AND WARM (30C) SEA SURFACE TEMPERATURES (SST) BEING OFFSET BY MODERATE (15-20 KTS) VERTICAL WIND SHEAR (VWS). NUMERICAL MODELS AGREE THAT 91W WILL TRACK NORTH-NORTHEAST OVER THE NEXT SEVERAL DAYS, BUT DISAGREE REGARDING INTENSIFICATION, WITH GFS AND NAVGEM SHOWING INTENSIFICATION BUT ECMWF AND JMA REMAINING BELOW WARNING CRITERIA.  MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.

JMA:TD