WDPN31 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (HAGUPIT) 
WARNING NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.3N 134.4E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 219 NM WEST OF YAP
   MOVEMENT PAST 6 HOURS: WESTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
DEPRESSION (TD) 05W WITH PERSISTENT DEEP CONVECTION OVER THE
EASTERN SEMI-CIRCLE AND A PARTIALLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC). A 091127Z ASCAT IMAGE REVEALS THE STORM IS HIGHLY
ELONGATED AND WEAK, WITH ELEVATED WINDS CONFINED TO THE NORTHEAST
QUADRANT. THE ASCAT DATA ALSO REVEALS THAT AT LEAST PART OF THE
PERSISTENT DEEP CONVECTION OBSCURING THE EASTERN PERIPHERY AND
EXTENDING SOUTHWARD IS A RESULT OF SURFACE CONVERGENCE RATHER THAN
THE CIRCULATION. ENVIRONMENTAL ANALYSIS REVEALS A MARGINALLY
UNFAVORABLE ENVIRONMENT, CHARACTERIZED BY HIGH (20-25 KTS)
MID-LEVEL VERTICAL WIND SHEAR, SIGNIFICANT DRY AIR ENTRAINMENT, AND
POOR OUTFLOW ALOFT, OFFSET BY WARM (29-30 C) SEA SURFACE
TEMPERATURES. THE INITIAL POSITION AND INTENSITY ARE PLACED WITH
HIGH CONFIDENCE BASED ON THE 091127Z ASCAT IMAGE.

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

CURRENT STEERING MECHANISM: A COMBINATION OF THE SUBTROPICAL RIDGE
(STR) CENTERED FAR TO THE NORTHEAST AND LOW-LEVEL SOUTHERLY FLOW


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.0 - 30 KTS
   KNES: T2.5 - 35 KTS
   CIMSS ADT: 41 KTS AT 091240Z
   CIMSS AIDT: 34 KTS AT 091240Z
   CIMSS D-PRINT: 31 KTS AT 091240Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 20-25 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: WEAK POLEWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT AND HIGH WESTERLY VERTICAL
WIND SHEAR IN THE MID-LEVELS

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TD 05W (HAGUPIT) IS FORECAST TO CONTINUE
TRACKING NORTHWESTWARD FOR THE DURATION OF THE FORECAST PERIOD
WHILE IT REMAINS UNDER THE STEERING INFLUENCE OF THE STR CENTERED
FAR TO ITS NORTHEAST. HOWEVER, LOW-LEVEL SOUTHERLY FLOW IS EXPECTED
TO PERSIST THROUGH TAU 48, WHICH COULD INTRODUCE A MORE SEVERE
NORTHWARD MOTION VECTOR, RESULTING IN A NORTH-NORTHWESTWARD TRACK
OR ERRATIC TRACK MOTION THROUGH TAU 48. REGARDING INTENSITY,
HAGUPIT IS FORECAST TO TEETER BETWEEN 30-35 KTS FOR THE NEXT 24
HOURS AS THE MARGINALLY UNFAVORABLE ENVIRONMENT PERSISTS AND
PROHIBITS DEVELOPMENT. AROUND TAU 36, ENVIRONMENT IS EXPECTED TO
FURTHER DETERIORATE INTO 25-30 KTS OF MID-LEVEL SHEAR THAT WILL
FURTHER FORCE DRY AIR INTO THE CORE AND STIFLE HAGUPIT. ULTIMATELY,
DISSIPATION IS EXPECTED NO LATER THAN TAU 48.

MODEL DISCUSSION: DETERMINISTIC TRACK MODEL GUIDANCE IS IN GOOD
AGREEMENT THAT 05W WILL TRACK NORTHWESTWARD TO NORTH-NORTHWESTWARD
FOR THE DURATION OF THE FORECAST PERIOD. THE JTWC TRACK FORECAST
LIES CLOSE TO THE MULTI-MODEL CONSENSUS WITH OVERALL MEDIUM
CONFIDENCE. RELIABLE INTENSITY AIDS ARE IN GOOD AGREEMENT THAT
HAGUPIT WILL STALL INTENSIFICATION AND DISSIPATE BY TAU 48. AS A
RESULT, THE JTWC INTENSITY FORECAST IS PLACED WITH HIGH CONFIDENCE.

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