WDPN31 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 31W (KALMAEGI) WARNING NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 10.5N 128.9E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 368 NM NORTH-NORTHWEST OF SONSOROL
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A COMPACT
CORE WITH A LARGE EXTENSION OF DEEP CONVECTION TO THE NORTH AND
ROBUST RADIAL OUTFLOW. DEEP CONVECTION NEAR THE CENTER IS BEGINNING
TO WRAP AROUND THE CORE TO THE UPSHEAR LEFT QUADRANT OF THE STORM,
INDICATING EYE FORMATION IS IMMINENT. A STUNNING 022314Z 37GHZ
GPM MICROWAVE IMAGE REVEALS A PINHOLE MICROWAVE EYE APPROXIMATELY
20NM IN DIAMETER. THE ENVIRONMENT REMAINS HIGHLY FAVORABLE FOR
INTENSIFICATION, WITH LOW (10-15 KTS) VERTICAL WIND SHEAR, VERY
WARM (29-30) SEA SURFACE TEMPERATURES, IN CONJUNCTION WITH THE
ROBUST OUTFLOW ENHANCED BY THE TRADE WINDS TO THE SOUTH AND THE
HIGH OCEAN HEAT CONTENT, HAVE ALLOWED TYPHOON (TY) 31W TO
SIGNIFICANTLY INTENSIFY WITHIN THE PAST 12 HOURS. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED
022314Z 37GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY OF 70 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE CIMSS OBJECTIVE
INTENSITY ESTIMATES AND THE AGENCY DVORAK FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: COMBINED STEERING INFLUENCE OF A LARGE
SUBTROPICAL RIDGE (STR) CENTERED FAR TO THE NORTHEAST AND A SECOND,
SMALLER STR CENTERED WEST OF THE LUZON STRAIT.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   CIMSS ADT: 57 KTS AT 030100Z
   CIMSS AIDT: 65 KTS AT 030100Z
   CIMSS D-MINT: 66 KTS AT 022313Z
   CIMSS D-PRINT: 55 KTS AT 030100Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

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: TY 31W (KALMAEGI) IS FORECAST TO MAINTAIN A
GENERALLY WESTWARD TRACK OVER THE NEXT 24 HOURS WHILE IT
TRANSITIONS STEERING RIDGES FROM THE STR TO ITS NORTHEAST TO THE STR
TO ITS NORTHWEST. LANDFALL IN LEYTE IS EXPECTED TO OCCUR BETWEEN
TAU 12-24 WITH REEMERGENCE IN THE SULU SEA ANTICIPATED BETWEEN TAU
24-36. AROUND TAU 36, THE DOMINANT STR TO THE NORTHWEST OF 31W WILL
SHIFT NORTHWARD, ALLOWING 31W TO TURN NORTHWESTWARD. KALMAEGI WILL
REMAIN OF A NORTHWESTWARD TRAJECTORY THROUGH THE REMAINDER OF THE
FORECAST PERIOD. TERMINAL LANDFALL IS EXPECTED BETWEEN TAU 72-96 IN
SOUTHERN VIETNAM. REGARDING INTENSITY, 31W IS FORECAST TO
CONTINUOUSLY AND RAPIDLY INTENSIFY UNTIL LANDFALL IN LEYTE. AS A
RESULT, A PEAK INTENSITY GREATER THAN 85 KTS MAY OCCUR JUST PRIOR
TO LANDFALL -- WHICH IS NOT REFLECTED IN THE FORECAST POINTS.
LIKEWISE, AN INTENSITY BELOW 65 KTS MAY OCCUR BETWEEN TAU 24-36
WHILE 31W IS OVER THE CENTRAL PHILIPPINES, WHICH IS ALSO NOT ABLE
TO BE REPRESENTED IN THE FORECAST POINTS. AFTER REEMERGING INTO THE
SULU SEA AROUND TAU 36, KALMAEGI WILL ENCOUNTER A SECOND HIGHLY
FAVORABLE ENVIRONMENT, CHARACTERIZED BY GOOD DIVERGENCE ALOFT, WARM
SEA SURFACE TEMPERATURES, AND HIGH MOISTURE CONTENT. AT THIS POINT,
31W WILL REINTENSIFY CONTINUOUSLY, WITH INTENSIFICATION ONLY HALTED
BY LANDFALL IN VIETNAM. KALMAEGI IS EXPECTED TO RAPIDLY WEAKEN OVER
THE MOUNTAINOUS TERRAIN OF SOUTHEAST ASIA, LEADING TO FULL
DISSIPATION BY TAU 120. 

MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN STRONG
AGREEMENT THAT 31W WILL MAKE LANDFALL IN NORTHERN LEYTE BEFORE
CURVING NORTHWESTWARD AND TRACKING JUST NORTH OF PALAWAN. MODELS
ARE ALSO IN STRONG AGREEMENT THAT 31W WILL MAKE TERMINAL LANDFALL
AROUND TAU 96, WITH SLIGHT VARIATION IN LANDFALL LOCATION. AS A
RESULT, THE JTWC TRACK FORECAST IS PLACED WITH HIGH CONFIDENCE FROM
TAU 0-72 AND MEDIUM CONFIDENCE FROM TAU 72-120. RELIABLE INTENSITY
GUIDANCE IS IN STRONG AGREEMENT THAT 31W WILL CONTINUE TO INTENSIFY
THROUGH LANDFALL; HOWEVER, MODELS DISAGREE ON THE WEAKENING TREND 
WHILE 31W IS OVER LAND IN ADDITION TO THE TIMING OF THE MINIMUM 
INTENSITY. THE DISAGREEMENT OVER WEAKENING BETWEEN TAU 24-36 CAUSES 
VARIATION IN THE RATE OF REINTENSIFICATION IN THE SOUTH CHINA SEA, 
AND 
THEREFORE THE SECOND PEAK INTENSITY BEFORE TERMINAL LANDFALL. AS A 
RESULT, THE JTWC INTENSITY FORECAST IS ASSESSED WITH MEDIUM 
CONFIDENCE 
OVERALL.

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