WDPS31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER) WARNING NR 
003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.2S 156.8E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 192 NM WEST OF HONIARA, SOLOMON ISLANDS
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS
TROPICAL CYCLONE (TC) 03P (JASPER) AS A CONSOLIDATING, QUASI-
STATIONARY
TROPICAL CYCLONE OVER THE PAST SIX HOURS. A 051140Z AMSU-B 89GHZ
MICROWAVE IMAGE SHOWS LOW-LEVEL SHALLOW BANDING WRAPPING INTO THE
LOW-LEVEL CIRCULATION CENTER (LLCC) INTER-MIXED WITH PERSISTING
SPIRAL BANDS OF DEEP CONVECTION, MOST PREVALENT IN THE SOUTHWESTERN
QUADRANT OF THE SYSTEM. A 051128Z METOP-B SCATTEROMETRY IMAGE SHOWS
THE HIGHEST SURFACE WIND CONCENTRATION NORTHEAST OF THE LLCC WITH
35-45KTS, APPROXIMATELY 25NM TO 40NM OUTWARD FROM THE SYSTEM
CENTER. SIGNIFICANT POLEWARD OUTFLOW IS MOST OBSERVABLE IN THE
SOUTHEAST QUADRANT AS CIRRUS FILAMENTS DRIFT SOUTHEASTWARD WITH THE
DOMINANT NORTHWESTERLY FLOW ALOFT. THE INITIAL POSITION IS PLACED
WITH MEDIUM CONFIDENCE BASED ON A THE AFOREMENTIONED MICROWAVE AND
SCATTEROMETRY IMAGES. THE INITIAL INTENSITY OF 45 KTS IS ASSESSED
WITH MEDIUM CONFIDENCE BASED ON THE SUBJECTIVE AND OBJECTIVE
INTENSITY GUIDANCE LISTED BELOW AND THE AFOREMENTIONED SCATTEROMETRY
IMAGE.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   ABRF: T3.0 - 45 KTS
   CIMSS ADT: 39 KTS AT 051130Z
   CIMSS DPRINT: 48 KTS AT 051300Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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 TRACK GENERALLY
SOUTH-SOUTHWESTWARD THROUGH TAU 48 DUE TO THE INFLUENCE OF A
DEEP-LAYER RIDGE TO EAST OF TC 03P AND THEN GRADUALLY TURN TO A
MORE SOUTHWESTWARD TRACK THROUGH TAU 120. FAVORABLE ALONG-TRACK
CONDITIONS OF HIGH (29-30 C) SEA SURFACE TEMPERATURES (SST), LOW
(5-15KTS) VERTICAL WIND SHEAR (VWS), AND SIGNIFICANT OUTFLOW ALOFT
WILL ALLOW THE TC TO RAPIDLY INTENSIFY AND RELISH IN THE FAVORABLE
ENVIRONMENT. AFTER TAU 72, MODERATE (15-20 KTS) VWS, DECLINING SST
AND DRY AIR ENTRAINMENT ARE FORECAST TO SET IN AND BRING ABOUT A
LESS FAVORABLE ENVIRONMENT AND WEAKENING OF TC 03P (JASPER).

MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE IS IN GOOD
AGREEMENT THAT TC 03P WILL TRACK SOUTHWARD GRADUALLY TURNING TO A
SOUTHWESTWARD TRACK THROUGH THE FORECAST INTERVAL. GALWEM OFFERS AN
ALTERNATIVE SCENARIO FROM THE REST OF THE JTWC CONSENSUS NEAR TAU
96, TAKING THE SYSTEM INTO A QUASI-STATIONARY STEERING SCENARIO
INSTEAD OF CARRYING ON WITH A SOUTHWESTWARD TRACK. REMOVING GALWEM
FROM THE ASSESSMENT FOR THIS REASON, THE CROSS-TRACK SPREAD IS
80NM AT BY TAU 72 AND 216NM BY TAU 120 BETWEEN JTWC CONSENSUS
MEMBERS. MULTIPLE INDICATIONS OF IMMINENT RAPID INTENSIFICATION
HAVE BEEN TRIGGERED IN BOTH STATISTICAL-DYNAMICAL INTENSITY
GUIDANCE AND THE COAMPS-TC ENSEMBLE 0600Z MODEL RUN, WHICH SHOWS A
77 PERCENT LIKELIHOOD BETWEEN TAU 06 AND TAU 30. DUE TO THE GENERAL
ALIGNMENT OF GUIDANCE AND TIGHTLY ALIGNED INTENSITY GUIDANCE, THE
FORECAST CONFIDENCE OF BOTH TRACK AND INTENSITY IS MEDIUM FROM TAU
00 TO TAU 120.


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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