WDIO31 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (TWO) WARNING NR 
001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 11.9N 66.0E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 657 NM SOUTHEAST OF MASIRAH ISLAND
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAPIDLY
CONSOLIDATING CIRCULATION WITH DEEP CONVECTIVE BANDING FEATURES
VISIBLE IN ALL QUADRANTS RESULTING IN A FULLY OBSCURED LLCC. AN
OMINOUS 060701Z GMI 89GHZ MICROWAVE IMAGE REVEALS A SYMMETRIC
MICROWAVE EYE FEATURE WITH PROMINENT BANDING FEATURES NORTH OF THE
LLCC. A PARTIAL 060501Z ASCAT-B SCATTEROMETRY IMAGE SHOWS A COMPACT
CIRCULATION OF 35-40KT WINDS TO THE EAST OF LLCC; BASED ON PREVIOUS
COMPLETE ASCAT PASSES AND CONVECTIVE ORGANIZATION, THE HIGHEST
WINDS ARE LIKELY TO THE SOUTH OF THE LLCC AND ARE THEREFORE MISSING
FOR THIS PASS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON MSI, GMI AND ASCAT IMAGERY. THE INITIAL INTENSITY OF 50
KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE PARTIAL ASCAT-B
PASS AS WELL AS PGTW AND KNES DVORAK INTENSITY ESTIMATES INDICATING
T3.0, WHICH BREAKS CONSTRAINTS TO KEEP PACE WITH THE SYSTEMS
DEVELOPMENT.

INITIAL WIND RADII BASIS: PARTIAL SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: NEAR-EQUITORIAL RIDGE (NER) TO THE
SOUTH AND A SUB-TROPICAL RIDGE (STR) TO THE NORTH. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   DEMS: T2.0 - 30 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 31-32 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: TC 02A IS FORECAST TO CONTINUE TRACKING
NORTH-NORTHEASTWARD UNDER THE STEERING INFLUENCE OF THE NER AND STR
TO THE SOUTH AND NORTH RESPECTIVELY. CURRENTLY IN A FAVORABLE
ENVIRONMENT CHARACTERIZED BY WARM SSTS AND MODERATE OUTFLOW ALOFT
WHICH IS OVERPOWERING MODERATE VERTICAL WIND SHEAR (VWS). BY TAU
48, AFTER REACHING 75KTS, THE SYSTEM WILL CONTINUE TO PUSH POLEWARD
INTO A DRY ENVIRONMENT WHICH WILL BEGIN TO SLOW ITS INTENSIFICATION
TREND. THROUGH TAU 120, AS THE NER CONTINUES TO BUILD TO THE SOUTH,
02A WILL BE FORCED POLEWARD AND DEEPER INTO THE ARABIAN SEA.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIR AGREEMENT WITH TWO
EXCEPTIONS. NVGM TAKES A BOLD AND SOLO TRACK EASTWARD OF 68E BEFORE
TURNING SHARPLY WESTWARD, WHILE GFS TAKES ITS MIRROR OPPOSITE
COURSE WESTWARD TOWARDS MASIRAH. THE BULK OF THE REMAINING GUIDANCE
FOLLOWS EACH OTHER CLOSELY UP THE MIDDLE OF THESE TWO OUTLIERS.
BASED ON THESE FACTORS THE JTWC FORECAST TRACK IS PLACED WITH
OVERALL MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS IN
FAIR AGREEMENT WITH A BULK OF THE GUIDANCE ALONG WITH SEVERAL RAPID
INTENSIFICATION (RI) AIDS FOLLOWING THE JTWC INTENSITY TREND
THROUGH TAU 24. AFTER TAU 24, THERE IS A NOTABLE SPREAD IN MODEL
OUTPUT THAT I WOULD NOT ANTICIPATE TO REMAIN AS INTENSITIES CLIMB
AND INITIALIZATION PARAMETERS IMPROVE. NEVERTHELESS, AT CURRENT
TIME THE JTWC INTENSITY FORECAST IS PLACED INITIALLY WITH MEDIUM
CONFIDENCE AND WITH LOW CONFIDENCE THEREAFTER.

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