Tropical Storm MATMO Advisory Mon Jul 21

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 10W (MATMO) WARNING NR 15//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 10W (MATMO), LOCATED APPROXIMATELY 597 NM
SOUTH-SOUTHEAST OF TAIPEI, TAIWAN, HAS TRACKED NORTH-NORTHWESTWARD AT
12 KTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS THE SYSTEM HAS MAINTAINED A LARGE CENTRAL CONVECTION
THAT CONTINUES TO OBSCURE THE LOW-LEVEL CIRCULATION CENTER. THE
INITIAL POSITION IS EXTRAPOLATED WITH FAIR CONFIDENCE FROM A LOW
REFLECTIVITY ARC ON A 202348Z SSMIS MICROWAVE IMAGE. THE INITIAL
INTENSITY IS AVERAGED FROM AGENCY DVORAK ESTIMATES. UPPER-LEVEL
ANALYSIS INDICATES THE VERTICAL WIND SHEAR, NOW AT 10-15 KNOTS, HAS
BEGUN TO RELAX AS THE CYCLONE APPROACHED THE RIDGE AXIS. ALSO, THE
VWS REMAINS OFFSET BY GOOD WESTWARD AND EQUATORWARD OUTFLOW. TY 10W
IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYERED
SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY 10W IS FORECAST TO REMAIN ON ITS CURRENT TRACK UNDER THE
STEERING INFLUENCE OF THE STR THROUGH TAU 72. UPPER-LEVEL CONDITIONS
ARE EXPECTED TO CONTINUE IMPROVING WITH DECREASING VWS AND THE
ADDITION OF A POLEWARD OUTFLOW CHANNEL AS THE SYSTEM GAINS LATITUDE.
ADDITIONALLY, WARM SEA SURFACE TEMPERATURES IN THE PHILIPPINE SEA ARE
CONDUCIVE FOR FURTHER INTENSIFICATION, LEADING TO A PEAK INTENSITY OF
100 KNOTS, POSSIBLY GREATER, BY TAU 48 AS IT APPROACHES TAIWAN.
AFTERWARDS, THE SYSTEM IS EXPECTED TO TRACK ACROSS NORTHERN TAIWAN
AND THE TAIWAN STRAIT. BY TAU 72, THE CYCLONE WILL HAVE MADE LANDFALL
OVER THE CHINESE SOUTHEASTERN SEABOARD.
   C. AFTER TAU 72, A MID-LATITUDE TROUGH APPROACHING FROM THE
NORTHWEST IS EXPECTED TO WEAKEN THE STR AND CAUSE TY MATMO TO TURN
POLEWARD. HOWEVER, RAPID DECAYING IS EXPECTED DUE TO THE FRICTIONAL
EFFECTS OF LAND. TY 10W WILL EMERGE BACK OVER WATER IN THE YELLOW SEA
AS A TROPICAL DEPRESSION BY TAU 108. AVAILABLE MODEL GUIDANCE REMAINS
IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC TRACK
FORECAST WHICH IS POSITIONED CLOSE TO THE MULTI-MODEL CONSENSUS.//
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