WDPN31 PGTW 110300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 29W (TWENTYNINE) 
WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.9N 125.7E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 588 NM SOUTH-SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 11 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A
PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) ON THE
EASTERN EDGE OF A DEEP CURVED CONVECTIVE BANDING. MSI ALSO SHOWS
WELL-DEFINED LOW-LEVEL CLOUD LINES WRAPPING INTO THE LLCC. A
102211Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS SHALLOW BANDING
WRAPPING INTO A LOW-LEVEL CIRCULATION POSITIONED ALONG THE EASTERN
EDGE OF A CURVED CONVECTIVE BAND. ENVIRONMENTAL ANALYSIS OF 29W
SHOWS THAT CONDITIONS REMAIN FAVORABLE FOR DEVELOPMENT WITH WARM
(28-29C) SEA SURFACE TEMPERATURES (SSTS), LOW (5-10 KNOTS) VERTICAL
WIND SHEAR (VWS), AND MODERATE RADIAL OUTFLOW. THE INITIAL POSITION
IS PLACED WITH HIGH CONFIDENCE BASED ON THE PARTIALLY EXPOSED LLCC
ALONG WITH THE SSMIS IMAGE. UNFORTUNATELY, THERE HAS BEEN NO USEFUL
ASCAT OVER THE PAST SIX HOURS. HOWEVER, THE INITIAL INTENSITY OF 30
KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE PGTW AND KNES
DVORAK ESTIMATES OF T2.0.

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

CURRENT STEERING MECHANISM: A DEEP-LAYERED SUBTROPICAL RIDGE (STR)
POSITIONED TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T2.0 - 30 KTS
   CIMSS ADT: 30 KTS AT 102340Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE RADIAL

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: OVER THE PAST SIX HOURS, TD 29W HAS TRACKED
NORTHEASTWARD ALONG THE WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) POSITIONED TO THE EAST AND WILL CONTINUE ON
A NORTHEASTWARD TRACK THROUGH TAU 24. ENVIRONMENTAL FACTORS WILL
REMAIN FAVORABLE OVER THE NEXT 24-36 HOURS, WHICH WILL ALLOW FOR A
GRADUAL INTENSIFICATION TREND TO A POTENTIAL MAXIMUM INTENSITY OF
45 KNOTS. AFTER TAU 36, THE SYSTEM WILL CROSS THE STR AXIS AND
BEGIN TO TRACK IN A MORE EAST-NORTHEAST DIRECTION. AS THIS OCCURS,
A STRONG LOW-LEVEL NORTHEASTERLY FLOW ASSOCIATED WITH A
HIGH-PRESSURE SYSTEM TO THE NORTHWEST, ALONG WITH STRONG
UPPER-LEVEL WESTERLIES, WILL INCREASE VWS. ADDITIONALLY, A MUCH
DRIER STABLE AIR MASS WILL IMPACT THE SYSTEM. AS A RESULT, THE
SYSTEM WILL BECOME SIGNIFICANTLY IMPACTED BY A MORE HOSTILE
ENVIRONMENT AND BEGIN DISSIPATING. BETWEEN TAU 48 AND TAU 72 TD 29W
WILL SUCCUMB TO THE UNFAVORABLE ENVIRONMENTAL FACTORS BEFORE
DISSIPATING AS THE SYSTEM MEANDERS SOUTHEASTWARD.   

MODEL DISCUSSION: WITH THE EXCEPTION OF THE JGSM TRACKER, NUMERICAL
MODEL TRACK GUIDANCE IS IN TIGHT AGREEMENT WITH ONLY A GRADUAL
SPREAD TO 82 NM BY TAU 48. HOWEVER, BETWEEN TAU 48 AND TAU 72 MODEL
TRACKERS INCREASE IN CROSS TRACKER SPREAD. WHICH LENDS MEDIUM
CONFIDENCE TO THE JTWC FORECAST TRACK. THUS, THE JTWC FORECAST
FOLLOWS A BLEND OF NUMERICAL MODEL TRACKERS AND FOLLOWS CLOSE TO
THE MULTI-MODEL CONSENSUS. INTENSITY GUIDANCE SUPPORTS A BRIEF
INTENSIFICATION TO 45 KNOTS THEN A RAPID WEAKENING TREND AFTER TAU
36. THE JTWC FORECAST FOLLOWS CLOSE TO THE MULTI MODEL CONSENSUS
THROUGH TAU 12, THEN CROSSES HIGHER THAN THE MEAN, INLINE WITH THE
HWRF AND COAMPS-TC SOLUTIONS WITH A PEAK NEAR 45 KNOTS AT TAU 36.
THEREAFTER, FOLLOWING NEAR THE MULTI-MODEL CONSENSUS THROUGH TAU
72.

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