WDPS31 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER)
WARNING NR 006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 11.0S 157.2E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 187 NM WEST-SOUTHWEST OF HONIARA, SOLOMON
ISLANDS
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 29 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
CYCLONE (TC) 03P (JASPER) SHOWING A NEARLY CLOUD-FREE DIMPLE
LOCATED OVERHEAD THE ASSESSED LOW-LEVEL CIRCULATION CENTER (LLCC),
FIGHTING TO CLEAR OUT AN EYE FEATURE. LIGHTNING OBSERVATIONS FLOOD
LARGE SPIRAL BANDS OF DEEP CONVECTION IN THE SOUTHWEST AND
NORTHEAST QUADRANTS OF THE SYSTEM. A RING OF OVERSHOOTING CLOUD
TOPS SURROUNDS THE FORMATIVE EYE FEATURE, MADE VERY OBSERVABLE IN A
060318Z AMSR2 36.5GHZ MICROWAVE SATELLITE IMAGE. UPPER-LEVEL CLOUDS
COMPLETELY OBSCURE THE LLCC AND CONTINUE TO EXPERIENCE STRONG POLEWARD 
OUTFLOW WITH EQUATORWARD OUTFLOW DEVELOPING. VERY LOW (0-5 KTS) 
VERTICAL WIND SHEAR, HIGH (29-30 C) SEA SURFACE TEMPERATURE (SST), AND 
A MOIST ENVIRONMENT CONTRIBUTE TO THE ASSESSMENT OF A HIGHLY FAVORABLE 
ENVIRONMENT. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED 
ON A 060540Z SSMIS MICROWAVE SATELLITE IMAGE. THE INITIAL INTENSITY OF 
70 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE SUBJECTIVE AND 
OBJECTIVE INTENSITY GUIDANCE LISTED BELOW.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE (NER) TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   KNES: T4.5 - 77 KTS
   ABRF: T4.5 - 77 KTS
   CIMSS SATCON: 72 KTS AT 060600Z
   CIMSS ADT: 87 KTS AT 0630Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 03P (JASPER) IS FORECAST TO CONTINUE
TRACKING SOUTHWARD TO SOUTH-SOUTHWESTWARD OVER THE NEXT 72 HOURS. 
ALONG-TRACK RAPID INTENSIFICATION IS EXPECTED, DRIVING UP THE
SYSTEMS INTENSITY TO A PEAK OF NEAR 115KTS AROUND TAU 36. AFTER TAU
36, VERTICAL WIND SHEAR VALUES ARE FORECAST TO RAMP UP TO 35KTS BY
TAU 60 AND WILL LIKELY INFLUENCE A WEAKENING TREND TO TRANSPIRE.
TANGENTIAL TO THE BIFURCATION DISCUSSION BELOW, THE JTWC FORECAST
IS SUPPORTED BY THE SUSTAINMENT OF THE NEAR EQUATORIAL RIDGE EAST
OF THE TC AND EVENTUALLY (TAU 72 TO TAU 120) THE BUILDING
SUBTROPICAL RIDGE TO THE SOUTH, WHICH IS EXPECTED TO RECURVE THE
SYSTEM TO A MORE WEST-SOUTHWESTWARD TRAJECTORY BY TAU 120.  SHOULD THE 
SOUTHERN RIDGE NOT BUILD IN AND INFLUENCE THE STEERING OF THE
SYSTEM, A QUASI-STATIONARY TRACK MAY OCCUR NEAR TAU 72.

MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE OFFERS TWO
DISTINCTLY SEPARATE SOLUTIONS. THE GFS, ECMWF, AND NAVGEM SOLUTIONS
COINCIDE WITH THE FORECAST TRACK, OF WHICH TRACKS TC 03P SOUTHWARD
GRADUALLY TURNING TO A WEST-SOUTHWESTWARD TRACK NEAR TAU 120. THE
BIFURCATION IN CONSENSUS MEMBERS OCCURS BETWEEN TAU 60 AND TAU 72
IN GALWEM AND UKMET SOLUTIONS, WHEREBY A QUASI-STATIONARY SCENARIO
ARISES AND THE TC LOITERS THROUGH TAU 120. DUE TO THE NATURE OF
THE BIFURCATED GUIDANCE AND TIMELINE, THE FORECAST CONFIDENCE FOR
TRACK IS HIGH THROUGH TAU 72, AND MEDIUM THEREAFTER. TIGHTLY
ALIGNED INTENSITY GUIDANCE CONTINUES TO SHOW SIGNIFICANT POSSIBILITY
FOR RAPID INTENSIFICATION TO OCCUR THROUGH TAU 24.  DUE TO GOOD
AGREEMENT IN INTENSITY GUIDANCE, THE FORECAST CONFIDENCE FOR
INTENSITY MIRRORS THAT OF THE TRACK FORECAST CONFIDENCE.

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