WDPN31 PGTW 132100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 02W (SURIGAE) 
WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
    TROPICAL DEPRESSION (TD) 02W (SURIGAE), LOCATED APPROXIMATELY
27 NM WEST-SOUTHWEST OF NGULU, HAS TRACKED NORTHWESTWARD AT 03 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY SHOWS THE SYSTEM HAS FURTHER CONSOLIDATED WITH CONVECTION 
INCREASING OVERHEAD THE LOW LEVEL CIRCULATION CENTER. THE INITIAL 
POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON 131910Z SSMIS 91GHZ 
MICROWAVE IMAGERY SHOWING BANDING WRAPPING AROUND THE LLCC FROM ITS 
WESTERN PERIPHERY. THE INTENSITY OF 30 KNOTS IS BASED ON A PGTW 
DVORAK FIX OF T2.0 (30 KNOTS) AND AN ADVANCED DVORAK TECHNIQUE 
ESTIMATE OF 29 KNOTS. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT 
WITH POLEWARD AND EQUATORWARD OUTFLOW CHANNELS, LOW (10-20 KNOTS) 
VERTICAL WIND SHEAR, AND VERY WARM (29-30 DEGREES CELSIUS) SEA 
SURFACE TEMPERATURES IN THE PHILIPPINE SEA. THE CYCLONE IS TRACKING 
ALONG THE SOUTHWEST PERIPHERY OF A SUBTROPICAL RIDGE EXTENSION 
LOCATED TO THE NORTHEAST. 
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.   
   B. TD 02W WILL TRACK SLOWLY NORTHWARD THEN NORTHWESTWARD OVER THE 
NEXT 72 HOURS AS THE AFOREMENTIONED SUBTROPICAL RIDGE (STR) 
REORIENTS. THE AFOREMENTIONED FAVORABLE ENVIRONMENT WILL MAINTAIN 
AND PROMOTE STEADY INTENSIFICATION TO 75 KNOTS BY TAU 72. NUMERICAL 
MODELS ARE IN OVERALL GOOD AGREEMENT WITH AN IMPROVED CROSS TRACK 
SPREAD OF 110NM BY TAU 72 WITH THE DETERMINISTIC ECMWF TRACKING 
CLOSER TO THE PHILIPPINES AND JGSM SHOWING A MORE POLEWARD TRACK, 
WITH THE REMAINING MODELS FALLING BETWEEN THE TWO. GIVEN THE 
UNCERTAINTY IN THE INITIAL STORM MOTION, THERE IS FAIR CONFIDENCE IN 
THIS PORTION OF THE JTWC TRACK FORECAST.
   C. AFTER TAU 72, TD 02W WILL CONTINUE NORTHWESTWARD TOWARD THE 
BREAK IN THE RIDGE FORMED BY A MIDLATITUDE TROUGH DIGGING IN FROM 
EASTERN ASIA. AFTER THE STR BREAKS, TD 02W WILL TRACK ALONG THE 
WESTERN PERIPHERY OF THE STR FEATURE POSITIONED TO ITS EAST, DRIVING 
IT FURTHER NORTHWESTWARD UNTIL REACHING THE STR AXIS AROUND TAU 120. 
CONTINUED INTENSIFICATION IS EXPECTED AS THE FAVORABLE CONDITIONS 
ARE FURTHER ENHANCED BY INCREASED POLEWARD OUTFLOW. BY TAU 120, TD 
02W IS EXPECTED TO REACH 115 KNOTS. NUMERICAL MODELS SPREAD OUT EVEN 
MORE TO OVER 250NM BY TAU 120, LENDING LOW CONFIDENCE TO THE 
EXTENDED PORTION OF THE JTWC TRACK FORECAST.//
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