WDPN32 PGTW 070900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (HALONG) WARNING NR 012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 27.6N 137.9E
   INITIAL INTENSITY: 95 KTS
   GEOGRAPHIC REFERENCE: 231 NM WEST OF CHICHI JIMA
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A CLEAR EYE
FEATURE WITH SYMMETRIC CONVECTION AROUND THE LOW-LEVEL CIRCULATION
CENTER (LLCC). COOLING CLOUD TOPS OBSERVED OVER FOR THE PAST SIX 
HOURS ALONG WITH GOOD RADIAL OUTFLOW ARE INDICATIVE OF CONTINUED
INTENSIFICATION. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE 
BASE ON SATELLITE IMAGERY OF THE EYE FEATURE. THE INITIAL INTENSITY 
OF 95 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE AGENCY AND 
OBJECTIVE FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: A 070029Z METOP-B ASCAT PASS 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   RJTD: T5.0 - 90 KTS
   RCTP: T5.0 - 90 KTS
   KNES: T5.5 - 102 KTS
   CIMSS SATCON: 108 KTS AT 070411Z
   CIMSS ADT: 107 KTS AT 070730Z
   CIMSS AIDT: 102 KTS AT 070730Z
   CIMSS D-MINT: 100 KTS AT 070600Z
   CIMSS D-PRINT: 101 KTS AT 070730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

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: TYPHOON (TY) 28W (HALONG) WILL TRACK 
NORTHWESTWARD AS IT ROUNDS THE AXIS OF THE SUBTROPICAL RIDGE TO THE 
EAST. AFTERWARDS, TY 28W WILL RECURVE TO THE NORTH-NORTHEAST THROUGH 
TAU 48. TY 28W IS FORECAST TO REMAIN IN A HIGHLY FAVORABLE 
ENVIRONMENT AT LEAST UNTIL TAU 48 WITH WARM (29-30 C) SEA SURFACE 
TEMPERATURES (SST), LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), AND 
GOOD OUTFLOW. FOLLOWING TAU 48 THE SYSTEM IS FORECAST TO ENCOUNTER 
COOLER WATERS, HIGHER WIND SHEAR, AND RELATIVELY DRY AIR - CONDITIONS 
THAT WILL CAUSE A WEAKENING TREND AND BEGIN THE TRANSITION INTO AN 
EXTRATROPICAL SYSTEM. MAXIMUM WIND SPEEDS ARE EXPECTED TO WEAKEN TO 
50 KTS BY TAU 96 AS THE SYSTEM WILL HAVE COMPLETED ITS EXTRATROPICAL 
TRANSITION. 

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
ON THE FORECASTED CURVE WITH A CROSS-TRACK SPREAD UNDER 50 NM UNTIL
JUST BEFORE TAU 72. INTENSITY GUIDANCE IS MORE SPREAD. WHILE THE
JTWC PEAK INTENSITY IS FORECASTED TO BE 120 KTS, GUIDANCE SUGGEST
THAT THERE IS A POSSIBILITY FOR SOME INTENSIFICATION BEFORE TAU 48, 
WITH COAMPS-TS AND HAFS PREDICTING PEAK INTENSITY IN THE RANGE OF 120 
- 130 KTS. PREVIOUS MODEL GUIDANCE SHOWED A GRADUAL DECLINE OF THE 
SYSTEM ALTHOUGH EXPECTATION IS FOR TY 28W TO EXPERIENCE RAPID 
DECAYING DURING THE EXTRATROPICAL TRANSITION, MORE IN LINE WITH THE
FORECASTED ENVIRONMENT, PROXIMITY OF THE SYSTEM TO THE JET, AND
TROPICAL SPECIFIC MODEL ANALYSIS WHICH IS REFLECTED IN THE JTWC
FORECAST.

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