Tropical Storm SINLAKU Advisory 8月1日

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 04W (SINLAKU)
WARNING NR 001//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 04W (SINLAKU), LOCATED APPROXIMATELY 174 NM
NORTH OF DA NANG, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 15
KNOTS OVER THE PAST SIX HOURS. TS 04W HAS TRANSITIONED FROM A
MONSOON DEPRESSION TO A WARM-CORE TROPICAL CYCLONE. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY-EXPOSED LOW-
LEVEL CIRCULATION CENTER (LLCC) WITH FORMATIVE BANDING WRAPPING INTO
A BROAD CENTER. HOWEVER, A 010716Z GMI 37GHZ IMAGE INDICATES LOW-
LEVEL BANDING WRAPPING TIGHTLY INTO A DEFINED LLCC. ADDITIONALLY, A
010158Z ASCAT-A IMAGE INDICATED INCREASING GALE-FORCE WINDS OVER THE
NORTHWEST QUADRANT AND SOUTHERN SEMICIRCLE WITH A RADIUS OF MAXIMUM
WINDS (RMW) OF 70-80NM, WHICH, ALONG WITH THE MICROWAVE IMAGE,
PROVIDES SUFFICIENT EVIDENCE THAT THE LLCC HAS CONSOLIDATED AND THAT
THE RMW HAS CONTRACTED. SURFACE OBSERVATIONS FROM BACH LONG VI
(48839), 83NM NNW OF THE CENTER, INDICATE NORTHEASTERLY WINDS AT 23
KNOTS (10-MINUTE AVERAGE) WHILE THE 01/00Z SOUNDING SHOWS 33-45 KNOT
WINDS JUST ABOVE THE SURFACE (500-1800 FEET). BASED ON THE ASCAT
DATA AND UPPER-AIR DATA, THE INITIAL INTENSITY IS ASSESSED AT 35
KNOTS. THE INITIAL POSITION IS BASED ON RECENT MICROWAVE IMAGERY
WITH FAIR CONFIDENCE. TS 04W IS CURRENTLY TRACKING WEST-
NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE LOW- TO MID-
LEVEL SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
  A. THIS IS THE INITIAL PROGNOSTIC REASONING MESSAGE AND SETS THE
FORECAST PHILOSOPHY.
  B. TS 04W IS FORECAST TO CONTINUE TRACKING WEST-NORTHWESTWARD
THROUGH THE FORECAST PERIOD, MAKING LANDFALL OVER VIETNAM NEAR TAU
18. THE SYSTEM IS EXPECTED TO INTENSIFY SLIGHTLY OVER THE WARM
WATERS (29-30C) OF THE GULF OF TONKIN, HOWEVER, PERSISTENT
NORTHEASTERLY VERTICAL WIND SHEAR (20-30 KNOTS) SHOULD LIMIT
INTENSIFICATION TO A PEAK OF 40 KNOTS. AFTER TAU 18, TS 04W WILL
TRACK INLAND AND DISSIPATE OVER MOUNTAINOUS TERRAIN BY TAU 36.
NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT, THEREFORE, THERE IS
MODERATE CONFIDENCE IN THE FORECAST TRACK.//
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