WDPN31 PGTW 190300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 10W (JONGDARI) 
WARNING NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 25.1N 125.9E
   INITIAL INTENSITY: 25 KTS
   GEOGRAPHIC REFERENCE: 133 NM SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 6 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
DEPRESSION 10W (JONGDARI) WITH A PARTIALLY EXPOSED LOW-LEVEL
CIRCULATION (LLC) AND FLARING CONVECTION TILTED SLIGHTLY TO THE
SOUTH-SOUTHWEST. STRONG VERTICAL WIND SHEAR (VWS) OF 25-30 KTS FROM
THE NORTHEAST HAS MAINTAINED A SHALLOW VORTEX FOR TD 10W, WHILE
CONVECTION HAS REMAINED OFFSET FROM THE CENTRAL CORE OVER THE LAST
SIX HOURS. A 182216Z 91 GHZ SSMIS MICROWAVE IMAGE (MI) DEPICTS A
SHALLOW LLC, WITH FRAGMENTED LOW-LEVEL CURVED CLOUD BANDS WRAPPING
INTO AN ELONGATED CENTER. THE INITIAL POSITION WAS PLACED WITH HIGH
CONFIDENCE BASED ON THE AFOREMENTIONED PARTIALLY EXPOSED LLC ON
ANIMATED MSI AND THE SSMIS MI. THE INITIAL INTENSITY OF 25 KTS WAS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON AGENCY FIXES LISTED BELOW
AND LOCAL SURFACE OBSERVATIONS FROM MIYAKOJIMA AT 0000Z.

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

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER STR
CENTERED TO THE EAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T1.5 - 25 KTS
   KNES: T1.5 - 25 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 25 KTS
   SST: 31-32 CELSIUS
   OUTFLOW: WEAK EQUATORWARD

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: TD 10W WILL TRACK NORTHWARD UNDER THE STEERING
INFLUENCE OF THE DEEP-LAYER STR POSITIONED TO THE EAST THROUGHOUT
THE 36 HOUR FORECAST PERIOD. DUE TO SUSTAINED MODERATE TO STRONG
VWS AND PREVALENT DRY-AIR LOCATED IN THE EAST CHINA SEA OVER THE NEXT 
24 TO 36 HOURS, THE SYSTEM WILL MAINTAIN TROPICAL DEPRESSION 
INTENSITIES BETWEEN 25-30 KTS UNTIL EXPECTED DISSIPATION BY TAU 36. 
ALTHOUGH SEA SURFACE TEMPERATURES ARE FORECASTED TO REMAIN HIGH (30-31 
C), AN UNFAVORABLE ENVIRONMENT WILL BROADEN THE SYSTEMS SURFACE
CIRCULATION AS DRY AIR WRAPS INTO THE CENTRAL CORE FROM THE SOUTHERN 
QUADRANT. VWS IS FORECASTED TO REMAIN ABOVE 20 KTS, WITH THE EXCEPTION 
OF A 12 HOUR WINDOW BETWEEN TAU 24 AND TAU 36, ULTIMATELY CAUSING THE 
SURFACE CIRCULATION TO OPEN INTO A SURFACE TROUGH DURING ITS NORTHWARD 
TRACK BY THE END OF THE FORECAST PERIOD.

MODEL DISCUSSION: THE DETERMINISTIC AND ENSEMBLE MODELS ARE IN
STRONG AGREEMENT THAT TD 10W WILL CONTINUE TO TRACK NORTHWARD
THROUGH TAU 36 ALONG THE WESTERN PERIPHERY OF THE STR, BOTH IN THE
ACROSS-TRACK AND ALONG-TRACK GUIDANCE, LENDING HIGH CONFIDENCE TO
THE JTWC FORECAST. INTENSITY GUIDANCE IS IN GOOD AGREEMENT, WITH A 10
KTS SPREAD BETWEEN THE MAJORITY OF INTENSITY CONSENSUS MEMBERS, 
WITH ONLY ONE OUTLIER (COAMPS-TC), EXPECTING A MAXIMUM OF
30-35 KTS BY TAU 36, LENDING MODERATE CONFIDENCE TO THE JTWC INTENSITY 
FORECAST.

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