WDPN31 PGTW 130300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (SIXTEEN) WARNING 
NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.7N 168.6E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 245 NM NORTH OF KWAJALEIN
   MOVEMENT PAST 6 HOURS: WESTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 11 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION
IS PLACED WITH MEDIUM CONFIDENCE BASED ON A 122209Z AMSU PASS
SHOWING A CONSOLIDATING LLCC WITH THE MOST SIGNIFICANT CONVECTION
DISPLACED TO THE NORTH. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED
WITH MEDIUM CONFIDENCE BASED ON DVORAK INTENSITY ESTIMATES AND ADT.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHWEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T2.5 - 35 KTS
   CIMSS SATCON: 42 KTS AT 122210Z
   CIMSS ADT: 35 KTS AT 122340Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL STORM (TS) 16W IS CURRENTLY TRACKING
GENERALLY WESTWARD ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL
RIDGE TO THE NORTHWEST. THE SYSTEM IS CURRENTLY BUFFETTED BY WIND
SHEAR, HOWEVER, THE APPROACHING TUTT CELL IN ITS PATH LEAVES
SIGNIFICANT UNCERTAINTY IN INTENSIFICATION IN THE NEAR TERM. IF
TRACK SHIFTS TOO FAR NORTH, SHEAR WILL SIGNIFICANTLY INHIBIT
DEVELOPMENT, BUT IF TS 16W PASSES TO THE SOUTH OF THE TUTT CELL,
THE ENHANCED OUTFLOW MAY CAUSE RAPID INTENSIFICATION BEFORE
REACHING THE MARIANAS. ADDITIONALLY, AROUND TAU 72 AN INCREASE IN
SEA SURFACE TEMPERATURES WILL FURTHER PROVIDE AN IMPROVED 
ENVIRONMENT FOR DEVELOPMENT. 

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS CONSISTENT WITH 
LOW CROSS-TRACK SPREAD, ONLY INCREASING UP TO ONLY 110NM THROUGH TAU 
120, DISREGARDING NAVGEM'S TRACK SIGNIFICANTLY RIGHT OF TRACK. 
DESPITE UNCERTAINTY IN THE NEAR TERM, THE MODEL INTENSITY GUIDANCE 
REMAINS CONSISTENT UP TO TAU 72, SUPPORTING A FLAT INTENSITY UP TO 
TAU 72. HOWEVER, AFTER TAU 72, MODELS STILL REMAIN BELOW TYPHOON 
STRENGTH, BUT VARY SIGNIFICANTLY ON INTENSITY.

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