WTXS21 PGTW 091000
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99S) CANCELLATION//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/082121ZDEC2020//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. REMARKS: THIS CANCELS REF A (WTXS21 PGTW 082130). THE AREA OF
CONVECTION (INVEST 99S), PREVIOUSLY LOCATED NEAR 17.9S 120.8E, IS
NOW LOCATED NEAR 20.0S 122.7E, APPROXIMATELY 949 NM EAST-NORTHEAST
OF LEARMONTH, AUSTRALIA. THE SYSTEM IS NOW TRACKING OVER LAND AFTER
HAVING MADE LANDFALL SOUTHWEST OF BROOME, AUSTRALIA. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS WEAK, LOW LEVEL
CONVECTIVE BANDS WRAPPING INTO A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC). THE SYSTEM AS DISSIPATED DUE TO INCREASED
VERTICAL WIND SHEAR IN THE AREA AND DUE TO INTERACTION WITH THE
UNDERLYING TERRAIN. NUMERICAL MODELS ARE IN GOOD AGREEMENT THAT
INVEST 99S WILL CONTINUE TO TRACK INLAND. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1004 MB. THERE NO LONGER REMAINS THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS DUE TO THE SYSTEM DISSIPATION.//
NNNN
WTXS21 PGTW 082130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
070 NM EITHER SIDE OF A LINE FROM 17.7S 120.6E TO 19.6S 121.8E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 28 TO 33 KNOTS. METSAT
IMAGERY AT 081800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 17.9S 120.8E. THE SYSTEM IS MOVING SOUTHEASTWARD AT 08
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 99S), PREVIOUSLY LOCATED
NEAR 15.8S 118.9E IS NOW LOCATED NEAR 17.9S 120.8E, APPROXIMATELY 81
NM WEST OF BROOME, AUSTRALIA. ANIMATED ENHANCED INFRARED IMAGERY
(EIR) DEPICTS PERSISTENT CONVECTION OBSCURING A LOW LEVEL
CIRCULATION CENTER (LLCC). A 081707Z AMSR2 89GHZ MICROWAVE IMAGE
REVEALS FORMATIVE BANDING WRAPPING INTO A LLCC. INVEST 99S IS IN A
MODERATELY FAVORABLE ENVIRONMENT WITH ROBUST POLEWARD OUTFLOW AND
WARM (30-31C) SEA SURFACE TEMPERATURES (SST) OFFSET BY MODERATE (10-
20 KT) VERTICAL WIND SHEAR (VWS). GLOBAL MODELS GENERALLY AGREE THAT
99S WILL BRIEFLY INTENSIFY BEFORE MAKING LANDFALL OVER AUSTRALIA
AROUND TAU 12. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28
TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
092130Z.//
NNNN
H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR DATA. 7/10
BANDING AROUND THE LLCC YIELDS A DT OF 3.0. MET AND PT ARE UNAVAILABLE
AS SYSTEM WAS NOT CLASSIFIED 24 HOURS AGO. FT IS BASED ON DT.
I. ADDL POSITIONS
NIL
...TUGGLE
TXXS24 KNES 081225
TCSSIO
A. NONAME (99S)
B. 08/1130Z
C. 17.4S
D. 120.4E
E. THREE/HIMAWARI-8
F. T3.0/3.0
G. IR/EIR/SWIR
H. REMARKS...7/10 BANDING AROUND THE LLCC YIELDS A DT OF 3.0. MET AND
PT ARE UNAVAIALBLE AS SYSTEM WAS NOT CLASSIFIED 24 HOURS AGO. FT IS
BASED ON DT.
ABIO10 PGTW 081800
(2) THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED NEAR
16.8S 119.4E IS NOW LOCATED NEAR 17.4S 120.2E, APPROXIMATELY 120 NM
WEST-NORTHWEST OF BROOME, AUSTRALIA. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS LOW LEVEL TURNING WITH PERSISTENT CONVECTION
OVERHEAD. A 081302Z MHS 89GHZ PARTIAL MICROWAVE IMAGE REVEALS AN
AREA OF DEEP CONVECTION WITH FORMATIVE BANDING WRAPPING INTO A LOW
LEVEL CIRCULATION CENTER (LLCC). INVEST 99S IS IN A MARGINAL
ENVIRONMENT FOR DEVELOPMENT WITH MODERATE (15-25KTS) VERTICAL WIND
SHEAR, POLEWARD OUTFLOW ALOFT, AND WARM (29-30C) SEA SURFACE
TEMPERATURES. GLOBAL MODELS ARE IN FAIR AGREEMENT THAT INVEST 99S WILL
CONSOLIDATE MARGINALLY AS IT TRACKS SOUTHEASTWARD TOWARDS AUSTRALIA.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN
THE NEXT 24 HOURS REMAINS LOW.