WDPN32 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (SAOLA) WARNING NR 018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.8N 124.3E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 232 NM NORTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 42 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
AS DEPICTED IN ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY,
TYPHOON (TY) 09W ACCELERATED ABRUPTLY NORTHEASTWARD OVER THE PAST
SIX HOURS AND RAPIDLY REFORMED A SMALL 6NM EYE. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON ANIMATED
MULTISPECTRAL SATELLITE IMAGERY. A 272220Z SSMIS 91 GHZ COLOR
COMPOSITE MICROWAVE IMAGE SHOWS A SMALL 40 NM INNER EYEWALL
SURROUNDED BY A MOAT AND A FRAGMENTED OUTER EYEWALL. AS MENTIONED IN 
THE 271800Z PROGNOSTIC REASONING MESSAGE, THE CIMSS M-PERC
PRODUCT INDICATED A HIGH PROBABILITY OF AN EYEWALL REPLACEMENT
CYCLE (ERC) OCCURRING. THE MOST RECENT PROBABILITIES HAVE DROPPED
FROM 90 PERCENT TO ABOUT 50 PERCENT BUT STILL SUGGEST AN IMMINENT
ERC.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: NEAR-EQUATORIAL (NER) RIDGE ENTRENCHED
TO THE SOUTH WITH A WEAK EXTENSION OF THE NER TO THE EAST,
SEPARATING 09W FROM A DEVELOPING TROPICAL SYSTEM (INVEST 93W) NEAR
THE NORTHERN MARIANAS. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T5.0 - 90 KTS
   RCTP: T6.5 - 127 KTS
   KNES: T5.5 - 102 KTS
   CIMSS SATCON: 78 KTS AT 272220Z
   CIMSS ADT: 84 KTS AT 272330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: AFTER A SHORT PERIOD OF WEAKENING, TY 09W
APPEARS TO BE POISED TO REINTENSIFY TO A PEAK OF 130 KNOTS BY TAU
24. THE SYSTEM SHOULD MAINTAIN SUPER TYPHOON STRENGTH THROUGH AT
LEAST TAU 36. AFTER TAU 24, STEERING SHOULD TRANSITION FROM THE NER
TO A BUILDING SUBTROPICAL RIDGE (STR) OVER THE EAST CHINA SEA. THIS
WILL ALLOW TY 09W TO TRACK WEST-NORTHWESTWARD THROUGH TAU 120. THE
STR, ESPECIALLY THE WESTERN EXTENT, SHOULD REMAIN WEAK DUE TO THE
PRESENCE OF A STRONG, BROAD UPPER LEVEL LOW AND TROUGH DEVELOPING
OVER NORTHEAST ASIA THUS TRACK SPEEDS WILL REMAIN CLIMATOLOGICALLY 
SLOW. STEADY WEAKENING WILL OCCUR IN THE EXTENDED FORECAST PERIOD DUE 
TO LAND INTERACTION WITH TAIWAN AND SOUTHEAST CHINA.

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, NUMERICAL MODEL
GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72 LENDING HIGH
CONFIDENCE TO THE JTWC FORECAST TRACK. THERE IS MEDIUM CONFIDENCE
IN THE JTWC INTENSITY FORECAST DUE TO POTENTIAL FOR AN ERC, WHICH
MAY TEMPORARILY WEAKEN THE SYSTEM. HOWEVER, CONDITIONS APPEAR
FAVORABLE FOR SIGNIFICANT INTENSIFICATION OVER THE NEXT TWO DAYS
WITH RAPID INTENSIFICATION GUIDANCE TRIGGERED AND THE 271800Z
COAMPS-TC ENSEMBLE SHOWING A 30-40 PERCENT PROBABILITY OF RAPID
INTENSIFICATION OCCURRING THROUGH TAU 48. AFTER TAU 72, TRACK
GUIDANCE DIVERGES WITH A 390 NM CROSS-TRACK SPREAD IN SOLUTIONS AT
TAU 120. THIS INCREASING UNCERTAINTY AND LOW TRACK CONFIDENCE IS
REFLECTED IN THE 271800Z EPS AND GEFS ENSEMBLES, WHICH SHOW A LARGE
SPREAD. BOTH THE GFS DETERMINISTIC SOLUTION AND GEFS ENSEMBLE
SUGGEST A PROBLEMATIC, POTENTIAL SCENARIO WHERE INVEST 93W
STRENGTHENS AND TRACKS WESTWARD TOWARD TAIWAN, CLOSING TO ABOUT 590
NM AT TAU 120. SOME DEGREE OF BINARY INTERACTION THEN OCCURS BETWEEN 
THE TWO SYSTEMS. THIS POTENTIAL SCENARIO IS COMPLEX AND WILL BE
MONITORED CLOSELY.


FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
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