ABPW10 PGTW 040600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH
PACIFIC OCEANS/040600Z-050600ZSEP2023//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/040153ZSEP2023//
REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/031352ZSEP2023//
NARR/REF A IS A TROPICAL CYCLONE WARNING. REF B IS A TROPICAL CYCLONE
FINAL WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 04SEP23 0000Z, TYPHOON 10W (HAIKUI) WAS LOCATED NEAR
23.2N 119.8E, APPROXIMATELY 147 NM SOUTHWEST OF TAIPEI, TAIWAN, AND
HAD TRACKED NORTH-NORTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS.
MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 75 KNOTS GUSTING TO
90 KNOTS. SEE REF A (WTPN33 PGTW 040300) FOR FURTHER DETAILS.
(2) AT 03SEP23 1200Z, TROPICAL DEPRESSION 09W (SAOLA) WAS
LOCATED NEAR 20.7N 109.0E, APPROXIMATELY 175 NM EAST OF HANOI,
VIETNAM, AND HAD TRACKED SOUTHWESTWARD AT 04 KNOTS OVER THE PAST SIX
HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 25 KNOTS
GUSTING TO 35 KNOTS. SEE REF B (WTPN32 PGTW 031500) FOR THE FINAL
WARNING ON THIS SYSTEM.
(3) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 99W) HAS PERSISTED NEAR 20.0N
129.1E, APPROXIMATELY 390 NM SOUTH-SOUTHEAST OF KADENA, AB. ANIMATED
MSI AND A 040124Z BULLSEYE ASCAT METOP-C PASS REVEAL A PARTIALLY-
OBSCURED LLC WITH A BAND OF 20-KNOT WINDS EXTENDING FROM THE SOUTH TO
THE EAST OF THE CENTER AND MOST OF THE CONVECTION SHEARED TO THE
SOUTH. PRESENTLY, ENVIRONMENTAL CONDITIONS ARE SUBOPTIMAL AS A RESULT
OF HIGH VWS (20-30KTS) PRESSING DOWN FROM THE NORTH ALONG THE WESTERN
SIDE OF A STRONG TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) POSITIONED
TO THE NORTH OF 99W. NONETHELESS, THE WARM SSTS (29-30C) AND AMPLE
MOISTURE WILL PROVIDE THE ENERGY TO BEGIN THE DEVELOPMENT PROCESS.
OVER THE NEXT 24 HOURS, THE TUTT WILL WEAKEN AND TRACK NORTHWARD,
POSITIONING 99W IN THE EASTERN, DIFFLUENT REGION, WHICH WILL SUPPLY
SUFFICIENT OUTFLOW TO COUNTERACT THE EFFECTS OF THE VWS. THERE IS A
CONSENSUS ACROSS GLOBAL MODELS THAT CONDITIONS WILL IMPROVE AS INVEST
99W TRACKS TOWARD THE NORTH-NORTHEAST, WHILE THE HIGH VWS SUBSIDES,
ENABLING STEADY DEVELOPMENT OVER THE NEXT 72 HOURS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS
IS LOW.