Tropical Storm MEKKHALA Advisory Sat Jan 17

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 01W (MEKKHALA) WARNING NR 16//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 01W (MEKKHALA), LOCATED APPROXIMATELY 316 NM EAST-
SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 13
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) SHOWS THE SYSTEM HAS MAINTAINED A CENTRAL DENSE
OVERCAST FEATURE THAT CONTINUES TO OBSCURE THE LOW LEVEL CIRCULATION
CENTER. THE INITIAL POSITION JUST EAST OF SAMAR IS BASED ON THE MSI
LOOP AND A 170523Z N-19 89 GHZ MICROWAVE IMAGE WITH GOOD CONFIDENCE.
THE INITIAL INTENSITY OF 70 KNOTS IS MAINTAINED DUE TO DVORAK
ESTIMATES FROM ALL AGENCIES. UPPER-LEVEL ANALYSIS DEPICTS A
FAVORABLE ENVIRONMENT WITH MODERATE (10 TO 20 KNOTS) EASTERLY
VERTICAL WIND SHEAR IN-PHASE WITH THE SYSTEM MOTION AND GOOD RADIAL
OUTFLOW. THE CYCLONE IS CURRENTLY TRACKING ALONG THE SOUTHWESTERN
PERIPHERY OF AN ELONGATED  SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY MEKKHALA WILL TRACK TO THE NORTHWEST UNDER THE INFLUENCE OF
THE STR. AS THE SYSTEM MAKES LANDFALL, EXPECT THE TERRAIN OF EASTERN
PHILIPPINES TO CAUSE TY 01W TO BEGIN TO DISSIPATE. EXPECT THIS DECAY
TO OCCUR AS THE SYSTEM TRACKS THROUGH THE BICOL REGION AND THEN
SOUTH OF CALABARZON, WITH THE SYSTEM LESS THAN STORM FORCE STRENGTH
BY THE TIME IT REACHES MANILA. TY MEKKHALA WILL BE COMPLETELY
DISSIPATED AS IT RE-EMERGES IN THE SOUTH CHINA SEA BY TAU 72.  THERE
REMAINS TO BE A LARGE SPREAD IN DYNAMIC MODEL GUIDANCE WHICH LEADS
TO LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
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