Tropical Storm KONG-REY Advisory 9月29日

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 30W (THIRTY) WARNING NR
04//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 30W (THIRTY), LOCATED APPROXIMATELY 177 NM
SOUTH-SOUTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED NORTHWESTWARD AT
23 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY SHOWS A BROAD AREA OF CONVECTION WITH LIMITED
FORMATIVE BANDING SLIGHTLY OFFSET OF AN OBSCURED LOW LEVEL
CIRCULATION (LLC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON A PARTLY EXPOSED LLC FEATURE IN THE 281728Z SSMI
MICROWAVE IMAGE. THE INITIAL INTENSITY OF 35 KNOTS IS BASED ON
EQUIVALENT DVORAK ESTIMATES OF T2.5/35 KNOTS FROM PGTW AND KNES.
ENVIRONMENTAL ANALYSIS SHOWS TS 30W IS IN A FAVORABLE AREA WITH LOW
(05-10 KNOT) VERTICAL WIND SHEAR (VWS) AND GOOD DUAL OUTFLOW. SEA
SURFACE TEMPERATURES ARE ALSO FAVORABLE AT 30-31 DEGREES CELSIUS. THE
CYCLONE IS TRACKING ALONG THE SOUTHWESTERN EDGE OF THE SUBTROPICAL
RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS 30W WILL CONTINUE TO TRACK NORTHWESTWARD UNDER THE
INFLUENCE OF THE STR THROUGHOUT THE FORECAST, PASSING APPROXIMATELY
70 NM TO THE SOUTH OF GUAM NEAR 290300Z. THE FAVORABLE CONDITIONS
WILL PERSIST AND FUEL GRADUAL INTENSIFICATION TO 105 KNOTS BY TAU 72.
DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT WITH GRADUAL SPREADING TO
150-NM BY TAU 72. THERE IS FAIR CONFIDENCE IN THIS PORTION OF THE
JTWC FORECAST TRACK THAT IS LAID NEAR THE CONSENSUS.
   C. AFTER TAU 72, TS 30W WILL CONTINUE ON A NORTHWESTWARD TRACK AND
BY TAU 120, WILL BE APPROXIMATELY 225 NM SOUTH-SOUTHEAST OF OKINAWA,
JAPAN. THE FAVORABLE ENVIRONMENTAL CONDITIONS WILL CONTINUE AND ALLOW
TS 30W TO REACH A PEAK INTENSITY OF 120 KNOTS (POSSIBLY HIGHER) BY
TAU 96 BEFORE WEAKENING MAINLY DUE TO INCREASING VWS. AFTER TAU 96,
TS 30W WILL BEGIN TO ROUND THE WESTERN EDGE OF THE STR AXIS AND TURN
SLIGHTLY NORTHWARD. DYNAMIC MODEL GUIDANCE SIGNIFICANTLY SPREADS OUT
WITH ECMWF AS THE NOTABLE LEFT OUTLIER AND CTCX ON THE RIGHT MARGIN
OF THE MODEL ENVELOPE. IN VIEW OF THE LARGE SPREAD (OVER 700 NM AT
TAU 120), THE CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC FORECAST
TRACK REMAINS LOW.//
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