WDPN32 PGTW 062100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (TAPAH) WARNING NR 
003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.5N 114.8E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 230 NM SOUTH OF HONG KONG
   MOVEMENT PAST 6 HOURS: WESTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 18 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
COMPACT SYSTEM, WITH PERSISTENT CONVECTIVE BURSTS DEVELOPING NEAR
AND TO THE IMMEDIATE SOUTH OF THE ASSESSED POSITION. THE LATEST EIR 
REVEALS OVERSHOOTING TOPS WITH TEMPERATURES APPROACHING -90C, 
EMBEDDED 
WITHIN A SYMMETRICAL CIRRUS CANOPY. ANIMATED WATER VAPOR IMAGERY 
INDICATES IMPROVED OUTFLOW TOWARDS THE EAST, WITH TRANSVERSE
BANDING FEATURES BEGINNING TO EMERGE ALONG THE EASTERN FLANK OF THE
SYSTEM, INDICATING A REDUCTION IN THE SHEAR PRESSURE ALONG THAT SIDE
OF THE SYSTEM. ADDITIONALLY, THE WATER VAPOR REVEALS THE FORMATION OF 
A THIN BAND OF CIRRUS TRAILED BY A WEDGE OF RELATIVELY DRIER AIR, A 
CLASSIC INDICATOR OF THE POTENTIAL FOR RAPID INTENSIFICATION IN THE 
NEXT 12 TO 18 HOURS. A PARTIAL 061606Z GMI COLOR-ENHANCED 89GHZ 
MICROWAVE IMAGE REVEALED A SHALLOW LOW LEVEL CIRCULATION CENTER
(LLCC) TO THE NORTH OF THE DEEP CONVECTION, AND SHALLOW BANDING
FEATURES EXTENDING WELL OUT TO THE EAST OF THE LLCC. THE INITIAL
POSITION IS ASSESSED WITH MEDIUM CONFIDENCE, USING EXTRAPOLATION OF
THE LLCC OBSERVED IN THE MICROWAVE IMAGE AS THE PRIMARY PLACEMENT
MECHANISM. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM
CONFIDENCE, HEDGED SLIGHTLY TOWARDS THE ADT ESTIMATE OF 39 KNOTS.
ENVIRONMENTAL CONDITIONS ARE FAVORABLE, WITH MINIMAL VWS, WARM SSTS
AND GOOD OUTFLOW ALOFT. THE ONLY HINDRANCE AT THE MOMENT IS THE
STILL DISORGANIZED VORTEX STRUCTURE.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) EXTENDING FROM JAPAN TO SOUTHERN CHINA. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T3.0 - 45 KTS
   CIMSS ADT: 39 KTS AT 061730Z
   CIMSS AIDT: 34 KTS AT 061730Z
   CIMSS D-PRINT: 32 KTS AT 061800Z

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

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL STORM (TS) 22W IS FORECAST TO TRACK
WEST-NORTHWESTWARD FOR THE NEXT 12 HOURS, BEFORE TURNING
NORTHWESTWARD TOWARDS A BREAK IN THE STEERING RIDGE ANTICIPATED TO
DEVELOP OVER SOUTHWESTERN CHINA. LANDFALL IS EXPECTED TO OCCUR
AROUND TAU 30, IN THE VICINITY OF YANGJIANG, CHINA, AFTER WHICH THE
SYSTEM WILL CONTINUE INLAND ON A GRACEFULLY ARCING TRACK TOWARDS
THE VIETNAM-CHINA BORDER REGION. AS INDICATED BY BOTH THE ANIMATED
EIR AND ANALYSIS OF THE MICROWAVE IMAGERY DISCUSSED ABOVE, THE
SYSTEM REMAINS SOMEWHAT DISORGANIZED DUE TO THE LACK OF A FULLY 
ALIGNED AND AXISYMMETRIC VORTEX. OTHERWISE, THE ENVIRONMENT IS 
CONDUCIVE TO STEADY TO POTENTIALLY RAPID INTENSIFICATION (RI). THE 
ANIMATED WATER VAPOR IMAGERY DEPICTS AN UPPER-LEVEL ANTICYCLONE 
POSITIONED NORTH OF TAIWAN, WITH STRONG EASTERLY FLOW OVER THE LUZON 
STRAIT, TURNING SHARPLY POLEWARD IN THE SOUTHERN PORTION OF THE 
TAIWAN 
STRAIT. CIRRUS BLOW OFF WEST OF LUZON IS ALREADY BEING DRAWN POLEWARD 
INTO THE WESTERN SIDE OF THIS ANTICYCLONE AND THE GLOBAL AND 
MESOSCALE 
MODELS SUGGEST THIS TREND WILL CONTINUE, FACILITATING INCREASED 
POLEWARD OUTFLOW IN ADDITION TO THE ALREADY MODERATE TO STRONG 
EQUATORWARD OUTFLOW. IF THE DEEP CONVECTION CAN PERSIST AND 
CONSOLIDATE AROUND THE CENTER, WHICH IS ANTICIPATED IN THE NEAR-TERM, 
THE SYSTEM WILL VERY LIKELY CAPITALIZE ON THE IMPROVED EXHAUST 
MECHANISM AND QUICKLY INTENSIFY PRIOR TO LANDFALL. THE CURRENT 
FORECAST CALLS FOR A PEAK OF 65 KNOTS AT TAU 24, BUT A SLIGHTLY 
HIGHER 
PEAK INTENSITY REMAINS POSSIBLE GIVEN THE ADDITIONAL TIME OVER WATER 
PRIOR TO LANDFALL. AFTER LANDFALL, THE SYSTEM WILL STEADILY WEAKEN 
AND 
DISSIPATE OVER LAND NO LATER THAN TAU 72. 

MODEL DISCUSSION: DETERMINISTIC, ENSEMBLE, AND ARTIFICIAL
INTELLIGENCE (AI) MODELS ARE ALL IN STRONG AGREEMENT ON THE TRACK, 
WITH ALL MODELS EXCEPT FOR THE NAVGEM, CONTAINED WITHIN THE
50NM WIDE ENVELOPE AT LANDFALL. NAVGEM CONTINUES TO BE THE ONLY
OUTLIER, PROJECTING A TRACK MORE DIRECTLY INTO THE RIDGE, WITH A 
LANDFALL CLOSER TO MACAU. THE JTWC FORECAST IS PLACED NEAR THE MULTI-
MODEL CONSENSUS WITH HIGH CONFIDENCE. INTENSITY GUIDANCE EXHIBITS 
MORE 
SPREAD, WITH THE MAJORITY OF THE GUIDANCE PEAKING AT A SLIGHTLY LOWER 
INTENSITY AROUND 55 KNOTS, WHILE THE RIDE, RICN, FRIA AND THE RI-
GUIDANCE INFLUENCED CONSENSUS ARE INDICATING PEAK INTENSITY AT TAU 24 
BETWEEN 65-80 KNOTS. IN LIGHT OF THE INDICATORS OBSERVED IN THE WATER 
VAPOR IMAGERY, THE JTWC FORECAST IS HEDGED ABOVE THE MAJORITY OF THE 
MODEL GUIDANCE, TOWARDS THE MORE AGGRESSIVE RI GUIDANCE, SPECIFICALLY 
THE FRIA WHICH PEAKS AT 65 KNOTS.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: MEDIUM//
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