WDPN32 PGTW 272100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W (SIX) WARNING 
NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.3N 136.1E
   INITIAL INTENSITY: 25 KTS
   GEOGRAPHIC REFERENCE: 919 NM SOUTH-SOUTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 18 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY VERIFIES
DEEPENING CONVECTION AND A LITTLE CONSOLIDATION OVER THE PAST SIX
HOURS. THE DEEPEST CONVECTION REMAINS TO THE SOUTH OF THE
LOW LEVEL CIRCULATION CENTER (LLCC) IN THE CONVERGENT
SOUTH WESTERLIES WHILE THE ACTUAL LLCC REMAINS EXTREMELY DIFFICULT
TO DISCERN DUE TO SLOPPY CLOUD COVER IN THE CENTER OF THE
SYSTEM. FORTUNATELY THERE WAS A DIRECT OVERHEAD SCATTEROMETRY PASS
NEAR 12Z THAT ALLOWS FOR REASONABLE CERTAINTY IN PLACEMENT ALONG A
CONSTANT BEARING AND SPEED OF ADVANCE. ANIMATED WATER VAPOR IMAGERY
SHOWS SUBSIDENCE AND 30 PLUS KNOTS OF VERTICAL WIND SHEAR (VWS)
NORTH OF THE 18TH LATITUDE BUT OVER THE SYSTEM THERE IS A NARROW
BAND OF GOOD POLEWARD OUTFLOW OVER THE NORTHEAST QUADRANT AND
EXCELLENT EQUATORWARD OUTFLOW. THE CURRENT INTENSITY IS BASED ON
THE JTWC AND KNES DVORAKS OF T1.5 AND SUPPORTED BY THE EARLIER
SCATTEROMETRY. THE SYSTEM HAS A WAYS TO GO BUT WE HAVE SEEN THE
EARLY INDICATIONS OF CONSOLIDATION VIA CONTRACTION IN THE
RADIUS OF MAXIMUM WINDS AND MORE COHERENT TURNING AROUND THE LLCC
IN THE SATELLITE ANIMATION. ANIMATED TOTAL PRECIPITABLE WATER LOOPS
AND 700-300MB MOISTURE PROFILES INDICATE A NARROW TONGUE OF DRY AIR
BEING DRAWN INTO THE NORTHWEST QUADRANT BUT OTHERWISE THE ALONG
TRACK ENVIRONMENT IS SATURATED WITH DEEP MOISTURE.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: THE SOUTHWESTERN PERIPHERY OF AN
850-500MB REFLECTION OF THE SUBTROPICAL RIDGE, WHICH IS ANCHORED
IN AN ANTICYCLONE NEAR 32N 152E. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T2.0 - 30 KTS
   KNES: T1.5 - 25 KTS
   CIMSS ADT: 33 KTS AT 271730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TD 06W WILL CONTINUE ORGANIZING AND
DEEPENING ALONG A NORTHWESTERLY BEARING FOR THE NEXT 12 HOURS, THEN
SHIFT TO A MORE POLEWARD TRACK AS IT LEAVES THE INFLUENCE OF THE
SUBTROPICAL RIDGE AND GETS A NUDGE FROM THE BOTTOM VIA THE NEAR
EQUATORIAL RIDGE. A STRONG ANTICYCLONE ALOFT BUILDING OVER TOKYO
WILL EVENTUALLY BLOCK THE POLEWARD MOVEMENT AND TURN THE SYSTEM
TOWARDS THE SOUTHERN PORTION OF THE RYUKYU ISLANDS, WITH A NEAR-
DIRECT PASSAGE TO OKINAWA. ALTHOUGH RECENT MODEL RUNS INDICATE 
PASSAGE NEAR OR JUST SOUTH OF THE ISLAND IT BEARS REITERATION THAT 
OPERATORS SHOULD NOT FIXATE ON THE VORTEX BUT RATHER THE WIND FIELDS 
AROUND IT, AS CPA ESTIMATES WILL OSCILLATE UNDER THE MOST MUNDANE 
PATTERNS, AND WITH THREE DIFFERENT STEERING FORCES AND 1000 MILES TO 
GO THERE WILL BE MORE THAN THE USUAL VARIATION IN CPAS. OPERATORS ARE 
REMINDED TO USE THE CAC-ENABLED DECISION SUPPORT PORTAL TO SEE WIND 
FIELD PROBABILITIES AND ONSET TIMES. AS TD 06W CROSSES THE TROPIC OF 
CANCER AND MAKES THE DOGLEG TOWARDS THE RYUKYUS THE ENVIRONMENT WILL 
BECOME EXTREMELY FAVORABLE AND THE SYSTEM WILL LIKELY TOP 100 KNOTS 
AS IT TRACKS INTO THE EAST CHINA SEA. 

MODEL DISCUSSION: BOTH DETERMINISTIC AND ENSEMBLE GUIDANCE HAS BEEN
TIGHTER THAN USUAL DURING THE FORMATION OF THIS STORM. TRACK
GUIDANCE IS TIGHT AND UNANIMOUS ABOUT THE TIMING AND LOCATION OF
THE DOGLEG TO THE NORTHWEST NEAR 30JUL18Z AND CROSS-TRACK SPREAD IS
FAR LESS THAN AVERAGE. INTENSITY AIDS ARE IN BETTER THAN AVERAGE
AGREEMENT AS WELL. THE JTWC FORECAST STAYS ABOVE THE PACK AND
CLOSER TO THE MESOSCALE GUIDANCE ESPECIALLY THE HHFI. THE COAMPS-TC
GUIDANCE IS ALSO TRIGGER RI INDICATORS IN THE 48-120 HR RANGE. THUS
THE JTWC TRACK FORECAST STAYS TIGHT ON THE CONSENSUS BUT THE
INTENSITY FORECAST IS MUCH HIGHER THAN THE MEAN GUIDANCE. 

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