WDPN32 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W (KHANUN) 
WARNING NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.1N 135.9E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 924 NM SOUTH-SOUTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: WESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) CONFIRMS TD 06W
(KHANUN) IS SLOWLY CONSOLIDATING AND ORGANIZING AROUND A LOW LEVEL
CIRCULATION CENTER (LLCC).  THE LLCC SITS AT THE POLEWARD TIP OF
THE BIGGEST AND DEEPEST CONVECTIVE SHIELD, WHICH EXTENDS ALONG THE
SOUTHERN PERIPHERY OF A RELATIVELY CLOUD-FREE CENTROID.  THREE
COMPLEXES OF DEEP CONVECTION ARE ROTATING AROUND THE CENTROID AND 
CLOSING IN ON THE CENTROID. RECENT SCATTEROMETRY THAT COVERED THE 
WESTERN SEMICIRCLE DOES NOT SHOW GALE FORCE WINDS OUTSIDE OF THE 
DEEPEST CONVECTION AND SUPPORTS THE JTWC DVORAK ASSESSMENT OF T2.0.
ANIMATED WATER VAPOR IMAGERY SHOWS SUBSTANTIAL SUBSIDENCE AND
ASSOCIATED DRYING TO THE DISTANT NORTHWEST OF THE SYSTEM BUT THE
ENVIRONMENT IN THE IMMEDIATE VICINITY OF THE STORM IS RICH IN DEEP 
MOISTURE. THE WATER VAPOR ALSO SHOWS THAT EQUATORWARD OUTFLOW TO THE
SOUTHWEST IS PARTICULARLY ROBUST. TOTAL PRECIPITABLE WATER LOOPS
ALSO INDICATE THAT THE SYSTEM IS COCOONING ITSELF FROM THE DRIER
POLEWARD ENVIRONMENT AND SATELLITE ANIMATION CONFIRMS THAT THE
EARLY STAGES OF CONSOLIDATION AND DEEPENING ARE UNDERWAY.

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: T2.0 - 30 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   CIMSS ADT: 35 KTS AT 272330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 20-25 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD
   OTHER FACTORS: THERE IS ALSO A NARROW AND COMPRESSED BUT VIABLE
POLEWARD OUTFLOW CHANNEL OVER THE NORTHEAST QUANDRANT. 

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: HIGH
   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: CONSOLIDATION AND DEEPENING OF TD 06W (KHANUN)
WILL CONTINUE AS THE SYSTEM TURNS TO A NORTHWESTERLY BEARING DURING
THE NEXT 12 HOURS. THE STEERING INFLUENCE OF AN EXTENSION OF THE
SUBROPICAL RIDGE IS WANING AND THE NEAR-EQUATORIAL RIDGE IS TAKING
OVER AS THE DOMINANT STEERING FORCE.  AS THE SYSTEM CROSSES THE
TROPIC OF CANCER A STRONG ANTICYCLONE ALOFT THAT IS SETTING UP OVER 
THE KANTO PLAIN REGION WILL BLOCK POLEWARD MOVEMENT AND DRIVE THE
SYSTEM TOWARDS THE SOUTHERN RYUKUS. AS THAT OCCURS IT WILL FORCE A
DOGLEG TOWARDS THE RYUKYUS AND TAKE THE SYSTEM INTO AN EXTREMELY
FAVORABLE ENVIRONMENT AND THE SYSTEM WILL LIKELY TOP 100 KNOTS
BEFORE IT TRACKS INTO THE EAST CHINA SEA. THE LATEST GUIDANCE HAS
SUBTLY SHIFTED THE TRACK TO JUST SOUTH OF OKINAWA BUT THE GUIDANCE
ENVELOPE HAS SPREAD A LITTLE. STILL, AT THIS EARLY JUNCTURE, THE
TRACK CERTAINTY IS HIGHER THAN AVERAGE. IT BEARS REPEATING THAT
OPERATORS SHOULD NOT FIXATE ON THE VORTEX BUT RATHER THE WIND
FIELDS AROUND IT, AS CPA ESTIMATES WILL OSCILLATE UNDER EVEN THE MOST
MUNDANE PATTERNS.  WITH THREE DIFFERENT STEERING FORCES AND OVER
900 MILES TO THE RYUKUS SOME VARIATION IN THE CPAS IS TO BE
EXPECTED. OPERATORS ARE REMINDED TO USE THE CAC-ENABLED DECISION
SUPPORT PORTAL TO SEE WIND FIELD PROBABILITIES AND ONSET TIMES. 

MODEL DISCUSSION: TRACK GUIDANCE SPREAD A LITTLE DURING THE MOST
RECENT CYCLE BUT STILL SHOWS EXCELLENT AGREEMENT AROUND A PASSAGE
NEAR OR JUST SOUTH OF OKINAWA. INTENSITY GUIDANCE SHOWS A LINEAR
INTENSIFICATION TREND AND MESOSCALE MODELS ARE SHOWING SIGNIFICANT
PROBABILITIES OF RAPID INTENSIFIATION IN THE 48 THROUGH 96 HOUR
PERIOD. THE JTWC TRACK FORECAST STAYS NEAR THE CONSENSUS WHILE THE
INTENSITY FORECAST RIDES THE HIGH SIDE OF THE GUIDANCE ENVELOPE,
FAVORING THE MESOSCALE GUIDANCE SUCH AS COAMPS-TC. 

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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