WDPN31 PGTW 102100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (MARIA) WARNING NR 
016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 36.8N 145.2E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 286 NM SOUTHEAST OF MISAWA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS DISTINCT
CONVECTIVE BANDING WRAPPING WITH A WEDGE OF DRY AIR FROM THE WEST
WRAPPING INTO A LOW-LEVEL CIRCULATION CENTER (LLCC) OBSCURED BY
DEEP CONVECTION. ANIMATED WATER VAPOR IMAGERY DEPICTS ENTIRELY
POLEWARD OUTFLOW AS DRY AIR PENETRATES THE CORE FROM THE SOUTH AND
SOUTHWEST. A 101828Z F18 SSMIS 91GHZ MICROWAVE IMAGE REVEALS THAT
THE UPPER-LEVEL CORE HAS BECOME DISORGANIZED AND CONVECTION HAS IS
NOW CENTRALIZED OVER THE LLCC, INDICATING A DEGRADING STORM
STRUCTURE. 101620Z GCOM AMSR2 WIND SPEED DATA REVEALS A MAXIMUM OF
44KTS IN THE EASTERN SEMICIRCLE OF THE SYSTEM AND AN ELONGATED
NORTH-SOUTH CORE STRUCTURE. THE WEAKENING IS ATTRIBUTED TO THE
UNFAVORABLE UPPER-LEVEL ENVIRONMENT THAT HAS BECOME MUDDLED OVER
THE LAST SIX HOURS DUE TO PROXIMITY TO AN UPPER-LEVEL JET LOCATED
TO THE NORTHWEST OVER HOKKAIDO ISLAND, JAPAN. THE INITIAL POSITION
IS PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED
MICROWAVE, AMSR2, AND EIR. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE AFOREMENTIONED AMSR2 DATA AND THE AGENCY
AND OBJECTIVE FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: AMSR2 DATA

CURRENT STEERING MECHANISM: A SUBTROPICAL RIDGE SPANNING FROM THE
EAST TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T3.0 - 45 KTS
   KNES: T2.5 - 35 KTS
   CIMSS SATCON: 48 KTS AT 1530Z
   CIMSS ADT: 35 KTS AT 1900Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 5-10 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL STORM (TS) 06W WILL CONTINUE TRACKING
NORTHWESTWARD UNDER THE INFLUENCE OF THE STR POSITIONED TO THE EAST
AND NORTHEAST, TRACKING ACROSS MAINLAND JAPAN BETWEEN TAU 24 AND
48. THE STORM WILL SLIGHTLY STRENGTHEN OVER THE NEXT 12 HOURS
TO 50KTS DUE TO A MORE FAVORABLE UPPER-LEVEL ENVIRONMENT ALLOWING
FOR SOME DIVERGENCE ALOFT SUPPORTED BY LOW SHEAR AND WARM SEA
SURFACE TEMPERATURES ABOVE 26C. FOLLOWING, THE SYSTEM WILL WEAKEN
DRASTICALLY AFTER TAU 24, WHEN THE SYSTEM WILL PULL COOLER WATERS
BELOW 26C SOUTHWARD DOWN THE NORTHERN JAPANESE COASTLINE. LAND
INTERACTION WITH THE MOUNTAINOUS TERRAIN OF NORTHERN JAPAN AFTER
LANDFALL WILL FURTHER THE SIGNIFICANT WEAKENING BEFORE THE SYSTEM
TRACKS BACK OUT OVER WARM WATERS BY TAU 48, AT WHICH TIME THE
SYSTEM WILL LIKELY BE WEAK AND NEARLY UNTRACKABLE. 

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN STRONG
AGREEMENT THAT THE SYSTEM WILL CONTINUE TRACKING NORTHWESTWARD
UNDER THE STEERING INFLUENCE OF THE STR TO THE EAST. THE JTWC
CONSENSUS HAS A MAXIMUM CROSS-TRACK DISTANCE OF 70NM BY TAU 48,
INCREASING THE CONFIDENCE IN THE TRACK FORECAST. THE JTWC INTENSITY
GUIDANCE ALSO IS IN GOOD AGREEMENT THAT THE SYSTEM WILL EITHER
INTENSIFY SLIGHTLY TO 50KTS OR REMAIN STAGNANT AT 45KTS OVER THE
NEXT 12 HOURS BEFORE CONTINUOUSLY WEAKENING TO DISSIPATION BY TAU
48 AS THE SYSTEM ENTERS COOL WATERS, APPROACHES THE UPPER-LEVEL
JET, AND INTERACTS WITH THE TOPOGRAPHY OF MAINLAND JAPAN. 

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM//
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