Advisories

WDPN31 PGTW 070900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (DOLPHIN) WARNING NR 046//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 26.7N 128.1E
   INITIAL INTENSITY: 90 KTS
   GEOGRAPHIC REFERENCE: 20 NM NORTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL IMAGERY (MSI) DEPICTS TYPHOON (TY) 12W
INTENSIFYING AS IT SCRAPES THE COAST OF NORTHWESTERN OKINAWA.
ANIMATED LONGWAVE INFRARED IMAGERY REVEALS THE INNER CORE HAS
COOLING CLOUD TOPS ASYMMETRICALLY SURROUNDING THE PINHOLE EYE. THE
070422Z AMSR2 MICROWAVE WINDSPEED PRODUCT REVEALS THAT THE
STRONGEST TYPHOON-FORCE WINDS ARE CONFINED TO THE NORTHERN AND
EASTERN QUADRANTS, THOUGH STORM-FORCE WINDS ARE PRESENT IN ALL
QUADRANTS. SURFACE OBSERVATIONS FROM NAGO PEAKED AT 49 KTS
SUSTAINED AT 070600Z, WHILE OBSERVATIONS FROM AMAMI PEAKED AT
070000Z AT 50 KTS SUSTAINED AND GUSTS UP TO 68 KTS. OBSERVATIONS
FROM AMAMI CONTINUE TO REMAIN NEAR 50 KTS SUSTAINED THROUGH
070700Z. THE 070422Z AMSR2 MICROWAVE 91 GHZ IMAGE REVEALS THE TIGHT
INNER CORE WITH A SINGLE LARGE BAND OF DEEP CONVECTION SPIRALING
OUT FROM THE CENTER. ENVIRONMENTAL ANALYSIS REVEALS A FAVORABLE
ENVIRONMENT, CHARACTERIZED BY LOW (0-5 KTS) VERTICAL WIND SHEAR,
WARM (29-30 C) SEA SURFACE TEMPERATURES (SST), AND GOOD RADIAL
OUTFLOW. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED
ON THE PINHOLE EYE IN ANIMATED MSI. THE INITIAL INTENSITY OF 90 KTS
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE CIMSS AUTOMATED
INTENSITY ESTIMATES AND THE AGENCY DVORAK FIXES LISTED BELOW,
SUPPORTED BY THE AFOREMENTIONED AMSR2 WINDSPEED PRODUCT.

INITIAL WIND RADII BASIS: ADJUSTED WIND RADII USING THE 070100Z
ASCAT DATA.

CURRENT STEERING MECHANISM: SOUTHWESTERN FLANK OF A SUBTROPICAL
RIDGE CENTERED OVER THE SEA OF JAPAN

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   RJTD: T5.5 - 102 KTS
   RCTP: T5.0 - 90 KTS
   KNES: T5.5 - 102 KTS
   CIMSS SATCON: 102 KTS AT 070610Z
   CIMSS ADT: 102 KTS AT 070610Z
   CIMSS AIDT: 89 KTS AT 070610Z
   CIMSS D-MINT: 76 KTS AT 070504Z
   CIMSS D-PRINT: 82 KTS AT 070630Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

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: AFTER A BRIEF SOUTHWESTWARD DETOUR, TY 12W
(DOLPHIN) IS FORECAST TO CONTINUE TRACKING WESTWARD WHILE IT
REMAINS UNDER THE INFLUENCE OF THE STR CENTERED OVER THE SEA OF
JAPAN. THE TROUGH CURRENTLY ERODING THE STR IS EXPECTED TO PASS BY
AROUND TAU 36, ALLOWING THE STR TO REORIENT AND BUILD TO THE
NORTHEAST OF THE SYSTEM, DRIVING A GENTLE NORTHWESTWARD CURVE
BEGINNING AROUND TAU 24. LANDFALL IN CHINA IS EXPECTED AROUND TAU
60. REGARDING INTENSITY, 12W HAS INTENSIFIED SLIGHTLY, BOLSTERED BY
ELEVATED OCEAN HEAT CONTENT (OHC) ASSOCIATED WITH THE KUROSHIO
CURRENT. IT IS EXPECTED TO MAINTAIN THIS INTENSITY APPROXIMATELY
FOR THE NEXT 24 HOURS. 12W WILL EXIT THE WARM POOL OF HIGHER OHC
VALUES AROUND TAU 24-36, CONTRIBUTING TO SLIGHT WEAKENING LEADING
UP TO LANDFALL. DOLPHIN IS FORECAST TO RAPIDLY WEAKEN OVER LAND AND
FULLY DISSIPATE BY TAU 96.

MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN STRONG
AGREEMENT THROUGH LANDFALL AT TAU 60, LENDING HIGH CONFIDENCE TO
THE SHORT-TERM TRACK FORECAST. MODELS DIVERGE SIGNIFICANTLY
POST-LANDFALL, CONTRIBUTING TO UNCERTAINTY SURROUNDING THE TRACK
FORECAST FROM TAU 72-96. AS A RESULT, THE JTWC TRACK FORECAST IS
PLACED WITH HIGH CONFIDENCE FROM TAU 0-72 AND LOW CONFIDENCE FROM
TAU 72-96. RELIABLE INTENSITY AIDS ARE IN STRONG AGREEMENT FOR THE
DURATION OF THE FORECAST PERIOD, SUPPORTING THE JTWC INTENSITY
FORECAST WITH HIGH CONFIDENCE.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 00-72 HR: HIGH
   INTENSITY 72-120 HR: HIGH//
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