WDPN31 PGTW 060300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 31W (KALMAEGI) WARNING NR 020//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.2N 112.1E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 277 NM SOUTHEAST OF DA NANG, VIETNAM
   MOVEMENT PAST 6 HOURS: WESTWARD AT 21 KTS
   SIGNIFICANT WAVE HEIGHT: 32 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON KALMAEIGI IS BARRELING TOWARDS THE VIETNAMESE COAST AND
REACHING PEAK INTENSITY. A LARGE EYE IS EVIDENT IN VISUAL IMAGERY
AND THE SYSTEM IS POSITIONED WITHIN THE EYE AND ON TOP OF THE JTWC
AND JMA FIXES. DVORAK ASSESSMENTS HAVE ALSO SURGED AND THE CURRENT
INTENSITY IS BASED ON THE JTWC T6.0 ALONG WITH DPRINT 111KTS AND
DMINT 110KTS. THE 060030 ADT RAW VALUE HAS SURGED ALL THE WAY TO T6.8
WHILE THE CI AND FINAL T NUMBERS ARE SET AT T5.9. ALONG WITH THE
INTENSIFICATION, THE SYSTEM IS ACCELERATING ALONG TRACK, WITH THE
LAST TWO BEST TRACKS AVERAGING A 20KT SPEED OF ADVANCE. ANIMATED 
WATER VAPOR IMAGERY VERIFIES THAT THE SYSTEM IS FIGHTING OFF WHATEVER 
VERTICAL WIND SHEAR MAY EXIST ALONG TRACK, AND THE ENVIRONMENT IS 
SATURATED WITH DEEP MOISTURE ALL THE WAY TO THE COAST.  BETWEEN THE 
110TH MERIDIAN AND THE COAST, HOWEVER, THERE IS MUCH STRONGER 
NORTHEASTERLY VERTICAL WIND SHEAR.

INITIAL WIND RADII BASIS: PERSISTENCE FROM EARLIER SCATTEROMETRY.

CURRENT STEERING MECHANISM: TYPHOON KALMAEGI IS BEING STEERED BY
THE SUBTROPICAL RIDGE, WHICH IS CENTERED IN A 591DM HGT CENTER JUST
WEST OF THE LUZON STRAIT. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T5.5 - 102 KTS
   RCTP: T6.5 - 127 KTS
   KNES: T6.5 - 127 KTS
   CIMSS ADT: 107 KTS AT 060030Z
   CIMSS AIDT: 94 KTS AT 052030Z
   CIMSS D-MINT: 110 KTS AT 052300Z
   CIMSS D-PRINT: 111 KTS AT 060030Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG WESTWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TYPHOON KALMAEIGI WILL CONTINUE RAPID PROGRESS
ALONG A BEARING JUST NORTH OF WEST AND SLAM INTO THE VIETNAMESE
COAST NEAR 14N 109E. INCREASING VERTICAL WINDSHEAR OVER THE LAST
100 NM OF THE TRACK WILL ACT TO WEAKEN THE STORM SLIGHTLY, BUT
LANDFALL INTENSITY WILL BE ROUGHLY 100KTS. ONCE INLAND, THE SYSTEM
WILL DECAY RAPIDLY AS THE RAPID SPEED OF MOVEMENT THROUGH A
MOUNTAINOUS REGION OVER WESTERN VIETNAM ACTS TO SEPARATE THE LOW 
LEVEL VORTEX FROM THE REST OF THE STORM.  

MODEL DISCUSSION: TRACK GUIDANCE IS TIGHT, WITH THE BEST TRACK
GUIDANCE AT THIS POINT BEING MOMENTUM. INTENSITY GUIDANCE SHOWS A
STEEP DECLINE BEGINNING ALMOST IMMEDIATELY BUT THE SYSTEM HAS
BECOME SO STRONG THAT THE DECLINE WILL NOT LIKELY BEGIN UNTIL THE
VORTEX CROSSES THE 110TH MERIDIAN. 

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