WDPN31 PGTW 270300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (MALOU) WARNING NR 013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.7N 139.3E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 270 NM SOUTH-SOUTHWEST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS SPIRAL
BANDING WRAPPING INTO A RAGGED, TRANSIENT EYE FEATURE, WHICH LENDS
HIGH CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY IS
ASSESSED WITH FAIR CONFIDENCE AND IS PLACED BETWEEN THE RJTD (T3.5,
55 KTS) AND PGTW AND KNES (T4.0, 65 KTS) DVORAK CURRENT INTENSITY
ESTIMATES AND NEAR THE CIMSS SATCON INTENSITY ESTIMATE OF 70 KTS.
TY MALOU IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW
(10-15 KTS) VERTICAL WIND SHEAR, WARM (28-29 CELSIUS) SEA SURFACE
TEMPERATURES AND ROBUST POLEWARD OUTFLOW. THESE FAVORABLE
CONDITIONS ARE OFFSET SLIGHTLY BY DRY AIR ENTRAINMENT ALONG THE
SOUTH AND EASTERN PERIPHERY OF THE SYSTEM.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: ALONG THE PERIPHERY OF A SUBTROPICAL
RIDGE POSITIONED TO THE EAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 70 KTS AT 262151Z
   CIMSS ADT: 57 KTS AT 262330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TY MALOU WILL CONTINUE A GENERALLY NORTH TO
NORTHEASTWARD TRACK THROUGHOUT THE REMAINDER OF THE FORECAST
PERIOD. THE SYSTEM WILL INTENSIFY GRADUALLY OVER THE NEXT 12 HOURS
AS DRY AIR ENTRAINMENT OFFSETS OTHERWISE FAVORABLE ENVIRONMENTAL
CONDITIONS. THEREAFTER, A CONTINUED FAVORABLE ENVIRONMENT THROUGH
TAU 48 WILL ALLOW FOR FURTHER INTENSIFICATION TO 85 KTS BY THAT
TIME. INCREASING VERTICAL WIND SHEAR DUE TO THE UPPER LEVEL
WESTERLY FLOW ALOFT, ALONG WITH COOLING SEA SURFACE TEMPERATURES
WILL LEAD TO WEAKENING THEREAFTER AS THE SYSTEM BEGINS
EXTRATROPICAL TRANSITION. BY TAU 72, TY MALOU WILL WEAKEN TO 55 KTS
AND COMPLETE EXTRATROPICAL TRANSITION WHEREUPON IT WILL PERSIST AND
CONTINUE TO TRACK GENERALLY EASTWARD AS A COLD CORE LOW. 

MODEL DISCUSSION: NUMERICAL MODEL SOLUTIONS PROVIDE TIGHT ALONG AND
ACROSS TRACK GUIDANCE THROUGHOUT THE FORECAST PERIOD AND LEND HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. INTENSITY GUIDANCE SOLUTIONS
HAVE BEGUN TO DIVERGE THROUGH TAU 12, LARGELY DUE TO THE
AFOREMENTIONED DRY AIR ENTRAINMENT. AFTER TAU 12, INTENSITY
GUIDANCE CONVERGES ONCE AGAIN ON AN INTENSIFICATION SCENARIO
THROUGH TAU 48 WHICH OVERALL LENDS MEDIUM CONFIDENCE IN THE JTWC
FORECAST INTENSITY.  

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