WDPN31 PGTW 040300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 02W (TWO) WARNING NR 
001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 8.8N 133.1E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 119 NM NORTHWEST OF KOROR
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
DEPRESSION 02W WITH A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION
CENTER (LLCC) THAT IS DISPLACED TO THE SOUTH OF FLARING CONVECTION.
THE LLCC HAS BECOME MUCH MORE DEFINED OVER THE PAST 6 HOURS,
PARTICULARLY WITHIN THE SOUTHERN SEMICIRCLE, WITH DEFINED
WESTERLIES NOW WRAPPING INTO THE CENTER. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE PARTIALLY EXPOSED LLCC IN
ANIMATED MSI. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH
MEDIUM CONFIDENCE BASED ON AGENCY DVORAK FIXES RANGING FROM
T1.5-T2.0. ENVIRONMENTAL ANALYSIS INDICATES THAT 02W IS IN A
MARGINALLY FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG POLEWARD
OUTFLOW ALOFT, LOW (10-15 KTS) EASTERLY VERTICAL WIND SHEAR, AND
WARM (29-30 C) SEA SURFACE TEMPERATURES. THE ENVIRONMENT IS
PRIMARILY HINDERED BY THE INTERACTION WITH THE NORTHEASTERLY SURGE
WINDS TO THE NORTH OF THE SYSTEM CAUSING A HIGHLY ASYMMETRIC WIND
FIELD.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: SOUTHEASTERN PERIPHERY OF AN ELONGATED
SUBTROPICAL RIDGE (STR) POSITIONED OVER LUZON

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T1.5 - 25 KTS
   CIMSS D-PRINT: 24 KTS AT 040000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: PRESSURE FROM THE INTERACTION WITH THE
NORTHEASTERLY SURGE WINDS TO THE NORTH

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: 02W IS FORECAST TO TRACK GENERALLY WESTWARD,
ALONG THE SOUTHERN PERIPHERY OF THE STR TO THE NORTH, THROUGH TAU
36. LANDFALL ALONG THE NORTHEASTERN COAST OF MINDANAO IS FORECAST
TO OCCUR BETWEEN TAU 36 AND 48 NEAR THE LIANGA BAY. AFTER TAU 36,
THE TRACK IS EXPECTED TO TURN NORTHWESTWARD AS THE SYSTEM BEGINS TO
ROUND THE SOUTHWESTERN EXTENT OF THE STR. 02W WILL THEN TRAVERSE
THROUGH THE SOUTHERN VISAYAS ISLANDS AND EVENTUALLY EMERGE WITHIN
THE NORTHERN SULU SEA AROUND TAU 72. 02W IS THEN FORECAST TO
CONTINUE ON A NORTHWESTWARD TRACK THROUGH TAU 96 AS IT TRACKS NEAR
THE NORTHERN TIP OF PALAWAN. REGARDING INTENSITY, 02W IS FORECAST
TO STEADILY INTENSIFY THROUGH TAU 36 TO A PEAK OF 45 KTS, BEFORE
MAKING LANDFALL. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN
GENERALLY FAVORABLE AS THE SYSTEM APPROACHES MINDANAO. THE WIND
FIELD IS EXPECTED TO CONTRACT BEFORE LANDFALL DUE TO THE
NORTHEASTERLY SURGE BACKING OFF. AFTER LANDFALL, 02W IS FORECAST TO
WEAKEN IN RESPONSE TO TERRAIN INTERACTION WITH MINDANAO AND THE
SOUTHERN VISAYAS ISLANDS. DISSIPATION IS CURRENTLY FORECAST TO
OCCUR NEAR TAU 96, THOUGH SOME MODELS HINT AT AN EARLIER
DISSIPATION OVER THE PHILIPPINES. NEAR TAU 96, THE NORTHEASTERLY
SURGE IS EXPECTED TO STRENGTHEN THROUGH THE TAIWAN STRAIT AND
EXTEND SOUTHWARD TOWARD 02W. THE INTERACTION WITH THIS SURGE FLOW
WILL CAUSE 02W TO BE ABSORBED WITHIN THE STRONG NORTHEASTERLY
WINDS, FURTHER AIDING IN THE DISSIPATION OF 02W. 

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT WITH THE EXCEPTION OF NAVGEM AND GFS, WHICH BOTH TRACK
THE SYSTEM MUCH FURTHER POLEWARD AFTER TAU 36 THAN THE REMAINDER OF
GUIDANCE. DISCOUNTING THE TWO OUTLIERS, THERE IS A MERE 45 NM
CROSS-TRACK SPREAD AT TAU 48, WHICH OPENS UP TO 105 NM AT TAU 96.
THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE ECMWF AND GOOGLE
DEEPMIND MODELS WITH MEDIUM CONFIDENCE THROUGHOUT THE FORECAST
PERIOD. INTENSITY GUIDANCE GENERALLY AGREES ON INTENSIFICATION
THROUGH TAU 36 BEFORE STEADY WEAKENING. A NOTABLE OUTLIER IS
HAFS-A, WHICH CONTINUES TO INTENSIFY THE SYSTEM ALL THE WAY THROUGH
TAU 96, AFTER IS CROSSES THE PHILIPPINES. THE JTWC INTENSITY
FORECAST IS PLACED CLOSE TO THE CONSENSUS THROUGH TAU 48, AND THEN
BELOW THE CONSENSUS THROUGH THE REMAINDER OF THE FORECAST PERIOD
DUE TO THE COMBINATION OF TERRAIN EFFECTS AND INTERACTION WITH THE
STRONG NORTHEASTERLY SURGE NEAR TAU 96. 

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