AN AREA OF CONVECTION (INVEST 93W) HAS PERSISTED NEAR
21.5N 135.3E, APPROXIMATELY 505 NM EAST-SOUTHEAST OF KADENA AB,
OKINAWA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 191227Z
MHS METOP-B 89GHZ MICROWAVE IMAGE DEPICT A BROAD LOW LEVEL
CIRCULATION (LLC) OBSCURED BY FLARING CONVECTION. A 190917Z SSMIS
IMAGE DEPICTS LOW LEVEL BANDING ASSOCIATED WITH A POORLY-ORGANIZED
AREA OF CYCLONIC TURNING. UPPER-LEVEL ANALYSIS DEPICTS A FAVORABLE
ENVIRONMENT WITH WEAK EQUATORWARD OUTFLOW IN AN AREA OF LOW (5-10
KTS) VERTICAL WIND SHEAR. ADDITIONALLY, WARM (29-30 CELSIUS) SEA
SURFACE TEMPERATURES ARE CONDUCIVE FOR TROPICAL TRANSITION. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO LOW.
(1) THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED
NEAR 21.5N 135.3E IS NOW LOCATED NEAR 24.0N 134.0E, APPROXIMATELY
367 NM EAST-SOUTHEAST OF KADENA, OKINAWA. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY AND A 200353Z AMSR2 89GHZ MICROWAVE IMAGE DEPICT
A BROAD LOW LEVEL CIRCULATION (LLC) INDICATED BY LOW LEVEL BANDING
OBSCURED BY FLARING CONVECTION IN THE NORTHEAST PERIPHERY. UPPER-
LEVEL ANALYSIS DEPICTS A FAVORABLE ENVIRONMENT WITH ROBUST POLEWARD
OUTFLOW IN AN AREA OF LOW (10-15 KTS) VERTICAL WIND SHEAR.
ADDITIONALLY, WARM (29-30 CELSIUS) SEA SURFACE TEMPERATURES ARE
CONDUCIVE FOR TROPICAL TRANSITION. GLOBAL MODELS ARE IN AGREEMENT
THAT THIS SYSTEM WILL BECOME SUB-TROPICAL WITHIN 24-48 HOURS AS IT
BECOMES EMBEDDED IN THE FRONTAL BOUNDARY EAST OF HONSHU. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 17 TO 23 KNOTS. MINIMUM
SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS IS UPGRADED TO MEDIUM.