WDPN31 PGTW 100900

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//

SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (HAGUPIT)

WARNING NR 019//

RMKS/

1. FOR METEOROLOGISTS.

2. 6 HOUR SUMMARY AND ANALYSIS.



SUMMARY:

   INITIAL POSITION: 10.1N 131.9E

   INITIAL INTENSITY: 25 KTS

   GEOGRAPHIC REFERENCE: 205 NM NORTHWEST OF KAYANGEL

   MOVEMENT PAST 6 HOURS: WESTWARD AT 11 KTS

   SIGNIFICANT WAVE HEIGHT: 12 FEET



SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:

ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL

DEPRESSION (TD) 05W AS A SHALLOW AND FULLY EXPOSED LOW LEVEL

CIRCULATION CENTER (LLCC) WITH NO ASSOCIATED CONVECTION. THE

100423Z AMSR2 MICROWAVE IMAGE REVEALS THE LOW-LEVEL CLOUD BANDS

WRAPPING INTO THE CENTER VOID OF DEEP CONVECTION. ENVIRONMENTAL

ANALYSIS REVEALS A HIGHLY UNFAVORABLE ENVIRONMENT, CHARACTERIZED BY

HIGH (20-25 KTS) MID-LEVEL WIND SHEAR, SIGNIFICANT DRY AIR

ENTRAINMENT, AND POOR UPPER-LEVEL OUTFLOW, OFFSET BY WARM (29-30)

SEA SURFACE TEMPERATURES. THE INITIAL POSITION IS PLACED WITH HIGH

CONFIDENCE BASED ON THE FULLY EXPOSED LLCC IN ANIMATED MSI,

SUPPORTED BY THE AFOREMENTIONED 100423Z AMSR2 DATA. THE INITIAL

INTENSITY OF 25 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE

AGENCY DVORAK FIXES LISTED BELOW; THE CIMSS OBJECTIVE INTENSITY

ESTIMATES ARE ASSESSED TO BE TOO HIGH GIVEN THE APPEARANCE OF THE

SYSTEM.



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: T1.5 - 25 KTS

   RJTD: T2.0 - 30 KTS

   RCTP: T1.5 - 25 KTS

   KNES: T2.5 - 35 KTS

   CIMSS SATCON: 38 KTS AT 100600Z

   CIMSS ADT: 41 KTS AT 100600Z

   CIMSS AIDT: 36 KTS AT 100600Z

   CIMSS D-MINT: 28 KTS AT 100429Z

   CIMSS D-PRINT: 26 KTS AT 100600Z



FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE

   VWS: 15-20 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: MEDIUM

   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 THE NORTHEAST. THE SOUTHERLY LOW-LEVEL FLOW MAY CONTRIBUTE

TO ERRATIC TRACK MOTION AS THE SHALLOW VORTEX IS SUSCEPTIBLE TO

STEERING INFLUENCE FROM THE LOWER LEVELS. REGARDING INTENSITY,

HAGUPIT IS FORECAST TO TEETER BETWEEN 20-25 KTS FOR THE NEXT 12 HOURS,

WITH DISSIPATION EXPECTED NO LATER THAN TAU 24 DUE TO HIGH

MID-LEVEL SHEAR CAUSING SIGNIFICANT DRY AIR ENTRAINMENT.



MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN STRONG

AGREEMENT IN A NORTHWESTWARD TRACK THROUGH TAU 24, LENDING HIGH

CONFIDENCE TO THE JTWC TRACK FORECAST. LIKEWISE, RELIABLE INTENSITY

AIDS ARE IN STRONG AGREEMENT THAT 05W WILL WEAKEN BELOW 25 KTS

WITHIN THE NEXT 6-12 HOURS. AS A RESULT, THE JTWC INTENSITY

FORECAST IS ASSESSED WITH HIGH CONFIDENCE.



FORECAST CONFIDENCE:

   TRACK 00-72 HR: HIGH

   INTENSITY 00-72 HR: HIGH//

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