Tropical Storm MATMO Advisory Cu, 18.07.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (TEN) WARNING
NR 02//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 10W (TEN), LOCATED APPROXIMATELY 193 NM WEST-
NORTHWEST OF YAP, HAS TRACKED NORTH-NORTHWESTWARD AT 04 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS A STEADY INCREASE IN CENTRALIZED DEEP CONVECTION WITH
DEVELOPING BANDS WRAPPING ALONG THE SOUTHERN AND EASTERN QUADRANTS OF
THE SYSTEM. THE CURRENT INTENSITY OF 35 KNOTS IS BASED ON DVORAK
ESTIMATES FROM PGTW AND RJTD. UPPER-LEVEL ANALYSIS INDICATES THE
SYSTEM IS LOCATED IN A MARGINAL ENVIRONMENT WITH MODERATE (15 TO 20
KNOTS) VERTICAL WIND SHEAR (VWS), WHICH IS PROVIDING EXCELLENT
EQUATORWARD OUTFLOW, EVIDENT IN ANIMATED WATER VAPOR IMAGERY.
TS 10W IS CURRENTLY POSITIONED IN A WEAK STEERING ENVIRONMENT
BETWEEN A DEEP-LAYER SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH
AND A NEAR EQUATORIAL RIDGE (NER) TO THE SOUTHEAST.
3. FORECAST REASONING.
   A. NO CHANGE TO FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC
REASONING MESSAGE.
   B. TS 10W IS EXPECTED TO TRACK SLOWLY NORTHWARD WITHIN THE WEAK
STEERING ENVIRONMENT THROUGH TAU 24. AFTER TAU 24 THE STR IS
FORECAST TO BECOME THE DOMINANT STEERING INFLUENCE AS THE NER
WEAKENS. TRACK SPEEDS WILL PICK UP AFTER TAU 36 TRACKING THE SYSTEM
TO THE NORTHWEST. VWS WILL REMAIN AT MODERATE LEVELS THROUGH TAU 48,
WHICH WILL INHIBIT STRONG INTENSIFICATION, BUT TS 10W IS EXPECTED
TO STRENGTHEN WITH THE VERY FAVORABLE SEA SURFACE TEMPERATURES AND
HIGH OCEAN HEAT CONTENT ALONG THE FORECAST TRACK. BEYOND TAU 48 THE
VWS WILL DECREASE, ALLOWING FOR FURTHER INTENSIFICATION. THE TRACK
WILL REMAIN ON A GENERAL NORTHWEST TRACK THROUGH TAU 72 ALONG THE
SOUTHWESTERN QUADRANT OF THE DEEP LAYERED STR.
   C. IN THE EXTENDED TAUS, A DIGGING MID-LATITUDE TROUGH WILL CAUSE
THE STR TO WEAKEN OVER SOUTHERN JAPAN, WITH THE POSSIBILITY OF TWO
SEPARATE STRS TO DEVELOP. AS THE TROUGH MOVES EASTWARD, THE TWO STRS
ATTEMPT TO BUILD BACK OVER SOUTHERN JAPAN. BETWEEN TAU 96 AND 120
MODEL GUIDANCE IS SPLIT BETWEEN A TURN NORTHWARD (GFS, COAMPS, GFDN)
AND A CONTINUED NORTHWEST TRACK TOWARDS NORTHERN TAIWAN (NAVGEM,
ECMWF). THIS FORECAST FAVORS A SLIGHT TURN NORTHWARD, REMAINING MORE
WITH THE CONSENSUS OF MODEL GUIDANCE. THE ENVIRONMENT WILL REMAIN
FAVORABLE FOR DEVELOPMENT THROUGH TAU 120, WITH A MAXIMUM INTENSITY
FORECAST TO BE 95 KNOTS. DUE TO THE SLOW AND/OR ERRATIC MOVEMENT IN
THE NEAR TERM AND THE UNCERTAINTY OF THE TRACK AT EXTENDED TAUS,
THE CONFIDENCE IN THE FORECAST TRACK REMAINS AT LOW CONFIDENCE.//
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