WDPN31 PGTW 030900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (AERE) 
WARNING NR 012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 28.2N 126.9E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 113 NM NORTH-NORTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TIGHTLY
WRAPPING LOW LEVEL CLOUD LINES CONVERGING INTO A FULLY EXPOSED LOW
LEVEL CIRCULATION CENTER (LLCC). ANIMATED WATER VAPOR IMAGERY AND
UPPER-LEVEL ATMOSPHERIC MOTION VECTORS INDICATE A TROPICAL UPPER
TROPOSPHERIC TROUGH (TUTT) IS STILL LOCATED DIRECTLY OVER THE
SYSTEM INDUCING UNFAVORABLE VERTICAL WIND SHEAR (VWS) AND
UPPER-LEVEL SUBSIDENCE. A 030512Z AMSR2 MICROWAVE SCALER WIND SPEED
IMAGE SHOWS A SMALL VERTICAL SWATCH OF 26-28 KNOT WINDS ARE
ISOLATED TO THE EASTERN SEMI-CIRCLE WITH 11-14 KNOT WINDS ELSEWHERE
IN THE SYSTEM. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON MSI IMAGERY. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED
WITH MEDIUM CONFIDENCE BASED ON THE AMSR2 WIND SPEED IMAGE, AGENCY
DVORAK INTENSITY ESTIMATES AND CIMMS ADT WHICH RANGE FROM 25-35
KNOTS.

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

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE TO THE
EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T2.0 - 30 KTS
   CIMSS ADT: 25 KTS AT 030250Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 15-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: WEAK POLEWARD
   OTHER FACTORS: TROPICAL UPPER TROPOSPHERIC TROUGH DIRECTLY OVER
THE LOW-LEVEL CIRCULATION

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 (AERE) IS FORECAST TO TRACK NORTH AND
EVENTUALLY NORTHEASTWARD THROUGH TAU 36 UNDER THE STEERING
INFLUENCE OF THE STR TO ITS EAST. CURRENTLY IN AN MARGINALLY
UNFAVORABLE ENVIRONMENT CHARACTERIZED BY INCREASING VERTICAL WIND
SHEAR (15-25 KNOTS), SUBSIDENCE ALOFT PROVIDED BY THE TUTT AND DRY
AIR ENTRAINMENT SOMEWHAT OFFSET NEAR TAU 36 WHEN THE TUTT IS
FORECAST TO FILL AND OUTFLOW IMPROVE. AFTER TAU 36 THE SYSTEM IS
FORECAST TO MAKE LANDFALL AND TRAVERSE THE ISLAND OF JAPAN TRACKING
EAST-NORTHEASTWARD EVENTUALLY RETURNING BACK OVER WATER BY TAU 96.
MODEL OUTPUT INCREASINGLY INDICATES THAT BAROCLINIC INFLUENCES FROM
THE MID-LATITUDE FLOW PATTERN WILL ALLOW FOR NOMINAL
INTENSIFICATION AND INDICATE A POTENTIAL FOR TRANSITION TO A
SUBTROPICAL OR EXTRATROPICAL STRUCTURE NEAR THE END OF THE FORECAST
PERIOD.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH THE
JTWC FORECAST SCENARIO HOWEVER THE TIMING AND SPEED OF THE EASTWARD
TURN IS UNCERTAIN. THERE ARE HOWEVER, STILL A FEW MEMBERS OF GFS,
ECMWF AND COAMPS ENSEMBLES THAT INDICATE A POTENTIAL NORTHERN TRACK
INTO THE YELLOW SEA. THEREFOR THE JTWC FORECAST TRACK HAS BEEN
PLACED WITH MEDIUM CONFIDENCE. RELIABLE INTENSITY GUIDANCE IS GOOD
AGREEMENT THROUGH TAU 60 WITH ALL MEMBERS SHOWING A STAGNATION IN
INTENSITY AFTER WHICH AS MENTIONED GFS, ECMWF, COAMPS-TC AND
ACCESS-TC ALL INDICATE AN INTENSIFICATION TREND IN THE EXTENDED
FORECAST. FOR THIS REASON THE JTWC INTENSITY FORECAST IS PLACED
INITIALLY WITH HIGH CONFIDENCE THEN AFTER TAU 72 WITH MEDIUM
CONFIDENCE.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: HIGH
   INTENSITY 72-120 HR: MEDIUM//
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