WDPN32 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (GAEMI) WARNING NR 
011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.2N 125.7E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 511 NM SOUTH-SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
STORM (TS) 05W (GAEMI) AS HAVING A SMOOTH CDO OBSCURING THE
SOUTHERN SEMICIRCLE OF THE SYSTEM. BANDING FEATURES CAN BE SEEN
ALONG THE SOUTHWEST QUADRANT, WRAPPING INTO THE CENTER. VERTICAL
WIND SHEAR HAS SHIFTED TO A MORE NORTHERLY DIRECTION AND IS STILL
EVIDENT BUT SEEMS TO BE SLIGHTLY WEAKENING AS THE CONVECTION IS NOT
BLOWING OFF AS VIGOROUSLY. THE NORTHERN PERIPHERY OF THE LOW-LEVEL
CIRCULATION CENTER (LLCC) REMAINS EXPOSED, DUE IN PART TO A TONGUE
OF DRY AIR THAT IS PLACED JUST NORTH OF THE LLCC, HINDERING
CONVECTIVE DEVELOPMENT AS WELL AS THE SHEAR. ENVIRONMENTAL ANALYSIS
INDICATES THAT 05W IS IN A MARGINALLY FAVORABLE ENVIRONMENT FOR
INTENSIFICATION CHARACTERIZED BY MODERATE EQUATORWARD OUTFLOW
ALOFT, LOW TO MODERATE (15-20 KTS) VERTICAL WIND SHEAR, AND WARM
(30-31 C) SEA SURFACE TEMPERATURES. THESE FACTORS ARE OFFSET BY THE
PRESENCE OF DRY AIR TO THE NORTH. THE INITIAL POSITION IS PLACED
WITH MEDIUM CONFIDENCE BASED ON A 220523Z AMSR2 36 GHZ MICROWAVE
IMAGE REVEALING LOW-LEVEL CLOUDS OUTLINING THE CENTER OF 05W. THE
INITIAL INTENSITY OF 55 KTS IS ALSO ASSESSED WITH MEDIUM CONFIDENCE
BASED ON THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES LISTED
BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T4.5 - 77 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 55 KTS AT 220600Z
   CIMSS ADT: 53 KTS AT 220600Z
   CIMSS AIDT: 45 KTS AT 220600Z
   CIMSS DPRINT: 60 KTS AT 220600Z
   CIMSS DMINT: 55 KTS AT 220524Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD
   OTHER FACTORS: PRESENCE OF DRY AIR TO THE NORTH.

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: TS O5W IS FORECAST TO CONTINUE TRACKING
NORTH-NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF A NORTH-SOUTH
ORIENTED STR PLACED TO ITS EAST THROUGH TAU 48. AFTER TAU 48,
RIDGING EXTENDING ACROSS EASTERN CHINA WILL TAKE OVER AS THE
STEERING MECHANISM AND DRIVE 05W WESTWARD THROUGH TAU 96. THE
SYSTEM IS FORECAST TO MAKE LANDFALL ALONG THE EASTERN COAST OF
CHINA, NORTHWEST OF TAIWAN, JUST AFTER TAU 72. AFTER MAKING
LANDFALL, 05W IS EXPECTED TO RAPIDLY WEAKEN AND THE LOW-LEVEL
STEERING PATTERN WILL PUSH THE SYSTEM POLEWARD AS IT DISSIPATES.
REGARDING THE INTENSITY FORECAST, 05W IS FORECAST TO CONTINUE TO
INTENSIFY THROUGH TAU 48 AS VERTICAL WIND SHEAR IS ANTICIPATED TO
DROP AND THE DRY AIR TO BE GONE. HIGH SEA SURFACE TEMPERATURES AND
OHC ARE GOING TO BE LARGE FACTORS IN THE INTENSIFICATION OF 05W.
THE PEAK INTENSITY OF 90 KTS IS FORECAST TO OCCUR AROUND TAU 48,
NEAR ISHIGAKIJIMA BEFORE THE WESTWARD TURN IS INITIATED. AFTER TAU
48, VERTICAL WIND SHEAR WILL RISE TO ABOVE 20 KTS AND SEA SURFACE
TEMPERATURES WILL DROP, WHICH WILL START THE WEAKENING TREND OF
05W. HOWEVER, AT LANDFALL, 05W IS FORECAST TO STILL BE OF TYPHOON
STRENGTH. AFTER LANDFALL, THE SYSTEM WILL DETERIORATE IN RESPONSE
TO TERRAIN INTERACTION AND WILL DISSIPATE NEAR THE END OF THE
FORECAST PERIOD. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT WITH A 200 NM CROSS-TRACK SPREAD AT TAU 72, AROUND THE
TIME OF LANDFALL. NAVGEM MAKES UP THE SOUTHERNMOST MEMBER, TRACKING
THE SYSTEM THROUGH CENTRAL TAIWAN. THE GFS ENSEMBLE MEAN MAKES UP
THE NORTHERNMOST MEMBER, TRACKING THE SYSTEM AROUND 60 NM NORTH OF
THE COAST OF TAIWAN. THE JTWC TRACK FORECAST IS PLACED WITH MEDIUM
CONFIDENCE JUST NORTH OF CONSENSUS, HUGGING THE NORTHERN COAST OF
TAIWAN. THE INTENSITY GUIDANCE IS IN RELATIVELY GOOD AGREEMENT WITH
THE EXCEPTION OF RAPID INTENSIFICATION AIDS APPEARING. GUIDANCE
OTHERWISE AGREES ON A PEAK INTENSITY OF AROUND 70 TO 90 KTS AT TAU
48 BEFORE WEAKENING RATHER QUICKLY. THE JTWC INTENSITY FORECAST IS
PLACED WITH MEDIUM CONFIDENCE, ALONG THE HIGHER END OF GUIDANCE
WITH A PEAK INTENSITY OF 90 KTS. 

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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