WDPN31 PGTW 061500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (NOUL) WARNING NR 15//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 06W (NOUL), LOCATED APPROXIMATELY 933 NM EAST-
SOUTHEAST OF MANILA, PHILIPPINES HAS TRACKED WEST-NORTHWESTWARD AT 
08 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED 
SATELLITE IMAGERY DEPICTS SPIRAL BANDING WRAPPING INTO A DEEP 
CENTRAL DENSE OVERCAST FEATURE OBSCURING THE LOW LEVEL CIRCULATION 
CENTER. A 061035Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS A DEEP 
CONVECTIVE CENTRAL CORE STRUCTURE WITH AN OPEN MICROWAVE EYE FEATURE 
AND BROKEN CONVECTIVE SPIRAL BANDING. THE INITIAL POSITION IS BASED 
ON THE AFOREMENTIONED MICROWAVE IMAGE AND A 061241Z SCATTEROMETER 
PASS WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS BASED ON AN 
OVERALL ASSESSMENT OF DVORAK INTENSITY ESTIMATES FROM ALL AGENCIES. 
UPPER LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH NEAR 
RADIAL OUTFLOW AND LOW TO MODERATE (10-15 KNOT) VERTICAL WIND SHEAR 
THAT IS IN PHASE WITH THE CURRENT MOVEMENT. TY NOUL IS MOVING WEST-
NORTHWESTWARD UNDER THE INFLUENCE OF A SUB-TROPICAL RIDGE (STR) TO 
THE NORTHWEST.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM 
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY NOUL WILL CONTINUE TO TRACK WEST-NORTHWESTWARD AS THE STR 
TO THE NORTHWEST REMAINS THE DOMINANT STEERING MECHANISM. 
ENVIRONMENTAL CONDITIONS WILL REMAIN MOSTLY FAVORABLE WITH LOW TO 
MODERATE VERTICAL WIND SHEAR AND GOOD DIVERGENT OUTFLOW LEADING TO 
GRADUAL INTENSIFICATION. BEYOND TAU 48, AN UPPER LEVEL RIDGE PASSING 
TO THE NORTH WILL BUILD THE STEERING STR, KEEPING THE SYSTEM ON A 
WEST-NORTHWESTWARD TRAJECTORY AS IT APPROACHES THE CENTRAL 
PHILIPPINES. NEAR TAU 72, AN UPPER LEVEL TROUGH IS FORECAST TO PASS 
TO THE NORTH CAUSING THE STR TO WEAKEN, ALLOWING TY 06W TO TURN 
POLEWARD AND ROUND THE SOUTHWESTERN PERIPHERY OF THE STEERING STR. 
ADDITIONALLY, TY 06W WILL MOVE DOWNSTREAM FROM THE STR AXIS AND GAIN 
AN ENHANCED POLEWARD OUTFLOW, FURTHER ASSISTING IN THE GRADUAL 
INTENSIFICATION AND LEADING TO A MAXIMUM INTENSITY OF 125 KNOTS AT 
TAU 72.
   C. AFTER TAU 72, THE SYSTEM WILL CONTINUE TO TURN POLEWARD AND 
START TO WEAKEN DUE TO LAND INTERACTION AS IT SKIRTS THE EASTERN 
COAST OF THE CENTRAL PHILIPPINES AND LUZON. DYNAMIC MODEL GUIDANCE 
HAS SHIFTED WESTWARD AGAIN DUE TO UNCERTAINTY IN THE MID-LATITUDE 
PATTERN IMPACTING THE STEERING STR. BASED ON THE RECENT INSTABILITY 
IN THE EXTENDED PORTION OF THE MULTI-MODEL CONSENSUS, THERE IS LOW 
CONFIDENCE IN THE JTWC TRACK FORECAST.//
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