WDPN31 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (MALAKAS) WARNING NR 
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 5.7N 146.0E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 484 NM SOUTH OF ANDERSEN AFB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD
LOW-LEVEL CIRCULATION WITH DEEP CONVECTIVE BANDING OVER THE
NORTHERN SEMICIRCLE WRAPPING INTO THE WESTERN QUADRANT. MSI
CONTINUES TO SHOW VIGOROUS NORTHWESTERLY FLOW ALONG THE SOUTHERN
FLANK OF THE SYSTEM WITH OUTFLOW BOUNDARIES EVIDENT OVER THE
SOUTHEASTERN QUADRANT PROPAGATING NORTHEASTWARD. A 080607Z SSMIS
91GHZ MICROWAVE IMAGE SHOWS FRAGMENTED CONVECTIVE BANDING PRIMARILY
OVER THE NORTHERN SEMICIRCLE WITH A BROAD, WEAKLY-DEFINED LOW-LEVEL
CIRCULATION CENTER. THE SSMIS WIND PRODUCT DOES SHOW A DEFINED,
ASYMMETRIC WIND MINIMUM, WHICH SUGGESTS THE CENTER COULD BE
SLIGHTLY EAST OR NORTHEAST OF THE INITIAL POSITION, HOWEVER, THERE
IS LITTLE CORROBORATING EVIDENCE IN THE 37GHZ AND COLOR COMPOSITE
IMAGERY. CONSEQUENTLY, THERE IS LOW CONFIDENCE IN THE INITIAL
POSITION, WHICH COULD LEAD TO SIGNIFICANT SHORT-TERM UNCERTAINTY IN
THE SHORT-TERM TRACK UNTIL THE SYSTEM CONSOLIDATES FURTHER. THIS
UNCERTAINTY IS REFLECTED IN THE 080000Z MODEL INITIAL POSITIONS
WHICH ARE SPREAD ACROSS A 54NM SWATH CENTERED ON THE JTWC 080000Z
INITIAL POSITION SO CLEARLY THE NUMERICAL MODELS ARE ALSO
STRUGGLING TO LOCATE THE SYSTEM CENTER. THE INITIAL INTENSITY OF 45 KTS 
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE KNES AND PGTW DVORAK
ESTIMATES. THE ADT ESTIMATES ARE BASED ON AN EMBEDDED CENTER SCENE
TYPE AND APPEAR TO BE A BIT TOO HIGH SINCE THE OVERALL ORGANIZATION
IS BROAD AND WEAKLY-DEFINED. UPPER-LEVEL ANALYSIS INDICATES
GENERALLY FAVORABLE CONDITIONS WITH MODERATE POLEWARD AND
EQUATORWARD OUTFLOW, LOW VERTICAL WIND SHEAR, WARM SST AND HIGH
OCEAN HEAT CONTENT, HOWEVER, THE BROAD NATURE OF THE LOW-LEVEL
CIRCULATION IS SLOWING DEVELOPMENT.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF A DEEP-LAYERED
SUBTROPICAL RIDGE TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T2.0 - 30 KTS
   KNES: T3.0 - 45 KTS
   CIMSS SATCON: 50 KTS AT 080353Z
   CIMSS ADT: 59 KTS AT 080540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   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. ALTERNATE SCENARIO POSSIBLE
(SEE BELOW).

FORECAST DISCUSSION: TS 02W CONTINUES TO STRUGGLE TO CONSOLIDATE AS
REVEALED IN THE RECENT MSI AND MICROWAVE IMAGERY DESPITE THE
FAVORABLE ENVIRONMENTAL CONDITIONS. UNCERTAINTY IN THE INITIAL
POSITION COULD LEAD TO RELOCATIONS AND SIGNIFICANT SHIFTS IN THE
SHORT-TERM FORECAST TRACK UNTIL THE LOW-LEVEL CIRCULATION CENTER
BECOMES STRONGER AND BETTER DEFINED. TS 02W IS FORECAST TO TRACK
NORTHWESTWARD ALONG THE SOUTHERN AND SOUTHWESTERN PERIPHERIES OF
THE STR THROUGH TAU 96. AFTER TAU 96, TS 02W WILL SLOW SLIGHTLY AND
TURN NORTHWARD AS IT APPROACHES A LARGE BREAK IN THE STR POSITIONED
SOUTH AND SOUTHEAST OF OKINAWA. TS 02W WILL INTENSIFY SLOWLY
THROUGH TAU 24 AS IT CONSOLIDATES UNDER GENERALLY FAVORABLE
CONDITIONS BUT IS FORECAST TO INTENSIFY AT A STEEPER RATE AFTER TAU
24 AS THE LOW-LEVEL CIRCULATION CONSOLIDATES AND POLEWARD OUTFLOW
IMPROVES. THE PEAK INTENSITY OF 100 KNOTS IS EXPECTED NEAR TAU 96
THROUGH TAU 120.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE THROUGH TAU 72 IS IN
BETTER AGREEMENT WITH A 175NM SPREAD IN SOLUTIONS AT TAU 72 LENDING
MEDIUM CONFIDENCE TO THE JTWC FORECAST TRACK. HOWEVER, AS MENTIONED
EARLIER, THERE COULD BE SOME SHORT-TERM ADJUSTMENTS TO THE JTWC
FORECAST TRACK OVER THE NEXT 1-2 DAYS AS THE SYSTEM CONSOLIDATES IN
THE LOW-LEVELS. INTENSITY GUIDANCE VARIES CONSIDERABLY WITH
COAMPS-TC (GFS AND NAVGEM VERSIONS) ON THE LOWER END OF THE
GUIDANCE AT TAU 72 (55-70 KNOTS) AND THE RAPID INTENSIFICATION
PREDICTION AID (RIPA) AT 110 KNOTS AT TAU 72, WHICH IS ASSESSED AS
UNLIKELY. THE JTWC INTENSITY FORECAST IS NOT AS AGGRESSIVE AS RIPA
BUT IS POSITIONED HIGHER (90 KNOTS) THAN THE JTWC INTENSITY
CONSENSUS (ICNW), WHICH HAS A PEAK OF 73 KNOTS AT TAU 72. AFTER TAU
72, MODEL GUIDANCE DIVERGES WITH TWO DISTINCT TRACK SCENARIOS:
FIRST IS THE SCENARIO CURRENTLY FAVORED BY JTWC, THE SLOW RECURVE
NORTHWARD TO NORTH-NORTHEASTWARD. SECOND, IS THE ALTERNATE SCENARIO
DEPICTED BY ECMWF, WHICH TRACKS THE SYSTEM MORE WESTWARD WHILE
STRONGLY INTERACTING WITH, AND UNDERGOING FUJIWHARA INTERACTION
WITH A DEVELOPING TROPICAL CYCLONE (INVEST 94W) NEAR THE
PHILIPPINES. DUE TO THE COMPLEXITY OF THE EVOLVING SYNOPTIC
ENVIRONMENT, THERE IS LOW CONFIDENCE IN THE 72-120 HOUR JTWC TRACK
AND INTENSITY FORECAST.      

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